213CNO31AUG2015
CNO Report 213
Release Date 31 AUG 2015
Draft Report Compiled by
Ralph Turchiano
In this Issue:
1. Mosquito-repelling chemicals identified in traditional sweetgrass
2. Hot chili may unlock a new treatment for obesity
3. Lice in at least 25 states show resistance to common treatments
4. Powdered cranberry combats colon cancer in mice
5. New research backs belief that tomatoes can be a gout trigger
6. Anti-aging tricks from dietary supplement seen in mice
7. Chestnut leaves yield extract that disarms deadly staph bacteria
8. A bottle of water before each meal could help in weight reduction, researchers say
9. Colorful potatoes may pack powerful cancer prevention punch
10. UEA research shows high protein foods boost cardiovascular health
11. Fish oil-diet benefits may be mediated by gut microbes
12. Antibiotic use linked to type 2 diabetes diagnosis
Public Release: 17-Aug-2015
Mosquito-repelling chemicals identified in traditional sweetgrass
American Chemical Society
BOSTON, Aug. 17, 2015 –Native North Americans have long adorned themselves and their homes with fragrant sweetgrass (Hierochloe odorata), a native plant used in traditional medicine, to repel biting insects, and mosquitoes in particular. Now, researchers report that they have identified the compounds in sweetgrass that keep these bugs at bay.
The team will describe their approach in one of more than 9,000 presentations at the 250th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society, taking place here through Thursday.
Mosquitoes and other insects remain a pesky part of everyday life in many parts of the world, and their bites are linked to a range of serious diseases, such as malaria. To add to the arsenal of insect repellents, Charles Cantrell, Ph.D., investigates the components of plants used in traditional therapies. “We found that in our search for new insect repellents, folk remedies have provided good leads.”
Sweetgrass is a meadow grass that is a native to northern climates, Cantrell says. “It gives off a sweet aroma that repels mosquitoes.”
He therefore suspected that the active insect-repelling chemicals must waft off sweetgrass at ambient temperatures and, like essential oils from lavender and other plants, could be extracted using a process known as steam distillation. This method involves passing hot steam through plant material, then lowering the temperature. The condensed liquid then separates into oil and water, with the oil fraction containing the volatile chemicals of interest. So, Cantrell’s team at the U.S. Department of Agriculture, in collaboration with researchers at the University of Guelph and the University of Mississippi, performed steam distillation on sweetgrass samples and evaluated its oil for the ability to deter mosquitoes from biting.
To test the mosquitoes’ aversion to the oil, the researchers filled small vials with a red-colored feeding solution that mimicked human blood and covered the vials with a thin membrane. Then, they coated the membranes with different substances: the sweetgrass oil, alternative sweetgrass extracts obtained without steam distillation, the gold-standard insect repellent N,N-diethyl-m-toluamide (DEET) or the ethanol solvent control. Then, the bugs got the chance to either bite the membranes to get to the blood or pass them by. The researchers observed what the insects did, counting how many mosquitoes went for a bite of each type of “blood” vat.
“Then you take the mosquitoes and squish them on some paper,” says Cantrell. “If they have the blood mimic in them, you see it right there on the paper.” Of the sweetgrass extracts, the steam-distilled oil got the fewest mosquito bites, matching the repellent potency of DEET.
The next step was to figure out the exact chemicals that give the sweetgrass oil its anti-mosquito power. The researchers purified the oil into 12 fractions and again checked their ability to ward off the bugs. They found three fractions that repelled mosquitoes as well as the oil. Using nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry, the researchers identified two chemicals in these active fractions that seemed to be responsible for putting off mosquitoes: phytol and coumarin.
Coumarin is an ingredient in some commercial anti-mosquito products, he adds, while phytol is reported to have repelling activity in the scientific literature. So although Cantrell didn’t find brand-new insect deterrents in this experiment, he is happy to have demonstrated that “we were able to find constituents that are known to act as insect repellents in a folk remedy, and now we understand that there’s a real scientific basis to this folklore.”
Public Release: 18-Aug-2015
Hot chilli may unlock a new treatment for obesity
University of Adelaide
University of Adelaide researchers have discovered a high-fat diet may impair important receptors located in the stomach that signal fullness.
Published today* in the journal PLOS ONE, researchers from the University’s Centre for Nutrition and Gastrointestinal Diseases (based at the South Australian Health and Medical Research Institute) investigated the association between hot chilli pepper receptors (TRPV1) in the stomach and the feeling of fullness, in laboratory studies.
