202CNO09MAR2015
CNO Report 202
Release Date 14 MAR 2015
Draft Report Compiled by
Ralph Turchiano
In This Issue:
1. Omega-3 fatty acids and vitamin D may control brain serotonin
2. Lycopene may ward off kidney cancer in older women
3. Vanderbilt-led study finds peanut consumption decreases mortality
4. Why nitrate supplementation may increase athletic performance
5. Moderate coffee consumption lessens risk of clogged arteries and heart attacks
6. Marijuana: The allergen you never knew existed
7. Adults only really catch flu about twice a decade, suggests study
8. Study shows who benefits most from statins
9. A high-salt diet could protect against invading microbes
10. Omega-3 fatty acids appear to protect damaged heart after heart attack
11. Study shows that use of statins increases risk of developing diabetes by 46 percent
12. Onion extract may improve high blood sugar and cholesterol
13. High cholesterol, triglycerides can keep vitamin E from reaching body tissues
14. You are when you
PUBLIC RELEASE: 26-FEB-2015
Omega-3 fatty acids and vitamin D may control brain serotonin
Affecting behavior and psychiatric disorders
CHILDREN’S HOSPITAL & RESEARCH CENTER OAKLAND
Oakland, CA (February 26, 2015) – Although essential marine omega-3 fatty acids and vitamin D have been shown to improve cognitive function and behavior in the context of certain brain disorders, the underlying mechanism has been unclear. In a new paper published in FASEB Journal by Rhonda Patrick, PhD and Bruce Ames, PhD of Children’s Hospital Oakland Research Institute (CHORI), serotonin is explained as the possible missing link tying together why vitamin D and marine omega-3 fatty acids might ameliorate the symptoms associated with a broad array of brain disorders.
In a previous paper published last year, authors Patrick and Ames discussed the implications of their finding that vitamin D regulates the conversion of the essential amino acid tryptophan into serotonin, and how this may influence the development of autism, particularly in developing children with poor vitamin D status.
Here they discuss the relevance of these micronutrients for neuropsychiatric illness. Serotonin affects a wide-range of cognitive functions and behaviors including mood, decision-making, social behavior, impulsive behavior, and even plays a role in social decision-making by keeping in check aggressive social responses or impulsive behavior.
Many clinical disorders, such as autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), bipolar disorder, schizophrenia, and depression share as a unifying attribute low brain serotonin. “In this paper we explain how serotonin is a critical modulator of executive function, impulse control, sensory gating, and pro-social behavior,” says Dr. Patrick. “We link serotonin production and function to vitamin D and omega-3 fatty acids, suggesting one way these important micronutrients help the brain function and affect the way we behave.”
Eicosapentaenoic acid (EPA) increases serotonin release from presynaptic neurons by reducing inflammatory signaling molecules in the brain known as E2 series prostaglandins, which inhibit serotonin release and suggests how inflammation may negatively impact serotonin in the brain. EPA, however, is not the only omega-3 that plays a role in the serotonin pathway. Docosahexaenoic acid (DHA) also influences the action of various serotonin receptors by making them more accessible to serotonin by increasing cell membrane fluidity in postsynaptic neurons.
Their paper illuminates the mechanistic links that explain why low vitamin D, which is mostly produced by the skin when exposed to sun, and marine omega-3 deficiencies interacts with genetic pathways, such as the serotonin pathway, that are important for brain development, social cognition, and decision-making, and how these gene-micronutrient interactions may influence neuropsychiatric outcomes. “Vitamin D, which is converted to a steroid hormone that controls about 1,000 genes, many in the brain, is a major deficiency in the US and omega-3 fatty acid deficiencies are very common because people don’t eat enough fish,” said Dr. Ames.
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This publication suggests that optimizing intakes of vitamin D, EPA, and DHA would optimize brain serotonin concentrations and function, possibly preventing and ameliorating some of the symptoms associated with these disorders without side effects.
Vitamin D and the Omega-3 Fatty Acids Control Serotonin Synthesis and Action Part 2: Relevance for ADHD, Bipolar, Schizophrenia, and Impulsive Behavior. FASEB Journal
Contact
Melinda Krigel
Media Relations
510-428-3069 office
510-388-5927 cell
mkrigel@mail.cho.org
Public Release: 2-Mar-2015
Lycopene may ward off kidney cancer in older women
Wayne State University – Office of the Vice President for Research
DETROIT – A higher intake by postmenopausal women of the natural antioxidant lycopene, found in foods like tomatoes, watermelon and papaya, may lower the risk of renal cell carcinoma, a type of kidney cancer.
A team led by Cathryn Bock, Ph.D., M.P.H., associate professor of Oncology at Wayne State University’s School of Medicine, made the conclusion after analyzing data from 96,196 women nationwide and in Detroit who enrolled in the Women’s Health Initiative from 1993 to 1998 and were followed through July 2013 by participating initiative sites, including Wayne State University.
“We were surprised to observe a protective effect of lycopene, as several previous studies in other populations did not detect a similar relationship,” Bock said.
The results are explained in “Antioxidant micronutrients and the risk of renal cell carcinoma in the Women’s Health Initiative cohort,” featured in the Feb. 15 issue of Cancer.
The investigators analyzed the risks for kidney cancer associated with intake of lycopene and other micronutrients that have antioxidant properties, including lutein and vitamins C and E. During follow-up, 240 women were diagnosed with kidney cancer. Compared with women who reported a lower intake of lycopene, those who ingested more had a 39 percent lower risk. No other micronutrient was significantly associated with the same risk.
The 63,920 estimated new cases of kidney and renal pelvis cancer in 2014 made up 3.8 percent of all new cancer cases, according to the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program. In 2011, there were an estimated 358,603 people living with the cancer in the United States.
It is the eighth-leading cancer among women and is commonly diagnosed at a more advance stage.
“Kidney cancer is a relatively rare cancer, and so focusing only on reducing risk of this disease would be short-sighted,” Bock said. “Rather, a diet focused on one’s own personal risk factors, such as family history, would be more beneficial.”
A low-salt diet is recommended for women with a risk of hypertension, a major risk factor for kidney cancer. There are other steps women can take now for their health, including eating more foods and fruits with naturally-occurring lycopene.
“Lycopene from food sources has also been associated with decreased risk of breast and prostate cancers, and a diet high in vegetables and fruits are generally well-accepted for promoting good health,” she said.
Good sources of lycopene include tomatoes and tomato-based products, watermelon, pink grapefruit, guava and papaya. Dr. Bock suggests consulting a doctor before taking a lycopene supplement.
