Release Date 06 DEC 2014
Draft Report Compiled by
In this Issue:
- Does a yogurt a day keep diabetes away?
- Study finds most older adults qualify for statin therapy under new cholesterol guidelines
- Healthy gut microbiota can prevent metabolic syndrome, researchers say
- Selenium compounds boost immune system to fight against cancer
- Elderly brains learn, but maybe too much
- Plant used in traditional Chinese medicine may treat metabolic diseases and obesity
- Supplemental co-enzyme Q may prevent heart disease in some individuals
- Vitamin D reduces lung disease flare-ups by over 40 percent
- Vitamin supplement successfully prevents noise-induced hearing loss
- Common prostate cancer treatment associated with decreased survival in older men
Does a yogurt a day keep diabetes away?
A high intake of yogurt has been found to be associated with a lower risk of developing type 2 diabetes, according to research published in open access journal BMC Medicine. This highlights the importance of having yogurt as part of a healthy diet.
Type 2 diabetes is a chronic condition that occurs when the body doesn’t produce enough insulin, or the body’s cells develop resistance to insulin. There is an increased risk of developing it if a relative has the condition or if an individual has an unhealthy lifestyle. Approximately 366 million people are affected by type 2 diabetes worldwide and it is estimated this will increase to 552 million people by 2030, which puts pressure on global healthcare systems.
Researchers from Harvard School of Public Health pooled the results of three prospective cohort studies that followed the medical history and lifestyle habits of health professionals. These studies were the Health Professionals’ Follow-up Study (HFPS), which included 51,529 US male dentists, pharmacists, vets, osteopathic physicians and podiatrists, aged from 40 to 75 years; Nurses’ Health Study (NHS), which began in 1976, and followed 121,700 female US nurses aged from 30 to 55 years; and Nurses’ Health Study II (NHS II), which followed 116,671 female US nurses aged from 25 to 42 years beginning in the year 1989.
At the beginning of each cohort study, participants completed a questionnaire to gather baseline information on lifestyle and occurrence of chronic disease. Participants were then followed up every two years with a follow-up rate of more than 90 per cent. Participants were excluded if they had diabetes, cardiovascular disease or cancer at baseline. People were also excluded if they did not include any information about dairy consumption. This left a total of 41,497 participants from HPFS, 67,138 from NHS and 85,884 from NHS II.
Mu Chen, the study’s lead author from Harvard School of Public Health, says: “Our study benefited from having such a large sample size, high rates of follow up and repeated assessment of dietary and lifestyle factors.”
Within the three cohorts 15,156 cases of type 2 diabetes were identified during the follow-up period. The researchers found that the total dairy consumption had no association with the risk of developing type 2 diabetes. They then looked at consumption of individual dairy products, such as skimmed milk, cheese, whole milk and yogurt. When adjusting for chronic disease risk factors such as age and BMI as well as dietary factors, it was found that high consumption of yogurt was associated with a lower risk of developing type 2 diabetes.
The authors then conducted a meta-analysis, incorporating their results and other published studies, up to March 2013, that investigated the association between dairy products and type 2 diabetes. This found that consumption of one 28g serving of yogurt per day was associated with an 18 per cent lower risk of type 2 diabetes.
Previous research has suggested calcium, magnesium, or specific fatty acids present in dairy products may lower the risk of type 2 diabetes. It has been shown that probiotic bacteria found in yogurt improves fat profiles and antioxidant status in people with type 2 diabetes and the researchers suggest this could have a risk-lowering effect in developing the condition. To confirm this observation, and investigate whether or not yogurt is causal in the lowering of risk, randomized controlled trials are needed.
Senior researcher on the study Frank Hu, Harvard School of Public Health, says: “We found that higher intake of yogurt is associated with a reduced risk of type 2 diabetes, whereas other dairy foods and consumption of total dairy did not show this association. The consistent findings for yogurt suggest that it can be incorporated into a healthy dietary pattern.”
Study finds most older adults qualify for statin therapy under new cholesterol guidelines
In a cohort of individuals aged 66-75 years, 97 percent now qualify for a statin
MINNEAPOLIS, MN – November 24, 2014 – Nearly all individuals in their late 60s and early 70s — including 100 percent of men — now qualify for and should consider starting a statin medication to reduce their risk of cardiovascular disease, under the recently released cholesterol guidelines from the American College of Cardiology (ACC) and the American Heart Association (AHA).
That’s according to a research letter published today in the 11/20/2014 (JAMA-IM) by Michael D. Miedema, MD, MPH, a research cardiologist at Minneapolis Heart Institute Foundation and cardiologist at Minneapolis Heart Institute® at Abbott Northwestern Hospital.
