The Best Diet For Brain Health Is Probably Not What You Think

Dietary fads come and go, but one particular healthy food plan may be here to stay.

Researchers at Harvard University have now led a study to compare six dietary patterns and their long-term associations with brain health.

While every single one of these diets was associated with health benefits, there was one clear, standout winner.

Spoiler: It was not a Mediterranean-like diet.

Instead, the winner was a lesser-known food plan called DASH, which is short for Dietary Approaches to Stop Hypertension.

As the name indicates, this dietary plan was originally designed to help lower blood pressure. Today, it is endorsed by the American Heart Association for those with hypertension or a family history of heart disease.

But it may achieve much more than that.

In recent observational studies, the DASH diet has emerged as a potential way of improving cardiovascular health.

Now, it also shows promise in protecting the aging brain.

Compared to the Mediterranean diet, which places an emphasis on healthy fats, fruits, vegetables, and whole grains, while still allowing for low amounts of sugar and alcohol, the DASH diet is not quite as flexible.

It was first developed in the 1990s, and while it also emphasizes fruits, vegetables, nuts, and berries, it requires low-salt intake and low-fat dairy options. Added sugars, red meat, and alcohol are to be limited.

In a long-term study of 159,347 participants, led by Harvard researchers, the DASH diet was consistently associated with the best brain health scores.

Every four years or so for three decades, participants reported their food intake. They were then scored on how well their diets aligned with six broad dietary plans.

While every diet examined showed beneficial brain associations, those who strictly adhered to the DASH diet reaped nearly twice as many benefits as those who strictly adhered to other diets.

Participants who adhered most closely to the DASH diet had a 41 percent lower chance of subjective cognitive decline compared to those who were the least faithful to the DASH diet.

The food plans that came in second and third – the healthful plant-based index and the hyperinsulinemia index –  were each associated with a 24 percent lower risk of subjective cognitive decline.

Meanwhile, the Planetary Health Index, which is similar to the Mediterranean diet, but with stricter rules on red meat, was associated with a 20 percent lower risk of subjective cognitive decline.

What’s more, those who stuck most faithfully to a Mediterranean-like diet plan, called AHEI-2010, had a 16 percent lower risk of subjective cognitive decline.

The DASH diet outperformed all these other options.

Compared with the bottom 10 percent of DASH dieters, the top 10 percent scored 0.76 years younger on objective cognitive aging tests.

These participants were also 1.37 years younger, on average, on working memory tests.

“The DASH diet was consistently associated with subjective cognitive decline (SCD) risk even when measured up to 26 years before… assessments,” the international team of authors write, “and had robust protective associations at various ages, particularly in midlife (45–54 years).”

In other words, the more a person sticks to a healthy diet from mid-adulthood, the better the health of their brain as they age.

That’s just an association, but it keeps popping up in study after study.

Recently, scientists in the US found that a mix of the Mediterranean and DASH diet, known as the MIND diet, shows neurological perks later in life.

Those who stick mostly closely to the MIND diet show healthier brain tissue when they die in a part of the central nervous system closely involved in memory.

Related: New Blood Pressure Guidelines Mean You Could Now Have Hypertension

These findings add weight to the idea that food choices may lower our risk of neurological disease, potentially protecting against Alzheimer’s or other forms of dementia.

That idea is still speculative and will require larger population studies and randomized controlled trials to confirm.

But diet and dementia seem to be closely linked in observational studies. Processed red meat, for instance, is identified as a potential risk factor for dementia.

The DASH diet may not be the best food plan for everybody, but broad, population-based studies like these can help researchers hone in on which foods may be most important for our overall health.

Lead author of the current study, Harvard epidemiologist Kjetil Bjornevik, told Everyday Health that if someone wants to improve the healthiness of their diet, they should make slow and gradual changes, as those are more likely to stick.

“What was encouraging was the consistency across different dietary patterns, which suggests that there is not just one right approach and that different dietary strategies can have beneficial effects on cognitive health,” Bjornevik said.

“More broadly, any dietary pattern that emphasizes vegetables, fish, and whole grains while limiting red and processed meats, fried foods, and sugary beverages aligns with what our findings suggest may be beneficial.”

What’s good for the heart may be good for the brain as well.

The study is published in JAMA Neurology.