The team is now examining whether there is a relationship between antioxidant nutrient intake and kidney cancer risk in a National Cancer Institute-funded case-control study primarily conducted with participants from the metropolitan Detroit area.
“This study included a broader population, including both men and women, and with greater representation of African-Americans, and therefore may help describe the associations in populations beyond post-menopausal women who are primarily of European descent,” Dr. Bock said.
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The Women’s Health Initiative program is funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health, U.S. Department of Health and Human Services through contracts HHSN268201100046C, HHSN268201100001C, HHSN268201100002C, HHSN268201100003C, HHSN268201100004C, and HHSN271201100004C.
About Wayne State University
Wayne State University is one of the nation’s pre-eminent public research universities in an urban setting. Through its multidisciplinary approach to research and education, and its ongoing collaboration with government, industry and other institutions, the university seeks to enhance economic growth and improve the quality of life in the city of Detroit, state of Michigan and throughout the world. For more information about research at Wayne State University, visit http://www.research.wayne.edu.
Public Release: 2-Mar-2015
Vanderbilt-led study finds peanut consumption decreases mortality
Vanderbilt University Medical Center
If you’re looking for a simple way to lower your risk of dying from a heart attack, consider going nuts.
Researchers at Vanderbilt University and the Shanghai Cancer Institute examined the association of nut consumption with mortality among low-income and racially diverse populations and found that intake of peanuts was associated with fewer deaths, especially from heart disease.
The study was published March 2 in JAMA Internal Medicine. The first author of the paper is Hung Luu, Ph.D., a post-doctoral fellow in the Division of Epidemiology, Vanderbilt University Medical Center. Senior author is Xiao-Ou Shu, M.D., Ph.D., associate director for Global Health at the Vanderbilt-Ingram Cancer Center and professor of Medicine in the Department of Epidemiology.
“Nuts are rich in nutrients, such as unsaturated fatty acids, fiber, vitamins, phenolic antioxidants, arginine and other phytochemicals. All of them are known to be beneficial to cardiovascular health, probably through their anti-oxidative, anti-inflammatory and endothelial function maintenance properties,” Shu said.
While research has previously linked nut consumption with lower mortality, those studies focused mainly on higher-income, white populations. This study was the first to discover that all races – blacks, whites, and Asians alike – could potentially increase heart health by eating nuts and peanuts.
“In our study, we found that peanut consumption was associated with reduced total mortality and cardiovascular disease mortality in a predominantly low-income black and white population in the U.S., and among Chinese men and women living in Shanghai,” Shu said.
This study was based on three large on-going cohort studies. Participants included over 70,000 Americans of African and European descent from the Southern Community Cohort Study (SCCS), who were mostly low-income, and over 130,000 Chinese from the Shanghai Women’s Health Study (SWHS) and the Shanghai Men’s Health Study (SMHS).
Information on nut consumption was collected by structured questionnaires at the baseline survey. For participants in the SCCS, deaths were determined by linking with the National Death Index and Social Security Administration mortality files, and for participants in the SWHS/SMHS, by linking with the Shanghai Vital Statistics Registry and by conducting home visits. In total, over 14,000 deaths were identified, with a median follow-up of 5.4 years in the SCCS, 6.5 years in the SMHS, and 12.2 years in the SWHS.
Peanut consumption was associated with decreased total mortality, particularly cardiovascular mortality (i.e., 17 percent-21 percent reduction in total mortality, and 23 percent-38 percent reduction in cardiovascular mortality for the highest quartile intake group compared to the lowest quartile group) across all three racial/ethnic groups, among both men and women, and among individuals from low-SES groups.
Because peanuts are much less expensive than tree nuts, as well as more widely available to people of all races and all socioeconomic backgrounds, increasing peanut consumption may provide a potentially cost-efficient approach to improving cardiovascular health, Shu said.
“The data arise from observational epidemiologic studies, and not randomized clinical trials, and thus we cannot be sure that peanuts per se were responsible for the reduced mortality observed,” said William Blot, Ph.D., associate director for Cancer Prevention, Control and Population-based Research at VICC and a co-author of the study.
He did note that “the findings from this new study, however, reinforce earlier research suggesting health benefits from eating nuts, and thus are quite encouraging.”
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The American Heart Association recommends eating four servings of unsalted, unoiled nuts a week. Nutrient-rich nuts are also high in calories, so don’t eat too many if you’re watching your weight. A serving size is a small handful or 1.5 ounces of whole nuts or 2 tablespoons of nut butter.
Public Release: 2-Mar-2015
Why nitrate supplementation may increase athletic performance
New research in The FASEB Journal suggests that nitrate — a nitric oxide metabolite — meets tissue oxygen demands without the side effects of increasing red blood cells or blood viscosity
Federation of American Societies for Experimental Biology
Walk down the aisles of any food supplement store and you’ll see that the use of nitrate supplements by athletes and fitness buffs has been popular for years. The hope is that these supplements will increase endurance (and possibly other performance/health benefits) by improving the efficiency at which muscles use oxygen. Now, a research study published in the March 2015 issue of The FASEB Journal helps explain how some of these supplements may work and why they may increase performance–they decrease the viscosity of blood, aiding in blood flow, while at the same time ensuring that tissue oxygen requirements are not compromised.
“Our research sheds new light on how oxygen delivery to bodily tissues is controlled to support mammalian life, and what role the kidneys and the liver play in achieving this,” said Andrew Murray, Ph.D., a researcher involved in the work from the Department of Physiology, Development and Neuroscience at the University of Cambridge in Cambridge, United Kingdom. “These findings offer potential therapeutic avenues for dietary intervention in polycythemia and other conditions that warrant a reduction in red cell mass, but may have broader implications related to the way that supply and demand of oxygen are matched.”
Scientists investigated the effects of nitrate supplementation on hemoglobin in four groups of rats, which were housed in either normoxic or hypoxic (low oxygen) conditions and supplemented with sodium nitrate (or sodium chloride, ordinary table salt, as a control). Intake of nitrate via diet and drinking water was carefully monitored. Hypoxia is known to elevate hemoglobin levels, but nitrate supplementation at a moderate dose largely suppressed this effect. Unexpectedly, nitrate also lowered hemoglobin levels in normoxic animals. They found that at higher doses of nitrate, hemoglobin levels began to rise again. Researchers investigated the mechanisms underlying these effects and found that the suppression of hemoglobin was due to nitrate enhancing liver oxygenation and suppressing its expression of the hormone, erythropoietin. Conversely, as hemoglobin levels fell, the kidney became less well supplied with oxygen and at higher doses of nitrate it expressed more erythropoietin, reversing the effect.
