Eating leafy greens, dark orange and red vegetables and berry fruits, and drinking orange juice may be associated with a lower risk of memory loss over time in men, according to a new study.
Researchers from the Harvard T.H. Chan School of Public Health in the United States analysed data from a study that had followed 27,842 men for 26 years.
The men had all filled in detailed surveys about their food and drink intake at the start of the study in 1986 – when they were aged 51 years, on average – and then every four years until 2002.
The follow-up lasted until 2012, by which time their average age was in the 70s.
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 six 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 per cent of the participants had good thinking and memory skills, 38 per cent had moderate skills, and 7 per cent 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 per cent less likely to develop poor thinking skills than the men who consumed the least amount of vegetables.
A total of 6.6 per cent of men in the top group developed poor cognitive function, compared to 7.9 per cent of men in the bottom group.
The men who drank orange juice every day were 47 per cent less likely to develop poor thinking skills than the men who drank less than one serving per month. A total of 6.9 per cent of men who drank orange juice every day developed poor cognitive function, compared to 8.4 per cent 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.
Read the full study.
Do you think you eat enough fruit and vegetables in your diet? Does this study make you want to start healthier eating habits?