Since there is no known cure for cognitive decline, prevention and deceleration of this condition are an important area of research. Most people’s diets change from time to time, so researchers wanted to study how these changes affect cognition. In a study of over 2000 Swedish older adults at least 60 years old, eating a “Western diet” (lots of refined or processed foods, red meats, high fat dairy products, saturated/trans fats, and sugar) was associated with more cognitive decline, whereas eating a more “prudent” diet (a healthy diet with lots of fruits, vegetables, whole grains, rice/pasta, legumes, nuts, fish, and low-fat dairy products) was associated with a deceleration of cognitive decline. However, the most fascinating finding is that every little bit helps. More frequent intake of foods from the “prudent” diet might weaken the negative cognitive effects associated with the Western diet, even if you’re unable to change all your habits.
Alzheimers and Dementia. 2016 Feb;12(2):100-9. (Shakersain B, et al.)

Seafood is a staple in many traditional diets, but many wonder if the health benefits of fish consumption outweigh the risk of mercury exposure. In a study of 334 infants in Ohio, researchers assessed the neurobehavior of infants and the fish intake and blood mercury levels in mothers and cord blood. The researchers “found minimal evidence of mercury associated detrimental effects” on the infants, with no statistically significant problems related to level of mercury consumption when other lifestyle and dietary factors were controlled for. In fact, the researchers also observed that the infants with higher (but still safe) blood mercury levels had better attention and less need for special handling, suggesting that the benefits of fish consumption may outweigh the risks of low-level mercury exposure.
Neurotoxicology and Teratology. 2016 Feb 12. Pii: S0892-0362(13)30007-1. (Xu Y et al.)

To see how fish consumption and mercury exposure relate to Alzheimer’s, scientists analyzed the food intake of over 500 retired adults in Chicago each year for several years. They then autopsied the brains of 286 of the deceased participants to study signs of Alzheimer’s disease and measure levels of mercury in the brain. The scientists found that eating at least one seafood meal per week was linked with less Alzheimer’s disease pathology (including lower density of neuritic plaques, less severe and widespread neurofibrillary tangles, and lower neuropathologically defined Alzheimer’s disease) in participants with genetic predisposition to Alzheimers disease (APoE4 allele carriers). They also found that higher brain concentrations of mercury were not linked with increased signs of Alzheimer’s disease, and that fish oil supplementation had no effect on these markers.
JAMA. 2016 Feb 2;315(5):489-97. (Morris MC et al.)

Dietary fiber is an important nutrient found in plant foods (mostly in whole grains, fruits, vegetables, and pulses). To study the link between fiber intake and breast cancer risk, Harvard scientists analyzed the adolescent and early adulthood diets of over 90,000 women, and noted any diagnosis of breast cancer. The researchers found that every 10g of fiber in adolescence and young adulthood was linked with a 14% and 13% lower risk of breast cancer, respectively. In fact, those eating the most fiber in adolescence and young adulthood (25g per day) were 25% less likely to get breast cancer than those eating the least fiber (12g per day).
Pediatrics. 2016 Feb 1. pii: peds.2015-1226. (Farvid MS et al). 

A “grain brain” seems to be a healthy defense against inflammation and accelerated cognitive decline. In a British study, researchers analyzed the diets, inflammation markers, and cognitive health of over 5,000 middle aged adults over six years. The scientists found that those eating diets high in red and processed meat, peas, legumes (mostly baked beans) and fried food, and lower in whole grains, were more likely to have higher levels of inflammation and accelerated cognitive decline. In fact, whole grains had the strongest link to anti-inflammatory markers among all 37 food groups studied.
Clinical Nutrition. 2016 Jan 29. Pii: S0261-5614(16)00035-2. (Ozawa M et al.)

We know that healthy whole grains are growing in popularity, but new data quantify this trend. Minnesota researchers analyzed the whole grain intake and BMI, waist circumference, and obesity of nearly 45,000 children and adults from 2001 to 2012. The scientists found that while less than 1% of kids and 8% of adults met whole grain recommendations (about 3 oz equivalents per day), whole grain consumption has improved in both groups (adults from 0.72 oz equivalents in 2001 to 0.97 in 2012, kids from 0.56 oz equivalents in 2001 to 0.74 in 2012). The biggest source of whole grains for both kids and adults alike were yeast breads and ready to eat cereals. Those eating the most whole grains had a lower BMI and waist circumference, and were less likely to be overweight or obese. The researchers conclude that “greater whole grain consumption is associated with better intakes of nutrients and healthier body weight in children and adults,” and that “Continued efforts to promote increased intake of whole grain foods are warranted.”
Nutrition Journal. 2016 Jan 22;15(1):8. (Albertson AM et al.)

