A long-running study questions the conventional wisdom that a healthy diet may help ward off dementia.
European researchers followed more than 8,200 middle-aged adults for 25 years — looking at whether diet habits swayed the odds of being diagnosed with dementia. In the end, people who ate their fruits and vegetableswere at no lower risk than those who favored sweets and steaks.
The findings, published March 12 in the Journal of the American Medical Association, stand in stark contrast to many past studies.
Those studies have linked heart-healthy diets to lower odds of mental decline and abnormalities in the brain that can foretell dementia. Currently, groups like the Alzheimer’s Association suggest that people adopt those diets as one potential way to stave off dementia.
Most studies, though, have followed people for only a fairly short time — less than 10 years, said lead researcher Tasnime Akbaraly, from the French national research institute INSERM.
This study is the first to look at diet quality starting in middle age and the long-term risk of dementia, explained Akbaraly.
Her team found that 344 people were diagnosed with Alzheimer’s over the quarter-century they were followed. And the rates were similar among the one-third of study participants with the “best” diet quality and the one-third with the “worst.”
People in that first group typically had several servings of fruits, vegetables and whole grains every day; at least a couple servings of nuts and legumes each week; regularly had unsaturated fats, like olive oil; and put limits on red meat, sodium and sugary drinks.
No one is advising people to give up on that type of eating, however.
“I would certainly not want anyone to come away from this thinking a healthy diet is futile,” said Keith Fargo, director of scientific programs and outreach for the Alzheimer’s Association.