“This doesn’t mean that taking a nitrate supplement will transform you into the next Marshawn Lynch,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. “What it does mean, however, is that we’re beginning to understand the science behind why some people feel they turn into the Seahawk’s ‘Beast Mode’ when taking these supplements.”
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Receive monthly highlights from The FASEB Journal by e-mail. Sign up at http://www.faseb.org/fjupdate.aspx. The FASEB Journal is published by the Federation of the American Societies for Experimental Biology (FASEB). It is the world’s most cited biology journal according to the Institute for Scientific Information and has been recognized by the Special Libraries Association as one of the top 100 most influential biomedical journals of the past century.
FASEB is composed of 27 societies with more than 120,000 members, making it the largest coalition of biomedical research associations in the United States. Our mission is to advance health and welfare by promoting progress and education in biological and biomedical sciences through service to our member societies and collaborative advocacy.
Details: Tom Ashmore, Bernadette O. Fernandez, Colin E. Evans, Yun Huang, Cristina Branco-Price, Julian L. Griffin, Randall S. Johnson, Martin Feelisch, and Andrew J. Murray. Suppression of erythropoiesis by dietary nitrate. FASEB J. March 2015 29:1102-1112; doi:10.1096/fj.14-263004 ; http://www.fasebj.org/content/29/3/1102.abstract
Public Release: 2-Mar-2015
Moderate coffee consumption lessens risk of clogged arteries and heart attacks
People consuming 3 to 5 cups of coffee a day have lowest risk of clogging
BMJ
There has been much debate over the effect of coffee consumption on cardiovascular health.
Despite earlier concerns about a potential increase in heart disease risk associated with drinking coffee, a recent meta-analysis of 36 studies showed that moderate coffee consumption was associated with a decreased risk of heart disease. Coffee consumption has been associated with improved insulin sensitivity and reduced risk of type 2 diabetes, but it has also been linked to increased cholesterol concentrations and heightened blood pressure.
An international team of researchers led by the Kangbuk Samsung Hospital, Seoul, in the Republic of Korea, set out to examine the association between coffee consumption and the presence of coronary artery calcium (CAC) which is a early indicator of coronary atherosclerosis – a potentially serious condition where arteries become clogged up by fatty substances known as plaques or atheroma and which can cause the arteries to harden and narrow, leading to blood clots which can trigger a heart attack or a stroke.
They studied a group of 25,138 men and women – average age of 41 – who had no signs of heart disease, attending a health screening examination.
The participants’ screening examination included a validated food frequency questionnaire and a multidetector cardiac CT (computed tomography) for diagnostic imaging to determine levels of coronary artery calcium (CAC) scores.
Annual or biennial health screening examinations are common in Korea, because health examinations are mandatory for all workers under the Industrial Safety and Health Law there and CAC scoring has become a common heart disease screening test.
The researchers estimated the CAC score ratios associated with different levels of coffee consumption compared with no coffee consumption and took potential confounders into account such as education level, physical activity level, smoking status, BMI, alcohol consumption, family history of heart disease and consumption of fruits, vegetables, and red and processed meats.
They categorised coffee consumption as none, less than one cup a day, one to three cups a day, three to five per day and at least five or more per day.
The researchers found the prevalence of detectable CAC was 13.4% amongst the whole group of people and the average consumption of coffee was 1.8 cups per day.
The calcium ratios were 0.77 for people who had less than one cup per day, 0.66 for those having one to three cups every day, 0.59 for those consuming three to five cups per day, and 0.81 for people having at least five cups or more every day compared with non coffee drinkers.
The association was similar in subgroups defined by age, sex, smoking status, alcohol consumption, and status of obesity, diabetes, hypertension, and hypercholesterolaemia.
The association, therefore, was U-shaped, with participants drinking three to five cups per day having the lowest prevalence of arteries that had clogged up.
Possible explanations for the findings, said the researchers, were that chronic coffee consumption had a possible link to reduced risk of type 2 diabetes, a strong risk factor for atherosclerosis, and that coffee drinking might improve insulin sensitivity and β-cell function.
The authors concluded: “Our study adds to a growing body of evidence suggesting that coffee consumption might be inversely associated with CVD [cardiovascular disease] risk. Further research is warranted to confirm our findings and establish the biological basis of coffee’s potential preventive effects on coronary artery disease.”
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Public Release: 3-Mar-2015
Marijuana: The allergen you never knew existed
American College of Allergy, Asthma, and Immunology
ARLINGTON HEIGHTS, Ill. (March 3, 2015) – Growing up, you may have been given reasons for not smoking marijuana. What you may not have heard is that marijuana, like other pollen-bearing plants, is an allergen which can cause allergic responses. A new article published in the Annals of Allergy, Asthma and Immunology, the scientific publication of the American College of Allergy, Asthma and Immunology (ACAAI), summarizes research on the ways in which cannabis can act as an allergen. The article draws attention to allergic responses that may be unfamiliar to marijuana users. Included in the article is information on case reports regarding episodes of allergic reactions, hypersensitivity and even anaphylaxis (a severe allergic reaction) to cannabis in its various forms. Among other things, cannabis pollen or cannabis smoke exposure has resulted in symptoms of allergic rhinitis (hay fever) conjunctivitis and asthma. Allergic asthma triggered by seasonal and occupational exposure to cannabis has also been reported.
The authors of the article point out that cannabis’ legal status may create barriers for accurate and clear patient reporting, and that legal limitations may pose diagnostic challenges. As with other allergens, the authors say that avoidance is recommended. Marijuana’s legal status in the United States is changing, making information about cannabis allergy timely and noteworthy. Twenty-three states and the District of Columbia currently have laws legalizing marijuana in some form, and four states have legalized marijuana for recreational use.
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Title: Cannabis Sativa: The Unconventional “Weed” Allergen
Authors: Thad Ocampo, MD, ACAAI member and Tonya Rans, MD, Fellow, ACAAI
By the Numbers: According to ACAAI, allergies, including allergic rhinitis, affect an estimated 40 million to 50 million people in the United States. Some allergies may interfere with day-to-day activities or lessen the quality of life. Triggers of non-allergic rhinitis include irritants such as cigarette smoke, strong odors and fumes, including perfume, hair spray, and other cosmetics, laundry detergents, cleaning solutions, pool chlorine, car exhaust and other air pollution.