Released in November 2013, the ACC/AHA guidelines for the treatment of blood cholesterol attempt to target individuals that are most likely to benefit from cholesterol-lowering statin therapy.
“The guidelines are a significant change from prior guidelines that relied heavily on levels of bad cholesterol to determine who to treat,” states Dr. Miedema. “Instead, the new guidelines recommend focusing statin therapy on the individuals that are at the highest risk for heart attack and stroke, even if their cholesterol levels are within normal limits.”
In addition to recommending statin therapy for individuals with known cardiovascular disease, diabetes, or markedly elevated cholesterol levels, the guidelines also recommend statin therapy for individuals without these conditions, but with an elevated estimated risk of a heart attack or stroke in the next 10 years based on a risk calculator. The calculator factors in an individual’s age, gender, race, and risk factors and recommends that patients with an estimated 10-year risk above 7.5% consider statin therapy.
While Dr. Miedema believes the scientific evidence supports this “risk-based” approach, one potential concern is that the risk calculator relies too heavily on age to determine an individual’s risk. “Older individuals will likely cross the 7.5% threshold based on age alone, even if they have normal cholesterol levels and no other cardiovascular risk factors, and our study confirms this notion.”
Miedema and his colleagues studied 6,088 black and white adults between the ages of 66 and 90 in the Atherosclerosis Risk in Communities (ARIC) Study, a longitudinal study of cardiovascular disease sponsored by the National Heart, Lung, and Blood Institute that has been following participants for about 25 years. The ARIC cohort was reassessed in 2013, and the study analyzed the volume of statin-eligible participants based on the previous Adult Treatment Panel (ATP) III cholesterol guidelines compared to the newer ACC/AHA guidelines.
“Based on the ATP III guidelines, we found that just over 70% of the ARIC participants were eligible for statin therapy,” Miedema said. “In contrast, 97 percent were statin eligible by ACC/AHA criteria. For men 66-75 years old, the qualification rate was 100 percent.”
While half of the cohort was older than 75, the ACC/AHA guidelines do not provide a recommendation for or against statin therapy for people of that age group. However, researchers noted that more than half of these older individuals in the study were taking a statin.
“We don’t have great data on the efficacy of statin medications in the elderly so the guidelines drew a cut-off for the recommendations at age 75,” Miedema said. “This is understandable, but it kind of leaves clinicians in the dark as to what to do with healthy elderly patients, who are often at high risk for heart attacks and strokes.”
“We clearly need more research looking at the best way to determine who should and should not take a statin, as well as the risks and benefits of statin therapy in elderly patients,” Miedema said.
Healthy gut microbiota can prevent metabolic syndrome, researchers say
ATLANTA–Promoting healthy gut microbiota, the bacteria that live in the intestine, can help treat or prevent metabolic syndrome, a combination of risk factors that increases a person’s risk for heart disease, diabetes and stroke, according to researchers at Georgia State University and Cornell University. Their findings are published in the journal Gastroenterology.
The study, a follow-up to the research team’s previous paper in Science, uses an improved technical approach, making the results more significant.
The research team includes Dr. Andrew Gewirtz, a professor in the Institute for Biomedical Sciences at Georgia State; Dr. Benoit Chassaing, a post doctoral fellow at Georgia State; and Dr. Ruth Ley of the departments of Microbiology and Molecular Biology at Cornell.
“These results suggest that developing a means to promote a more healthy microbiota can treat or prevent metabolic disease,” Gewirtz said. “They confirm the concept that altered microbiota can promote low-grade inflammation and metabolic syndrome and advance the underlying mechanism. We showed that the altered bacterial population is more aggressive in infiltrating the host and producing substances, namely flagellin and lipopolysaccharide, that further promote inflammation.”
Metabolic syndrome is a serious health condition that affects 34 percent of American adults, according to the American Heart Association. A person is diagnosed with metabolic syndrome when they have three of these risk factors: a large waistline, high triglyceride (type of fat found in the blood) level, low HDL cholesterol level, high blood pressure and high fasting blood sugar. A person with metabolic syndrome is twice as likely to develop heart disease and five times as likely to develop diabetes, according to the National Institutes of Health.
Because metabolic syndrome is becoming more common, scientists are exploring possible causes. In their previous study in Science, Gewirtz, Ley and other researchers showed altered gut microbiota plays a role in promoting metabolic syndrome.
Gut microbiota performs key functions in health and when it becomes dysregulated it can promote chronic inflammatory diseases such as Crohn’s disease and ulcerative colitis. In addition, altered gut microbiota promotes inflammation that leads to metabolic syndrome.
