Health Research Report
150th Issue Date 08 Mar 2013
Compiled By Ralph Turchiano
www.facebook.com/engineeringevil
In this Is Issue:
Prenatal DHA reduces early preterm birth, low birth weight
Study finds higher levels of several toxic metals in children with autism
Women’s iron intake may help to protect against PMS
Lipid researcher, 98, reports on the dietary causes of heart disease
Grape seed and skin extract – a weapon in the fight against kidney disease caused by high-fat diets
BPA raises risk for childhood asthma
Why your brain tires when exercising
New mechanism for relaxing airways using bitter tasting substances
Green tea extract interferes with the formation of amyloid plaques in Alzheimer’s disease
Processed meat linked to premature death
Prenatal DHA reduces early preterm birth, low birth weight
LAWRENCE — University of Kansas researchers have found that the infants of mothers who were given 600 milligrams of the omega-3 fatty acid DHA during pregnancy weighed more at birth and were less likely to be very low birth weight and born before 34 weeks gestation than infants of mothers who were given a placebo. This result greatly strengthens the case for using the dietary supplement during pregnancy.
Susan CarlsonThe results are from the first five years of a 10-year, double-blind randomized controlled trial to be published in the April issue of the American Journal of Clinical Nutrition. It is also available online. A followup of this sample of infants is ongoing to determine whether prenatal DHA nutritional supplementation will benefit children’s intelligence and school readiness.
“A reduction in early preterm and very low birth weight delivery could have clear clinical and public health significance,” said Susan Carlson, A.J. Rice Professor of Dietetics and Nutrition at the KU Medical Center, who directed the study with John Colombo, KU professor of psychology and director of the Life Span Institute.
John Colombo“We believe that supplementing U.S. women with DHA could safely increase mean birth weight and gestational age to numbers that are closer to other developed countries such as Norway and Australia,” she said.
DHA (docosahexaenoic acid) occurs naturally in cell membranes with the highest levels in brain cells, but levels can be increased by diet or supplements. An infant obtains DHA from his or her mother in utero and postnatally from human milk, but the amount received depends upon the mother’s DHA status.
“U.S. women typically consume less DHA than women in most of the developed world,” said Carlson.
During the first five years of the study, children of women enrolled in the study received multiple developmental assessments at regular intervals throughout infancy and at 18 months of age. In the next phase of the study, the children will receive twice-yearly assessments until they are 6 years old. The researchers will measure developmental milestones that occur in later childhood and are linked to lifelong health and welfare.
Previous research has established the effects of postnatal feeding of DHA on infant cognitive and intellectual development, but DHA is accumulated most rapidly in the fetal brain during pregnancy, said Colombo. “That’s why we are so interested in the effects of DHA taken prenatally, because we will really be able to see how this nutrient affects development over the long term.”
The study is funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development. See past news on this research here.
The University of Kansas is a major comprehensive research and teaching university. The university’s mission is to lift students and society by educating leaders, building healthy communities and making discoveries that change the world. The KU News Service is the central public relations office for the Lawrence campus.
Study finds higher levels of several toxic metals in children with autism
James Adams, a professor of materials science and engineering, has done extensive research into autism. He directs the ASU Autism/Asperger’s Research Program. Photo: Jessica Slater/ASU
Posted February 25, 2013
In a recently published study in the journal Biological Trace Element Research, Arizona State University researchers report that children with autism had higher levels of several toxic metals in their blood and urine compared to typical children. The study involved 55 children with autism ages 5–16 years compared to 44 controls of similar age and gender.
The autism group had significantly higher levels of lead in their red blood cells (+41 percent) and significantly higher urinary levels of lead (+74 percent), thallium (+77 percent), tin (+115 percent), and tungsten (+44 percent). Lead, thallium, tin, and tungsten are toxic metals that can impair brain development and function, and also interfere with the normal functioning of other body organs and systems.
