The Diet That Helps Keep Your Brain Young

The study adds to growing evidence that a healthy diet can help prevent Alzheimer’s disease and age-related cognitive decline. While most previous studies on the topic have focused on the eating habits of people in their 60s and 70s, this new study is the first to track diet and cognitive ability across the lifespan (ages 4 to 70) and suggests that the links may occur much earlier than previously thought.

“These initial findings generally support current public health recommendations that it is important to establish healthy diets early in life to maintain health throughout life,” said Dr. Kelly Kara of the Gerald J. and Dorothy R. Friedman School of Nutritional Sciences and Policy at Tufts University. “Our findings also provide new evidence that improving dietary patterns in midlife may impact cognitive function and help mitigate or reduce cognitive decline in the following years,” he adds.

Cognitive ability, or the ability to think, may continue to improve into middle age, but typically begins to decline after age 65. As the incidence of disease declines with age, more serious conditions, such as dementia, may develop.

Researchers say a healthy diet (especially one rich in plant foods that contain high levels of antioxidants, monounsaturated and polyunsaturated fats) may support brain health by reducing oxidative stress and improving blood flow to the brain.

For the new study, the researchers used data from 3,059 British adults who participated in a study called the National Survey of Health and Development as children. Members of the cohort, called the 1946 UK Birth Cohort, provided data on dietary intake, cognitive outcomes and other factors through questionnaires and tests for more than 75 years.

The researchers found that diet quality was closely related to trends in overall cognitive ability. For example, Only about 8% of people on a poor diet retained high cognitive abilities. and only about 7% of people who ate a high-quality diet maintained low cognitive performance over time compared to their peers.

Cognitive ability can have a significant impact on quality of life and independence as we age. For example, at ages 68–70, participants in the highest cognitive level group showed significantly better retention of working memory, processing speed, and overall cognitive performance than participants in the lowest cognitive level group. In addition, nearly a quarter of participants in the lowest cognitive level group showed signs of dementia at that time, whereas None of the participants in the highest cognitive group showed signs of dementia.

The researchers noted that small differences in nutrition quality in childhood seemed to set the tone for diet later in life, for better or worse. “This suggests that early-life diets can influence our dietary decisions later in life, and the cumulative effects of diet over time are linked to the development of our global cognitive abilities,” says Dorogoi.

To assess diet quality, the researchers used the 2020 Healthy Eating Index, which found that those who maintained higher cognitive performance over time compared to their peers tended to eat more of the recommended foods, such as vegetables, fruits, legumes, and whole grains, and less sodium, added sugar, and refined grains.

“Diet patterns rich in whole or less processed plant food groups, such as green leafy vegetables, legumes, whole fruits, and whole grains, may be the most protective“Kara says, adding, “Adjusting our diets at any age to include more of these foods and aligning them more closely with current dietary recommendations will likely improve our health in many ways, including our cognitive health.”

The researchers believe more research is needed to determine whether the findings apply to populations with greater racial, ethnic and dietary diversity.