Eating a variety of healthy plant foods is one of the best ways to nurture our friendly gut bacteria, and new research suggests that Mediterranean and vegetarian diets may be useful models. Scientists analyzed the eating patterns and gut bacteria of 153 Italian adults. They found that those most closely following a Mediterranean diet or vegetarian/vegan diet had higher levels of short chain fecal acids, a compound associated with many health benefits. On the other hand, those not following a Mediterranean diet had higher levels of urinary trimethylamine oxide, a potential risk factor for heart disease. The researchers also noted that both vegetarian/vegans and those on a Mediterranean diet scored highly on the Healthy Food Diversity Index, meaning that these eating styles could be a useful blueprint for people wanting to incorporate a variety of nutritious foods into their diet.
Gut. 2015 Sept 28. [Epub ahead of print] (De Filippis F et al.)

Science and common sense tell us that eating a wide variety of fruits and vegetables is one of the best defenses against obesity and weight gain. To quantify this relationship, Harvard researchers analyzed the eating patterns and weight changes in over 130,000 adults for over 20 years. Eating vegetables of all kinds was linked to a 0.25 pound weight loss per daily serving over four years, while eating fruit of any kind was linked to a 0.53 pound weight loss per daily serving over four years. Upon closer inspection, they found that this relationship was strongest for berries, apples, pears, tofu, soy, cauliflower, and cruciferous and green leafy vegetables. On the other hand, starchy vegetables like peas, corn, and potatoes were associated with weight gain. The researchers concluded that these “findings support benefits of increased fruit and vegetable consumption for preventing long-term weight gain.”
PLOS Medicine. 2015 Sept 22. [Epub] (Bertoia ML et al.)

Age related macular degeneration (AMD) is the leading cause of vision loss in older adults, mostly occurring in those over 60 years old. To see if eating patterns play a role in this disease, researchers analyzed the diet of nearly 900 Portuguese adults (ages 55+), half with AMD, and half without. Those without AMD ate foods more closely aligned with the Mediterranean diet (grains, green leafy vegetables, fruit, and olive oil) than those who did have AMD. The group without AMD also exercised more, and ate less fast food, meat, dairy, and ready-made meals. This study suggests that a Mediterranean style diet, along with exercise, may be protective against AMD.
Presentation at the European Society of Retina Specialists 15th EURETINA Congress. Nice, France. September 17, 2015. (Farina C et al.)

With incidence of breast cancer increasing in recent years, lifestyle and prevention measures are more important than ever. Using data from the PREDIMED study (where adults at risk for heart disease were assigned to either a low fat diet, a Mediterranean diet with olive oil, or a Mediterranean diet with nuts), scientists analyzed the eating patterns and health outcomes of over 4,200 women (ages 60-80). During the 5-year follow up period, 35 women developed breast cancer.  Those in the Mediterranean diet groups were 51% less likely to get breast cancer than those on a low-fat diet. The Mediterranean diet with olive oil group was 62% less likely to get breast cancer, while the Mediterranean diet group with nuts had a non-significant lower risk of breast cancer.
JAMA Internal Medicine. 2015 Sep 14:1-9. [Epub ahead of print.] (Toledo E et al.)

Whole grains are important to our brain health today, but new evidence suggests that they were also vital to our brain development millions of years ago. Researchers in Europe and Australia examined diet’s role in the development of early humans, and found that carbohydrates (such as whole grains, root vegetables, and other starchy plant foods) were “necessary to accommodate the increased metabolic demands of a growing brain.” While most depictions of early human foods emphasize hunter-gatherer diets full of meat, the scientists argue that cooked starches permitted “the acceleration in brain size increase from the Middle Pleistocene onward.”
The Quarterly Review of Biology. 2015 Sept;90(3):251-268. (Hardy K et al.)