A statistical analysis was conducted to determine if the levels of toxic metals were associated with autism severity, using three different scales of autism severity. It was found that 38-47 percent of the variation of autism severity was associated with the level of several toxic metals, with cadmium and mercury being the most strongly associated.
In the paper about the study, the authors state “We hypothesize that reducing early exposure to toxic metals may help ameliorate symptoms of autism, and treatment to remove toxic metals may reduce symptoms of autism; these hypotheses need further exploration, as there is a growing body of research to support it.”
The study was led by James Adams, a President’s Professor in the School for Engineering of Matter, Transport and Energy, one of ASU’s Ira A. Fulton Schools of Engineering. He directs the ASU Autism/Asperger’s Research Program.
Adams previously published a study on the use of DMSA, an FDA-approved medication for removing toxic metals. The open-label study found that DMSA was generally safe and effective at removing some toxic metals. It also found that DMSA therapy improved some symptoms of autism. The biggest improvement was for children with the highest levels of toxic metals in their urine.
Overall, children with autism have higher average levels of several toxic metals, and levels of several toxic metals are strongly associated with variations in the severity of autism for all three of the autism severity scales investigated.
The study was funded by the Autism Research Institute and the Legacy Foundation.
Women’s iron intake may help to protect against PMS
Women who reported eating a diet rich in iron were 30 to 40 percent less likely to develop PMS than women who consumed lower amounts, in a study reported this week by researchers at UMass Amherst and Harvard
AMHERST, Mass. – Women who reported eating a diet rich in iron were 30 to 40 percent less likely to develop pre-menstrual syndrome (PMS) than women who consumed lower amounts, in a study reported this week by researchers at the University of Massachusetts Amherst School of Public Health and Health Sciences and Harvard. It is one of the first to evaluate whether dietary mineral intake is associated with PMS development.
Senior author Elizabeth Bertone-Johnson and others at UMass Amherst, with lead author Patricia Chocano-Bedoya and colleagues at Harvard, assessed mineral intake in approximately 3,000 women in a case-control study nested within the prospective Nurses’ Health Study II. Participants were free from PMS at baseline. Results appear in the early online edition of the American Journal of Epidemiology.
Women in the study completed three food frequency questionnaires over the 10-year study period. After 10 years, 1,057 women were diagnosed with PMS and 1,968 remained free from PMS. Adjusting for calcium intake and other factors, the researchers then compared previous mineral intake reported by the women diagnosed with PMS with that of women who had few or no menstrual symptoms.
“We found that women who consumed the most non-heme iron, the form found primarily in plant foods and in supplements, had a 30 to 40 percent lower risk of developing PMS than women who consumed the lowest amount of non-heme iron,” says Bertone-Johnson. Women in the highest intake group for non-heme iron had a relative risk of PMS of 0.60 compared to women in the lowest intake group.
She adds, “We also saw some indication that high intake of zinc was associated with lower risk. In contrast, we were somewhat surprised to find that women consuming the highest amount of potassium had a higher risk of being diagnosed with PMS than women consuming the lowest amount of potassium. In general, results for mineral from food sources and minerals from supplements were similar.”
Overall, “Our findings need to be replicated in other studies. However, women at risk for PMS should make sure they are meeting the RDA for non-heme iron and zinc.”
“The level of iron intake at which we saw a lower risk of PMS, roughly greater than 20 mg per day, is higher than the current recommended daily allowance (RDA) for iron for premenopausal women, which is 18 mg per day,” Bertone-Johnson says. This amount may be obtained in 1 to 1.5 servings per day of iron-fortified cereal or with supplements.
“However, as high iron intake may have adverse health consequence, women should avoid consuming more than the tolerable upper intake level of 45 mg per day unless otherwise recommended by a physician,” she notes. Iron may be related to PMS because it is involved in producing serotonin, a neurotransmitter that helps to regulate mood, she and colleagues point out.