About ACAAI
The ACAAI is a professional medical organization of more than 6,000 allergists-immunologists and allied health professionals, headquartered in Arlington Heights, Ill. The College fosters a culture of collaboration and congeniality in which its members work together and with others toward the common goals of patient care, education, advocacy and research. ACAAI allergists are board-certified physicians trained to diagnose allergies and asthma, administer immunotherapy, and provide patients with the best treatment outcomes. For more information and to find relief, visit AllergyandAsthmaRelief.org. Join us on Facebook, Pinterest and Twitter.
Public Release: 3-Mar-2015
Adults only really catch flu about twice a decade, suggests study
PLOS
Adults over the age of 30 only catch flu about twice a decade, a new study publishing March 3rd in PLOS Biology suggests.
Flu-like illness can be caused by many pathogens, making it difficult to assess how often people are infected by influenza.
The immune system responds to flu viruses by producing antibodies that specifically target proteins on the virus surface. These proteins can change as the virus evolves, but we keep antibodies in the blood that have a memory for strains we’ve encountered before.
Researchers analysed blood samples from volunteers in Southern China, looking at antibody levels against nine different influenza strains that circulated from 1968 to 2009.
They found that while children get flu on average every other year, flu infections become less frequent as people progress through childhood and early adulthood. From the age of 30 onwards, flu infections tend to occur at a steady rate of about two per decade.
Dr Adam Kucharski, who worked on the study at Imperial College London before moving to the London School of Hygiene & Tropical Medicine, said: “There’s a lot of debate in the field as to how often people get flu, as opposed to flu-like illness caused by something else. These symptoms could sometimes be caused by common cold viruses, such as rhinovirus or coronavirus. Also, some people might not realise they had flu, but the infection will show up when a blood sample is subsequently tested. This is the first time anyone has reconstructed a group’s history of infection from modern-day blood samples.”
Dr Steven Riley, senior author of the study, from the Medical Research Council Centre for Outbreak Analysis and Modelling at Imperial, said: “For adults, we found that influenza infection is actually much less common than some people think. In childhood and adolescence, it’s much more common, possibly because we mix more with other people. The exact frequency of infection will vary depending on background levels of flu and vaccination.”
In addition to estimating the frequency of flu infection, the researchers, from the UK, the US and China, developed a mathematical model of how our immunity to flu changes over a lifetime as we encounter different strains of the virus.
The model supported evidence from other studies that the strains of influenza virus we encounter earlier in life evoke stronger immune responses than those we meet later.
The findings will help understanding how the immunity in the population affects the evolution of flu viruses, and potentially make predictions about how the virus will change in the future. They could also help scientists consider how immunity to historical strains will influence the way vaccines work and how effective they will be.
Dr Kucharski said: “What we’ve done in this study is to analyse how a person’s immunity builds up over a lifetime of flu infections. This information helps us understand the susceptibility of the population as a whole and how easy it is for new seasonal strains to spread through the population.”
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Contact:
Sam Wong
Research Media Officer
Imperial College London
Email: sam.wong@imperial.ac.uk
Tel: +44(0)20 7594 2198
Out of hours duty press officer: +44(0)7803 886 248
Citation: Kucharski AJ, Lessler J, Read JM, Zhu H, Jiang CQ, Guan Y, et al. (2015) Estimating the Life Course of Influenza A(H3N2) Antibody Responses from Cross-Sectional Data. PLoS Biol 13(3): e1002082. doi:10.1371/journal.pbio.1002082
Funding: This work is supported by the Medical Research Council (UK, Project MR/J008761/1); Wellcome Trust (UK, Project 093488/Z/10/Z); Fogarty International Centre (USA, R01 TW008246-01); Fogarty International Centre with the Science & Technology Directorate, Department of Homeland Security (USA, RAPIDD program); National Institute for General Medical Sciences (US, MIDAS U01 GM110721-01); and National Institute for Health Research (UK, for Health Protection Research Unit funding). JL’s work was supported by a grant from NIAID (K22 AI092150-01). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Public Release: 3-Mar-2015
Study shows who benefits most from statins
IMAGE: For each of the risk categories, Stitziel and his colleagues calculated the number of patients that doctors would need to treat with statins to prevent one heart attack over a… view more
Credit: Eric Young, Washington University in St. Louis.
New research suggests that widely used statin therapy provides the most benefit to patients with the highest genetic risk of heart attack. Using a relatively straightforward genetic analysis, the researchers assessed heart attack risk independently of traditional risk factors such as age, sex, so-called good and bad cholesterol levels, smoking history, family history and whether the patient has diabetes.
Patients in intermediate and low-risk categories still benefit from statin therapy, but that benefit is progressively smaller because they’re starting at lower baseline risk, according to the investigators.
The research, from Washington University School of Medicine in St. Louis, Brigham and Women’s Hospital, Massachusetts General Hospital and Harvard Medical School appears March 4 in The Lancet.
For patients at risk of heart disease, doctors routinely prescribe statins, known for their cholesterol-lowering effect. In 2013, the American College of Cardiology and the American Heart Association changed the guidelines for statin therapy, dramatically increasing the number of patients recommended to take it. The move has stirred debate over whether these drugs are overused, especially in light of increasing health-care costs.
“There is ongoing debate over which individuals should be allocated statin therapy to prevent a first heart attack,” said co-first author Nathan O. Stitziel, MD, a Washington University cardiologist and human geneticist. “Some have said we should be treating more people, while others say we need to treat fewer. As an example of precision medicine, another approach is to identify people at high risk and preferentially prescribe statin therapy to those individuals. Genetics appears to be one way to identify high-risk patients.”
Stitziel noted that this genetic analysis is not available to patients right now. More research is needed to validate the findings before such a test could be developed for clinical use.
Using statistical methods to combine data on 49,000 people enrolled in five studies, the researchers reported that individuals in the high-risk category have a 70 percent higher risk of heart attacks compared with those at lowest genetic risk. They went on to show that statin therapy results in a 13 percent reduction in risk in the low genetic-risk group, a 29 percent reduction in the intermediate group and a 48 percent reduction in the high-risk group.
Stitziel said the new results differ from past research that consistently has shown statins provide about the same relative risk reduction — 30-45 percent depending on dose — across all categories of patients.
“We need more research to confirm these results,” Stitziel said. “Regardless, we can at least say that patients with a high genetic-risk score appear to benefit more from statin therapy because they’re starting at a higher baseline risk, even controlling for all the clinical measures we routinely examine.”
