What you eat in your 40s may determine how your brain would function later in life

NE DELHI: If you want to recall what you had for breakfast in your 80s, it may be time to pay closer attention to what you eat in your 40s.A large study published in JAMA Neurology, tracking over 1.5 lakh adults, has found that healthier diets in midlife are associated with better memory and thinking abilities later. Those eating more fruits, vegetables, whole grains and fish were less likely to report early signs of cognitive decline and performed better on cognitive tests over time. The findings put the spotlight on a crucial but often ignored window-ages 45 to 54, when long-term brain health appears to be shaped. AIIMS Delhi dietician Monita Gahlot said this is when many risk factors-such as high blood pressure, blood sugar imbalance, inflammation and vascular damage-begin silently and gradually to affect the brain. "Midlife is a critical window because the brain still retains enough flexibility for lifestyle changes, especially diet, to make a meaningful impact. Habits formed during this phase help build cognitive reserve and can delay or reduce dementia risk," she said.Among the diets studied, the DASH (Dietary Approaches to Stop Hypertension) diet showed one of the strongest links with lower risk of cognitive decline, reinforcing its benefits beyond heart health. Ritika Samaddar, chief clinical nutritionist at Max Super Speciality Hospital, said diet plays a direct and sustained role in brain health across adulthood. "Plant-based diets rich in fruits, vegetables, whole grains, nuts, seeds and healthy fats like olive oil and fish are key. At the same time, intake of red and processed meat, refined carbs, sugary drinks and ultra-processed foods should be reduced," she said.She added that diet affects the brain through multiple pathways. "A healthy gut microbiome supports cognition and mood, while poor diets increase inflammation and oxidative stress, damaging brain cells. Stable blood sugar and good vascular health are equally important for maintaining brain function," she said.The study also flags diets high in red and processed meat and those linked to inflammation or blood sugar spikes as being associated with poorer brain outcomes.Experts say brain ageing begins much earlier, and prevention needs to start in midlife. For a country like India, where cases of dementia are expected to rise sharply, the findings reinforce the importance of prevention.