The unexpected finding of higher PMS risk with high potassium intake, even at levels below current recommendations of 4,700 mg per day, may be related to potassium’s role in regulating fluid balance in the body. It may affect PMS symptoms such as swelling in the extremities and bloating by affecting fluid retention. “More studies of potassium and menstrual symptoms are needed to better understand this,” they say.
“The level of zinc intake at which we saw suggestion of a lower risk of PMS, greater than 15 mg per day, was also higher than current recommendations of 8 mg per day. However, as high zinc intake may also have adverse health consequences, women should avoid consuming more than the tolerable upper intake level of 40 mg per day unless recommended by a physician.”
Intake of other minerals, including magnesium, copper, sodium and manganese were not associated with PMS risk, the authors point out.
Lipid researcher, 98, reports on the dietary causes of heart disease
CHAMPAIGN, Ill. — A 98-year-old researcher argues that, contrary to decades of clinical assumptions and advice to patients, dietary cholesterol is good for your heart – unless that cholesterol is unnaturally oxidized (by frying foods in reused oil, eating lots of polyunsaturated fats, or smoking).
The researcher, Fred Kummerow, an emeritus professor of comparative biosciences at the University of Illinois, has spent more than six decades studying the dietary factors that contribute to heart disease. In a new paper in the American Journal of Cardiovascular Disease, he reviews the research on lipid metabolism and heart disease with a focus on the consumption of oxidized cholesterol – in his view a primary contributor to heart disease.
“Oxidized lipids contribute to heart disease both by increasing deposition of calcium on the arterial wall, a major hallmark of atherosclerosis, and by interrupting blood flow, a major contributor to heart attack and sudden death,” Kummerow wrote in the review.
Over his 60-plus-year career, Kummerow has painstakingly collected and analyzed the findings that together reveal the underlying mechanisms linking oxidized cholesterol (and trans fats) to heart disease.
Many of Kummerow’s insights come from his relentless focus on the physical and biochemical changes that occur in the arteries of people with heart disease. For example, he has worked with surgeons to retrieve and examine the arteries of people suffering from heart disease, and has compared his findings with those obtained in animal experiments.
He and his colleagues first reported in 2001 that the arteries of people who had had bypass operations contained elevated levels of sphingomyelin (SFING-oh-my-uh-lin), one of several phospholipids (phosphate-containing lipids) that make up the membranes of all cells. The bypass patients also had significantly more oxidized cholesterols (oxysterols) in their plasma and tissues than people who had not been diagnosed with heart disease.
Human cells incubated with the blood plasma of the cardiac patients also picked up significantly more calcium from the culture medium than cells incubated in the plasma of healthy patients. When the researchers added oxysterols to the healthy plasma, the proportion of sphingomyelin in the cells increased, as did the uptake of calcium.
Earlier research, including studies conducted by medical pioneer Michael DeBakey, noted that the most problematic plaques in patients with heart disease occurred at the branch-points of the arteries of the heart. Kummerow followed up on these reports by looking at the phospholipid content of the arterial walls in pigs and humans. He found (and reported in 1994) that the branch points of the arteries in humans and in swine also had significantly more sphingomyelin than other regions of the same arteries.
For Kummerow, the increase in sphingomyelin was a prime suspect in the blocked and calcified arteries of the cardiac patients. He had already found that the arteries of the newborn human placenta contained only about 10 percent sphingomyelin and 50 percent phosphatidylcholine (FOSS-fuh-tih-dul-COH-lean), another important phospholipid component of cell membranes.
“But when we looked at the arteries of people who had had bypass operations, we found up to 40 percent sphingomyelin and about 27 percent phosphatidylcholine,” Kummerow said. “It took us many more years to discover that when you added large amounts of oxysterols to the cells, then the phosphatidylcholine changed to sphingomyelin.”
Further evidence supported sphingomyelin’s starring role in atherosclerosis. When Kummerow and his colleagues compared the blocked and unblocked arteries of patients needing second bypass operations, they found that the arteries with blockages contained twice as much sphingomyelin as the unblocked arteries. The calcium content of the blocked arteries (6,345 parts per million) was also much higher than that of the unblocked arteries (182 ppm).