In a large study, researchers from the Global Burden of Diseases Nutrition and Chronic Diseases Expert Group analyzed the fat consumption and coronary heart disease statistics of 186 nations across the world. They found that 10.3% of coronary heart disease deaths were attributable to not eating enough n-6 polyunsaturated fats (found in soy, walnuts, sunflower seeds, and some plant oils), while 7.7% were due to eating too much trans fat (found in margarine and highly processed foods), and 3.6% were due to eating too much saturated fat (found in red meat and butter). In 80% of nations studied, deaths from heart disease due to inadequate n-6 polyunsaturated fats was at least double the heart disease deaths due to too much saturated fat. This suggests that positive messages focused on adding in healthy foods (such as cooking vegetables in plant oils, and sprinkling nuts and seeds on meals) can have an important impact on public health.
Journal of the American Heart Association. 2016 Jan 20;5(1). Pii: e002891. (Wang Q et al.) 

To determine if vegetarian diets might be useful for weight loss, Harvard researchers analyzed results from 12 different clinical trials encompassing 1,151 people. Those assigned to vegetarian diets lost 4.5 pounds more compared to those assigned to a non-vegetarian control diet, regardless of whether or not calories were restricted. Participants assigned to vegan diets (excluding all animal products) lost more weight (5.6 pounds) than those assigned to lacto-ovo vegetarian diets (3.2 pounds). The diets ranged from 9 weeks to 74 weeks, with a median duration of 18 weeks. The scientists conclude that “Vegetarian diets appeared to have significant benefits on weight reduction compared to non-vegetarian diets.”
Journal of General Internal Medicine. 2016 Jan;31(1):109-16. (Huang RY et al.)

Primary open-angle glaucoma is an eye disease that can lead to irreversible vision loss. Because there is currently no cure for this disease, scientists are very interested in preventive measures, including diet. In a study analyzing over 100,000 health professionals, Harvard researchers found that those eating 1.45 servings of green leafy vegetables per day had an 18% lower risk of developing primary open-angle glaucoma than those only eating 0.31 servings of leafy greens per day. Dietary nitrate (a nutrient found in green leafy vegetables), was also significantly related to a lower risk of primary open-angle glaucoma.
JAMA Opthalmology. 2016 Jan 14:1-11. (Kang JH et al.) [Epub ahead of print]

Spanish researchers randomly assigned 239 adults (half with metabolic syndrome, half without) to either a Mediterranean diet, or a low fat, high complex carbohydrate diet (with foods like pasta and cereals) for two years. They found that the Mediterranean diet was able to “restore potentially beneficial members of the gut microbiota,” in patients both with and without metabolic syndrome. The low fat, high complex carbohydrate diet did not result in as many positive changes in gut microbiota as the Mediterranean diet did, although some beneficial changes still occurred.
The Journal of Nutritional Biochemistry. 2016 Jan;27:27-31. (Haro C et al.)

Over a quarter of cancer cases in men are prostate cancer, so dietary strategies to prevent prostate cancer could benefit many. To study this relationship, scientists analyzed the diet and prostate cancer diagnoses in a group of over 26,000 men for nearly 8 years. They found that vegan diets (diets that exclude all animal products, including dairy and eggs) were linked with a 35% lower risk of prostate cancer than non-vegetarian diets that included meat, poultry, fish, dairy, and eggs. Other vegetarian diets (that include dairy and eggs) did not show a statistically significant protective effect.
American Journal of Clinical Nutrition. 2016 Jan;103(1):153-60. (Tantamango-Bartley Y et al.)

Maintaining a healthy weight and optimal nutrition can be a struggle for patients with celiac disease, but nutritious diets can help. In a small Italian study, researchers assigned 39 celiac patients to a Mediterranean gluten-free diet. The scientists found that celiac patients following a gluten free diet based on the Mediterranean diet improved their nutritional status, without inducing overweight or obesity. In fact, two of the four malnourished celiac patients were able to reach a healthy BMI, without becoming overweight or obese.
European Journal of Clinical Nutrition. 2016 Jan;70(1):23-7. (Barone M et al.)