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Mediterranean Diet Linked with Better Brain Health in Adults at Risk for Alzheimer's

Numerous studies have observed a link between the Mediterranean Diet and slower cognitive decline, but researchers wonder how this might relate to the development of Alzheimer’s disease. To better understand diet’s relationship with Alzheimer’s pathology, scientists analyzed the eating patterns and buildup of Aβ (small pieces of protein that can accumulate in the brain, potentially creating plaques and causing brain cells to be destroyed) in 77 older adults who were already on the path to Alzheimer’s disease (by being flagged as being Aβ accumulators). Those most closing following a Mediterranean diet had significantly less Aβ accumulation over time, with fruit standing out as a particularly beneficial food. The authors suggest that improving your Mediterranean diet score by just 1 point (0-9 point scale) may result in a 20% decrease in Aβ accumulation over 1 year, and up to a 60% decrease over 3 years.
Translational Psychiatry. 2018 Oct 30;8(1):238. doi: 10.1038/s41398-018-0293-5. (Rainey-Smith SR et al.)

Waist Circumference Guidelines May Differ for African Americans

Waist circumference is an easy-to-measure predictor of diabetes and heart disease risk, but one measurement may not indicate the same level of risk across all races or body types. In this study, researchers analyzed the waist circumference, body fat, and insulin resistance of 375 African-born black adults living in America. They found that a waist circumference of 38 inches or greater in black women, and 36 inches or greater in black men is predictive of insulin resistance, which indicates increased diabetes risk. This differs from the existing waist circumference thresholds for white adults. The researchers suggest that public health organizations review the research on waist circumference and adopt African-centered thresholds for African Americans, rather than a one-size-fits-all approach.
BMJ Global Health. 2018 Oct 15;3(5):e001057. doi: 10.1136/bmjgh-2018-001057. (Kabakambira JD et al.)

Unhealthy "Southern Diet" Partially Explains High Blood Pressure Risk in African Americans

African Americans are disproportionally affected by high blood pressure (a risk factor for heart disease), so health experts wonder what might contribute to this risk. In a study of 6,897 adults, researchers found that eating a “southern diet” (lots of fried food, processed meats, added fats, and sugar sweetened beverages) accounted for 51.6% of the increased risk of high blood pressure in black men, and 29.2% of the increased risk among black women. Celebrating traditional, nutrient-dense African heritage cuisine could be a helpful approach to encourage people of diverse backgrounds to make healthier food choices, thereby reducing risk for high blood pressure.
JAMA. 2018 Oct 2;320(13):1338-1348. doi: 10.1001/jama.2018.13467. (Howard G et al.)

Mediterranean Diet Linked with 33% Lower Risk of Depression

Scientists are eager to learn more about the link between a healthy diet and a healthy mind. In this study, researchers analyzed existing observational studies between healthy diets (measured by the Mediterranean Diet score, the Healthy Eating Index, the Dietary Inflammatory Index, and related scoring systems) and depression. According to the researchers, “the most compelling evidence was found for the Mediterranean diet and incident depression.” Specifically, those most closely following a Mediterranean diet were 33% less likely to develop incident depression than those not following a Mediterranean diet. People whose diets scored well on some of the other diet scores also tended to have a lower risk of depression, though there were fewer studies using those indices.
Molecular Psychiatry. 2018 Sep 26. doi: 10.1038/s41380-018-0237-8. [Epub ahead of print] (Lassale C et al.)

Whole Grains Linked with Better Blood Sugar Management

Metabolic syndrome is a cluster of conditions (high blood pressure, high blood sugar, high cholesterol, and excess fat around the waist) that can increase your risk of heart disease, stroke, and diabetes if they occur together. In this study, researchers randomly assigned more than 100 adults with metabolic syndrome from Finland and Italy to a diet with whole grains or a control diet without whole grains for 12 weeks. The whole grain group had better blood sugar control after meals. Researchers hypothesize that this may be because eating whole grains may help stimulate the production of certain chemical compounds (betaine compounds, such as pipecolic acid betaine) which are linked with improved insulin resistance and insulin secretion.
American Journal of Clinical Nutrition. Am J Clin Nutr. 2018 Sep 25. doi: 10.1093/ajcn/nqy169. [Epub ahead of print]. (Kärkkäinen O et al.)

Mediterranean Diet Linked with 22% Lower Risk of Stroke in Women

The Mediterranean diet has been well studied for its link to stroke prevention, but researchers wonder how the effects may differ between different types of patients. In this study, scientists monitored the eating patterns and health status of 23,232 white Europeans in the UK. After 17 years, those most closely following a Mediterranean diet had a 17% lower risk of stroke. However, the findings seem to be driven primarily by women. Women who most closely followed a Mediterranean diet had a 22% lower risk of stroke, while the trend towards lower risk in men was not statistically significant. Additionally, the findings were stronger in people who had a higher risk of heart disease (due to family history or other factors).
Stroke. 2018 Sept 20. doi: 10.1161/STROKEAHA.117.020258. [Epub ahead of print.] (Paterson KE et al.)