“We’ve filled in a lot of the details about how it works,” Gewirtz said. “It’s the loss of TLR5 on the epithelium, the cells that line the surface of the intestine and their ability to quickly respond to bacteria. That ability goes away and results in a more aggressive bacterial population that gets closer in and produces substances that drive inflammation.”
Normally, the bacteria are in the mucous layer at a certain distance away from epithelial cells. The researchers showed altered gut microbiota is more aggressive in infiltrating the host and gets very close to the epithelium. This altered population produces flagellin and lipopolysaccharide, which further promote inflammation.
The research team improved the study by comparing mice that were siblings and littermates, making all conditions in the study the same. The mice only differed by whether they were missing a specific gene, TLR5. Previously, the researchers studied mice that were from two different strains and lived in separate environments. In this study, they found the absence of TLR5 on the intestinal surface leads to alterations in bacteria that drive inflammation, leading to metabolic syndrome.
Selenium compounds boost immune system to fight against cancer
Cancer types such as melanoma, prostate cancer and certain types of leukaemia weaken the body by over-activating the natural immune system. Researchers from the University of Copenhagen have now demonstrated that selenium – naturally found in, e.g., garlic and broccoli – slows down the immune over-response. In the long term, this may improve cancer treatment. The findings have been published in the Journal of Biological Chemistry.
The immune system is designed to remove things not normally found in the body. Cells undergoing change, e.g. precursors of cancer cells, are therefore normally recognised and removed by the immune system. Unfortunately, the different cancer cells contain mechanisms that block the immune system’s ability to recognise them, allowing them to freely continue cancer development.
“We have now shown that certain selenium compounds, which are naturally found in, e.g., garlic and broccoli, effectively block the special immunostimulatory molecule that plays a serious role for aggressive cancers such as melanoma, prostate cancer and certain types of leukaemia,” says Professor Søren Skov.
Certain cancer cells overexpress immunostimulatory molecules in liquid form. Such over-stimulation has a negative impact on the immune system:
“You can say that the stimulating molecules over-activate the immune system and cause it to collapse, and we are, of course, interested in blocking this mechanism. We have now shown that certain selenium compounds, which are naturally found in, e.g., garlic and broccoli, effectively block the special immunostimulatory molecule that plays a serious role for aggressive cancers such as melanoma, prostate cancer and certain types of leukaemia,” says Professor Søren Skov, Department of Veterinary Disease Biology, University of Copenhagen.
In this study, the researchers are focusing on the so-called NGK2D ligands. There are eight variants, of which one in particular has caught the researchers’ attention, because it assumes liquid form. It is precisely the molecular dissolution that causes serious problems, once the cancer is raging. The entire bloodstream is, so to speak, infected, and the molecule is therefore used as a marker of serious illness:
“Molecules are found both on the surface of the cancer cells and dissolved in the blood of the affected person. We are now able to show that selenium compounds appear to have a very beneficial effect when it comes to neutralising the special variant of the NGK2D ligand – both in soluble form and when the molecule is placed on the cell surface,” says Professor Søren Skov.
Better drugs in future
The researchers are constantly learning more about the disease mechanisms causing aggressive cancers in the skin, blood and reproductive organs:
“The overexpression seen in cancers such as melanoma, prostate cancer and certain types of leukaemia significantly impairs the immune system. If we can find ways to slow down the over-stimulation, we are on the right track. The new results are yet another small step towards better cancer drugs with fewer adverse effects,” says Søren Skov.
Søren Skov’s research team is part of a major EU project tasked with examining the potential for improving cancer treatment by boosting the immune system (link)
Elderly brains learn, but maybe too much
PROVIDENCE, R.I. [Brown University] — A new study led by Brown University reports that older learners retained the mental flexibility needed to learn a visual perception task but were not as good as younger people at filtering out irrelevant information.
The findings undermine the conventional wisdom that the brains of older people lack flexibility, or “plasticity,” but highlight a different reason why learning may become more difficult as people age: They learn more than they need to. Researchers call this the “plasticity and stability dilemma.” The new study suggests older people may indeed be facing it.
“Plasticity may be kept OK, in contrast with the view of many researchers on aging who have said that the degree of plasticity of older people gets lower,” said Takeo Watanabe, the Fred M. Seed Professor at Brown University, corresponding author of the study in Current Biology. “However, we have found that the stability is problematic. Our learning and memory capability is limited. You don’t want older, existing important information that is already stored to be replaced with trivial information.”
Numerals, not dots
To conduct the study, Watanabe and his team enrolled a group of 10 people between 67 and 79 years old and another group of 10 people ages 19 to 30 for an experiment. Over a nine-day period, they trained on a simple visual exercise: Shown a quick sequence of six symbols – four letters and two numerals – volunteers were asked to report the numerals they saw. Their performance on a test at the end of training was compared to their score on a pre-test.