Even modest reductions in cholesterol are thought to help prevent heart disease, so heart healthy diets are an important area of research. To determine the link between whole grains and cholesterol, scientists analyzed the results of 24 randomized controlled trials (totaling 2,275 participants). They found that eating whole grains is associated with lower LDL (“bad”) cholesterol and total cholesterol, with no significant effect on HDL (“good”) cholesterol or triglycerides (a type of fat in the blood). Whole grain oats specifically seemed to be linked with the greatest cholesterol lowering effects compared to other whole grain foods. The length of the study was also associated with positive changes in cholesterol, indicating health benefits are greater for those who make whole grains a regular part of their daily lifestyle.
The American Journal of Clinical Nutrition. 2015 Sept;102(3):556-72. (Hollaender PLB et al.)

It is estimated that up to 80% of strokes can be prevented, so food choices to protect against strokes are an important area of research. Scientists in China analyzed six large prospective studies following over 247,000 people to see how whole grain intake related to stroke risk. Those eating the most whole grains had a 14% lower risk of stroke than those eating the least whole grains. The authors concluded that “higher whole grain intake has a protective effect on stroke.”
International Journal of Clinical and Experimental Medicine. 2015 Sep 15;8(9):16978-83 (Fang L et al.)

Complications from diabetes can lead to serious health problems, including vision impairment, blindness, and kidney damage. Using data from the PREDIMED study (where adults at risk for heart disease were assigned to either a low fat diet, a Mediterranean diet with olive oil, or a Mediterranean diet with nuts), researchers analyzed data from over 3,600 Spanish adults with type 2 diabetes, to see how diet affects the risk of diabetic nephropathy (kidney damage from diabetes) or diabetic retinopathy (eye damage from diabetes). Those following a Mediterranean diet with olive oil had a 43% lower risk of diabetic retinopathy compared to the low fat control group, and those following a Mediterranean diet with nuts had a non-significant 38% lower risk of diabetic retinopathy. There were no significant changes in the risk for diabetic nephropathy.
Diabetes Care. 2015 Sept 13. [Epub ahead of print] (Diaz-Lopez A et al.)

Fish is well known for its place in many of the healthiest diets around the world. To determine the link between eating fish and depression risk, Chinese scientists reviewed 26 studies of over 150,000 people. The researchers concluded that “high fish consumption can reduce the risk of depression.”  
Journal of Epidemiology and Community Health. 2015 Sep 10. pii: jech-2015-206278. [Epub ahead of print.] (Li Fu et al.)

Congenital heart defects (heart problems that occur before birth) affect nearly 1% of newborns in America. In a study of over 19,000 American women, researchers compared mothers of babies with congenital heart defects to mothers of babies without this condition. Scientists analyzed the mothers’ diets in the year before pregnancy using both the Mediterranean Diet Score and the Diet Quality Index for Pregnancy. Babies whose moms’ diets ranked healthy on both scores were significantly less likely to suffer from certain specific subgroups of congenital heart defects, such as tetralogy of Fallot (a defect in heart structure which causes oxygen poor blood to flow throughout the body), but not all heart defects. The relationship between diet and congenital heart defects was stronger with the Diet Quality Index for Pregnancy than with the Mediterranean Diet.
Archives of Disease in Childhood. Fetal and Neonatal Edition. 2015 August 24. pii: fetalneonatal-2014-308013. [Epub ahead of print.] (Botto LD et al.) 

Whole grains are well known for their fiber; however, fiber is not the only benefit of a diet rich in whole grains. This study uses nutritional metabolomics (a field of that looks at how different foods affect metabolism) to explore how the different compounds in whole grains may affect metabolism, and suggests scientific reasons behind the health benefits of whole grains, beyond just their fiber content. Specifically, this analysis suggests that whole grains may have positive effects on insulin sensitivity and protein metabolism, and may contain other beneficial compounds, such as glycine betaine.
Proceedings of the Nutrition Society. 2015 Aug;74(3):320-7. doi: 10.1017/S0029665114001542. Epub 2014 Oct 23. (Ross AB et al.)