Other studies had demonstrated a link between increases in sphingomyelin and the deposit of calcium in the coronary arteries. The mechanism by which this occurred was unclear, however. Kummerow’s team searched the literature and found a 1967 study that showed that in the presence of certain salts (in the blood, for example), lipids like sphingomyelin develop a negative charge. This explains the attraction of the positively charged calcium to the arterial wall when high amounts of sphingomyelin are present, Kummerow said.
“So there was a negative charge on the wall of this artery, and it attracted calcium from the blood until it calcified the whole artery,” he said.
Oxidized fats contribute to heart disease (and sudden death from heart attacks) in an additional way, Kummerow said. He and his collaborators found that when the low-density lipoprotein (LDL, the so-called “bad cholesterol”) is oxidized, it increases the synthesis of a blood-clotting agent, called thromboxane, in the platelets.
If someone eats a diet rich in oxysterols and trans fats and also smokes, he or she is endangering the heart in three distinct ways, Kummerow said. The oxysterols enhance calcification of the arteries and promote the synthesis of a clotting agent. And the trans fats and cigarette smoke interfere with the production of a compound, prostacyclin, which normally keeps the blood fluid.
“And that causes 600,000 deaths in this country each year,” Kummerow said.
Kummerow is the author of “Cholesterol Won’t Kill You, But Trans Fats Could.”
Grape seed and skin extract – a weapon in the fight against kidney disease caused by high-fat diets
Ottawa, ON (February 28, 2013) – New insight into grape seed extract as a therapeutic and preventative measure to fight obesity-induced kidney damage is presented in a new study. Grape seed and skin extract (GSSE) is known to contain powerful antioxidants. This study, published in the journal Applied Physiology, Nutrition, and Metabolism, is the first to make a link between GSSEs and high-fat-diet-induced renal disease.
The authors examined the effect of GSSE processed from a grape cultivar (‘Carignan’) of Vitis vinifera from northern Tunisia on rats. Rats were fed a high-fat diet that induced a low-grade reno-lipotoxicity, that is, kidney damage associated with lipids. This was characterized by elevations in plasma urea and protein in the urine. The researchers found increased deposits of triglycerides (TG) (especially saturated fatty acids), increased signs of oxidative stress and depleted copper levels in the kidneys. There was also histological evidence of disturbance in the kidney structure. When the animals received GSSE at 500 mg/kg bw (which corresponds to 35g/day for a 70 kg human adult) along with the high-fat diet there was a partial reversal of the TG deposition as well as the histological damage. The authors suggest polyphenols including resveratrol are likely the components in GSSE responsible for the positive effects. Furthermore the GSSE prevented the oxidative stress and copper depletion.
“In our research, obesity-induced leaky kidney and proteinuria are shown to be prevented by GSSE, which suggests the use of GSSE as a preventive nutriceutical for high-risk patients,” said co-author Kamel Charradi, a researcher with the Laboratory of Bioactive Substance at the Center of Biotechnology of Borj-Cedria (CBBC) in Tunisia. This research group has previously published work showing the benefits of GSSE in combating obesity, heart dysfunction, brain lipotoxicity and kidney cancer.
The article “Grape seed and skin extract alleviates high-fat-diet-induced renal lipotoxicity and prevents copper depletion in rats” is available Open Access in the journal Applied Physiology, Nutrition, and Metabolism, DOI: 10.1139/apnm-2012-0416
BPA raises risk for childhood asthma
Children exposed to the plastics chemical bisphenol A had an elevated risk for asthma
Researchers at the Columbia Center for Children’s Environmental Health at the Mailman School of Public Health are the first to report an association between early childhood exposure to the chemical bisphenol A (BPA) and an elevated risk for asthma in young children. BPA is a component of some plastics and is found in food can liners and store receipts.
Results appear in the March edition of the Journal of Allergy and Clinical Immunology.
