By Emily Woodruff | November 23rd, 2018
It sounds like the beginning of an ingredient list for a morning smoothie, but it’s also the three things scientists have found might lower the risk of dementia for men. Researchers have found that orange juice, leafy greens and berries could bolster cognitive health for older men.
Researchers at Harvard T.H. Chan School of Public Health in Boston tracked 27,842 men who were an average age of 51 for a study that spanned 20 years. They filled out a questionnaire about their eating habits at the beginning of the study, then again every four years. The participants also answered questions about their cognitive health and took tests four years before the end of the study, when they were an average age of 73.
The tests were designed to rely on a person’s assessment of their own memory, a measure researchers are finding can be a good indicator of brain health when a person is still relatively young and may not yet be showing life-changing symptoms of Alzheimer’s disease.
They asked questions like “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?”
At the 16-year mark, the tests showed that 55 percent had good thinking and memory skills, 38 percent had moderate skills, and 7 percent had poor thinking and memory skills.
At the end of the study, the men were divided into five different groups based on how many fruits and vegetables they reported in their diet over the years. For reference: The top group for vegetable consumption ate six servings (each serving was measured as one cup of raw vegetables or two cups of leafy greens) per day; the lowest group ate two servings. In fruit consumption, a serving was defined as one cup of fruit or a half-cup of fruit juice. The highest fruit-consuming group ate three servings per day; the lowest ate half a serving.
When researchers compared the amount of vegetables the men consumed to the cognitive test scores, they found that men who consumed the most amount of vegetables were 34 percent less likely to be in the poor thinking skills group than those who consumed the least vegetables. Percentage-wise, 6.6 percent of the men in the top-consuming vegetable group had poor cognition versus 7.9 percent in the least-consuming group.
When the researchers narrowed the data to observe the effect of drinking orange juice, they found that men who drank orange juice daily were almost half as likely to develop poor thinking skills than those who reported less than one serving per month.
Fruit alone didn’t have as much as an effect on thinking skills, but men who ate the most fruit—especially berries—did have better cognitive health.
Long-term health also played a part in healthy brains. Those who ate larger fruits and vegetables at the beginning of the study were less likely to have poor cognitive health regardless of if they kept eating large amounts of fruits and vegetables in the six years before the memory test.
However, the study doesn’t prove that fruits and vegetables protect brain health—just that those who report eating higher amounts of them are associated with a lower risk of poor memory. But the results point to healthy eating as something that might help keep your brain in shape.
“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,” said study author Changzheng Yuan, of Harvard T.H. Chan School of Public Health in Boston. “Our studies provide further evidence dietary choices can be important to maintain your brain health.”