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Published on Leave a comment on Gut Bacteria Imbalance and Diabetes

Another view of  type 2 diabetes - that the gut microbiome is involved, specifically two gut bacteria: Prevotella copri and Bacteroides vulgatus. View them as the bad guys. The researchers point out "... the majority of overweight and obese individuals are insulin resistant and it is well known that dietary shifts to less calorie-dense eating and increased daily intake of any kind of vegetables and less intake of food rich in animal fat tend to normalize imbalances of gut microbiota and simultaneously improve insulin sensitivity of the host." In other words, eat more vegetables and fewer calories (if you're overweight or obese) to improve the gut microbes. This is similar to yesterday's post of research that viewed type 2 diabetes as "a response to overnutrition" and potentially reversible. From Medical Express:

Gut bacteria imbalance increases diabetes risk

Currently, scientists think the major contributors to insulin resistance are excess weight and physical inactivity, yet ground-breaking new research by an EU funded European-Chinese team of investigators called MetaHit have discovered that specific imbalances in the gut bacteria can cause insulin resistance, which confers an increased risk of health disorders like type 2 diabetes.

We show that specific imbalances in the gut microbiota are essential contributors to insulin resistance, a forerunner state of widespread disorders like type 2 diabetes, hypertension and atherosclerotic cardiovascular diseases, which are in epidemic growth," says Professor Oluf Pedersen, Metabolism Center, University of Copenhagen, and senior lead author of the paper.

In the Danish study of 277 non-diabetic individuals and 75 type 2 diabetic patients, there was close collaboration between the University of Copenhagen and the Technical University of Denmark with extensive international participation from a team of investigators, who performed analyses of the action of the insulin hormone. They monitored the concentrations of more than 1200 metabolites in blood and did advanced DNA-based studies of hundreds of bacteria in the human intestinal tract to explore if certain imbalances in gut microbiota are involved in the causation of common metabolic and cardiovascular disorders.

The researchers observed that people who had a decreased capacity of insulin action, and therefore were insulin resistant, had elevated blood levels of a subgroup of amino acids called branched-chain amino acids (BCAAs). Importantly, the rise of BCAAs levels in blood was related to specific changes in the gut microbiota composition and function.

The main drivers behind the gut bacterial biosynthesis of BCAAs turned out to be the two bacteria Prevotella copri and Bacteroides vulgatus. To test mechanistically if gut bacteria were a true cause of insulin resistance, the researchers fed mice with the Prevotella copri bacteria for 3 weeks. Compared with sham fed mice the Prevotella copi fed mice developed increased blood levels of BCAAs, insulin resistance and intolerance to glucose.

"Most people with insulin resistance do not know that they have it. However, it is known that the majority of overweight and obese individuals are insulin resistant and it is well known that dietary shifts to less calorie-dense eating and increased daily intake of any kind of vegetables and less intake of food rich in animal fat tend to normalize imbalances of gut microbiota and simultaneously improve insulin sensitivity of the host," adds Pedersen. (Original study)

Published on Leave a comment on Type 2 Diabetes May Be Reversible

This study gives hope to those with type 2 diabetes that it may be reversible - even if they've had it for up to 10 years. Researchers demonstrated that in 40% of the 30 study participants on a very low calorie diet (VLCD) of 600 to 700 calories daily for 8 weeks achieved remission of their diabetes for as long as 6 months (the length of the study). They returned to nondiabetic blood glucose levels, had improvement in acute insulin secretion, normalization of liver fat content and insulin sensitivity, and were off all diabetes medicine. The average weight loss was 31 pounds and they maintained this weight loss over the length of the study, even though most remained obese or overweight. The researchers mention that there is already evidence that diabetes reversal lasts for at least 3 years, as long as weight is not regained.