“Asthma prevalence has increased dramatically over the past 30 years, which suggests that some as-yet-undiscovered environmental exposures may be implicated. Our study indicates that one such exposure may be BPA,” says lead author Kathleen Donohue, MD, an assistant professor of Medicine at Columbia University College of Physicians and Surgeons and an investigator at the Center for Children’s Environmental Health.
Dr. Donohue and her co-investigators followed 568 women enrolled in the Mothers & Newborns study of environmental exposures. BPA exposure was determined by measuring levels of a BPA metabolite in urine samples taken during the third trimester of pregnancy and in the children at ages 3, 5, and 7. Physicians diagnosed asthma at ages 5 to 12 based on asthma symptoms, a pulmonary function test, and medical history. A validated questionnaire was used to evaluate wheeze.
After adjusting for secondhand smoke and other factors known to be associated with asthma, the researchers found that post-natal exposure to BPA was associated with increased risk of wheeze and asthma. BPA exposure during the third trimester of pregnancy was inversely associated with risk of wheeze at age 5. This unexpected finding is in contrast to the results of a previous study, which found that BPA exposure during the second trimester, a critical period for the development of airways and the immune system, was positively linked with risk for asthma.
Increased risk for wheeze and asthma was seen at “fairly routine, low doses of exposure to BPA,” says Dr. Donohue. “Like most other scientists studying BPA, we do not see a straightforward linear dose-response relationship.”
At all three time points, more than 90% of the children in the study had detectable levels of BPA metabolite in their bodies, a finding that is in line with previous research. This does not mean that they will all develop asthma, cautions Dr. Donohue. “Just as smoking increases the risk of lung cancer but not everyone who smokes gets lung cancer, not every child exposed to BPA will develop asthma.”
The biological mechanism behind the BPA-asthma connection is unclear. The current study found no evidence that exposure to BPA increased the risk that the immune system would develop more antibodies to common airborne allergens. “Other possible pathways may include changes to the innate immune system, but this remains an open question,” says Dr. Donohue.
The new study builds on existing evidence linking BPA exposure to respiratory symptoms, as well as to obesity, impaired glucose tolerance, and behavioral issues, among a range of health problems. In July, the Food and Drug Administration banned BPA in baby bottles and sippy cups.
“It is very important to have solid epidemiologic research like ours to give the regulators the best possible information on which to base their decisions about the safety of BPA,” says senior author Robin Whyatt, DrPH, professor of Environmental Health Sciences and deputy director of the Columbia Center for Children’s Environmental Health.
To reduce exposure to BPA, the National Institute of Environmental Health Sciences (NIEHS) recommends avoiding plastic containers numbers 3 and 7, eating less canned food, and, when possible, choosing glass, porcelain, or stainless steel containers, especially for hot food and liquids.
Why your brain tires when exercising
A marathon runner approaches the finishing line, but suddenly the sweaty athlete collapses to the ground. Everyone probably assumes that this is because he has expended all energy in his muscles. What few people know is that it might also be a braking mechanism in the brain which swings into effect and makes us too tired to continue. What may be occurring is what is referred to as ‘central fatigue’.
“Our discovery is helping to shed light on the paradox which has long been the subject of discussion by researchers. We have always known that the neurotransmitter serotonin is released when you exercise, and indeed, it helps us to keep going. However, the answer to what role the substance plays in relation to the fact that we also feel so exhausted we have to stop has been eluding us for years. We can now see it is actually a surplus of serotonin that triggers a braking mechanism in the brain. In other words, serotonin functions as an accelerator but also as a brake when the strain becomes excessive,” says Associate Professor Jean-François Perrier from the Department of Neuroscience and Pharmacology, who has spearheaded the new research.