“The stomach stretches when it is full, which activates nerves in the stomach to tell the body that it has had enough food. We found that this activation is regulated through hot chilli pepper or TRPV1 receptors,” says Associate Professor Amanda Page, Senior Research Fellow in the University of Adelaide’s School of Medicine and lead author on the paper.
“It is known from previous studies that capsaicin, found in hot chillies, reduces food intake in humans. And what we’ve discovered is that deletion of TRPV1 receptors dampens the response of gastric nerves to stretch – resulting in a delayed feeling of fullness and the consumption of more food. Therefore part of the effect of capsaicin on food intake may be mediated via the stomach.
“We also found that TRPV1 receptors can be disrupted in high fat diet induced obesity,” she says.
Dr Stephen Kentish says these findings will inform further studies and the development of new therapies.
“It’s exciting that we now know more about the TRPV1 receptor pathway and that the consumption of capsaicin may be able to prevent overeating through an action on nerves in the stomach,” says Dr Kentish, National Health and Medical Research Council (NHMRC) Fellow from the University of Adelaide’s School of Medicine.
“The next stage of research will involve investigation of the mechanisms behind TRPV1 receptor activation with the aim of developing a more palatable therapy.
“We will also do further work to determine why a high-fat diet de-sensitises TRPV1 receptors and investigate if we can reverse the damage,” he says.
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This research was funded by the Blue Gum bequest, Royal Adelaide Hospital.
Public Release: 18-Aug-2015
Lice in at least 25 states show resistance to common treatments
American Chemical Society
BOSTON, Aug. 18, 2015 — For students, the start of the school year means new classes, new friends, homework and sports. It also brings the threat of head lice. The itch-inducing pests lead to missed school days and frustrated parents, who could have even more reason to be wary of the bug this year. Scientists report that lice populations in at least 25 states have developed resistance to over-the-counter treatments still widely recommended by doctors and schools.
The researchers are presenting their work today at the 250th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society. The meeting features more than 9,000 presentations on a wide range of science topics and is being held here through Thursday.
“We are the first group to collect lice samples from a large number of populations across the U.S.,” says Kyong Yoon, Ph.D. “What we found was that 104 out of the 109 lice populations we tested had high levels of gene mutations, which have been linked to resistance to pyrethroids.”
Pyrethroids are a family of insecticides used widely indoors and outdoors to control mosquitoes and other insects. It includes permethrin, the active ingredient in some of the most common lice treatments sold at drug stores.
Yoon, who is with Southern Illinois University, Edwardsville, explains that the momentum toward widespread pyrethroid-resistant lice has been building for years. The first report on this development came from Israel in the late 1990s. Yoon became one of the first to report the phenomenon in the U.S. in 2000 when he was a graduate student at the University of Massachusetts, Amherst.
“I was working on insecticide metabolism in a potato beetle when my mentor, John Clark, suggested I look into the resurgence of head lice,” he says. “I asked him in what country and was surprised when he said the U.S.”
Intrigued, Yoon followed up on the lead and contacted schools near the university to collect samples. He suspected that the lice had developed resistance to the most common insecticides people were using to combat the bugs. So he tested the pests for a trio of genetic mutations known collectively as kdr, which stands for “knock-down resistance.” kdr mutations had initially been found in house flies in the late ’70s after farmers and others had shifted to pyrethroids from DDT and other harsh insecticides.
Yoon found that many of the lice did indeed have kdr mutations, which affect an insect’s nervous system and desensitize them to pyrethroids. Since then, he has expanded his survey.
In the most recent study, he cast the widest net yet, gathering lice from 30 states with the help of a broad network of public health workers. Population samples with all three genetic mutations associated with kdr came from 25 states, including California, Texas, Florida and Maine. Having all the mutations means these populations are the most resistant to pyrethroids. Samples from four states — New York, New Jersey, New Mexico and Oregon — had one, two or three mutations. The only state with a population of lice still largely susceptible to the insecticide was Michigan. Why lice haven’t developed resistance there is still under investigation, Yoon says.
The solution? Yoon says that lice can still be controlled by using different chemicals, some of which are available only by prescription.
But the situation also offers a cautionary tale. “If you use a chemical over and over, these little creatures will eventually develop resistance,” Yoon says. “So we have to think before we use a treatment. The good news is head lice don’t carry disease. They’re more a nuisance than anything else.”
Public Release: 18-Aug-2015
Powdered cranberry combats colon cancer in mice
American Chemical Society
BOSTON, Aug. 18, 2015 — Cranberries are often touted as a way to protect against urinary tract infections, but that may be just the beginning. Researchers fed cranberry extracts to mice with colon cancer and found that the tumors diminished in size and number. Identifying the therapeutic molecules in the tart fruit could lead to a better understanding of its anti-cancer potential, they say.
