According to a recent study, eating leafy greens, red vegetable, berry fruits and drinking orange juice may be linked with a lower risk of memory loss in men over time.
The study was published in the Journal of Neurology. It looked at 27,842 men with an average age of 51 who were all health professionals. Participants filled out questionnaires about how many servings of fruits, vegetables and other foods they had each day at the beginning of the study and then every four years for 20 years.
“One of the most important factors in this study is that we were able to research and track such a large group of men over a 20-year period of time, allowing for very telling results. Our studies provide further evidence dietary choices can be important to maintain your brain health,” said study author Changzheng Yuan, ScD, of Harvard T.H. Chan School of Public Health in Boston.
Participants also took subjective tests of their thinking and memory skills at least four years before the end of the study, when they were an average age of 73. The test is designed to detect changes that people can notice in how well they are remembering things before those changes would be detected by objective cognitive tests. Changes in memory reported by the participants would be considered precursors to mild cognitive impairment. The questions included: “Do you have more trouble than usual remembering a short list of items, such as a shopping list?” and “Do you have more trouble than usual following a group conversation or a plot in a TV program due to your memory?”
A total of 55% of the participants had good thinking and memory skills, 38% had moderate skills, and 7% had poor thinking and memory skills.
The participants were divided into five groups based on their fruit and vegetable consumption. For vegetables, the highest group ate about six servings per day, compared to about two servings for the lowest group. For fruits, the top group ate about three servings per day, compared to half a serving for the bottom group.
The men who consumed the most vegetables were 34% less likely to develop poor thinking skills than the men who consumed the least amount of vegetables. A total of 6.6% of men in the top group developed poor cognitive function, compared to 7.9% of men in the bottom group.
The men who drank orange juice every day were 47% less likely to develop poor thinking skills than the men who drank less than one serving per month. A total of 6.9% of men who drank orange juice every day developed poor cognitive function, compared to 8.4% of men who drank orange juice less than once a month.
The men who ate the most fruit each day were less likely to develop poor thinking skills, but that association was weakened after researchers adjusted for other dietary factors that could affect the results, such as consumption of vegetables, fruit juice, refined grains, legumes and dairy products.
The researchers also found that people who ate larger amounts of fruits and vegetables 20 years earlier were less likely to develop thinking and memory problems, whether or not they kept eating larger amounts of fruits and vegetables about six years before the memory test.