What they did: A) 3 diet shakes per day and 240 grams (1 cup or 1/2 pound) of non-starchy vegetables taking in between 600 and 700 calories per day for 8 weeks, B) volunteers then gradually returned to eating normal food over the next two weeks with very careful instruction on how much to eat, C) volunteers were seen once a month and supported with an individualized weight maintenance program over the next 6 months, D) to keep weight steady after the weight loss, they were eating around one third less than before the study.

Overall, 12 patients who had had diabetes for less than 10 years reversed their condition, and 6 months later they remained diabetes free. In fact, after 6 months a thirteenth patient had reversed their diabetes. The 30 people with diabetes in the study had it between 0.5 and 23 years. The best results were in those who had it for a shorter time. Thus, while 40% of study participants overall reversed their diabetes, 60% of those with short-duration of diabetes (under 10 years) reversed their diabetes. These are fantastic results!

The researchers say that the study results "...supports our theory of a Personal Fat Threshold. If a person gains more weight than they personally can tolerate, then diabetes is triggered, but if they then lose that amount of weight then they go back to normal. Individuals vary in how much weight they can carry without it seeming to affect their metabolism -- don't forget that 70% of severely obese people do not have diabetes." The researchers say type 2 diabetes can now be understood to be a metabolic syndrome that is potentially reversible by substantial weight loss, and that this is an important paradigm shift. They also comment that studies and population data indicate that type 2 diabetes is solely a response to overnutrition.

Excerpts from Diabetes Care:  Very Low-Calorie Diet and 6 Months of Weight Stability in Type 2 Diabetes: Pathophysiological Changes in Responders and Nonresponders.

Type 2 diabetes mellitus (T2DM) is generally regarded as an irreversible chronic condition. Because a very low-calorie diet (VLCD) can bring about acute return to normal glucose control in some people with T2DM, this study tested the potential durability of this normalization. The underlying mechanisms were defined.

People with a T2DM duration of 0.5-23 years (n = 30) followed a VLCD for 8 weeks. All oral agents or insulins were stopped at baseline.....Weight fell (98.0 ± 2.6 to 83.8 ± 2.4 kg) and remained stable over 6 months (84.7 ± 2.5 kg). Twelve of 30 participants achieved fasting plasma glucose <7 mmol/L after return to isocaloric diet (responders), and 13 of 30 after 6 months. Responders had a shorter duration of diabetes and a higher initial fasting plasma insulin level....A robust and sustainable weight loss program achieved continuing remission of diabetes for at least 6 months in the 40% who responded to a VLCD by achieving fasting plasma glucose of <7 mmol/L. T2DM is a potentially reversible condition.

However, restoration of normal glucose control is possible after weight loss in some individuals with T2DM . Although most commonly seen after bariatric surgery, reversal of diabetes can occur after any sharp decrease in calorie intake. In short-duration T2DM, fasting plasma glucose becomes normal within days on a very-low-calorie diet (VLCD) because of a rapid decrease in liver fat and return of normal hepatic insulin sensitivity, and normal b-cell function returns over 8 weeks.

This prospective, longitudinal, single center study comprised three phases: VLCD for 8 weeks; a stepped return to isocaloric intake of normal food over 2 weeks; and a structured, individualized weight maintenance program over 6 months. Assessments were carried out before the VLCD, after return to isocaloric eating, and at the end of the 6-month follow-up. The primary outcome measure was fasting blood glucose at 6 months in the group achieving nondiabetic levels after VLCD and return to normal eating, and the primary comparison was the change between post– weight loss and 6 months in responders.

We demonstrate that in 40% of study participants who responded to a VLCD by achieving fasting plasma glucose ,7 mmol/L, remission of T2DM lasts for at least 6 months. Return to nondiabetic blood glucose levels was characterized by improvement in acute insulin secretion, and this was sustained while off all hypoglycemic agents. Hepatic insulin sensitivity improved in both responders and nonresponders....Weight loss brought about normalization of liver fat content and insulin sensitivity in both responders and nonresponders. Of note, no redistribution of fat was seen to the liver from the subcutaneous or other deposits over 6 months of weight stability, even though the participants remained obese or overweight.

