Pre-diabetes can increase the risk of diabetes and heart disease, so understanding lifestyle factors is important. To see how diet relates to pre-diabetes, scientists analyzed the eating habits of 150 pre-diabetic adults in Iran, and 150 healthy, matched controls. Two distinct eating patterns emerged: the “vegetable, fruit, legume” pattern, with lots of plant foods including produce, whole grains, nuts, low fat dairy, and fish, and the “sweet, solid fat, meat, and mayonnaise” pattern, with lots desserts, red meat, fried potatoes, and solid fats. Those whose diets more aligned with the “vegetable, fruit, legume” pattern were significantly less likely to be pre-diabetic than those whose diets more closely resembled the “sweet, solid fat, meat, and mayonnaise” pattern.
British Journal of Nutrition. 2016 Sep;116(5):874-81. (Bagheri F et al.)

To see how various fat sources relate to heart disease, Harvard researchers analyzed the fat intake and health outcomes of more than 222,000 people across 3 large cohorts. They found that while dairy fat intake in itself was not significantly related to heart disease risk, replacing 5% of calories from dairy fat with whole grains, polyunsaturated fat (found in fish, nuts, and seeds) or vegetable fat was linked with a 28%, 24% and 10% lower risk of heart disease, respectively. Additionally, replacing 5% of calories from other animal fats (such as red meat) with dairy fat was linked with a 6% lower risk of heart disease, indicating that while dairy fat might not be as harmful as red meat, replacing animal fats with plant foods could offer more protection. This supports the evidence that we consume and what we don’t consume both contribute to health outcomes. 
American Journal of Clinical Nutrition. 2016 Aug 24. pii: ajcn134460. [Epub ahead of print] (Chen M et al.)

In a study of 307 Italian women with early breast cancer, who had undergone treatment and were in complete remission, researchers assigned 199 of the women to their normal diet, but with healthy advice from a dietitian, while the other 108 women were assigned to a Mediterranean diet (with lots of fruits and vegetables, fish, olive oil, and up to one glass of wine per day). After 3 years, breast cancer returned to 11 patients from the standard diet group, but none in the Mediterranean diet group relapsed. This indicates a statistically significant reduced risk of breast cancer recurrence for those following a Mediterranean diet.  
Journal of Clinical Oncology. 2016 ASCO Annual Meeting. 2016 June 3-7;34(15):Suppl:e13039. (Biasini C et al).

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.)

Harvard researchers followed over 120,000 adults for 24-30 years, tracking their diet and health records. The scientists found that replacing 5% of daily calories from saturated fat with polyunsaturated fats (found in fish, nuts, seeds, and safflower oil), monounsaturated fats (found in olive oil and canola oil), or whole grains is linked with a 25%, 15%, and 9% lower risk of heart disease, respectively. Additionally, they found that replacing 5% of daily calories from refined grains and added sugars with whole grains or polyunsaturated fats can also significantly reduce heart disease risk, and that replacing saturated fat with refined grains or added sugars does not lower heart disease risk. The researchers concluded, “Our findings provide epidemiological evidence of the current dietary guidelines, which recommend both “replacing saturated fatty acids with monounsaturated and polyunsaturated fatty acids” and “replacing refined grains with whole grains.”” The Mediterranean diet, which spotlights whole grains, fish, olive oil, nuts, and seeds, is the perfect eating plan to put these lessons into practice.
Journal of the American College of Cardiology. 2015 Oct;66(14):1538-48. (Li Y et al.)