The team will describe their approach in one of more than 9,000 presentations at the 250th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society, taking place here through Thursday.
According to the American Cancer Society, one in 20 Americans will develop colon cancer at some point in his or her lifetime. While progress has been made on the detection and treatment of colon cancer, it remains the second leading cause of cancer-related deaths in the U.S.
Colon cancer may offer a particularly good target for a dietary treatment, says Catherine Neto, Ph.D., simply due to the anatomy of digestion. “Cranberry extracts may also afford protection toward other cancers, but it seems reasonable to look at colon cancer,” she says. “Cranberry constituents and metabolites should be bioavailable to the colon as digestion proceeds.”
In previous studies, Neto and colleagues at the University of Massachusetts, Dartmouth, found that chemicals derived from cranberry extracts could selectively kill off colon tumor cells in laboratory dishes. “We’ve identified several compounds in cranberry extracts over the years that seemed promising, but we’ve always wanted to look at what happens with the compounds in an animal model of cancer,” Neto says. This led to a collaboration with Hang Xiao, Ph.D., of the University of Massachusetts, Amherst. His team had developed a mouse model that mimics the type of colon cancer associated with colitis, an inflammatory bowel condition that affects hundreds of thousands of people in the U.S.
For Neto’s part, her team generated three powdered cranberry extracts: a whole fruit powder, an extract containing only the cranberry polyphenols, and one containing only the non-polyphenol components of the fruit. Some evidence suggests that polyphenols have anti-inflammatory properties, and she wanted to assess their contribution to the cranberry’s overall impact.
The researchers mixed the cranberry extracts into the meals of mice with colon cancer. She notes that the mice do not seem to mind the tart flavor. After 20 weeks, the mice given the whole cranberry extract had about half the number of tumors as mice that received no cranberry in their chow. The remaining tumors in the cranberry-fed mice were also smaller. Plus, the cranberry extracts seemed to reduce the levels of inflammation markers in the mice.
“Basically, what we found was pretty encouraging. All preparations were effective to some degree, but the whole cranberry extract was the most effective,” says Neto. “There may be some synergy between polyphenol and non-polyphenol constituents.” Neto’s graduate student Sarah Frade will present the work at the ACS meeting.
In the study, the researchers were careful not to give the mice an absurd amount of cranberry. “This is approximately equivalent to a cup a day of cranberries if you were a human instead of a mouse,” Neto says. However, she’s not sure someone could get the same benefits from juice, which lacks some of the components in the skin of the cranberry.
Currently, Neto is looking deeper into the cranberry to see if she can isolate individual components responsible for its anti-cancer properties. The researchers are also analyzing the metabolites in the mice that consumed the fruit extracts to better understand what happens due to mouse metabolism after the cranberry components are digested.
Public Release: 18-Aug-2015
New research backs belief that tomatoes can be a gout trigger
University of Otago
People who maintain that eating tomatoes can cause their gout to flare up are likely to welcome new research from New Zealand’s University of Otago that has, for the first time, found a biological basis for this belief.
Gout is a painful and debilitating form of arthritis that affects approximately three times more men than women. Four to five percent of European men in New Zealand suffer from gout. Amongst Māori and Pacific Island men this figure rises to 10-15% due to a greater genetic risk in these people.
Once a person has gout, eating certain foods can cause their gout to flare up in a painful attack. A group of Otago Department of Biochemistry researchers noticed that a large number of gout sufferers believe tomatoes to be one of these gout trigger foods.
The researchers surveyed 2051 New Zealanders with clinically verified gout. Of these people 71% reported having one or more food triggers. Tomatoes were listed as a trigger in 20% of these cases.
One of the study authors, Genetics PhD student Tanya Flynn, says that tomatoes were found to be the fourth most commonly mentioned trigger, after seafood, alcohol and red meat.
“We thought it important to find a biological reason for this to add weight to what gout patients are already saying,” Miss Flynn says.
After determining tomatoes are a commonly cited trigger food, the authors pooled and analysed data from 12,720 male and female members of three long-running US health studies. This data showed that tomato consumption is linked to higher levels of uric acid in the blood, which is the major underlying cause of gout.
Miss Flynn says that while their research is not geared to prove that tomatoes trigger gout attacks, it does suggest that this food can alter uric acid levels to a degree comparable to other commonly accepted gout trigger foods.
“We found that the positive association between eating tomato and uric acid levels was on a par with that of consuming seafood, red meat, alcohol or sugar-sweetened drinks,” she says.
