New Research on Brain Health and Diet

Interesting news has emerged about how certain foods, like green tea, walnuts, and a tiny plant known as mankai, might help keep our brains youthful. A recent 18-month study involving nearly 300 adults points to a plant-heavy “green Mediterranean” diet being beneficial, as it correlates with lower levels of galectin-9—this specific blood protein is linked to signs of speeding up brain aging, as shown in MRI scans. The findings were released in the journal Clinical Nutrition.

Researchers from institutions like Harvard, Ben-Gurion University in Israel, and the University of Leipzig in Germany conducted comprehensive analyses comparing blood protein levels to MRI images to calculate participants’ “brain age.”

Those adhering to a leafy Mediterranean diet—rich in plants and light on red and processed meats—exhibited the most significant drops in galectin-9. This suggests their brains were effectively “younger” than their actual age. Iris Shai, a senior author of the study and an adjunct professor at Harvard’s T.H. Chan School of Public Health, mentioned that lowering galectin-9 could mitigate inflammation linked to cognitive decline, memory loss, and neurodegenerative disorders like Alzheimer’s.

“This indicates that nutrition could influence brain biology at a molecular level, offering a non-drug way to safeguard cognitive function as we grow older,” Shai explained.

She further noted their goal was to assess whether a fortified, plant-forward Mediterranean diet, abundant in natural polyphenols and low in red and processed meat, could indeed slow biological brain aging.

A leafy Mediterranean diet typically includes higher levels of polyphenols—compounds found in foods like nuts, olive oil, red wine, tea, fruits, and vegetables—which combat inflammation and protect cells.

In the study, one group maintained a traditional Mediterranean diet rich in vegetables and red meat instead of chicken or fish, while another group followed standard healthy eating practices.

Shai pointed out that components like the antioxidant EGCG found in green tea, along with healthy fats and polyphenols from walnuts, likely played a significant role in promoting beneficial changes. Mankai could also contribute support via the gut-brain connection through metabolic pathways.

Though mankai might be a bit tricky to source, focusing on green tea and walnuts alone could still yield competitive benefits for most people, without needing additional unique ingredients.

This small aquatic plant gained researchers’ interest due to its impressive nutritional profile, being a complete plant-based protein enriched with easily absorbable vitamin B12 and iron.

Earlier studies from this team linked mankai to improved blood sugar management, better metabolic and gut health, and reduced inflammation—all of which could positively influence brain and cognitive performance.

Shai acknowledged, however, that while there’s promise surrounding green tea and mankai in reducing neurodegeneration markers, more extensive human trials are necessary to look at actual cognitive impacts.

The findings stem from the comprehensive 18-month DIRECT PLUS trial, regarded as one of the most prolonged studies on diet and its effects on brain health.

Notably, many participants were men dealing with obesity and cholesterol issues, leading to the need for additional research to explore whether these outcomes extend to women and healthier populations. Yet, there’s accumulating evidence that increasing plant intake while minimizing red and processed meat could assist in slowing brain aging.

Looking ahead, researchers aspire that future blood tests utilizing proteins like galectin-9 might offer early alerts on brain health threats.

While the study’s current insights are worth noting, researchers emphasize that they are still preliminary. They do not definitively establish that diet alone can protect against Alzheimer’s or decline in cognitive faculties.

According to Jenny Finke, a metabolic health dietitian in Connecticut who wasn’t connected to this study, it’s reasonable to speculate that green tea and mankai might be effective in reducing markers related to neurodegeneration. However, robust human clinical trials measuring real cognitive effects are crucial.

Finke also highlighted that green tea is packed with antioxidants while walnuts provide healthy fats, including omega-3 fatty acids. These can easily be part of a morning or afternoon snack to enhance metabolic health and offer anti-inflammatory effects.

She suggested limiting red meat consumption to twice a week as well.

While these dietary adjustments won’t miraculously fix brain issues overnight, incorporating them into a balanced approach could be supportive for overall brain health over time.