The volunteers were explicitly instructed to only bother with spotting the two numerals, but each symbol they saw had a background of moving dots. Unbeknownst to the subjects, those dots would move with varying degrees of cohesiveness of direction. In the pre- and post-tests the researchers also asked the volunteers to report the direction of dot movement when they saw the numerals.
The results of the testing were telling. Older people improved as much as younger people on the relevant task of identifying the two numerals.
“These results indicate that older subjects as well as younger subjects showed significant amounts of task-relevant learning,” the authors wrote. “No evidence was obtained that indicates that older individuals have a problem with plasticity.”
Last week, in fact, Watanabe and colleagues published a study showing that plasticity during visual learning occurs in older people as well as younger ones, but it is manifest differently in the brains of the different groups.
But in this study when it came to the irrelevant skill of discerning the prevailing direction of dot movement, older people learned that, too, even when it was at its most obvious. Younger people, meanwhile, only showed improvement on discerning movement when it was insidiously subtle. If it was clear, they recognized it and filtered it out.
The idea that the most obvious signals were the most easily filtered, suggested that the difference between older and younger learners was a matter of attention.
The researchers therefore subjected the volunteers to another test for the ability to find a relevant stimulus amid a number of distractors. Older people did notably worse than younger ones, adding evidence that the attentional systems for filtering out irrelevant stimuli were indeed weaker in older learners. Importantly, the poorer an older subject was at the ability to filter out irrelevant stimuli, the more irrelevant stimuli the subject learned.
Watanabe said the finding is not necessarily discouraging news. Perhaps filtering can be improved with some kind of training.
“The hope is that maybe what older people need to do is to learn a skill to avoid learning what is not necessary,” he said.
Plant used in traditional Chinese medicine may treat metabolic diseases and obesity
New research published in the Journal of Leukocyte Biology suggests that a component of a flowering plant used in traditional Chinese medicine thwarts development of obesity, type 2 diabetes and hepatic steatosis
New research published in the December 2014 issue of the Journal of Leukocyte Biology, shows that a component found in in the plant, Glycyrrhiza uralensis, may inhibit the development of metabolic disorders by stopping the activation of NLRP3, a protein involved in the disease process. Specifically, the researchers identified isoliquiritigenin as having the ability to attenuate high-fat, diet-induced obesity, type 2 diabetes and hepatic steatosis in mice.
“Identification of small compounds that inhibit the NLRP3 inflammasome is required to design effective therapeutics,” said Kiyoshi Takatsu, Ph.D., a researcher involved in the work from the Department of Immunobiology and Pharmacological Genetics, Graduate School of Medicine and Pharmaceutical Science for Research at the University of Toyama in Toyama Japan. “We hope that our findings will provide new information and strategy that can be exploited for development of new herbal medication of those diseases.”
To make this find, scientists stimulated mouse macrophages with different inflammasome activators in the presence of isoliquiritigenin. Then, activation of NLRP3 inflammasome was examined by measuring IL-1beta production in the culture supernatants. Results showed that relatively low concentrations of isoliquiritigenin were highly effective in inhibiting IL-1beta production compared with known NLRP3 inflammasome inhibitors, such as parthenolide and sulfonylurea drug glyburide. For animal studies, three groups of mice were used. The first group of mice was fed a normal diet and the second group of mice was fed a high-fat diet. The third group of mice was fed a high-fat diet supplemented with 0.5 percent isoliquiritigenin. High-fat diet feeding for 20 weeks induced obesity, type 2 diabetes and hepatic steatosis in mice, but supplementation of ILG markedly improved these disorders. Finally, supplementation of isoliquiritigenin inhibited high-fat diet-induced IL-1beta production in adipose tissue.
“Obesity and associated metabolic disorders are one of the most important emerging medical conditions. Recent work demonstrates a critical role for obesity-driven inflammation in a multitude of medical problems arising from obesity with a central role for the inflammasome,” said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology. “This new work not only identifies a novel class of potential inflammasome inhibitors, but also demonstrates effectiveness in a preclinical model of obesity induced disease.”
Supplemental co-enzyme Q may prevent heart disease in some individuals
New research in The FASEB Journal suggests that low birth weight in rats leads to a reduction in co-enzyme Q in the aorta and that supplemental dosage prevents age-associated damage leading to heart disease
New research involving rats, and published in the December 2014 issue of The FASEB Journal, suggests that if you were born at a low birth weight, supplemental co-enzyme Q (CoQ) may lower your risk for heart disease. This enzyme, which is naturally made in the body, is required to ensure the proper functioning of cell mitochondria and also protects cells from oxidative damage. Feeding low birth weight rat offspring extra CoQ prevented the age-associated damage that causes heart disease. Additionally, the reports shows that CoQ is reduced in white blood cells from low birth weight offspring, and levels of CoQ in the blood can be an indicator of how much damage to the aorta has already occurred.