Miss Flynn emphasised that the most important thing that people with gout can do to prevent attacks is take a drug–such as Allopurinol–that is very effective at reducing uric acid levels.
“Avoiding tomatoes may be helpful for people who have experienced a gout attack after eating them, but with proper treatment this doesn’t have to be a long-term avoidance,” she says.
The findings are published in a paper in the international journal BMC Musculoskeletal Disorders.
“Further intervention studies are needed to determine whether tomatoes should be added to the list of traditional dietary triggers of gout flares, but this research is the first step in supporting this idea,” says Miss Flynn.
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This research was supported by the Health Research Council of New Zealand, Lottery Health New Zealand, Arthritis New Zealand and the University of Otago.
Public Release: 21-Aug-2015
Anti-aging tricks from dietary supplement seen in mice
Alpha-lipoic acid stimulates telomerase in vascular smooth muscle
Emory Health Sciences
In human cells, shortened telomeres, the protective caps at the ends of chromosomes, are both a sign of aging and contribute to it. Scientists at Emory University School of Medicine have found that the dietary supplement alpha lipoic acid (ALA) can stimulate telomerase, the enzyme that lengthens telomeres, with positive effects in a mouse model of atherosclerosis.
The discovery highlights a potential avenue for the treatment for chronic diseases.
The results were published Thursday, August 20 in Cell Reports.
“Alpha-lipoic acid has an essential role in mitochondria, the energy-generating elements of the cell,” says senior author Wayne Alexander, MD, PhD, professor of medicine at Emory University School of Medicine. “It is widely available and has been called a ‘natural antioxidant’. Yet ALA’s effects in human clinical studies have been a mixed bag.”
ALA appears to exert its effects against atherosclerosis by spurring the smooth muscle cells that surround blood vessels to make PGC1 (peroxisome proliferator-activated receptor gamma co-activator 1)-alpha. PGC1-alpha was already well known to scientists as controlling several aspects of how skeletal muscles respond to exercise. While the Emory researchers did not directly assess the effects of exercise in their experiments, their findings provide molecular clues to how exercise might slow the effects of aging or chronic disease in some cell types.
“The effects of chronic diseases such as atherosclerosis and diabetes on blood vessels can be traced back to telomere shortening,” Alexander says. “This means that treatments that can restore healthy telomeres have great potential.”
“What’s new here is that we show that PGC1-alpha is regulating telomerase, and that has real beneficial effects on cellular stress in a mouse model of atherosclerosis,” says Shiqin Xiong, PhD, instructor in the division of cardiology and first author of the paper.
Xiong and Alexander used a model of atherosclerosis where mice lacked the ApoE cholesterol processing gene and were fed a high-fat diet. In this model, mice also lacking PGC1-alpha have more advanced plaques in their blood vessels, but only in older animals, the authors show.
Consistent with the poorer state of their blood vessels, aortic cells from PGC1-alpha-disrupted mice had shorter telomeres and reduced telomerase activity. Having shortened telomeres led the smooth muscle cells to display more oxidative stress and damage to the rest of their DNA.
The authors show that introducing PGC1-alpha back into vascular smooth muscle cells lacking that gene with a gene-therapy adenovirus could restore telomerase activity and lengthen the cells’ telomeres.
Telomerase is off in most healthy cell types and only becomes turned on when cells proliferate. Because telomerase is active in cancer cells and enables their continued growth, researchers have been concerned that stimulating telomerase in all cells might encourage cancer growth or have other adverse effects.
As a way to boost PGC1-alpha in cells more conveniently, Xiong and Alexander turned to alpha lipoic acid or ALA. ALA is a sulfur-containing fatty acid used to treat diabetic neuropathy in Germany, and has previously been shown to combat atherosclerosis in animal models.
Treating isolated smooth muscle cells with ALA for one day could both stimulate PGC1-alpha and telomerase, the authors found. ALA’s effects on vascular smooth muscle cells could also be seen when it was injected into mice. Xiong and Alexander say they are now investigating the effects of ALA on other tissues in mice. They have not observed increased cancers in ALA-treated mice, but say more thorough investigation is needed to fully assess cancer risk.
“While ALA is present in many foods and its effects in animal models look promising, it may be problematic for clinical use because of its poor solubility, stability and bioavailability,” Xiong says. “We are designing new ways to formulate and deliver ALA-related compounds to resolve these issues.”
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Co-authors include assistant professor Lu Hilenski, PhD, Nikolay Patrushev, MD and Farshad Forouzandeh, MD, PhD.
