If there’s one piece of advice almost every kid got growing up, it’s this: “Eat your vegetables!” Now, research is again showing that such pearls of parental common sense are steeped in wisdom and backed by science.
A recent study from Canada has found a link between people who have a higher intake of fruits, vegetables, legumes and nuts and better scores on verbal fluency tests, an important measure of cognitive function.
Scientists and healthcare professionals have long reported that some individual foods can help maintain and even boost good cognitive ability, including eating more nuts, using acai berries to boost brain function and staying mindful of the connection between gut health and mental health.
But this study, published in the Journal of Nutrition, Health and Aging, took a different approach in that it focused on a direct relationship between diet and test scores. It also took into account not just what people ate, but how much they ate.
Foods That Act As Protectives Against Cognitive Decline
The study looked at verbal fluency among a group of 8,574 Canadians between the ages of 45 and 85. Of those, 1,126 were immigrants who arrived in Canada 20 or more years earlier. Everyone involved lived in the community and were free from dementia.
Researchers tested verbal fluency by asking subjects to list as many words as possible from a given category in one minute. The test measured both language and executive function and can detect possible signs of cognitive impairment.
Participants with insufficient nutrition scored lower in verbal fluency, while those who ate fruits and vegetables scored higher. What’s more, researchers found that test scores improved with every additional increase in daily fruit and vegetable intake.
Researchers from Kwantlen Polytechnic University in British Columbia led the research. Dr. Karen Davison, a nutrition informatics research program director at the university, said that the study’s findings were consistent with others that found a Mediterranean diet high in fruits, vegetables, nuts and legumes protects against cognitive decline.
She said the best outcomes occurred with those who had consumed at least six servings of fruits and vegetables a day.
Other Factors Related To Cognitive Function
The study found other factors beyond diet that influenced verbal fluency.
Education played a role. For example, due to age-related cognitive decline, researchers expected young people to score higher on the test than older people. However, those between the age of 75 and 85 who held high school diplomas scored higher than people 10 years younger than them who did not finish high school.
The researchers noted that the high level of education attained by recent generations may help mitigate cognitive decline in the future.
The study also found obesity was a factor on test scores. Obesity has been linked in the past to inflammation and greater insulin resistance, both of which are associated with cognitive decline, the researchers noted.
The researchers also noted that the study’s findings make another good argument for public officials to design programs that reduce nutritional risk and improve people’s diet. Addressing these issues, as well as obesity and hypertension among older citizens, could help slow cognitive decline in more people.