(NewsNation) — Older women who eat a traditional Japanese diet may experience less brain shrinkage compared to those who follow a Western-style diet, according to new research.

The observational study, published in the journal Nutrition, analyzed data from over 1,600 Japanese adults ages 40-89 over a 2-year period.

Japan is well-known for its longevity, with the Okinawa Prefecture in southern Japan having an unusually high number of centenarians. Due to this, Okinawa is considered a Blue Zone, which is an area where people live exceptionally long lives, according to the researchers.

The traditional diet of those living in this region is often credited as one of the reasons for their longevity.

What is the Japanese Diet?

The traditional Japanese diet is characterized by a focus on rice, soybean products, vegetables, seaweed and small amounts of fish and meat. It is typically low in fat and high in complex carbohydrates, fiber, vitamins and minerals, according to the researchers.

Benefits of the Japanese Diet

The results showed that among women, those who most closely followed the traditional Japanese diet had significantly less total gray matter atrophy compared to those on a Western diet.

The findings suggest the nutritional components of the Japanese diet, such as omega-3 fatty acids from fish, antioxidants from vegetables and soy and low saturated fat intake, may have protective effects on the aging brain.

Limitations and Future Research

The study was observational, so it cannot prove the diet directly causes less brain shrinkage. Larger, long-term trials are needed to further explore the relationship, the researchers said.

No similar association was found for men in the study.

The findings add to growing evidence that diet plays an important role in brain health and cognitive decline prevention, with potential sex-specific differences warranting additional research.