Can an experimental diet keep your brain healthy as you age? Nutrition Diva takes a closer look at the evidence to support the MIND diet.
“I’ve been reading a lot about the MIND diet lately. A 50% reduction in Alzheimer’s cases seems pretty significant. Even if it’s not a controlled study, I’m willing to eat a few more blueberries just to hedge my bets. But I’m not ready to give up cheese quite so easily! How strong is the evidence that cheese increases the risk of Alzheimer’s?”
What Is the MIND Diet?
The MIND diet is a set of dietary guidelines proposed by researchers from Rush University. The diet combines elements from both the Mediterranean and DASH diets—two dietary patterns that have a long track record for promoting health and longevity—with a particular emphasis on foods and nutrients that have been associated with cognitive health or decline.
The researchers hypothesized that following this diet could keep your brain healthy, preserve your cognitive abilities as you age, and perhaps even ward off dementia and Alzheimer’s disease. To test their theory, they reviewed dietary and medical records for almost a 1,000 people to see how closely their diets adhered to the MIND guidelines and how they fared in terms of brain health.
Their findings made quite a splash. Last year, in a study published in the Journal of the American Alzheimer’s Association, they reported that those whose diets conformed most closely to the MIND diet principles were only half as likely to develop Alzheimer’s as those whose diets conformed the least well. The risk for those whose diets conformed only moderately well still was reduced by a third.
As Cheryl says, that certainly got everyone’s attention
What’s on the MIND Diet?
The MIND diet promotes ten “brain healthy” foods and discourages five foods. Along with the berries that Cheryl mentioned, you’re encouraged to eat plenty of vegetables, especially the green leafy kinds, nuts, legumes, whole grains, fish, poultry, olive oil, and wine. The foods that you’re supposed to limit are red meat, butter, and margarine, pastries and sweets, fried and fast food, and cheese. (Hey, who are they trying to kid here? That’s actually eight categories of foods!)
How Strong Is the Evidence?
The MIND diet study has a few limitations. First, as Cheryl points out, this was not a controlled study, where one group was put on a specific diet and another group served as a control. This was an observational study. That means that the subjects weren’t given any particular dietary instructions. They just agreed to let researchers gather information on what they ate and to take various neurological tests over time.
The researchers found an association or correlation between the MIND dietary pattern and improved cognitive health. But we don’t know how much of that benefit was due to the diet as opposed to some other factor(s) that the lucky subjects had in common. For example, those who had the best diet scores also exercised significantly more than those who had the lowest diet scores. Although the researchers adjusted for that particular variable, it could be people who eat well and exercise more have other healthy habits or attributes that they didn’t control for.
It’s also possible that, out of the 15 foods singled out in the MIND diet, some have a much bigger impact on brain health than others. This analysis doesn’t attempt to see how big a role each individual dietary factor plays in the overall effect.
My recent episode on the DASH diet offers a perfect illustration of why that could be significant.