New research finds that a diet high in polyphenols and polyunsaturated fatty acids may not only help the brain make new neurons but may also prevent the kind of cell damage seen in degenerative diseases like Alzheimer’s. The study adds to a growing body of evidence elucidating the relationship between various compounds in foods and brain health.

In the Universitat Autònoma de Barcelona study, mice were fed a diet known as the LMN diet; similar to the Mediterranean diet, this patented diet is rich in both polyphenols found in teas, wine, olive oil, nuts, fruits, and veggies and in the healthy polyunsaturated fats found in some fish and soy beans. Control mice were fed regular laboratory mouse chow.

Mice were fed a diet... rich in both polyphenols found in teas, wine, olive oil, nuts, fruits, and veggies and in the healthy polyunsaturated fats found in some fish and soy beans.

After 40 days of keeping the mice on their respective diets, the researchers looked at two key areas of the brain: the hippocampus and the olfactory bulb. Both regions have been shown to be damaged in Alzheimer’s disease, but earlier studies have also indicated that new cells may also be “born” in these areas. In the current study, mice fed the LMN diet had significantly more stem cells and newly differentiated neurons (i.e., cells that had recently developed into nerve cells) in these two regions, compared to control mice.

The LMN diet also seemed to reduce or completely avert damage to cultured brain cells when researchers exposed them to compounds that cause oxidative stress. Exposing the cells to the damaging effects of hydrogen peroxide killed up to 40% of the cultured cells; if, however, they were pretreated with LMN compounds, this damage was greatly prevented. What’s more, when the researchers instead exposed the cultured cells to amyloid beta, the protein that builds up on the brain cells of people suffering from Alzheimer’s disease, the damage was greatly reduced in cells that were pretreated with LMN extracts.

The study’s findings are intriguing, as they strongly indicate that what we eat may well delay or even prevent the onset of common – but disabling – neurodegenerative diseases like Alzheimer’s.

The study was led by Mercedes Unzeta and published in the December 2009 issue of Journal of Alzheimer’s Disease.