Healthy Eating from Childhood to Old Age Proven to Boost Cognitive Function

There’s plenty of evidence that a diet rich in plants and low in salt, saturated fats, and processed foods benefits overall health. Healthful diets can reduce the risk of cardiovascular disease, diabetes, and cancer. 

Several studies have shown that eating a healthy diet in older age can help reduce the risk of cognitive decline and dementia. Now, research presented at NUTRITION 2024, the annual meeting of the American Society for Nutrition, has provided further evidence that healthy eating throughout life is key to maintaining cognitive function as we age. 

The study suggests the earlier that people adopt healthy eating patterns, the more likely they are to stay mentally sharp into old age. The findings have not yet been published in a peer-reviewed scientific journal. 

The study collected data from 3,059 people over seven decades. All participants were born in March 1946 and enrolled as children into the Medical Research Council’s National Survey of Health and Development in the United Kingdom. 

Over the course of more than 75 years, the participants in this survey completed questionnaires and tests on diet, cognition, general health, and other factors. For this study, the researchers assessed participants’ dietary intakes at five time points between the ages of 4 and 63, using recall and food diaries. They also measured their cognitive ability at seven time points between ages 8 and 69. 

They then used group-based trajectory modeling to investigate the relationship between diet and cognition. The researchers used the 2020 Healthy Eating Index (HEI) from the U.S. Department of Agriculture Health and Nutrition Service to assess the quality of the participants’ diets. 

In this index, higher intakes of foods such as fruits and vegetables, whole grains, protein, dairy, and seafood increase scores, while higher intakes of refined grains, sugar, sodium, and saturated fats reduce scores. 

The researchers found a strong association between diet quality over time and cognitive trajectory. Participants who retained high cognitive abilities into older age tended to eat more of the index’s high-scoring foods, such as vegetables, fruits, legumes, and whole grains, and less added sugars, refined grains, and sodium —the foods that decreased HEI scores. 

According to the study abstract, 47% of participants with the lowest-quality diets were in the lowest cognitive trajectory, and only 7% were in the highest cognitive trajectory. Conversely, 48% of those with the highest-quality diets were in the highest cognitive trajectory (8% in the lowest cognitive trajectory). 

This suggests that early life dietary intakes may influence our dietary decisions later in life, and the cumulative effects of diet over time are linked with the progression of our global cognitive abilities. Costa agreed but emphasized that improving diet later in life can still have a beneficial effect. 

The findings suggest making changes to have a healthier diet up to midlife correlate well with later-life cognitive outcomes. This adds a ray of hope that the effects of an early poor diet can be at least somewhat reversed. A combination of Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets, the “Mediterranean-DASH Intervention for Neurodegenerative Delay” (MIND) diet has been demonstrated to slow brain aging by something on the order of 7.5 years and significantly reduce one’s risk of developing Alzheimer’s disease.