The present demonstration of ongoing reversal of T2DM (in 41% of the cohort overall or 60% of individuals with short-duration diabetes) is reflected in population data that indicate that T2DM is solely a response to overnutrition. Ready access to low-cost food is uniformly accompanied by high rates of T2DM, and when food supply becomes limited for any reason, the prevalence of T2DM falls.....The present data confirm reversal of T2DM for at least 6 months in those who achieve nondiabetic plasma glucose levels after VLCD. However, the critical question for health-care delivery is whether truly long-term reversal of T2DM can be achieved in primary care.

The likelihood of VLCD responders remaining free of diabetes indefinitely must be considered. After media coverage of our earlier study, many people with T2DM reversed their own diabetes (37). For such motivated individuals who avoid weight regain, maintenance of normoglycemia for up to 3 years has been reported.... Because progression of longterm complications of diabetes relates to ambient blood glucose control, durable reversal of diabetes would be expected to be associated with longterm health. T2DM can now be understood to be a metabolic syndrome potentially reversible by substantial weight loss, and this is an important paradigm shift. 

Published on Leave a comment on Eating Meals Prepared At Home Linked To Lower Incidence of Type 2 Diabetes

Of course eating meals prepared at home is healthier! The study results - that people who often consume meals prepared at home are less likely to suffer from type 2 diabetes than those who consume such meals less frequently shouldn't be surprising. The researchers attributed the higher incidence of type 2 diabetes to weight gain in those eating fewer meals prepared at home, but there are other things going on also.

Restaurant and fast food meals tend to have very large portions, frequently with rich sauces, and the meal choices tend to be heavy on fat and salt. The meals can be high in calories, contain many artificial ingredients, and may be low in nutritional quality (and so also not nourishing the beneficial gut microbes that are linked to health). At home you can limit portions, control the food ingredients, and eat only healthy foods (see earlier post on this). From Science Daily:

Enjoying meals prepared at home: Short-cut to avoiding diabetes?

People who often consume meals prepared at home are less likely to suffer from type 2 diabetes than those who consume such meals less frequently, according to  new epidemiological research reported by Qi Sun, of the Harvard T.H. Chan School of Public Heath, Boston, USA and colleagues as part of PLOS Medicine's special issue on Preventing Diabetes.

Internationally, there is an increasing tendency for people to eat out, and this could involve consumption of fast food, for example. Concerns have been raised that such people have a diet that is rich in energy but relatively poor in nutrients -- this could lead to weight gain which is, in turn, associated with an increased risk of type 2 diabetes.

Sun and colleagues employed large prospective data sets in which US health professionals -- both men and women--were followed-up for long periods, with rigorous collection of data on health indicators, including self-reported information on eating habits and occurrence of diabetes. The results were corrected for various known factors that could affect dining habits, including marital status. All in all, the study analyzed 2.1 million years of follow-up data.

The findings indicate that people who reported consuming 5-7 evening meals prepared at home during a week had a 15% lower risk of type 2 diabetes than those who consumed 2 such meals or fewer in a week. A smaller, but still statistically significant, reduction was apparent for those who reported consuming more midday meals prepared at home. Other analyses suggest that less weight gain could partially explain the reported reduction in occurrence of type 2 diabetes in those often eating meals prepared at home.

Published on Leave a comment on Omega-3s and Heart Disease

Previous research on the health benefits of eating fish, fish oil supplements, and other sources of omega-3 fatty acids has shown mixed results, with some studies revealing cardiac health benefits and others finding no benefit. However, when looking at recent studies separating eating foods rich in omega-3 fatty acids versus taking supplements, it appears that eating foods has various beneficial health effects, while taking a supplement may not find health benefits (here and here).