In other words, if a patient has a 10 percent risk of having a heart attack over the next decade and statins cut that risk to 7 percent (a 30 percent reduction), the therapy has a greater absolute benefit than in a patient who starts with a 1 percent risk that is reduced to 0.7 percent (the same 30 percent reduction).
“The panel of genetic markers we analyzed provide a way to identify the patients starting out at higher baseline risk,” Stitziel said. “This is important because it appears to be independent of cholesterol levels and other traditional markers of heart disease that we typically use to estimate risk.”
For each of the risk categories, Stitziel and his colleagues, including co-first author Jessica L. Mega, MD, of Brigham and Women’s Hospital, also calculated the number of patients that doctors would need to treat with statins to prevent one heart attack over a 10-year period. This “number needed to treat” statistic also showed the greater benefit of statins in patients in the high genetic-risk category.
For patients in the lowest risk group, the researchers calculated that doctors would need to treat 57-66 patients for 10 years to prevent one heart attack. In the intermediate risk group, doctors would need to treat 42-47 patients over 10 years to get the same benefit. And in the highest risk group, 20-25 patients would need to take a statin for 10 years to prevent one heart attack.
To calculate the genetic-risk score, the investigators analyzed 27 individual “letters” in each patient’s DNA code. Past work by many different research groups has established significant association between these 27 positions in the genome and risk of coronary heart disease.
Individually, many locations are linked to only a minor increase in risk, and the high-risk letter may be quite common. For example, a T instead of a G in a particular spot may be associated with a 6 percent increase in risk, and that T may be present in 70 percent of the population. But combined, the risk score appears to become a clinically meaningful measure of coronary heart disease risk.
Stitziel also pointed out that these 27 markers do not change with age or lifestyle, so theoretically a person at high risk of developing coronary heart disease could be identified early, before traditional measures of the disease would be detected with a doctor’s physical exam or routine blood work.
Although this approach is currently not available to patients, Stitziel indicated that with additional research this type of genetic-risk score might one day become a useful tool in estimating the degree to which an individual is likely to benefit from statin therapy.
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This work was supported in part by the National Institutes of Health (NIH), grant number K08 HL114642.
Mega JL, Stitziel NO, Smith JG, Chasman DI, Caulfield M, Devlin JJ, Nordio F, Hyde C, Cannon CP, Sacks F, Poulter N, Sever P, Ridker PM, Braunwald E, Melander O, Kathiresan S, Sabatine MS. Genetic risk score, coronary heart disease events, and the clinical benefit of statin therapy: an analysis of primary and secondary prevention trials. The Lancet. March 4, 2015.
Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.
Public Release: 3-Mar-2015
A high-salt diet could protect against invading microbes
Cell Press
Most people consume more salt than they need and therefore have a higher risk of heart disease and stroke, which are the two leading causes of death worldwide. But a study published by Cell Press March 3rd in Cell Metabolism reveals that dietary salt could have a biological advantage: defending the body against invading microbes. A high-salt diet increased sodium accumulation in the skin of mice, thereby boosting their immune response to a skin-infecting parasite. The findings suggest that dietary salt could have therapeutic potential to promote host defense against microbial infections.
“Up to now, salt has been regarded as a detrimental dietary factor; it is clearly known to be detrimental for cardiovascular diseases, and recent studies have implicated a role in worsening autoimmune diseases,” says first study author Jonathan Jantsch, a microbiologist at Universitätsklinikum Regensburg and Universität Regensburg. “Our current study challenges this one-sided view and suggests that increasing salt accumulation at the site of infections might be an ancient strategy to ward off infections, long before antibiotics were invented.”
Large amounts of sodium stored in the skin, especially in older individuals, can lead to high blood pressure and increase the risk for heart disease and stroke. A high-salt diet, which increases sodium storage in the skin, can also worsen autoimmune disease and even increase the risk of stomach cancer. “Despite the overwhelming evidence linking dietary salt to disease in humans, the potential evolutionary advantage of storing so much salt in the body has not been clear,” says senior study author Jens Titze, who studies the link between sodium metabolism and disease at Vanderbilt University School of Medicine.
A clue to this mystery came when Titze and his collaborators noticed an unusually high amount of sodium in the infected skin of mice that had been bitten by cage mates. Intrigued by this observation, Titze teamed up with Jantsch to examine the link between infection and salt accumulation in the skin. They found that infected areas in patients with bacterial skin infections also showed remarkably high salt accumulation. Moreover, experiments in mice showed that a high-salt diet boosted the activity of immune cells called macrophages, thereby promoting the healing of feet that were infected with a protozoan parasite called Leishmania major.
Moving forward, the researchers will examine how salt accumulates in the skin and triggers immune responses, and why salt accumulates in the skin of aging adults. “A further understanding of the regulatory cascades might not only help to design drugs that specifically enhance local salt deposition and help to combat infectious diseases, but also may lead to novel strategies to mobilize sodium stores in the aging population and prevent cardiovascular disease,” Jantsch says. “We also think that local application of high-salt-containing wound dressings and the development of other salt-boosting antimicrobial therapies might bear therapeutic potential.”
In the meantime, the researchers urge caution over the potential health benefits of a high-salt diet. “Due to the overwhelming clinical studies demonstrating that high dietary salt is detrimental to hypertension and cardiovascular diseases, we feel that at present our data does not justify recommendations on high dietary salt in the general population,” Jantsch says. “Nevertheless, in situations where endogenous accumulation of salt to sites of infection is insufficient, supplementation of salt might be a therapeutic option. But this needs to be addressed in further studies.”
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This work was primarily supported by the Deutsche Forschungsgemeinschaft, the German Ministry for Economics and Technology, the Interdisciplinary Center for Clinical Research Erlangen, and the U.S. National Institutes of Health.
Cell Metabolism, Jantsch et al.: “Cutaneous Na+ Storage Strengthens the Antimicrobial Barrier Function of the Skin and Boosts Macrophage-Driven Host Defense”
Cell Metabolism, published by Cell Press, is a monthly journal that publishes reports of novel results in metabolic biology, from molecular and cellular biology to translational studies. The journal aims to highlight work addressing the molecular mechanisms underlying physiology and homeostasis in health and disease. For more information, please visit http://www.​cell.​com/​cell-metabolism. To receive media alerts for Cell Metabolism or other Cell Press journals, contact press@cell.com.
Public Release: 4-Mar-2015
Omega-3 fatty acids appear to protect damaged heart after heart attack
Study suggests this therapy may provide added benefits to standard care
American College of Cardiology
WASHINGTON (March 4, 2015) — Taking omega-3 fatty acids appeared to lower inflammation and guard against further declines in heart function among recent heart attack survivors already receiving optimal standard care, according to results from a randomized, controlled trial to be presented at the American College of Cardiology’s 64th Annual Scientific Session in San Diego.
