For many folks my age, the specter of cognitive decline and dementia is far more frightening than any physical disease.

But one factor related to cognitive decline, brain aging and dementia is quite physical…

It’s brain shrinkage — also known as brain atrophy.

People with brain atrophy experience a decrease in brain volume, brain cells and connections between brain cells. This leads to problems with thinking skills, memory and even performing daily activities.

But the right food may be the key to keeping plump brains…

Does a Japanese diet protect your brain?

In a two-year study, scientists at Japan’s National Center for Geriatrics and Gerontology monitored 589 adults ages 40 to 89 who followed a traditional Japanese diet, consisting largely of rice, fish and shellfish, and fruits (especially citrus fruits).

But it’s the traditional Japanese foods that make this diet unique: miso (fermented soybean paste), seaweed, pickles, green tea, soybeans, soybeans sprouts and mushrooms such as shiitake mushrooms.

People following this diet eat very little or no red meat or coffee.

Another 697 participants ate a typical Western diet consisting of a lot of refined carbs, high-fat foods, soft drinks and alcohol.

Information was collected on participants’ genetic disposition to dementia, their level of physical activity, and any pre-existing conditions, such as diabetes.

Finally, the researchers used MRI scans to analyze the progression of brain atrophy (shrinkage) in all participants over the course of the two-year study period.

Women’s brains shrank less

Women who followed the traditional Japanese diet had less brain shrinkage over the two-year study period compared with women who followed the Western diet.

Interestingly, this effect was only apparent in women. There was no difference in the amount of brain shrinkage seen in men who followed the traditional Japanese diet compared to those following other diets.

There are a few possible reasons for this. For one, it’s been found that, for some reason, certain nutrients, including magnesium and estrogens found in fish, shellfish, and mushrooms have a stronger protective effect on women’s brains.

Also, male participants were more likely to smoke, drink alcohol and eat refined carbs while on the trial.

Not just good for your brain

The researchers note that “it will now be important for further research to be conducted – not only to confirm our findings, but to explore some of the reasons for the differences seen between men and women when it comes to their preferred diet and brain health.”

As far as the health effects of Japanese diet, one previous study held a clue: it had to do with a soy metabolite believed to support the brain by improving arterial stiffness — which improves blood flow to white matter in the brain — and increasing mitochondria function.

While research is ongoing, there’s nothing stopping any of us from including more of the elements of a traditional Japanese diet into our eating habits.

The Okinawan diet is eaten by natives of Okinawa, a small island off Japan’s coast. It’s not all that different from the diet we’ve been discussing.

The Okinawan diet leans on fermented foods like miso. It also includes tofu, colorful vegetables like sweet potatoes, and fish (mostly on special occasions).

The proof, as they say, is in the pudding: the rate of heart disease on Okinawa is one fifth the rate in the United States.

And brain health? Dementia is less than half as likely as it is among Americans of similar ages.

Take a cue from the Okinawans and try baking a sweet potato in the oven, remove the skin and add just a bit of maple syrup or brown sugar and cinnamon. Heaven!

Sources:

This Japanese Diet Is Linked to Less Brain Shrinkage in Women, Experts Say — Science Alert

Associations of dietary patterns and longitudinal brain-volume change in Japanese community-dwelling adults: results from the national institute for longevity sciences-longitudinal study of aging — Nutrition Journal

Dietary magnesium intake is related to larger brain volumes and lower white matter lesions with notable sex differences — European Journal of Nutrition

Brain Atrophy — Cleveland Clinic