Older people who eat a diet high in carbohydrates are four times more likely to develop mild cognitive impairment, and the risk is also higher with a diet heavy in sugar, according to Mayo Clinic researchers. On the other hand, those who consume plenty of protein and fat relative to carbohydrates are less likely to suffer cognitive decline.
The study emphasizes the importance of a well-rounded diet, said lead author Rosebud Roberts, M.B., Ch.B., a Mayo Clinic epidemiologist.
“We think it’s important that you eat a healthy balance of protein, carbohydrates and fat, because each of these nutrients has an important role in the body,” Roberts said.
For the study, researchers followed 1,230 people ages 70 to 89 who reported what they ate during the previous year. Their cognitive function was evaluated by an expert panel of physicians, nurses and neuropsychologists.
Of those participants, approximately 940 who showed no signs of cognitive impairment were asked to come back for follow-up evaluations of their cognitive function.
About four years into the study, 200 of those 940 were starting to exhibit mild cognitive impairment — problems with memory, language, thinking and judgment worse than normal age-related changes.
Individuals who had the highest carbohydrate intake at the beginning of the study were 1.9 times more likely to develop mild cognitive impairment than those with the lowest intake of carbohydrates.
People with the highest sugar intake were 1.5 times more likely to experience mild cognitive impairment than those with the lowest levels.
But those whose diets were highest in fat were 42 percent less likely to develop cognitive impairment, and those who consumed the most protein had a reduced risk of 21 percent.
When total fat and protein intake were taken into account, people with the highest carbohydrate intake were 3.6 times more likely to exhibit mild cognitive impairment.
“A high carbohydrate intake could be bad for you because carbohydrates impact your glucose and insulin metabolism,” Roberts said. “Sugar fuels the brain—so moderate intake is good. However, high levels of sugar may actually prevent the brain from using the sugar—similar to what we see with type 2 diabetes.”
The findings are published in the Journal of Alzheimer’s Disease.
Source: Mayo Clinic