Patients in the study taking 4 grams of prescription-only omega-3 fatty acid capsules daily for six months after a heart attack were significantly more likely to show improvements in heart function compared to patients taking a placebo. Heart function was measured by an expansion of the left ventricular endsystolic volume index. Patients taking omega-3 fatty acids also had significantly less evidence of fibrosis — a thickening or scarring of the areas of the heart remote from the heart attack, which can develop when the surviving heart muscle works harder and under high pressure to compensate for the damage to the heart. The data suggests that patients who were able to mount a substantial change in levels of omega-3 fatty acids in their blood derived the most benefit.
“Giving a high dose of omega-3 fatty acids soon after a heart attack appears to improve cardiac structure and heart functioning above and beyond the standard of care,” said Raymond W. Kwong, M.D., M.P.H, director of cardiac magnetic resonance imaging at Brigham and Women’s Hospital in Boston and the study’s senior author. “Because this is a unique group of patients with remarkably high adherence to [guideline-directed] treatments for acute myocardial infarction already, we feel fairly confident that the benefits from this therapy are additive. The implications of this study could be fairly large.”
An estimated 720,000 Americans have heart attacks each year. After a heart attack, the heart can remodel or reorganize itself to maintain or improve function. In some cases, the heart may undergo adverse changes such as enlargement of the heart, decreased pumping ability or added cardiac strain that can predispose someone to heart failure and arrhythmias later in life.
Although earlier studies have shown that omega-3 fatty acids may lower the risk of irregular heartbeats and death from a heart attack, research has not consistently shown a benefit. Kwong said his research is the first to use quantitative cardiac imaging to look at how omega-3 fatty acids might actually protect the heart after a major heart attack.
Researchers randomized 374 patients recovering from a heart attack and receiving standard treatment to take either 4 grams of omega-3 fatty acids or a placebo; groups were balanced in terms of location of the infarct–anterior or non-anterior–and age. Blood work and cardiac imaging were analyzed at two to four weeks post-heart attack and again at six months. Compared to previous research, this study used a much higher dose of omega-3 fatty acids, 4 grams compared to 1 gram daily, and a small amount of corn oil, which does not contain fatty acids, as the placebo.
By using cardiac magnetic resonance imaging, researchers were able to look at changes in patients’ hearts and see the disease process before and after treatment. Adverse changes in left ventricular remodeling and function, in addition to the worsening of fibrosis, were used as surrogates for poor outcomes after heart attack.
Patients taking the omega-3 fatty acids were 39 percent less likely to show a deterioration of heart function as compared to patients taking a placebo. The analysis also looked at key markers of systemic inflammation, which were also more likely to be improved in those taking the fish oil. In particular, the percent reduction in ST2, a marker of the severity of adverse cardiac remodeling and tissue fibrosis, was substantially greater in the treatment arm after six months.
“Omega-3 fatty acids may have anti-inflammatory effects and also promote better cardiac healing,” Kwong said. “This is important because other anti-inflammatory agents, including steroids and NSAIDS, have failed to make a difference after myocardial infarction.” Patients in the study who had a 5 percent increase in the amount of omega-3 fatty acid in their blood seem to have the best chance of improving heart function.
“If this becomes a useful therapy, it seems a 5 percent increase in the serum level of omega-3 fatty acids correlates with a 10 percent improvement in left ventricular remodeling,” he said. In this study, most (92 percent) of patients randomized to fish oil increased omega-3 fatty acid by at least 5 percent, compared with less than half (42 percent) of patients receiving placebo.
Kwong said the higher-dose omega-3 fatty acids was not found to be associated with any major safety issues, such as increased bleeding. “It’s a very well-tolerated therapy,” he said, adding that it is unlikely patients could get the amount of omega-3 fatty acids from diet alone. He said the daily 4 gram dose is roughly equivalent to someone eating a large, 8-ounce serving of salmon every day for six months.
For many years, the American College of Cardiology and the American Heart Association have recommended that people eat fish rich in omega-3 fatty acids at least twice a week because of its potential heart benefits.
Kwong said most North Americans do not follow this advice, while Japanese populations with higher levels of omega-3 and an otherwise similar risk profile to North Americans have lower risks of heart disease and sudden cardiac death. The increase in the omega-3 blood content of many patients in Kwong’s study at six months was similar to levels found in Japanese populations with a diet very rich in omega-3 fatty acids.
Fatty fish such as salmon, tuna, trout and sardines contain the most omega-3 fatty acids. Fatty acids are a key component of cell membranes and they help with cell signaling, proper immune function and may also improve cognitive functioning. This study is limited in that it did not investigate the association between omega-3 fatty acids and cardiac events after heart attack; assessing this relationship would require a large group of patients over many years. It also did not evaluate this treatment immediately after having a heart attack.
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The study was funded by the National Institutes of Health.
GlaxoSmithKline provided the medication (Lovaza) for the study, but the authors report the pharmaceutical company was not involved with the study or its analysis. Unlike supplements available without a prescription, Lovaza is regulated by the U.S. Food and Drug Administration and is approved to treat high triglycerides.
The study, “Effect of Purified Omega-3 Fatty Acids on Reducing Left Ventricular Remodeling after Acute Myocardial Infarction (OMEGA-REMODEL Study: A Double-Blind Randomized Clinical Trial),” will be presented on March 16 at 10:45 a.m. PT/1:45 p.m. ET/5:45 p.m. UTC the American College of Cardiology’s 64th Annual Scientific Session in San Diego. The meeting will run March 14-16.
The ACC’s Annual Scientific Session brings together cardiologists and cardiovascular specialists from around the world each year to share the newest discoveries in treatment and prevention. Follow @ACCMediaCenter and #ACC15 for the latest news from the meeting.
The American College of Cardiology is a 49,000-member medical society that is the professional home for the entire cardiovascular care team. The mission of the College is to transform cardiovascular care and to improve heart health. The ACC leads in the formation of health policy, standards and guidelines. The College operates national registries to measure and improve care, provides professional medical education, disseminates cardiovascular research and bestows credentials upon cardiovascular specialists who meet stringent qualifications. For more information, visit acc.org.
