What you put into your mouth, affects your brain health. A new study in this week’s JAMA Internal Medicine suggests that eating a Mediterranean-style diet (more veggies, olive oil, nuts, fish and less red meat) is good for your mind and your heart. This finding in JAMA is from a long-term clinical trial of various diets, and is the first ever to show brain-boosting benefits of one eating pattern compared to others.

The study participants were part of a large Spanish trial known as PREDIMED (Prevención con Dieta Mediterránea) which stands for “prevention with Mediterranean diet”). The Mediterranean diet is plant-based. It focuses on vegetables, fruits, whole grains, beans and other legumes, nuts, seeds, olive oil with moderate amounts of seafood, poultry, eggs, and dairy, but very little red meat and sugary sweet foods.

The 447 participants were in mid life mostly in their 60s and 70s, most were overweight, many had high blood pressure or high cholesterol so many were at high risk of heart disease. They were divided into three groups: one followed a Mediterranean-type diet and also ate an extra ounce of mixed nuts (walnuts, hazelnuts, and almonds) a day; another followed a Mediterranean-type diet and also ate an extra five tablespoons of extra-virgin olive oil a day; the third group served as the control following a low-fat diet.

All participants took six different cognitive function tests — assessing, memory, focus and thinking skills — at the start of the trial. Three-quarters of those involved in the study completed the same tests four years later.

Average scores on the memory tests improved in those eating the Mediterranean-type diet with extra servings of nuts, and scores on the tests of thinking skills improved in those eating the Mediterranean diet with extra servings of olive oil. In contrast, the control group scores worsened.

This isn’t a hard and fast link between this diet and brain health as this study wasn’t designed to look exactly this link. But it’s still hopeful and points a way.

  • Low fat not = so good (actually many trials, i.e. The Stanford diet comparison study) are saying that.
  • Good fats = good. For hearts and brains, and even for maintain a better Scarlett O’Hara waistline.
  • Plant based foods = contain healthy polyphenolic compounds that are powerful anti-compounds: anti-oxidants, anti-inflammatory agent. They tamp down harmful inflammation and damage to blood vessels and the brain.


These new findings are consistent with earlier studies showing that people who closely follow a Mediterranean diet are more likely to maintain their memory and thinking skills over time and better brain volume. Size matters. As we age our brains shrink. But diet, like this one, can slow down that “shrinkage.”

Always a note of caution. Any fat in excess is calories in excess. Just because fats, avocadoes and oil are healthy, doesn’t mean you can consume them with wild fat abandon. Too much fat = too many calories and then extra weight isn’t good either as that creates pro-inflammatory compounds. Moderation is always a moderate consideration.

And there you have.