Public Release: 21-Aug-2015
Chestnut leaves yield extract that disarms deadly staph bacteria
The extract shuts down staph without boosting its drug resistance
Emory Health Sciences
Leaves of the European chestnut tree contain ingredients with the power to disarm dangerous staph bacteria without boosting its drug resistance, scientists have found.
PLOS ONE is publishing the study of a chestnut leaf extract, rich in ursene and oleanene derivatives, that blocks Staphlococcus aureus virulence and pathogenesis without detectable resistance.
The use of chestnut leaves in traditional folk remedies inspired the research, led by Cassandra Quave, an ethnobotanist at Emory University.
“We’ve identified a family of compounds from this plant that have an interesting medicinal mechanism,” Quave says. “Rather than killing staph, this botanical extract works by taking away staph’s weapons, essentially shutting off the ability of the bacteria to create toxins that cause tissue damage. In other words, it takes the teeth out of the bacteria’s bite.”
The discovery holds potential for new ways to both treat and prevent infections of methicillin-resistant S. aureus, or MRSA, without fueling the growing problem of drug-resistant pathogens.
Antibiotic-resistant bacteria annually cause at least two million illnesses and 23,000 deaths in the United States, according to the Centers for Disease Control and Prevention. MRSA infections lead to everything from mild skin irritations to fatalities. Evolving strains of this “super bug” bacterium pose threats to both hospital patients with compromised immune systems and young, healthy athletes and others who are in close physical contact.
“We’ve demonstrated in the lab that our extract disarms even the hyper-virulent MRSA strains capable of causing serious infections in healthy athletes,” Quave says. “At the same time, the extract doesn’t disturb the normal, healthy bacteria on human skin. It’s all about restoring balance.”
Quave, who researches the interactions of people and plants – a specialty known as ethnobotany – is on the faculty of Emory’s Center for the Study of Human Health and Emory School of Medicine’s Department of Dermatology. She became interested in ethnobotany as an undergraduate at Emory.
For years, she and her colleagues have researched the traditional remedies of rural people in Southern Italy and other parts of the Mediterranean. “I felt strongly that people who dismissed traditional healing plants as medicine because the plants don’t kill a pathogen were not asking the right questions,” she says. “What if these plants play some other role in fighting a disease?”
Hundreds of field interviews guided her to the European chestnut tree, Castanea sativa. “Local people and healers repeatedly told us how they would make a tea from the leaves of the chestnut tree and wash their skin with it to treat skin infections and inflammations,” Quave says.
For the current study, Quave teamed up with Alexander Horswill, a microbiologist at the University of Iowa whose lab focuses on creating tools for use in drug discovery, such as glow-in-the-dark staph strains.
The researchers steeped chestnut leaves in solvents to extract their chemical ingredients. “You separate the complex mixture of chemicals found in the extract into smaller batches with fewer chemical ingredients, test the results, and keep honing in on the ingredients that are the most active,” Quave explains. “It’s a methodical process and takes a lot of hours at the bench. Emory undergraduates did much of the work to gain experience in chemical separation techniques.”
The work produced an extract of 94 chemicals, of which ursene and oleanene based compounds are the most active.
Tests showed that this extract inhibits the ability of staph bacteria to communicate with one another, a process known as quorum sensing. MRSA uses this quorum-sensing signaling system to manufacture toxins and ramp up its virulence.
“We were able to trace out the pathways in the lab, showing how our botanical extract blocks quorum sensing and turns off toxin production entirely,” Quave says. “Many pharmaceutical companies are working on the development of monoclonal antibodies that target just one toxin. This is more exciting because we’ve shown that with this extract, we can turn off an entire cascade responsible for producing a variety of different toxins.”
A single dose of the extract, at 50 micrograms, cleared up MRSA skin lesions in lab mice, stopping tissue damage and red blood cell damage. The extract does not lose activity, or become resistant, even after two weeks of repeated exposure. And tests on human skin cells in a lab dish showed that the botanical extract does not harm the skin cells, or the normal skin micro-flora.
The Emory Office of Technology Transfer has filed a patent for the discovery of the unique properties of the botanical extract. The researchers are doing further testing on individual components of the extract to determine if they work best in combination or alone.
“We now have a mixture that works,” Quave says. “Our goal is to further refine it into a simpler compound that would be eligible for FDA consideration as a therapeutic agent.”
Potential uses include a preventative spray for football pads or other athletic equipment; preventative coatings for medical devices and products such as tampons that offer favorable environments for the growth of MRSA; and as a treatment for MRSA infections, perhaps in combination with antibiotics.
