Some of the same diets that are good for cardiovascular health also are good for the brain. But there’s a new diet—combining the best aspects of other diets—that is so effective it reduces the risk for Alzheimer’s disease even in those who don’t give the diet their best effort.

The MIND diet blends components from DASH (a blood pressure-lowering diet) and the popular Mediterranean diet, with an extra emphasis on berries, leafy greens and a few other brain-healthy foods.

How good is it? People who carefully followed the diet were about 53% less likely to develop Alzheimer’s disease in subsequent years. Those who approached it more casually didn’t do quite as well but still reduced their risk considerably, by about 35%.

BLENDED BENEFITS

The MIND diet was developed by researchers at Rush University who examined years of studies to identify specific foods and nutrients that seemed to be particularly good—or bad—for long-term brain health. The MIND (it stands for Mediterranean-DASH Intervention for Neurodegenerative Delay) diet is a hybrid plan that incorporates the “best of the best.”

In a study in the journal Alzheimer’s & Dementia, the researchers followed more than 900 participants. None had dementia when the study started. The participants filled out food questionnaires and had repeated neurological tests over a period averaging more than four years.

Some participants followed the MIND diet. Others followed the older DASH diet or the Mediterranean diet. All three diets reduced the risk for ­Alzheimer’s disease. But only the MIND diet did so even when the participants followed the plan only “moderately well.”

This is an important distinction because few people are perfect about sticking to diets. Most cheat now and then and eat more unhealthy foods than they should.

The MIND diet specifies “brain-healthy” food groups and five groups that need to be limited, either eaten in moderation or preferably not at all.

WHAT TO EAT

  • More leafy greens. Kale really is a superfood for the brain. So are spinach, chard, beet greens and other dark, leafy greens. The Mediterranean and DASH diets advise people to eat more vegetables, but they don’t specify which ones.
    The MIND diet specifically recommends one serving of greens a day, in addition to one other vegetable. Previous research has shown that a ­vegetable-rich diet can help prevent cognitive decline, but two of the larger studies found that leafy greens were singularly protective.
  • Lots of nuts. The diet calls for eating nuts five times a week. Nuts are high in vitamin E and monounsaturated and polyunsaturated fats—all good for brain health.The study didn’t look at which nuts were more likely to be beneficial. Eating a variety is probably a good idea because you’ll get a varied mix of protective nutrients and antioxidants. Raw or roasted nuts are fine (as long as they’re not roasted in fat and highly salted). If you are allergic to nuts, seeds such as sunflower and pumpkin seeds are good sources of these nutrients as well.
  • Berries. These are the only fruits that are specifically included in the MIND diet. Other fruits are undoubtedly good for you, but none has been shown in studies to promote cognitive health. Berries, on the other hand, have been shown to slow age-related cognitive decline. In laboratory studies, a berry-rich diet improves memory and protects against abnormal changes in the brain. Blueberries seem to be particularly potent. Eat berries at least twice a week.
  • Beans and whole grains. These fiber-rich and folate-rich foods provide high levels of protein with much less saturated fat than you would get from an equivalent helping of meat. The MIND diet calls for three daily ­servings of whole grains and three weekly servings of beans.
  • Include fish and poultry—but you don’t need to go overboard. Seafood is a key component of the Mediterranean diet, and some proponents recommend eating it four times a week or more. The MIND diet calls for only one weekly serving, although more is OK. A once-a-week fish meal is enough for brain health. There is no data to specify the number of poultry servings needed for brain health, but we recommend two ­servings a week.
  • A glass of wine. People who drink no wine—or those who drink too much—are more likely to suffer cognitive ­declines than those who drink just a little. Recommended: One glass a day. Red wine, in particular, is high in flavonoids and polyphenols that may be protective for the brain.

FOODS TO LIMIT

  • Limit red meat, cheese, butter and margarine—along with fast food, fried food and pastries and other sweets. The usual suspects, in other words.

All of these food groups increase the risk for Alzheimer’s disease, probably because of their high levels of saturated fat (or, in the case of some margarines, trans fats). Saturated fat has been linked to higher cholesterol, more systemic inflammation and possibly a disruption of the blood-brain barrier that may allow harmful substances into the brain.

However, most nutritionists acknowledge the importance of letting people enjoy some treats and not being so ­restrictive that they give up eating healthfully altogether.

Try to follow these recommendations…

Red meat: No more than three servings a week.

Butter and margarine: Less than one tablespoon daily. Cook with olive oil instead.

Cheese: Less than one serving a week.

Pastries and sweets: Yes, you can enjoy some treats, but limit yourself to five servings or fewer a week.

Fried or fast food: Less than one serving a week.