“We believe our study provides the first steps in the development of a routine diagnostic test for blood coenzyme Q levels which can be used to identify individuals who are at risk of cardiovascular disease later in life,” said Jane L. Tarry-Adkins, a researcher involved in the work from the Institute of Metabolic Science at the University of Cambridge Metabolic Research Laboratories in the United Kingdom. “Additionally, simple co-enzyme Q supplements may be able to lower these individuals risk.”
To make their discovery, Tarry-Adkins and colleagues fed pregnant rats either a control diet or a diet that had the same total calories but contained less protein and more carbohydrates. The mothers fed the low protein diet had pups which had a low birth weight but grew quickly when suckled by a control fed mother. Researchers examined the aorta from the rats which were born small and grew very quickly after birth and showed that their cells aged more quickly than those from the normal birth weight offspring and that this was associated with a deficit in co-enzyme Q, in both the aorta and in the blood compared to the normal birth weight rats. Administering extra coenzyme Q in their diet from weaning prevented the accelerated aging of and damage to their aortas.
“Coenzyme Q is in the drug store now, but if you think that what you buy is going to keep you from having a heart attack or stroke, don’t get your hopes up just yet,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. “This promising research was conducted in rats, and if it also applies to people, still doesn’t tell us how much to take, for how long, and if it’s safe for these purposes. We’ve got a long way to go on this one, but so far, so good!”
Vitamin D reduces lung disease flare-ups by over 40 percent
Vitamin D supplements can reduce COPD lung disease flare-ups by over 40% in patients with a vitamin D deficiency – according to new research from Queen Mary University of London. COPD (chronic obstructive pulmonary disease) includes conditions such as chronic bronchitis and emphysema, and is thought to affect more than 3 million people in the UK.
The NIHR-funded randomised trial, published in the journal Lancet Respiratory Medicine, included 240 patients with COPD in and around London. Half of the patients (122) received vitamin D supplements (6 x 2-monthly oral doses of 3mg) and the other half (118) received an equivalent placebo. The risk, severity and duration of flare-ups was then compared between the two groups.
Flare-ups (also referred to as ‘exacerbations’) are when a COPD patient’s usual symptoms (coughing, excess mucus, shortness of breath, tightness in chest) get worse and stay worse, sometimes resulting in hospitalisation.
Patients with a vitamin D deficiency benefited dramatically from taking the supplements but the striking reduction in flare-ups was not seen among patients who had a higher vitamin D status at the start of the trial. However, researchers did find vitamin D supplementation modestly reduced the severity and duration of flare-up symptoms in all patients in the vitamin D group, regardless of their baseline vitamin D levels, compared to the placebo group.
This is the first clinical trial to investigate the impact of vitamin D supplementation on severity and duration of COPD symptoms. One previous trial has linked vitamin D to a reduction in COPD disease flare ups but this was limited to patients with very severe conditions. This trial is larger and studied patients with a much broader spectrum of diseases, ranging from mild to severe.
Professor Adrian Martineau, Lead Author, Queen Mary University of London, comments: “Flare-ups of chronic bronchitis and emphysema (COPD) can be debilitating for patients, sometimes leading to hospitalisation and even death. Our research has shown how an inexpensive vitamin supplement can significantly reduce the risk of flare-ups for patients who are vitamin D deficient, which could have a major public health benefit. Our findings suggest that patients with COPD should have their vitamin D status tested and should begin taking supplements if their levels are found to be low.”
Vitamin supplement successfully prevents noise-induced hearing loss
Loss of hearing is linked to a decrease in a critical cellular protein, and elevating the activity of this protein could prevent noise-induced hearing loss, as well as potentially benefiting a host of other aging-related conditions
Researchers from Weill Cornell Medical College and the Gladstone Institutes have found a way to prevent noise-induced hearing loss in a mouse using a simple chemical compound that is a precursor to vitamin B3. This discovery has important implications not only for preventing hearing loss, but also potentially for treating some aging-related conditions that are linked to the same protein.
Published today in Cell Metabolism, the researchers used the chemical nicotinamide riboside (NR) to protect the nerves that innervate the cochlea. The cochlea transmits sound information through these nerves to the spiral ganglion, which then passes along those messages to the brain. Exposure to loud noises damages the synapses connecting the nerves and the hair cells in the cochlea, resulting in noise-induced hearing loss.