The latest research (reported in the journal JAMA Internal Medicine) looked at heart disease events (heart attack, cardiac related death) and actually measured the actual levels of omega-3 fatty acids in the participants' blood, as opposed to relying on questionnaires in which people report what they eat. The new study could not assess the usefulness of taking fish oil supplements, as opposed to eating fish, because so few people in the study took supplements. Thus the findings were generally from eating a diet rich in omega-3s from either fish or plant-based sources. (Note: By far the best source is fish. Some plant-based sources are: flaxseed, walnuts, edamame, black beans, kidney beans).

The new study — which combined 19 studies from 16 countries with more than 45,000 participants — found that higher circulating blood levels of omega-3 fatty acids were associated with a nearly 10 percent lower risk of a fatal heart attack, on average, compared with lower levels. The participants with the highest level of omega-3s in their blood had the greatest risk reduction — a more than 25 percent lower risk of having a fatal heart attack, the study found.

From Science Daily: Consumption of omega-3s linked to lower risk of fatal heart disease

A global consortium of researchers banded together to conduct an epidemiological study analyzing specific omega-3 fatty acid biomarkers and heart disease. They found that blood levels of omega-3 fatty acids from seafood and plant-based foods are associated with a lower risk of fatal heart attack.

A total of 19 studies were involved from 16 countries and including 45,637 participants. Of these, 7,973 people developed a first heart attack over time, including 2,781 deaths and 7,157 nonfatal heart attacks.

Overall, both plant-based and seafood-based omega-3s were associated with about a 10 percent lower risk of fatal heart attacks. In contrast, these fatty acids biomarkers were generally not associated with a risk of nonfatal heart attacks, suggesting a more specific mechanism for benefits of omega-3s related to death."At a time when some but not other trials of fish oil supplementation have shown benefits, there is uncertainty about cardiovascular effects of omega-3s," said Mozaffarian. "Our results lend support to the importance of fish and omega-3 consumption as part of a healthy diet."

Fish is the major food source of omega-3 fatty acids, including eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). According to the U.S. Department of Agriculture's National Nutrient Database, fatty fish such as salmon, trout, anchovies, sardines, and herring contain the highest amounts of omega-3 fatty acids, although all fish contain some levels. In addition to omega-3 fatty acids, fish provide specific proteins, vitamin D, selenium, and other minerals and elements. Alpha-linolenic acid (ALA) is the plant-based omega-3 fatty acid found in walnuts, flaxseed oil, and canola oil and some other seed and nuts and their oils.

Published on Leave a comment on Eating Whole Grains Linked To Living Longer

A second study was just published about the benefits of eating whole grains daily - again a significantly lower risk of premature death, and again the effects were dose-related. That is, the more whole grains eaten daily, the lower the risk of early death. Like the first study, this also was a review study. This study (published in BMJ) found that whole grain consumption was associated with a reduction in the risk for death from cancer, coronary heart disease (heart attack and stroke), respiratory disease, infectious disease, and diabetes.

A slice of 100 percent whole grain bread contains about 16 grams of whole grains, and current U.S. dietary guidelines recommend 48 grams or more of whole grains daily, but this study suggests that eating even more whole grains daily is best (eating 90 grams of whole grains a day reduced the risk for mortality from all causes by 17 percent).

Grains are divided into two subgroups: whole grains and refined grains. Whole grains or foods made from them contain all the essential parts and naturally-occurring nutrients of the entire grain seed in their original proportions. This definition means that 100% of the original kernel – all of the bran, germ, and endosperm – must be present to qualify as a whole grain. Some whole grains are: whole wheat. barley. buckwheat, corn (including whole cornmeal and popcorn), millet, oats (including oatmeal), quinoa, brown rice, rye, sorghum, spelt, bulgur, and wild rice. From Eurekalert:

Seven servings of whole grains a day keep the doctor away

Eating three more portions of dietary fiber a day--say, two pieces of whole grain bread and a bowl of whole grain breakfast cereal--is associated with a lower risk for all cardiovascular diseases and for dying of cancer, diabetes, and respiratory and infectious diseases, a study just published in the BMJ has shown. The study is strong proof that consuming lots of whole grains is good for our health, says first author Dagfinn Aune, a PhD candidate at the Norwegian University of Science and Technology who is currently working at Imperial College, London.