“It’s easy to dismiss traditional remedies as old wives’ tales, just because they don’t attack and kill pathogens,” Quave says. “But there are many more ways to help cure infections, and we need to focus on them in the era of drug-resistant bacteria.”
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The research was funded by the NIH National Center for Complementary and Integrative Health. In addition to Quave and Horswill, the study’s authors include: Emory researchers James Lyles and Kate Nelson; and Jeffery Kavanaugh, Corey Parlet, Heidi Crosby and Kristopher Heilmann from the University of Iowa.
Public Release: 26-Aug-2015
A bottle of water before each meal could help in weight reduction, researchers say
University of Birmingham
Researchers from the University of Birmingham have shown that drinking 500ml of water at half an hour before eating main meals may help obese adults to lose weight. They believe that the simple intervention could be hugely beneficial, and be easily promoted by healthcare professionals and through public health campaigns.
Obese adult participants were recruited from general practices and monitored over a 12 week period.
Each of the participants, all adults with obesity, were given a weight management consultation, where they were advised on how to adapt their lifestyle and improve their diet and levels of physical activity. 41 of those recruited were asked to preload with water, and 43 were advised to imagine that they had a full stomach before eating.
Those in the group who were instructed to ‘preload’ with water lost, on average, 1.3kg (2.87lbs) more than those in the control group.
Those who reported preloading before all three main meals in the day reported a loss of 4.3kg (9.48lbs) over the 12 weeks, whereas those who only preloaded once, or not at all, only lost an average of 0.8kg (1.76lbs).
Dr Helen Parretti, NIHR Clinical Lecturer at the University of Birmingham, explained, “The beauty of these findings is in the simplicity. Just drinking a pint of water, three times a day, before your main meals may help reduce your weight.”
“When combined with brief instructions on how to increase your amount of physical activity and on a healthy diet, this seems to help people to achieve some extra weight loss – at a moderate and healthy rate. It’s something that doesn’t take much work to integrate into our busy everyday lives.”
Participants were encouraged to drink tap water. Sparkling water, sodas or sweetened drinks were not allowed as part of the study.
The study, published in the journal Obesity, showed encouraging initial results for the trial, and the team hope that the findings will inform further research into the benefits of water preloading before meals. They hope to receive backing for a trial with a larger number of participants and over a longer period of time in order to confirm the findings.
Dr Parretti added, “Losing a few extra pounds over the course of a year can be significant to an individual, and this could be an easy way to help with that weight loss. It’s a simple message that has the potential to make a real contribution to public health.”
Public Release: 26-Aug-2015
Colorful potatoes may pack powerful cancer prevention punch
Penn State
Compounds found in purple potatoes may help kill colon cancer stem cells and limit the spread of the cancer, according to a team of researchers.
Baked purple-fleshed potatoes suppressed the growth of colon cancer tumors in petri dishes and in mice by targeting the cancer’s stem cells. Colon cancer is the second leading cause of cancer-related deaths in the U.S. and responsible for more than 50,000 deaths annually, according to the American Cancer Society.
Attacking stem cells is an effective way to counter cancer, according to Jairam K.P. Vanamala, associate professor of food sciences, Penn State and faculty member, at the Penn State Hershey Cancer Institute.
“You might want to compare cancer stem cells to roots of the weeds,” Vanamala said. “You may cut the weed, but as long as the roots are still there, the weeds will keep growing back and, likewise, if the cancer stem cells are still present, the cancer can still grow and spread.”
The researchers, who released their findings in the Journal of Nutritional Biochemistry, currently online, used a baked purple potato because potatoes are widely consumed and typically baked before they are consumed, especially in western countries. They wanted to make sure the vegetables maintained their anti-cancer properties even after cooking.
In the initial laboratory study, the researchers found that the baked potato extract suppressed the spread of colon cancer stem cells while increasing their deaths. Researchers then tested the effect of whole baked purple potatoes on mice with colon cancer and found similar results. The portion size for a human would be about the same as eating a medium size purple-fleshed potato for lunch and dinner, or one large purple-fleshed potato per day.
According to the researchers, there may be several substances in purple potatoes that work simultaneously on multiple pathways to help kill the colon cancer stem cells, including anthocyanins and chlorogenic acid, and resistant starch.
“Our earlier work and other research studies suggest that potatoes, including purple potatoes, contain resistant starch, which serves as a food for the gut bacteria, that the bacteria can covert to beneficial short-chain fatty acids such as butyric acid,” Vanamala said. “The butyric acid regulates immune function in the gut, suppresses chronic inflammation and may also help to cause cancer cells to self-destruct.”