Help in the battle against doping
Jean-François Perrier hopes that mapping the mechanism that prompts central fatigue will be useful in several ways. Central fatigue is a phenomenon which has been known for about 80 years; it is a sort of tiredness which, instead of affecting the muscles, hits the brain and nervous system. By conducting scientific experiments, it is possible to observe and measure that the brain sends insufficient signals to the muscles to keep going, which in turn means that we are unable to keep performing. This makes the mechanism behind central fatigue an interesting area in the battle against doping, and it is for this reason that Anti Doping Danmark has also helped fund the group’s research.
“In combating the use of doping, it is crucial to identify which methods athletes can use to prevent central fatigue and thereby continue to perform beyond what is naturally possible. And the best way of doing so is to understand the underlying mechanism,” says Jean-François Perrier.
Developing better drugs
The brain communicates with our muscles using so-called motoneurons (see fact box). In several diseases, motoneurons are hyperactive. This is true, for example, of people suffering from spasticity and cerebral palsy, who are unable to control their movements. Jean-François Perrier therefore hopes that, in the long term, this new knowledge can also be used to help develop drugs against these symptoms and to find out more about the effects of antidepressants.
“This new discovery brings us a step closer to finding ways of controlling serotonin. In other words, whether it will have an activating effect or trigger central fatigue. It is all about selectively activating the receptors which serotonin attaches to,” explains Jean-François Perrier.
“For selective serotonin re-uptake inhibitor (SSRI) drugs which are used as antidepressants, we can possibly help explain why those who take the drugs often feel more tired and also become slightly clumsier than other people. What we now know can help us develop better drugs,” concludes Jean-François Perrier.
New mechanism for relaxing airways using bitter tasting substances
A team of scientists at the University of Massachusetts Medical School have found that substances which give some foods their bitter flavors can also act to reverse the contraction of airway cells. This reversal, known as bronchodilation, is needed to treat airway obstructive diseases such as asthma and chronic obstructive pulmonary disease. The new findings, which could have significant implications for such treatments, are published March 5 in the open access journal PLOS Biology.
The sense of taste is mediated by taste receptor cells bundled in our taste buds. These receptors were thought to only exist in the tongue, but recent discoveries have shown that they are actually expressed in various cell types throughout the body. In particular, bitter taste receptors exist in smooth muscle cells in the airway, acting to relax the cells when exposed to bitter-tasting substances.
A hallmark of an asthma attack is excessive contraction of these smooth muscle cells, which causes narrowing of the airways and breathing difficulties. The fact that bitter substances can relax these smooth muscle cells suggests that they may have the potential to halt asthma attacks, and in fact could even be an improvement over current treatments since the relaxation effects are quite fast. Indeed, experiments in mice suggest that the effects are stronger.
However, the mechanisms through which bitter taste receptor activation leads to cell relaxation were unknown. To help unravel these mechanisms, Dr. Ronghua ZhuGe and his colleagues examined the effect of bitter substances on the contraction of airways and in single isolated cells.
During an asthma attack, membrane channels on smooth muscle cells in the airways are opened, allowing calcium to flow into the cell and causing the cell to contract. This leads to the airways becoming narrower, and making breathing more difficult. Dr. ZhuGe and colleagues determined that bitter substances shut down these calcium channels, allowing bronchodilation.
Bitter taste receptors, like most receptors, span the plasma membrane of the cell. Part of the receptor is outside the cell, able to bind to (and hence “sense”) bitter substances outside the cell. When a bitter compound binds to a bitter taste receptor, the receptor releases a G-protein, which then splits into two parts: a G alpha subunit and G beta-gamma dimer. “It is the G beta-gamma dimer that likely acts to close the calcium channels on the plasma membrane,” explained Kevin Fogarty, director of the Biomedical Imaging Group in the Program in Molecular Medicine at UMMS, and a co-author of the study. “Once the channels are closed, the calcium level returns to normal and the cell relaxes,” he said. “This ends the asthma attack.”
“With this new understanding of how bitter substances are able to relax airways, we can focus our attention on studying these receptors and on finding even more potent bitter compounds with the potential to be used therapeutically to end asthma attacks,” said Dr. ZhuGe.