....In general, the study showed that the higher the consumption, the better protected you are. "We saw the lowest risk among people who ate between seven and seven and a half servings of whole grain products a day, which was the highest intake across all the studies. This corresponds to 210-225 grams of whole grain products in fresh weight and about 70-75 grams of whole grains in dry weight, and is about the same as the health authorities in Norway and other Nordic countries recommend as the minimum daily allowance," says Aune.

The researchers' analyses showed fewer risk factors for people who consumed more bread and cereal with whole grains, as well as foods with added bran. On the other hand, people who ate a lot of white bread, rice or cereals with refined grains did not show reduced risk.

Nine studies with a total of more than 700,000 participants examined the risk for all types of cardiovascular disease and correlated cardiovascular deaths....The risk of dying prematurely from all causes was 18% lower for individuals who consumed a lot of whole grains compared to those who consumed lesser amounts, while three additional servings each day were associated with a 17% reduction in mortality. The risk for deaths associated with cancer (15%), respiratory diseases (22%), diabetes (51%) and infectious diseases (26%) was also lower the more whole grains individuals consumed.

Published on Leave a comment on Whole Grains Are Very Good For You

Eating whole grains is good - lower death rate, fewer cardiovascular disease related deaths, fewer cancer deaths! And recent research (a review of studies) showed that the more whole grains consumed, the lower the death rate. Current dietary guidelines suggest 3 servings a day. Whole grains include: whole wheat, barley, buckwheat, millet, oats, quinoa, brown rice, rye, bulgur, spelt,and wild rice. Whole grains provide many nutrients, such as fiber, B vitamins, and minerals. From Medical Xpress:

Eating more whole grains linked with lower mortality rates

Eating at least three servings of whole grains every day could lower your risk of death, according to new research in the American Heart Association's journal Circulation. Although dietary guidelines around the world have included whole grains as an essential component of healthy eating patterns, people aren't eating enough, according to the analysis. In the United States average consumption remains below one serving a day, despite the long-time recommendation of three servings a day.

In the first meta-analysis review of studies reporting associations between whole grain consumption and death, researchers noted that for about every serving (16 grams) of whole grains there was a: 7 percent decreased risk in total deaths; 9 percent decline in cardiovascular disease-related deaths; and 5 percent decline in cancer-related deaths.

The more whole grains consumed, the lower the death rate. According to researchers, when three servings (48 grams) were consumed daily the rates declined: 20 percent for total deaths; 25 percent for cardiovascular deaths; and 14 percent for cancer-related deaths.

"Previous studies have suggested an association with consumption of whole grains and reduced risk of developing a multitude of chronic diseases that are among the top causes of deaths, although data linking whole grain intake and mortality were less consistent," said Qi Sun, M.D., Sc.D., senior author of the study and assistant professor at the Harvard T.H. Chan School of Public Health in Boston, Massachusetts. "These findings lend further support to the U.S. government's current Dietary Guidelines for Americans, which suggest higher consumption of whole grains to facilitate disease prevention."

Whole grains, such as whole wheat, oats and brown rice, contain dietary fiber, which may help improve blood cholesterol levels, and lower the risk of heart disease, stroke, obesity and type 2 diabetes. Dietary fiber can also make you feel full longer, so you may eat fewer calories.

This analysis included 12 studies published through February 2016 and unpublished results from the National Health and Nutrition Examination Survey (NHANES) III, conducted from 1988 to 1994, and NHANES 1999-2004. Of the reviewed studies, 10 were conducted in U.S. populations, three in Scandinavian countries and one in the United Kingdom. The combined studies involved 786,076 men and women with 97,867 total deaths, 23,597 deaths from cardiovascular disease, and 37,492 deaths from cancer.

