Eating a healthy diet from a young age could keep you mentally sharp into your 70s and ward off dementia, a study following thousands of Britons over 70 years has found.
Most research on diet and cognition has focused on people who are already elderly or well into old age, but the new study is the first to follow people throughout their entire lives, from age 4 to 70, suggesting that the link may start much earlier than previously realized.
The study adds to a growing body of evidence that a healthy diet may reduce the risk of Alzheimer’s disease and slow cognitive decline as we age. American Academy of Nutrition.
“These initial findings broadly support current public health guidance that establishing healthy eating patterns early in life is important for maintaining and supporting health throughout life,” said Kelly Kara of Tufts University in Massachusetts.
“Our findings also provide new evidence suggesting that improving dietary habits up until midlife may influence cognition and potentially mitigate or even ameliorate cognitive decline in later life.”
According to the researchers, cognitive abilities can improve into middle age, but typically begin to decline after age 65. Along with age-related decline, more serious conditions such as dementia can also develop.
In the new study, scientists looked at 3,059 adults in the UK who, as children, took part in a survey called the National Survey of Health and Development. For more than 75 years, members of the cohort, called the 1946 British Birth Cohort, provided data on their dietary intake, cognitive ability, and other factors through questionnaires and tests.
The researchers analyzed participants’ dietary habits in relation to cognitive performance across five and seven time points, and found that diet quality was closely related to cognitive performance trends.
For example, compared to their peers, only 8% of people consuming a low-quality diet maintained high cognitive performance, and only 7% of people consuming a high-quality diet maintained low cognitive performance.
The researchers said cognitive ability can have a significant impact on quality of life and independence as we age. For example, by age 70, participants in the highest cognitive ability group had much greater retention of working memory, processing speed, and general cognitive ability compared to those in the lowest cognitive ability group.
What’s more, about a quarter of the participants in the poorest cognitive group showed signs of dementia at that time, but none of the participants in the most cognitive group showed any signs of dementia.
While most people’s diets steadily improve throughout adulthood, the researchers noted that small differences in the quality of diet during childhood appear to set the tone for eating patterns later in life, for better or worse.
“This suggests that dietary intake in early life may influence eating decisions later in life and that the cumulative effects of diet over time are associated with our overall cognitive development,” Kara said.
Study participants who maintained the best cognitive performance over time compared to their peers tended to eat more of recommended foods like vegetables, fruits, legumes and whole grains, and less sodium, added sugars and refined grains.
“Dietary patterns rich in whole or less processed plant foods, such as dark green leafy vegetables, beans, whole fruits and whole grains, may be most protective,” Kara said.
“For people of all ages, adjusting their dietary intake to include more of these foods and be more in line with current dietary recommendations may improve their health in a number of ways, including cognitive performance.”