Green tea extract interferes with the formation of amyloid plaques in Alzheimer’s disease
ANN ARBOR—Researchers at the University of Michigan have found a new potential benefit of a molecule in green tea: preventing the misfolding of specific proteins in the brain.
The aggregation of these proteins, called metal-associated amyloids, is associated with Alzheimer’s disease and other neurodegenerative conditions.
A paper published recently in the Proceedings of the National Academy of Sciences explained how U-M Life Sciences Institute faculty member Mi Hee Lim and an interdisciplinary team of researchers used green tea extract to control the generation of metal-associated amyloid-β aggregates associated with Alzheimer’s disease in the lab.
The specific molecule in green tea, (—)-epigallocatechin-3-gallate, also known as EGCG, prevented aggregate formation and broke down existing aggregate structures in the proteins that contained metals—specifically copper, iron and zinc.
“A lot of people are very excited about this molecule,” said Lim, noting that the EGCG and other flavonoids in natural products have long been established as powerful antioxidants. “We used a multidisciplinary approach. This is the first example of structure-centric, multidisciplinary investigations by three principal investigators with three different areas of expertise.”
The research team included chemists, biochemists and biophysicists.
While many researchers are investigating small molecules and metal-associated amyloids, most are looking from a limited perspective, said Lim, assistant professor of chemistry and research assistant professor at the Life Sciences Institute, where her lab is located and her research is conducted.
“But we believe you have to have a lot of approaches working together, because the brain is very complex,” she said.
The PNAS paper was a starting point, Lim said, and her team’s next step is to “tweak” the molecule and then test its ability to interfere with plaque formation in fruit flies.
“We want to modify them for the brain, specifically to interfere with the plaques associated with Alzheimer’s,” she said.
Lim plans to collaborate with Bing Ye, a neurobiologist in the LSI. Together, the researchers will test the new molecule’s power to inhibit potential toxicity of aggregates containing proteins and metals in fruit flies.
Processed meat linked to premature death
In a huge study of half a million men and women, research in Biomed Central’s open access journal BMC Medicine demonstrates an association between processed meat and cardiovascular disease and cancer.
One of the difficulties in measuring the effect of eating meat on health is the confounding effect of lifestyle on health. Often vegetarians have healthier lifestyles than the general population, they are less likely to smoke, are less fat, and are more likely to be physically active. Only within a very large study can the consequences of eating meat and processed meat be isolated from other lifestyle choices.
This EPIC (European Prospective Investigation into Cancer and Nutrition) study involved ten countries and 23 centres in Europe and almost half a million people. In general a diet high in processed meat was linked to other unhealthy choices. Men and women who ate the most processed meat ate the fewest fruit and vegetables and were more likely to smoke. Men who ate a lot of meat also tended to have a high alcohol consumption.
A person’s risk of premature death (increased risk of all cause mortality) increased with the amount of processed meat eaten. This is also true after correcting for confounding variables, although residual confounding cannot be excluded. However, a small amount of red meat appeared to be beneficial which the researchers suggest is because meat is an important source of nutrients and vitamins.
Prof Sabine Rohrmann, from the University of Zurich, who led this analysis explained, “Risks of dying earlier from cancer and cardiovascular disease also increased with the amount of processed meat eaten. Overall, we estimate that 3% of premature deaths each year could be prevented if people ate less than 20g processed meat per day.”
This article marks the launch of an article collection on Medicine for Global Health in BMC Medicine. The collection focuses on public health initiatives, the development of health care policies and evidence-based guidelines which are needed to address the global burden of disease. Vulnerable populations, especially in low and middle income countries, continue to be seriously affected by non-communicable and infectious diseases including neglected tropical diseases, while complications during pregnancy and childbirth in these regions leave mothers and infants at risk of severe disability or death.
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These reports are done with the appreciation of all the Doctors, Scientist, and other Medical Researchers who sacrificed their time and effort. In order to give people the ability to empower themselves. Without base aspirations of fame, or fortune. Just honorable people, doing honorable things.