Published on Leave a comment on Should a Healthy Plant-based Diet Include Lots of Sweets?

A plant-based diet (eating lots of plant foods - fruits, vegetables, whole grains, legumes, seeds and nuts) once again shows health benefits in a new study - here a lower incidence of type 2 diabetes. But what kind of plant-based foods one eats is important: consumption of a plant-based diet that emphasized healthy plant foods was associated with a larger decrease (34%) in diabetes risk, while consumption of a plant-based diet high in less healthy plant foods (soda, fruit juices, sweets/desserts, refined grains) was associated with a 16% increased diabetes risk. From Medical Xpress:

Healthy plant-based diet linked with substantially lower type 2 diabetes risk

Consuming a plant-based diet—especially one rich in high-quality plant foods such as whole grains, fruits, vegetables, nuts, and legumes—is linked with substantially lower risk of developing type 2 diabetes, according to a new study from Harvard T.H. Chan School of Public Health.

While previous studies have found links between vegetarian diets and improved health outcomes, including reduced risk of type 2 diabetes, this new study is the first to make distinctions between healthy plant-based diets and less healthy ones that include things like sweetened foods and beverages, which may be detrimental for health. The study also considered the effect of including some animal foods in the diet.

The researchers followed more than 200,000 male and female health professionals across the U.S. for more than 20 years who had regularly filled out questionnaires on their diet, lifestyle, medical history, and new disease diagnoses as part of three large long-term studies. The researchers evaluated participants' diets using a plant-based diet index in which they assigned plant-derived foods higher scores and animal-derived foods lower scores.

The study found that high adherence to a plant-based diet that was low in animal foods was associated with a 20% reduced risk of type 2 diabetes compared with low adherence to such a diet. Eating a healthy version of a plant-based diet was linked with a 34% lower diabetes risk, while a less healthy version—including foods such as refined grains, potatoes, and sugar-sweetened beverages—was linked with a 16% increased risk. Even modestly lowering animal food consumption—for example, from 5-6 servings per day to about 4 servings per day—was linked with lower diabetes incidence, the study found.

The researchers suggested that healthful plant-based diets could be lowering type 2 diabetes risk because such diets are high in fiber, antioxidants, unsaturated fatty acids, and micronutrients such as magnesium, and are low in saturated fat. Healthy plant foods may also be contributing to a healthy gut microbiome, the authors said.

Published on Leave a comment on Maybe Daily Meat Consumption Is Not So Bad

Surprising results (to me at least) from research comparing various diets and incidence of several cancers in 11,082 individuals in the Netherlands over a 20 year period. I expected the daily meat eaters to have higher rates of the 3 cancers studied, but no....

According to this study, looks like frequent meat consumption is OK when looking at lung, postmenopausal breast, and prostate cancer. Meat consumption did not increase the risk for these cancers.

Their main conclusion: vegetarians, pescatarians (eats fish, but no meat), and low-meat consumers did not have a reduced risk of lung, postmenopausal breast, and overall prostate cancer when compared with individuals consuming meat on a daily basis. This is after taking confounders such as smoking into account (because smokers have higher rates of cancers such as lung cancer).

The researchers do point out that some other similar studies had mixed results, but that perhaps those studies did not take confounders (variables that distort the results) such as smoking, physical activity levels, alcohol consumption, etc. into account.