The researchers set about trying to prevent this nerve damage by giving mice NR before or after exposing them to loud noises. NR was successful at preventing damage to the synaptic connections, avoiding both short-term and long-term hearing loss. What’s more, NR was equally effective regardless of whether it was given before or after the noise exposure.
“One of the major limitations in managing disorders of the inner ear, including hearing loss, is there are a very limited number of treatments options. This discovery identifies a unique pathway and a potential drug therapy to treat noise-induced hearing loss,” says Kevin Brown, MD, PhD, an associate professor of otolaryngology-head and neck surgery at the University of North Carolina School of Medicine and first author on the paper. Brown conducted the research while at Weill Cornell.
The researchers chose NR because it is a precursor to the chemical compound nicotinamide adenine dinucleotide (NAD+), which had previously been shown by Dr. Brown and co-senior author Samie Jaffrey, MD, PhD, to protect cochlea nerve cells from injury. However, NAD+ is an unstable compound, calling into question whether it could be used out of the petri dish and in a live animal. That led the scientists to use NR instead.
Methods for synthesizing NR were recently developed by Anthony Sauve, PhD, a professor of pharmacology at Weill Cornell and co-author of the study. This resulted in quantities of NR that were sufficient to test in animals.
“NR gets into cells very readily and can be absorbed when you take it orally. It has all the properties that you would expect in a medicine that could be administered to people,” said Dr. Jaffrey, a professor of pharmacology at Weill Cornell.
Beyond just preventing hearing loss, the researchers think the results may have broader applications because of the underlying way NR protects nerve cells. The scientists showed that NR and NAD+ prevent hearing loss by increasing the activity of the protein sirtuin 3 (SIRT3), which is critically involved in the function of mitochondria, the powerhouses of the cell.
The researchers hypothesized that it was this enhancement of SIRT3 that was behind the protective properties of NR. To test this, they manipulated SIRT3 levels independently of NR to see if they could still prevent noise-induced hearing loss by administering NR. Sure enough, deleting the SIRT3 gene in mice abolished any of the protective properties of NR. The researchers also showed that a new strain of mice, generated in the lab of co-senior author Eric Verdin, MD, at the Gladstone Institutes and engineered to express high levels of SIRT3, were inherently resistant to noise-induced hearing loss, even without administration of NR.
SIRT3 decreases naturally as we age, which could partially explain aging-related hearing loss. Additionally, some individuals carry different versions of the SIRT3 genes that result in reduced enzyme activity, which may make them more susceptible to noise-induced hearing loss.
Dr. Verdin, an investigator at the Gladstone Institute of Virology and Immunology and professor of medicine at the University of California, San Francisco, says, “The success of this study suggests that targeting SIRT3 using NR could be a viable target for treating all sorts of aging-related disorders–not only hearing loss but also metabolic syndromes like obesity, pulmonary hypertension, and even diabetes.”
Vitamin D deficiency, depression linked in UGA-led international study
Athens, Ga. – Vitamin D deficiency is not just harmful to physical health—it also might impact mental health, according to a team of researchers that has found a link between seasonal affective disorder, or SAD, and a lack of sunlight.
“Rather than being one of many factors, vitamin D could have a regulative role in the development of SAD,” said Alan Stewart of the University of Georgia College of Education.
An international research partnership between UGA, the University of Pittsburgh and the Queensland University of Technology in Australia reported the finding in the November 2014 issue of the journal Medical Hypotheses.
Stewart and Michael Kimlin from QUT’s School of Public Health and Social Work conducted a review of more than 100 leading articles and found a relationship between vitamin D and seasonal depression.
“Seasonal affective disorder is believed to affect up to 10 percent of the population, depending upon geographical location, and is a type of depression related to changes in season,” said Stewart, an associate professor in the department of counseling and human development services.
“People with SAD have the same symptoms every year, starting in fall and continuing through the winter months.”
Stewart said, based on the team’s investigations, vitamin D was likely to be a contributing factor in seasonal depression.
“We believe there are several reasons for this, including that vitamin D levels fluctuate in the body seasonally, in direct relation to seasonally available sunlight,” he said. “For example, studies show there is a lag of about eight weeks between the peak in intensity of ultraviolet radiation and the onset of SAD, and this correlates with the time it takes for UV radiation to be processed by the body into vitamin D.
Vitamin D is also involved in the synthesis of serotonin and dopamine within the brain, both chemicals linked to depression, according to the researchers.
“Evidence exists that low levels of dopamine and serotonin are linked to depression, therefore it is logical that there may be a relationship between low levels of vitamin D and depressive symptoms,” said Kimlin, a Cancer Council Queensland Professor of Cancer Prevention Research.
“Studies have also found depressed patients commonly had lower levels of vitamin D.”
