Mediterranean diet first rose to prominence in the 1950’s and since that time has become one of the most-studied diets in the world. In this study, researchers summarize the Mediterranean diet’s scientific history and key takeaways, including its benefits for weight loss and the prevention of heart disease and type II diabetes. The Mediterranean diet has also been linked with the possible prevention of certain types of cancer and neurodegenerative diseases such as Alzheimer’s. The authors note that the erosion of tradition threatens the Mediterranean diet in its place of birth, and that more populations could benefit from adopting a more Mediterranean inspired diet.
International Journal of Environmental Research and Public Health. 2019 Mar 15;16(6). pii:E942. doi: 10.3390/ijerph16060942. (Lăcătușu C-M et al.)

Replacing saturated fats, like those in butter, cheese, and red meat, with unsaturated fats, like those in walnuts, olive oil, and avocados, can help reduce risk of heart disease. But are all saturated fats created equal? To better assess this relationship, scientists analyzed the diets of 2 large groups of European adults (from Denmark & the U.K.) totaling more than 75,000 participants, and then monitored their health outcomes more than a decade later. In one of the groups (the Denmark group), saturated fats from meat were linked with a higher risk of a heart attack, but other sources of saturated fat were not significantly linked with heart attack risk in either direction. Scientists also noted that lauric acid and myristic acid (saturated fats found in foods like coconut oil) were also linked with lower heart attack risk in the Denmark group, but not the U.K. group. More research is needed to better understand how different foods might relate to heart attack risk.
International Journal of Cardiology.  2019 Mar 15;279:18-26. doi: 10.1016/j.ijcard.2018.10.064. (Praagman J et al.)

Seventh-Day Adventism is a religion which promotes a vegetarian diet and overall healthy lifestyle as a spiritual practice. In this study, researchers followed a cohort of over 90,000 Seventh-Day Adventists for an average of about 12 years and analyzed their consumption of red and processed meats. They found that participants who ate the most red and processed meat tended to be less physically active, were more likely to smoke tobacco and drink alcohol, and had a lower intake of fruits, vegetables, legumes, and whole grains than the participants who ate no meat at all. Compared to vegetarians, participants who ate red and processed meat were more likely to die of any cause and of cardiovascular disease. Notably, the participants who ate the most red and processed meat in this study (about 1.5 ounces per day) still have a relatively low consumption when compared to the average American diet (sometimes closer to 5 ounces per day). This suggests that even a low consumption of red and processed meats may have negative health effects.
Nutrients.  2019 Mar 14;11(3). pii: E622. doi: 10.3390/nu11030622. (Alshahrani SM et al)

Cochrane reviews are some of the most rigorous reviews in scientific research. In this Cochrane review, researchers analyzed 30 existing randomized controlled trials (the “gold standard” of nutrition research) and 7 ongoing trials of the Mediterranean diet and its impact on heart disease risk. The study found small to moderate evidence for benefits of the Mediterranean diet for preventing heart disease, but note that more research is needed to better understand the benefits, particularly in patients who already have heart disease.
The Cochrane Database of Systematic Reviews. 2019 Mar 13;3:CD009825. doi: 10.1002/14651858.CD009825.pub3. (Rees K et al.)

Olive oil is a well-known heart healthy food, and new research sheds light on a potential explanation behind this benefit. In this study, researchers analyzed the eating habits of 63 obese but otherwise healthy adults, and also analyzed the platelet activity in their blood. (Platelets are the building blocks of blood clots when they stick together.) Those eating olive oil at least once per week had significantly lower platelet activation, indicating that their blood may be less likely to clot. (Note that findings presented at meetings are considered preliminary until published in a peer-reviewed journal.)
Presentation at American Heart Association’s Epidemiology and Prevention | Lifestyle and Cardiometabolic Health Scientific Sessions. Houston, TX. March 7, 2019 (Heffron SP et al.)

Eat a nutritious diet while you’re young, and your brain may thank you later. Scientists analyzed the diets of 2,621 young adults (average age: 25) and then assessed their brain health 25 & 30 years later (average ages: 50 & 55, respectively). Those most closely following a Mediterranean diet in young adulthood had a significantly lower decline in cognitive function than those not following a Mediterranean diet.
Neurology. 2019 Mar 6. pii: 10.1212/WNL.0000000000007243. doi: 10.1212/WNL.0000000000007243. [Epub ahead of print] (McEvoy CT et al.)