In addition to resistant starch, the same color compounds that give potatoes, as well as other fruits and vegetables, a rainbow of vibrant colors may be effective in suppressing cancer growth, he added.
“When you eat from the rainbow, instead of one compound, you have thousands of compounds, working on different pathways to suppress the growth of cancer stem cells,” said Vanamala. “Because cancer is such a complex disease, a silver bullet approach is just not possible for most cancers.”
The next step would be to test the whole food approach using purple potatoes in humans for disease prevention and treatment strategies. The researchers also plan to test the purple potatoes on other forms of cancer.
Using evidenced-based foods as a proper cancer prevention strategy could complement current and future anti-cancer drug therapies. Vanamala said that foods could actually offer a healthier way to prevent cancer because they often have limited side effects compared to drug treatments.
“Indeed, we have seen that the animals that consumed purple potatoes are healthier compared to animals that received drug treatment,” said Vanamala.
Purple potatoes could be potentially used in both primary and secondary prevention strategies for cancer, Vanamala suggested. Primary prevention is aimed at stopping the initial attack of cancer, while secondary prevention refers to helping patients in remission remain cancer-free.
Most of the funding in cancer research currently goes to cancer cures but not to prevention, Vanamala said. However, as cancer incidences are predicted to surge in the next two decades, an equal emphasis on both food-based cancer prevention and therapeutic drug approaches should be used to counter the growing epidemic of cancer in the U.S. and around the world.
Public Release: 27-Aug-2015
UEA research shows high protein foods boost cardiovascular health
University of East Anglia
Eating foods rich in amino acids could be as good for your heart as stopping smoking or getting more exercise – according to new research from the University of East Anglia (UEA).
A new study published today reveals that people who eat high levels of certain amino acids found in meat and plant-based protein have lower blood pressure and arterial stiffness.
And the magnitude of the association is similar to those previously reported for lifestyle risk factors including salt intake, physical activity, alcohol consumption and smoking.
Researchers investigated the effect of seven amino acids on cardiovascular health among almost 2,000 women with a healthy BMI. Data came from TwinsUK – the biggest UK adult twin registry of 12,000 twins which is used to study the genetic and environmental causes of age related disease.
They studied their diet and compared it to clinical measures of blood pressure and blood vessel thickness and stiffness.
They found strong evidence that those who consumed the highest amounts of amino acids had lower measures of blood pressure and arterial stiffness.
But they found that the food source was important – with a higher intake of amino acids from plant-based sources associated with lower blood pressure, and a higher intake from animal sources associated with lower levels of arterial stiffness.
Lead researcher Dr Amy Jennings, from UEA’s Norwich Medical School, said: “This research shows a protective effect of several amino acids on cardiovascular health.
“Increasing intake from protein-rich foods such as meat, fish, dairy produce, beans, lentils, broccoli and spinach could be an important and readily achievable way to reduce people’s risk of cardiovascular disease.
“Results from previous studies have provided evidence that increased dietary protein may be associated with lower blood pressure. We wanted to know whether protein from animal sources or plant-based sources was more beneficial – so we drilled down and looked at the different amino acids found in both meat and vegetables.
“We studied seven amino acids – arginine, cysteine, glutamic acid, glycine, histidine, leucine, and tyrosine. Glutamic acid, leucine, and tyrosine are found in animal sources, and a higher intake was associated with lower levels of arterial stiffness.
“All seven amino acids, and particularly those from plant-based sources, were associated with lower blood pressure.
“The really surprising thing that we found is that amino acid intake has as much of an effect on blood pressure as established lifestyle risk factors such as salt intake, physical activity and alcohol consumption. For arterial stiffness, the association was similar to the magnitude of change previously associated with not smoking.
“High blood pressure is one of the most potent risk factors for developing cardiovascular disease. A reduction in blood pressure leads to a reduction in mortality caused by stroke or coronary heart disease – so changing your diet to include more meat, fish, dairy produce and pulses could help both prevent and treat the condition.
“Beneficial daily amounts equate to a 75g portion of steak, a 100g salmon fillet or a 500ml glass of skimmed milk,” she added.
Prof Tim Spector from the department of Twin Research at King’s college London said: “The finding that eating certain meat and plant proteins are linked to healthier blood pressure is an exciting finding. We need to understand the mechanism to see if it is direct or via our gut microbes.”
Amino Acid Intake Is Inversely Associated with Arterial Stiffness and Central Blood Pressure in Women’ is published in the September edition of the Journal of Nutrition.