Vitamin D levels varied according to the pigmentation of the skin. People with dark skin often record lower levels of vitamin D, according to the researchers.
“Therefore it is suggested that persons with greater skin pigmentation may experience not only higher risks of vitamin D deficiency, but also be at greater risk of psychological and psychiatric conditions,” he said.
Kimlin, who heads QUT’s National Health and Medical Research Council Centre for Research Excellence in Sun and Health, said adequate levels of vitamin D were essential in maintaining bone health, with deficiency causing osteomalacia in adults and rickets in children. Vitamin D levels of more than 50 nanomoles per liter are recommended by the U.S. Institute of Medicine.
“What we know now is that there are strong indications that maintaining adequate levels of vitamin D are also important for good mental health,” Kimlin said. “A few minutes of sunlight exposure each day should be enough for most people to maintain an adequate vitamin D status.”
“Queensland is known as the Sunshine State in Australia but that doesn’t mean all Queenslanders get enough vitamin D,” Kimlin said. “This research is of international importance because no matter where you live, low levels of vitamin D can be a health concern.”
Vitamin E deficiency linked to greater risk of miscarriage among poor women
Pregnant Bangladeshis lacking vitamin nearly twice as likely to suffer losses
Pregnant women in Bangladesh with low levels of the most common form of vitamin E are nearly twice as likely to have a miscarriage than those with adequate levels of the vitamin in their blood, according to new research led by the Johns Hopkins Bloomberg School of Public Health.
The findings, published online last week in the American Journal of Clinical Nutrition, suggest that improving the diet of women in impoverished nations or encouraging intake of vitamin E through prenatal supplements could have a direct impact on fertility, though more research is needed.
“For nearly a century, we have known about vitamin E and its role in the fertility of animals,” says one of the study’s leaders, Kerry Schulze, PhD, an associate scientist in the Department of International Health at the Johns Hopkins Bloomberg School of Public Health. “To our knowledge, this is the first study in humans that has looked at the association of vitamin E and miscarriage. The findings from this study support a role for vitamin E in protecting the embryo and fetus in pregnancy.”
Vitamin E is an important vitamin required for the proper function of many organs in the body. It works as an antioxidant, which means it helps to slow down processes that damage cells. It is found in a variety of foods, though the main source of vitamin E in Bangladesh is believed to be in vegetable oils used in cooking.
The researchers analyzed data from 1,605 rural Bangladeshi pregnant women in the JiVitA-1 study that ran from 2001 to 2007. Blood samples were taken upon enrollment in the first trimester and any miscarriages were recorded on a weekly basis thereafter. Of the 1,605 women in the study, 141 (8.8 percent) subsequently miscarried.
The researchers looked at two forms of vitamin E – alpha-tocopherol (the most active form of the vitamin in the body) and gamma-tocopherol. Nearly three out of four women in the study had what was considered vitamin E deficiency, with low alpha-tocopherol levels. When looking at alpha-tocopherol, 5.2 percent of women with adequate levels in their blood miscarried in the first or second trimester as compared with 10.2 percent of women who miscarried with low levels.
The relationship with gamma-tocopherol, however, went the other way, with higher levels associated with increased miscarriage risk, though to a lesser degree, Schulze says.
Pregnant women in developing countries are traditionally not given a prenatal multivitamin like women in the United States typically take before or after becoming pregnant. Instead, the current standard of care is to provide them with iron and folic acid supplements because of the proven links between deficiencies of those nutrients and poor pregnancy outcomes.
“The new findings suggest that having pregnant women consume an adequate amount of vitamin E early in pregnancy could be beneficial,” says Abu Ahmed Shamim, MS, an associate in the Department of International Health at the Bloomberg School and the lead Bangladeshi author. But since miscarriages occur so early in pregnancy, Shamim says levels of vitamin E ideally need to be boosted in women of childbearing age by improving access to a diverse diet that includes better vitamin E sources so they already have what they need once they become pregnant.
“Vitamin deficiencies are considered a form of hidden hunger because they are not readily apparent but they can have huge health consequences,” Schulze says. “What we really want to do is optimize health before women become pregnant, because if they don’t start with a good vitamin E status, they are at a high risk of negative outcomes.”
Schulze says that the study may not be generalizable to higher-income nations where women of childbearing age tend to have better nutritional status.
Common prostate cancer treatment associated with decreased survival in older men
DETROIT – A common prostate cancer therapy should not be used in men whose cancer has not spread beyond the prostate, according to a new study led by researchers at Henry Ford Hospital.
The findings are particularly important for men with longer life expectancies because the therapy exposes them to more adverse side effects, and it is associated with increased risk of death and deprives men of the opportunity for a cure by other methods.
The research study has been published online in European Urology.