Whole Grains Linked with Lower Cholesterol

To better understand whole grains’ relationship with heart health, New Zealand’s Heart Foundation analyzed 19 meta analyses encompassing thousands of participants, for their September 2018 report entitled “Whole Grains and the Heart.” The authors conclude that “observational research suggests three [servings] of whole grains per day are associated with heart health benefits, and there are likely to be additional benefits with higher intakes. Intervention studies on risk factors are less compelling but show most consistent evidence of benefits for a small reduction in total and LDL cholesterol, especially in relation to oats and barley, and possibly improved [glycemic] control.”
Heart Foundation. 2018 Sept. (Gorton D et al.)

Cheese Production in Mediterranean May Have Helped Reduced Infant Mortality in Middle Neolithic Period

The Neolithic Period, when communities transitioned from a largely hunter-gatherer lifestyle to a largely agricultural lifestyle, began about 12,000 years ago. Cheese production in the Mediterranean was thought to have begun in the Bronze Age (after the Neolithic Period). However, newly discovered fatty acid residue on pottery from Neolithic sites in Croatia indicates that milk was fermented into cheese much earlier than had been assumed, in the Middle Neolithic period (5200 BCE). The researchers suggest that “dairying and fermentation had additional human life-history dependent advantages by reducing infant mortality,” which “helped stimulate demographic shifts that propelled farming communities to expand and provided the demographic and dietary risk buffering to allow Neolithic farming to spread to colder, temperate climates.”
PLoS One. 2018 Sep 5;13(9):e0202807. doi: 10.1371/journal.pone.0202807. (McClure SB et al.)

Whole Grains Linked with Lower Risk of Type 2 Diabetes

Not all carbohydrates are created equal, and when it comes to diabetes prevention, whole grains may be particularly beneficial. To see how diabetes risk relates to whole grain intake, researchers analyzed the grain foods eaten by 55,465 older adults and monitored them for diabetes. Over the 15-year study period, each 16-gram serving of whole grains was linked with an 11% and 7% lower risk of type 2 diabetes in men and women, respectively. The researchers also looked at the benefit of different whole grain foods, noting that rye bread, whole-grain bread, and oatmeal/muesli were all significantly linked with a lower risk of type 2 diabetes in both men and women.
Journal of Nutrition . 2018 Sep 1;148(9):1434-1444. doi: 10.1093/jn/nxy112. (Kyrø C et al.)

Shifting to Healthy Vegetarian Diets Could Lower Earth's Water Footprint by 35-55%

Scientists are beginning to discover that eating choices that are best for people also happen to be best for the planet. Researchers from the European Commission’s Directorate for Sustainable Resources analyzed national food surveys, water footprint databases, and other datasets across the UK, France, and Germany to determine how the water footprint changes when people shift their diet. They found that shifting from the current eating pattern to a healthy eating pattern (that contains meat) cut reduce the water footprint by 11-35%, and that even larger reductions could be made by shifting to a healthy pescatarian (vegetarian with fish) diet (33-35% reduction) or a healthy vegetarian diet (35-55% reduction).
Nature Sustainability. 2018 Sept 1. doi: 10.1038/s41893-018-0133-x. (Vanham D et al.)

Healthy Diets (Like Mediterranean, Vegetarian) May Improve Gut Microbiome

Scientists are increasingly interested in researching the gut microbiome, the community of bacteria of our digestive tract, as studies suggest that the types of microbes we produce and carry around may impact our risk for chronic disease. In this review, researchers analyzed the existing research on diet and the gut microbiome, focusing on vegetarian diets and Mediterranean diets. Both epidemiological studies and randomized clinical trials demonstrate that healthy Mediterranean and vegetarian diets are linked with various beneficial changes to the gut microbiome (such as increased short chain fatty acid production, increases in Prevotella, and decreases in trimethylamine). They suggest that these healthy diets may lower risk of chronic disease by impacting our gut microbiome, but that more research is needed to identify the exact mechanism.
Journal of Nutrition. 2018 Sep 1;148(9):1402-1407. doi: 10.1093/jn/nxy141. (Tindall AM et al.)

Whole Grains Associated with Lower Risk of Diabetes

Whole grains are healthy carbohydrate foods that may be especially protective against type 2 diabetes. In this study, researchers analyzed the eating habits and health status of 55,465 middle-aged adults in Denmark. Those eating more whole grains were 11% and 7% less likely to develop type 2 diabetes (for men and women, respectively) over the 15-year study period. Rye bread, whole-grain bread, oatmeal, and muesli were all significantly associated with a lower risk of type 2 diabetes for both men and women, indicating a benefit for whole grains in general, rather than just one specific type of whole grain food.
The Journal of Nutrition. 2018 Sep 1;148(9):1434-1444. doi: 10.1093/jn/nxy112. (Kyrø C et al.)

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