From the European Journal of Clinical Nutrition: Vegetarianism, low meat consumption and the risk of lung, postmenopausal breast and prostate cancer in a population-based cohort study

The few prospective studies that examined lung, female breast and prostate cancer risk in vegetarians have yielded mixed results, whereas none have studied the effects of low meat diets. ... The Netherlands Cohort Study—Meat Investigation Cohort (NLCS-MIC)— is an analytical cohort of 11,082 individuals including 1133 self-reported vegetarians (aged 55–69 years at baseline). At baseline (1986), subjects completed a questionnaire on dietary habits and other risk factors for cancer and were classified into vegetarians (n=691), pescetarians (n=389), 1 day per week (n=1388), 2–5 days per week (n=2965) and 6–7 days per week meat consumers (n=5649).

After 20.3 years of follow-up, 279 lung, 312 postmenopausal breast and 399 prostate cancer cases (including 136 advanced) were available for analyses. After adjustment for confounding variables, we found no statistically significant association between meat consumption groups and the risk of lung cancer. As well, no significant associations were observed for postmenopausal breast and overall prostate cancer. After adjustment for confounders, individuals consuming meat 1 day per week were at a 75% increased risk of advanced prostate cancer compared with 6–7 days per week meat consumers.

Vegetarians, pescetarians and 1 day per week meat consumers did not have a reduced risk of lung, postmenopausal breast and overall prostate cancer compared with individuals consuming meat on a daily basis after taking confounders into account.

Although vegetarian diets are primarily defined by the absence of meat and fish, they are also shown to be associated with high intakes of fruits and vegetables and a favorable distribution of non-dietary factors.1, 2 Consequently, vegetarian diets may reduce the risk of different types of cancers through multiple mechanisms, depending on the etiology and preventability of the tumor.3, 4

We previously reported a nonsignificantly reduced risk of vegetarian and low meat diets on colorectal, and especially rectal, cancer5 and set out to study its effect on three other major cancers.

Although meat consumption has been hypothesized to be implicated in the etiology of lung, female breast and prostate cancer, data are not consistent across studies and meat subtypes.6, 7, 8However, on the basis of the existing body of literature, vegetarians may be at a lower risk of developing lung cancer (because of lower smoking rates) and to postmenopausal breast cancer (because of lower alcohol consumption, lower body mass index and higher physical activity levels).

Results from this prospective cohort study showed that, in age- and sex-adjusted models, vegetarians and pescetarians were at a reduced risk of lung cancer compared with individuals consuming meat on a daily basis. This effect disappeared after taking confounders, especially smoking, into account. We did not observe an association between the meat consumption group and the risk of post-menopausal breast and overall prostate cancer.

Our null findings regarding post-menopausal breast cancer risk are in line with other prospective studies comparing vegetarians with non-vegetarians and a pooled analysis of five cohort studies on breast cancer mortality. In contrast, the UK Women’s Cohort Study reported a lower post-menopausal breast cancer risk among non-meat consumers compared with high meat consumers,14 although this was not observed in their dietary pattern analyses.15 Vegetarian diets are rich in fiber and soy. Fiber was associated with a reduced risk of breast cancer in a meta-analysis of prospective studies,19 and soy contains isoflavones, which have previously been associated with a significant reduced risk of postmenopausal breast cancer in Asian populations.20 However, compared with the average soy intake in four Asian countries (ranging from 38 to 134 g/day21), the soy product intake among vegetarians in our population was likely too low to exert an effect (~15 g per day).

Published on Leave a comment on Dietary Fiber and Successful Aging

New research looked at people who "aged successfully" over a 10 year period compared with those who were "suboptimal agers" or had died. The successful agers were less likely to smoke, and have higher intakes of fiber from fruits, breads, and cereals (primarily from rolled oats and whole grain breads), but not from vegetables. Successful aging was defined as including an absence of disability, depressive symptoms, cognitive impairment, respiratory symptoms, and chronic diseases including cancer, coronary artery disease, and stroke. Fiber intake was more important for successful aging than glycemic index, glycemic load, carbohydrate intake, or sugar intake. From Medical Xpress:

Dietary fiber intake tied to successful aging, research reveals

A new paper—published in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences by scientists from The Westmead Institute for Medical Research—reports that eating the right amount of fiber from breads, cereals, and fruits can help us avoid disease and disability into old age. 