Public Release: 4-Mar-2015
Study shows that use of statins increases risk of developing diabetes by 46 percent
Even after adjustment for confounding factors
Diabetologia
New research published in Diabetologia (the journal of the European Association for the Study of Diabetes) shows that use of statins is associated with a 46% increase in the risk of developing diabetes, even after adjustment for confounding factors. The study is by Professor Markku Laakso, Institute of Clinical Medicine, University of Eastern Finland and Kuopio University Hospital, Finland, and colleagues.
Previous studies have suggested an increased risk (of varying levels) of developing diabetes associated with statin use. However, these studies have had limitations: study populations have been selective especially in statin trials which have included participants at high risk of cardiovascular disease. Therefore, the risk of diabetes in clinical trials is likely to differ from that in the general population. Very often in previous studies the diagnosis of diabetes has been based on self-reported diabetes or fasting glucose measurement, leading to an underestimation of the actual numbers of incident diabetes cases.
In this new study, the authors investigated the effects of statin treatment on the risk of type 2 diabetes and deterioration of blood sugar control in 8,749 non-diabetic men in a 6-year follow-up of the population-based Metabolic Syndrome in Men (METSIM) study, based in Kuopio, Finland. The authors also investigated the mechanisms of statin-induced diabetes by evaluating changes in insulin resistance and insulin secretion.
The participants, aged 45-73 years, were followed up for 5.9 years. New diabetes was diagnosed in 625 men with either an oral glucose tolerance test (OGTT), an HbA1c level of 6.5% or higher, or anti-diabetic medication started during the follow-up. Insulin sensitivity and secretion were evaluated.
The researchers found that, after the results were adjusted for age, body mass index (BMI), waist circumference, physical activity, smoking, alcohol intake, family history of diabetes, and beta-blocker and diuretic treatment, patients treated with statins were 46% more likely to develop diabetes than those not treated with statins.
The risk was dose-dependent for simvastatin and atorvastatin. Statin treatment significantly increased 2-h glucose (2hPG) at follow-up, with a nominally significant increase in fasting glucose (FPG). Insulin sensitivity was decreased by 24% and insulin secretion by 12% in individuals on statin treatment.
Furthermore, decreases in insulin sensitivity and insulin secretion were dose-dependent for simvastatin and atorvastatin. And, after adjustment for all the confounders mentioned above, high-dose simvastatin was associated with a 44% increased risk of developing diabetes , while for low-dose simvastatin the increased risk was 28% and for high-dose atorvastatin the increased risk was 37%. Overall, 29% of participants were taking simvastatin, while 53% were taking atorvastatin.
The authors say “The association of statin use with increased risk of developing diabetes is most likely directly related to statins decreasing both insulin sensitivity and secretion.”
Furthermore, they stress that while the size of the study makes their conclusions reliable, the study sample was Caucasian men, so the applicability to women or people of other ethnic origin cannot be confirmed without further research.
They conclude: “Statin therapy was associated with a 46% increased risk of type 2 diabetes after adjustment for confounding factors, suggesting a higher risk of diabetes in the general population than previously reported.”
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Public Release: 6-Mar-2015
Onion extract may improve high blood sugar and cholesterol
The Endocrine Society
San Diego, CA– The extract of onion bulb, Allium cepa, strongly lowered high blood glucose (sugar) and total cholesterol levels in diabetic rats when given with the antidiabetic drug metformin, according to a new study. The study results will be presented Thursday at The Endocrine Society’s 97th annual meeting in San Diego.
“Onion is cheap and available and has been used as a nutritional supplement,” said lead investigator Anthony Ojieh, MBBS (MD), MSc, of Delta State University in Abraka, Nigeria. “It has the potential for use in treating patients with diabetes.”
To three groups of rats with medically induced diabetes, Ojieh and his colleagues gave metformin and varying doses of onion extract–200, 400 and 600 milligrams per kilograms of body weight daily (mg/kg/day)–to see if it would enhance the drug’s effects. They also gave metformin and onion extract to three groups of nondiabetic rats with normal blood sugar, for comparison. Two control groups, one nondiabetic and one diabetic, received neither metformin nor onion extract. Another two groups (one with diabetes, one without) received only metformin and no onion extract. Each group contained five rats.
Two doses of onion extract, 400 and 600 mg/kg/day, strongly reduced fasting blood sugar levels in diabetic rats by 50 percent and 35 percent, respectively, compared with “baseline” levels at the start of the study before the rodents received onion extract, Ojieh reported.
Allium cepa also reportedly lowered the total cholesterol level in diabetic rats, with the two larger doses again having the greatest effects.
Onion extract led to an increase in average weight among nondiabetic rats but not diabetic rats.
“Onion is not high in calories,” Ojieh said. “However, it seems to increase the metabolic rate and, with that, to increase the appetite, leading to an increase in feeding.”
Histologic study of the pancreas removed from each diabetic rat showed that neither metformin nor onion extract healed the damage that resulted from the drug-caused diabetes.
“We need to investigate the mechanism by which onion brought about the blood glucose reduction,” Ojieh said. “We do not yet have an explanation.”
The onion extract used for the experiment was a crude preparation from onion bulb, which is available in the local market. If this were to be administered to humans, it would usually be purified so that only the active ingredients would be quantified for adequate dosing, Ojieh said.
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Nigeria’s Tertiary Education Trust Fund supported this research.
Public Release: 12-Mar-2015
High cholesterol, triglycerides can keep vitamin E from reaching body tissues
Oregon State University
CORVALLIS, Ore. – In the continuing debate over how much vitamin E is enough, a new study has found that high levels of blood lipids such as cholesterol and triglycerides can keep this essential micronutrient tied up in the blood stream, and prevent vitamin E from reaching the tissues that need it.
The research, just published in the American Journal of Clinical Nutrition, also suggested that measuring only blood levels may offer a distorted picture of whether or not a person has adequate amounts of this vitamin, and that past methods of estimating tissue levels are flawed.
The findings are significant, the scientists say, because more than 90 percent of the people in the United States who don’t take supplements lack the recommended amount of vitamin E in their diet.
Vitamin E is especially important in some places such as artery walls, the brain, liver, eyes and skin, but is essential in just about every tissue in the body. A powerful, fat-soluble antioxidant, it plays important roles in scavenging free radicals and neurologic function. In the diet, it’s most commonly obtained from cooking oils and some vegetables.
Some experts have suggested that recommended levels of vitamin E should be lowered. But because of these absorption issues, the recommended level of 15 milligrams per day is about right, said Maret Traber, the lead author of this study. Inadequate vitamin E intake remains a significant societal problem, she said.
“This research raises particular concern about people who are obese or have metabolic syndrome,” said Traber, who is the Helen P. Rumbel Professor for Micronutrient Research in the College of Public Health and Human Sciences at Oregon State University, and a principal investigator in OSU’s Linus Pauling Institute.