A traditional Mediterranean diet includes frequent, but low-to-moderate amounts of dairy products, mostly in the form of artisanal cheeses and yogurts. In this study, researchers analyzed the eating habits and bone density in 442 pre-menopausal women in Spain. Following a Mediterranean diet was linked with significantly better bone mass.
Nutrients. 2019 Mar 5;11(3). pii: E555. doi: 10.3390/nu11030555. (Pérez-Rey J et al.)

Hepatocellular carcinoma, a common type of liver cancer, has been on the rise in the US, and researchers wonder if eating habits might play a role. In a study of 125,455 adults followed for 24 years, those eating the most whole grains (33g per day, or about 2 servings) were 37% less likely to develop hepatocellular carcinoma than those eating the least whole grains (7g per day, or less than half a serving). When looking at the isolated relationship of fiber, bran, and germ, the results were not statistically significant, indicating that whole grains are greater than the sum of their parts.
JAMA Oncology. 2019 Feb 21. doi: 10.1001/jamaoncol.2018.7159. [Epub ahead of print] (Yang W et al.)

Proper nutrition is increasingly becoming an important aspect of athletic training, and it is easy to see why. In a small study, 11 young adults ran a 5K after 4 days of eating a Mediterranean diet, and after 4 days of eating a typical Western diet. The 5K time after the Mediterranean diet was about 2 minutes faster than the race time after eating a Western diet. However, there were no significant differences in vertical jump height or hand grip strength between the 2 diets.
Journal of the American College of Nutrition. 2019 Feb 13:1-9. doi: 10.1080/07315724.2019.1568322. [Epub ahead of print] (Baker ME et al.)

While there have been several studies investigating the link between specific foods or food groups and the risk of bladder cancer, studies investigating overall diet patterns are limited. In this analysis, researchers pooled data from 13 studies investigating the link between diet and bladder cancer. They analyzed the diet of over 600,000 participants to evaluate how closely the participants follow the Mediterranean diet. The researchers found that participants who most closely followed the Mediterranean diet had a significantly lower risk of bladder cancer than those who did not follow the diet. The researchers believe that the high intake of plant-based foods and olive oil in the Mediterranean diet may have a protective effect against bladder cancer due to the antioxidants and vitamins present in these foods.
European Journal of Nutrition. 2019 Feb 8. doi: 10.1007/s00394-019-01907-8. (Witlox WJA, et al)

Diet is intimately linked both to human and environmental health. In this article, a commission of distinguished scientists from different fields set out to examine the components of a healthy diet and the link between diet and environmental health. Through an extensive review of literature, the researchers found that an ideal diet that meets basic nutritional needs and can be sustainably produced is mostly plant-based. Specifically, this diet is based around about 11 ounces vegetables, 9 ounces of dairy foods (a little over a cup of milk) 8 ounces of whole grains (about 8 servings, such as a slice of bread or a ½ cup cooked grains), 7 ounces of fruit, 3 ounces of legumes, 2 ounces of nuts, and an optional 2 ounces of other animal foods (like eggs, poultry, or meat) per day. The authors suggest that a global shift towards these dietary principles can prevent approximately 11 million deaths per year, and can sustainably produce enough food for the growing population without further damage to the environment.
Lancet.  2019 Feb 2;393(10170):447-492. doi: 10.1016/S0140-6736(18)31788-4. (Willett W et al)

Whole grains are one of the most popular food sources of fiber, and both whole grains and fiber are important for overall health. In this study, researchers analyzed data from more than 200 studies encompassing 4,635 participants to better understand fiber and whole grains’ relationship with disease prevention. Fiber was linked with a 15-30% lower risk of heart disease, stroke, type 2 diabetes, colorectal cancer, and death, with similar findings for whole grains. The researchers noted a dose-response relationship for both whole grains and fiber, indicating that those who eat the most may confer an even greater benefit.
The Lancet. 2019 Feb 02;393(10170):434-445. doi: 10.1016/S0140-6736(18)31809-9 (Reynolds A et al.)