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Public Release: 27-Aug-2015
Fish oil-diet benefits may be mediated by gut microbes
Cell Press
Diets rich in fish oil versus diets rich in lard (e.g., bacon) produce very different bacteria in the guts of mice, reports a study published August 27 in Cell Metabolism. The researchers transferred these microbes into other mice to see how they affected health. The results suggest that gut bacteria share some of the responsibility for the beneficial effects of fish oil and the harmful effects of lard.
In particular, mice that received transplants of gut microbes associated with a fish oil diet were protected against diet-induced weight gain and inflammation compared with mice transplanted with gut microbes associated with a lard diet. This demonstrates that gut microbes are an independent factor aggravating inflammation associated with diet-induced obesity and gives hope that a probiotic might help counteract a “greasy” diet.
“We wanted to determine whether gut microbes directly contribute to the metabolic differences associated with diets rich in healthy and unhealthy fats,” says first study author Robert Caesar of the University of Gothenburg. Even though the study was done in mice, “our goal is to identify interventions for optimizing metabolic health in humans.”
Caesar, working in the lab of senior study author Fredrik Bäckhed, began by feeding either lard or fish oil to mice for 11 weeks and monitoring signs of metabolic health. While the consumption of lard promoted the growth of bacteria called Bilophila, which have been linked to gut inflammation, the fish oil diet increased the abundance of bacteria called Akkermansia muciniphila, known to reduce weight gain and improve glucose metabolism in mice.
“We were surprised that the lard and the fish oil diet, despite having the same energy content and the same amount of dietary fiber–which is the primary energy source for the gut bacteria–resulted in fundamentally different gut microbiota communities and that the microbiota per se had such large effects on health,” Caesar says.
In the next set of experiments, Caesar conducted “fecal transplants” to test whether fish oil-diet microbes could improve the health of mice fed only lard and vice versa. The results provide additional evidence that gut microbe communities can both determine and recover health problems caused by poor diet.
“Our paper supports previous reports indicating the bacteria Akkermansia muciniphila is a promoter of a healthy phenotype,” Bäckhed says. “However, further investigations will be needed to determine if this bacteria can be used as probiotic strain and, in that case, how it should be combined with diet to optimize health outcomes.”
Public Release: 27-Aug-2015
Antibiotic use linked to type 2 diabetes diagnosis
Antibiotics may contribute to or serve as early signal of developing condition
The Endocrine Society
Washington, DC–People who developed Type 2 diabetes tended to take more antibiotics in the years leading up to the diagnosis than people who did not have the condition, according to a new study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.
A person develops diabetes, which is characterized by high blood sugar levels, when the individual cannot produce enough of the hormone insulin or insulin does not work properly to clear sugar from the bloodstream.
More than 29 million Americans have diabetes, according to the Society’s Endocrine Facts and Figures report. Type 2 diabetes, the most common form of the condition, accounts for 90 to 95 percent of all cases.
“In our research, we found people who have Type 2 diabetes used significantly more antibiotics up to 15 years prior to diagnosis compared to healthy controls,” said one of the study’s authors, Kristian Hallundbæk Mikkelsen, MD, of Gentofte Hospital in Hellerup, Denmark. “Although we cannot infer causality from this study, the findings raise the possibility that antibiotics could raise the risk of Type 2 diabetes. Another equally compelling explanation may be that people develop Type 2 diabetes over the course of years and face a greater risk of infection during that time.”
As part of the population-based case-control study, researchers tracked antibiotic prescriptions for 170,504 people who had Type 2 diabetes and for 1.3 million people who did not have diabetes. The researchers identified the subjects using records from three national health registries in Denmark.
People who had Type 2 diabetes filled 0.8 prescriptions a year, on average. The rate was only 0.5 prescriptions a year among the study’s control subjects. Individuals who filled more prescriptions were more likely to be diagnosed with Type 2 diabetes. Many types of antibiotics were associated with a higher risk of diabetes, but there was a stronger link with the use of narrow-spectrum antibiotics such as penicillin V.
Past research has shown that antibiotic treatments can alter the bacteria in an individual’s gut. Studies suggest certain gut bacteria may contribute to the impaired ability to metabolize sugar seen in people with diabetes. This may explain why higher rates of antibiotic use are associated with the development of Type 2 diabetes, but more research is needed to explain the findings, Mikkelsen said.
“Diabetes is one of the greatest challenges facing modern health care, with a globally increasing incidence” he said. “Further investigation into long-term effect of antibiotic use on sugar metabolism and gut bacteria composition could reveal valuable answers about how to address this public health crisis. Patterns in antibiotic use may offer an opportunity to prevent the development of the disease or to diagnose it early.”