The focus of the new study is androgen deprivation therapy (ADT), in which an injectable or implanted medication is used to disrupt the body’s ability to make testosterone. ADT is known to have significant side effects such as heart disease, diabetes, increased weight gain and impotence; however a growing body of evidence suggests ADT may in fact lead to earlier death.
Since the 1940s, the therapy has been a mainstay of treatment for prostate cancer that has metastasized, or spread beyond the prostate gland. Still other studies support the use of ADT when it is used as an adjuvant, or in addition to, radiation therapy for higher risk prostate cancer. No evidence exists to support the exclusive use of ADT for low risk or localized prostate cancer.
“The use of ADT as the primary treatment for localized and low risk prostate cancer increased over time, despite known harmful side effects and a lack of data to support such use,” says Jesse D. Sammon, D.O., a researcher at Henry Ford Hospital’s Vattikuti Urology Institute and lead author of the new study. “In the 1990’s it became exceedingly common to use ADT in place of radical prostatectomy or radiation therapy.”
Concerns over the possible misuse of ADT alone in the treatment of prostate cancer, as well as a growing awareness of its potential damage, led to changes in Medicare reimbursement policies for ADT in 2004.
This resulted in a 40 percent drop in reimbursement, and a reduction in inappropriate use of ADT from 38.7 percent to 25.7 percent for newly diagnosed localized prostate cancers.
“At the same time, there was a growing awareness of ADT’s many possible adverse effects, including decreased libido, anemia and fatigue, and a higher risk of metabolic and cardiovascular disease,” Dr. Sammon says.
“In designing our study, we hypothesized that the adverse effects of ADT might be more pronounced in men with longer life expectancies since they would likely be treated with ADT for a longer period- and be exposed to more treatment-related side effects.”
Drawing on data from nations largest cancer registry (SEER) (Surveillance, Epidemiology, and End Results) the researchers then linked to records from Medicare and identified 46,376 men diagnosed with localized prostate cancer who did not undergo radical prostatectomy or radiation therapy for prostate cancer, diagnosed between 1992-2009. Among them, 38.5 percent were treated with ADT.
Further statistical analysis confirmed the study’s hypothesis, notes Dr. Sammon.
“No evidence supports the use of ADT in men with low risk, localized prostate cancer, while use of this therapy is decreasing over time it is still very common,” he says
“We found that primary ADT is associated with decreased survival in men with localized prostate cancer relative to men who receive no active treatment, particularly in men with longer life expectancies. So we concluded that ADT should not be used as a primary treatment for men with prostate cancer that has not spread beyond the prostate or men with moderate to high risk disease undergoing radiation therapy.”
Cons of regular low-dose aspirin to stave off serious illness in women outweigh pros
But limiting to over-65s may boost net health gain, suggest researchers
The pros of giving healthy women regular low dose aspirin to stave off serious illness, such as cancer and heart disease, are outweighed by the cons, suggests a large study published online in the journal Heart.
But the balance begins to shift with increasing age, and limiting this form of primary prevention to women aged 65 and above, was better than not taking aspirin at all, or treating women from the age of 45 onwards, say the researchers.
They base their findings on almost 30,000 healthy women, who were at least 45 years old and taking part in the Women’s Health Study.
Participants were randomly assigned to take either 100 mg of aspirin or a dummy tablet (placebo) every other day, to see whether aspirin curbed their risk of heart disease, stroke, and cancer.
During the trial period, which lasted 10 years, 604 cases of cardiovascular disease, 168 cases of bowel cancer, 1832 cases of other cancers, and 302 major gastrointestinal bleeds requiring admission to hospital were diagnosed.
Over the subsequent seven years, a further 107 cases of bowel cancer and 1388 other cancers were diagnosed.
Compared with placebo, regular aspirin was linked to a lower risk of heart disease, stroke, bowel cancer, and in some women, other cancers, but only marginally so.
And this slight health gain was trumped by the prevalence of internal gastrointestinal bleeding, which affected two thirds of the women taking the non-steroidal anti-inflammatory drug.
The risk of gastrointestinal bleeding rose with age, but so too did the drug’s impact on lowering the risk of bowel cancer and cardiovascular disease, with the balance appearing to tip in favour of the drug for women aged 65 and above.
The researchers calculated that over 15 years, 29 over-65s would need to be treated with aspirin to prevent one case of cancer or heart disease/stroke.
“Recent findings that both daily and alternate day aspirin can reduce cancer risk, particularly for colorectal cancer, have re-ignited the debate on aspirin in primary prevention,” write the researchers.
But they conclude that blanket treatment “is ineffective or harmful in the majority of women with regard to the combined risk of cardiovascular disease, cancer and major gastrointestinal bleeding.”