Dietary choices could slash brain aging: new study explains how

A recent international study led by Ben-Gurion University of the Negev, as part of the DIRECT PLUS Brain MRI trial, has unveiled a crucial link between blood sugar management and brain health. Its findings suggest that specific dietary interventions could help mitigate cognitive decline associated with aging.

Age-related brain atrophy, involving the gradual loss of neurons and brain tissue shrinkage, is a natural process contributing to cognitive and neurological challenges. While aging itself is inevitable, the study's findings provide hope that lifestyle changes can slow the brain’s aging trajectory. Using MRI scans to measure hippocampal shrinkage and the expansion of the lateral ventricles, researchers identified a discrepancy between biological and chronological brain ages, with some individuals showing slower or faster rates of brain aging.

Published in The American Journal of Clinical Nutrition in 2024, the research features collaborations with Harvard University and Leipzig University. Prof. Iris Shai and doctoral student Dafna Pachter highlighted the importance of blood sugar control in protecting the brain.

Shai, who led the research, told The Media Line that the findings are groundbreaking in how they demonstrate the power of lifestyle interventions on brain health.

“One of the most fascinating parts of this study is that lifestyle interventions, particularly diet—and more precisely the Green Mediterranean diet—can significantly reduce age-related brain atrophy,” she explained. “It’s incredible to see that we could achieve up to a 50% reduction in brain aging compared to the control group within just 18 months. That’s a substantial and dramatic effect.”

Influencing the rate of aging

According to Pachter, an integral part of the research team, “We cannot prevent aging, but we can influence the rate at which our brain ages,” she told The Media Line. “We’ve identified that glycemic control is the primary process driving this impact. It’s amazing to think that through nutrition, we can actually attenuate the aging of our brain.” Pachter emphasized the importance of glycemic control beyond the context of diabetes.

“What’s crucial here is that glycemic control starts when we’re younger. Our research didn’t involve participants with diabetes, yet we found that even among generally healthy individuals, blood glucose levels gradually rise as we age. It’s not a sudden change but a slow process,” she said.

“That’s why it’s so important to eat well, stay physically active, reduce sugar intake, and follow a more plant-based diet. These lifestyle choices can help prevent the gradual rise in glucose that accelerates brain aging,” Pachter added.

Shai shared that the research uncovered a clear mechanism behind these improvements.“When we examined what could mediate the link between the Mediterranean diet andreduced brain atrophy, we found that glycemic control was the main pathway,” she said.

“This means that one reason the diet is so beneficial is that it lowers blood sugar levels. What’s crucial is that even within the normal range of blood glucose—between 70 and 100 milligrams per deciliter—lower levels are better for brain health. There’s no exact threshold; instead, the effect is continuous. The more you can control your sugar levels, the better it is for your brain. Even so-called normal levels can still be improved,” Shai added.

Describing the components of the Mediterranean diet, Pachter listed key elements: “The diet emphasizes vegetables, fruits, nuts, olive oil, green tea, whole grains, and avocado. It’s low in sugar and red meat, focusing on plant-based oils like olive oil and avocado oil instead of butter. This plant-based approach is crucial for brain health,” she explained.

According to Shai, brain aging is gradual. “Thankfully, we don’t feel these anatomical changes immediately,” she said. “The hippocampus, related to memory, and the lateral ventricles, which expand with aging, are among the brain regions affected. We use MRI scans to measure these changes.”

“Memory decline is one of the earliest signs, which starts with small issues like forgetting where you left your keys. It’s not something you immediately notice in your everyday life, but over time, cognitive tests can reveal these deficits. Importantly, we’re talking about anatomical brain health, not overall physical health, though blood glucose also affects many other aspects of health,” she added.

Pachter clarified the difference between chronological age and brain age. “We know that people have their chronological age, but we can now use MRI scans to estimate their brain age,” she said.

“With these scans, we calculate the gap between brain age and chronological age. It’s interesting because some 70-year-olds have a brain age equivalent to someone who’s 60, while others might have a brain age closer to 75. Understanding this gap helps us see how lifestyle factors, like diet and physical activity, influence brain health,” she added.

“As we get older, we lose neurons, and our brain volume decreases. This is a natural process, but with good nutrition and exercise, especially with the green Mediterranean diet, we can slow it down. This is incredibly important because a more atrophied brain puts someone at a higher risk for Alzheimer’s and dementia,” Pachter said. “Slowing this processhelps preserve cognitive functions and reduces these risks.”

Shai also emphasized that while diet is important, physical activity cannot be overlooked.

“We didn’t measure exercise effects separately in our study because every participant had a gym membership and was encouraged to stay active,” she noted. “Aerobic exercise is foundational, but on top of that, diet makes a significant difference.”

Shai revealed that the study is part of ongoing research for the future. “We are continuing to follow participants for years to observe the dynamics and trajectory of brain aging,” she said.

“The brain is dynamic, and understanding how dietary changes influence brain health over time is critical. We’re also studying the link between the brain and the gut microbiome, which is a fascinating area of emerging research,” she noted.

“Our lifespan is now longer thanks to advances in medicine, but that also means we need to take better care of our brains,” Pachter stressed. “Starting to pay attention to our diet and lifestyle when we’re younger can have a big impact on our future cognitive health.”