A meta-analysis published in Frontiers in Nutrition has found that intake of fruits and vegetables is negatively correlated with cognitive decline in older adults. No less than sixteen different studies were used for this meta-analysis. Some of these studies were based on Alzheimer’s disease and dementia, and others were more focused on cognitive impairment. Some studies reported fruit intake, others reported vegetable intake, and a few reported both. This meta-analysis contained studies from all over the world.
On average, people who consumed more fruits and vegetables were less likely to have cognitive decline and less likely to have dementia. When the two categories were separated, fruit consumers were about a sixth less likely to have cognitive decline, and vegetable consumers were about a quarter less likely to have it.
While there was evidence that fruit and vegetable consumption could be linked to a reduced risk of Alzheimer’s disease, the data in this respect did not meet the level of statistical significance. Whether or not the well-known Food Frequency Questionnaire or other analyses were used did not seem to matter much.
Most importantly, a dose-response relationship was reported. According to this meta-analysis, there is a direct, linear correlation between consuming more fruits and vegetables and having a reduced likelihood of suffering from cognitive decline.