Using data compiled from the Blue Mountains Eye Study, a benchmark population-based study that examined a cohort of more than 1,600 adults aged 49 years and older for long-term sensory loss risk factors and systemic diseases, the researchers explored the relationship between carbohydrate nutrition and healthy aging.

They found that out of all the factors they examined—which included a person's total carbohydrate intake, total fiber intake, glycemic index, glycemic load, and sugar intake—it was the fiber that made the biggest difference to what the researchers termed "successful aging." Successful aging was defined as including an absence of disability, depressive symptoms, cognitive impairment, respiratory symptoms, and chronic diseases including cancer, coronary artery disease, and stroke.

"Out of all the variables that we looked at, fiber intake—which is a type of carbohydrate that the body can't digest—had the strongest influence," she said. "Essentially, we found that those who had the highest intake of fiber or total fiber actually had an almost 80 percent greater likelihood of living a long and healthy life over a 10-year follow-up. That is, they were less likely to suffer from hypertension, diabetes, dementia, depression, and functional disability."

While it might have been expected that the level of sugar intake would make the biggest impact on successful aging, Gopinath pointed out that the particular group they examined were older adults whose intake of carbonated and sugary drinks was quite low.

This study backs up similar recent findings by the researchers, which highlight the importance of the overall diet and healthy aging. In another study published last year in The Journals of Gerontology, Westmead Institute researchers found that, in general, adults who closely adhered to recommended national dietary guidelines reached old age with an absence of chronic diseases and disability, and had good functional and mental health status.

Published on Leave a comment on Vitamin B12 and the Aging Brain

Another piece of the puzzle on how the brain ages. Vitamin B12 is important for brain health, and higher levels are associated with slower rates of brain changes associated with aging. And the opposite is true with homocysteine levels - increased levels are associated with faster rates of brain changes that are associated with aging (such as higher rates of total brain tissue volume loss). Keep in mind that these effects were modest, but this also raises the question of whether long-term B12 supplementation would benefit everyone or only those with a deficiency? From Medscape:

Vitamin B12 May Slow Brain Aging

Individuals with increased levels of circulating homocysteine have faster rates of brain changes associated with aging than other people, whereas higher levels of vitamin B12 are associated with slower rates of brain aging, new research suggests.

Babak Hooshmand, MD, PhD, Center for Alzheimer Research–Aging Research Center, Karolinska Institutet, Stockholm, Sweden, and colleagues found that total brain volume losses were lower in individuals with higher baseline vitamin B12 levels, whereas the opposite was true of those with increased homocysteine levels.

"Vitamin B12 and tHcy [total homocysteine] might be independent predictors of markers of brain aging in elderly individuals without dementia," the investigators write. They add, "[I]f the association is causal, supplementation with B vitamins may be effective for prevention of brain damage due to increased levels of total homocysteine. Adequately timed and powered randomized clinical trials are needed to determine efficient treatment guidelines." The research was published online April 27 in JAMA Psychiatry.

The researchers examined data on 501 participants aged 60 years and older from the Swedish National Study on Aging and Care, in Kungsholmen. All participants were free of dementia at baseline. Of these, 299 underwent repeated structural brain MRI between 2001 and 2009....Venous blood samples were collected at baseline, from which circulating levels of vitamin B12, red blood cell folate, and sulfur amino acids were determined. These were correlated with changes in brain tissue volumes and total white matter hyperintensity (WMH) over 6 years.

He also pointed to the single-center, randomized VITACOG study, in which 271 individuals older than 70 years who had mild cognitive impairment received supplementation with high-dose folic acid and vitamins B6 and B12. "They lost less brain compared to people who had normal homocysteine and normal vitamin levels, meaning that those with high levels of homocysteine or with clinical or biochemical vitamin deficiency can benefit from supplementation," said Dr Hooshmand.