New study links leafy greens, berries, and fish to better cognitive health

Eating a diet rich in vegetables, berries, fish, and whole grains may help slow memory loss and protect the brain, according to a new study published in Scientific Reports. Researchers found that both the Mediterranean and MIND diets were linked to better cognitive health, with the MIND diet showing a slight edge.

Alzheimer’s disease, a condition that gradually erodes memory and thinking skills, affects more than 55 million people worldwide. While there is no cure, lifestyle factors such as diet have emerged as powerful tools in reducing risk.

The Mediterranean diet has long been praised for its heart and brain benefits, emphasizing fruits, vegetables, fish, olive oil, and moderate wine consumption. The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet, developed more recently, incorporates elements of the Mediterranean diet, with a sharper focus on foods believed to protect the brain—like leafy greens, berries, nuts, and whole grains. Both diets limit red meat and processed foods.

Led by Xiaofang Liu from the Huadu District People’s Hospital of Guangzhou, researchers in China set out to compare the long-term effects of these two diets on brain health. They recruited 1,500 participants between the ages of 50 and 75, including 750 healthy individuals and 750 patients already diagnosed with Alzheimer’s disease.

Over five years, participants’ diets were tracked using questionnaires and mobile apps, while their memory and thinking skills were tested regularly. Blood and spinal fluid samples were analyzed for biomarkers linked to Alzheimer’s, such as amyloid-beta and tau proteins. Brain scans were also conducted to measure changes in hippocampal volume and cortical thickness—key indicators of neurodegeneration.

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Participants who closely followed either diet scored higher on memory and thinking tests and showed lower levels of harmful proteins associated with Alzheimer’s. They also had reduced inflammation, a known contributor to brain decline. Importantly, brain scans revealed that those with strong dietary adherence experienced slower shrinkage of the hippocampus, the brain’s memory center, and less thinning of the cortex, which is critical for higher-level thinking.

The authors noted, “While both diets offer neuroprotection, our findings suggest that the MIND diet may provide slightly superior benefits due to its targeted inclusion of neuroprotective nutrients such as berries, leafy greens, and whole grains.” Nutrients such as omega-3 fatty acids, polyphenols, and B vitamins were also linked to improved cognitive performance.

Genetics played a role too. People carrying the APOE-ε4 gene variant, which increases Alzheimer’s risk, experienced faster decline overall. However, even they benefited from adhering to these diets, suggesting that nutrition can help offset genetic vulnerability.

However, the study is not without caveats. Dietary intake was partly self-reported, which can introduce inaccuracies. Furthermore, the exclusion of participants with other serious health conditions may also limit how broadly the findings apply.

The study, “The long-term neuroprotective effect of MIND and Mediterranean diet on patients with Alzheimer’s disease,” was authored by Xiaofang Liu, Bo Yang, Qiong Liu, Mengge Gao, and Miaoqing Luo.