“People with elevated lipids in their blood plasma are facing increased inflammation as a result,” Traber said. “Almost every tissue in their body is under oxidative attack, and needs more vitamin E. But the vitamin E needed to protect these tissues is stuck on the freeway, in the circulatory system. It’s going round and round instead of getting to the tissues where it’s needed.”
This research was done with 41 men and women, including both younger and older adults, who obtained vitamin E by eating deuterium-labeled collard greens, so the nutrient could be tracked as it moved through the body. Of some interest, it did not find a significant difference in absorption based solely on age or gender. But there was a marked difference in how long vitamin E stayed in blood serum, based on higher level of lipids in the blood – a more common problem as many people age or gain weight.
The study also incorporated a different methodology, using a stable isotope instead of radioactive tracers, than some previous research, to arrive at the estimates of vitamin E that made it to body tissues. Using the stable isotope methodology that these researchers believe is more accurate, they concluded that only 24 percent of vitamin E is absorbed into the body, instead of previous estimates of 81 percent measured by the use of radioactive vitamin E.
“In simple terms, we believe that less than one third the amount of vitamin E is actually making it to the tissues where it’s most needed,” Traber said.
Vitamin E in the blood stream is not completely wasted, Traber noted. There, it can help protect LDL and HDL cholesterol from oxidation, which is good. But that doesn’t offset the concern that not enough of this micronutrient may be reaching tissues, she said.
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Collaborators on this study were from the USDA Human Nutrition Center on Aging at Tufts University, and the Children’s Nutrition Research Center at the Baylor College of Medicine. The work was supported by the USDA Agricultural Research Service and the National Institutes of Health.
Public Release: 12-Mar-2015
You are when you eat
A new study finds that limiting flies to specific eating hours protected their hearts against aging
San Diego State University
SAN DIEGO (Thursday, March 12, 2015) — If you’re looking to improve your heart health by changing your diet, when you eat may be just as important as what you eat. In a new study published today in Science, researchers at San Diego State University and the Salk Institute for Biological Studies found that by limiting the time span during which fruit flies could eat, they could prevent aging- and diet-related heart problems. The researchers also discovered that genes responsible for the body’s circadian rhythm are integral to this process, but they’re not yet sure how.
Previous research has found that people who tend to eat later in the day and into the night have a higher chance of developing heart disease than people who cut off their food consumption earlier.
“So what’s happening when people eat late?” asked Girish Melkani, a biologist at SDSU whose research focuses on cardiovascular physiology. “They’re not changing their diet, just the time.”
Melkani, one of the paper’s senior authors, teamed up with Satchidananda Panda, a circadian rhythms expert at the Salk Institute, to address whether changing the daily eating patterns of fruit flies could affect their heart health. Fruit flies have long been used as model organisms to identify the genetic basis of human disease, including cardiovascular disease.
Shubhroz Gill, a postdoctoral researcher in Panda’s lab and now at the Broad Institute in Boston, was the lead author on this study. Hiep D. Le of the Salk Institute also contributed to the study.
Time flies
In their experiments, one group of 2-week-old fruit flies was given a standard diet of cornmeal and allowed to feed all day long. Another group was allowed access to the food for only 12 hours a day. Over the course of several weeks, Melkani and Gill recorded how much food the flies were eating and tested a battery of health measures related to their sleep, body weight and heart physiology.
After three weeks, the results were clear: Flies on the 12-hour time-restricted feeding schedule slept better, didn’t gain as much weight and had far healthier hearts than their “eat anytime” counterparts, even though they ate similar amounts of food. The researchers observed the same results after five weeks.
“In very early experiments, when we compared 5-week-old flies that were fed for either 24 hours or 12 hours, the hearts of the latter were in such good shape that we thought perhaps we had mistaken some young 3-week-old fruit flies for the older group,” Gill said. “We had to repeat the experiments several times to become convinced that this improvement was truly due to the time-restricted feeding.”
What’s more, another set of experiments revealed that the benefits of a time-restricted diet weren’t exclusive to young flies. When the researchers introduced these dietary time restrictions to older flies, their hearts became healthier, too. (The average lifespan of a fruit fly is about 60 days.)
“Even if you introduce time-restricted feeding very late, you still have some benefit,” Melkani said.
Some degree of heart protection persisted even for flies that went back to eating whenever they wanted, he added.
Key genes
Next, the researchers sequenced the RNA of the flies at various points in the experiment to find which of their genes had changed as a result of time-restricted feeding. They identified three genetic pathways that appear to be involved: the TCP-1 ring complex chaperonin, which helps proteins fold; mitochondrial electron transport chain complexes (mETC); and a suite of genes responsible for the body’s circadian rhythm.
Melkani and Gill repeated their experiments using mutant strains of flies with nonfunctional versions of the TCP-1 and circadian rhythm genes. In these flies, time-restricted feeding granted no health benefits, strengthening the case that these genetic pathways play key roles.
Conversely, in mutant flies with altered mETC genes, the flies showed increased protection against cardiac aging.
“If and how these three pathways all work together, we don’t yet know entirely,” Melkani said.
Nix the late-night snacks
The results complement earlier research from Panda’s lab showing benefits of time-restricted feeding for obesity, metabolic diseases and type-2 diabetes in rodents.
“All together, these results reinforce the idea that the daily eating pattern has a profound impact on both the body and the brain,” Panda said.
Gill noted that there are some hurdles to clear before extrapolating this research to humans.
“Humans don’t consume the same food every day,” he said. “And our lifestyle is a major determinant of when we can and cannot eat. But at the very minimum, our studies offer some context in which we should be pursuing such questions in humans.”
Melkani is optimistic that the results could one day translate into cardiac- and obesity-related health benefits for humans. “Time-restricted feeding would not require people to drastically change their lifestyles, just the times of day they eat,” Melkani said. “The take-home message then would be to cut down on the late-night snacks.”
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About San Diego State University
San Diego State University is a major public research institution offering bachelor’s degrees in 89 areas, master’s degrees in 78 areas and doctorates in 21 areas. The university provides transformative experiences, both inside and outside of the classroom, for its 34,000 students. Students participate in research, international experiences, sustainability and entrepreneurship initiatives, and a broad range of student life and leadership opportunities. The university’s rich campus life features opportunities for students to participate in, and engage with, the creative and performing arts, a Division I athletics program and the vibrant cultural life of the San Diego region. For more information, visit http://www.sdsu.edu.
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