Eat your 5-a-day for a better memory (if you're a man): Orange juice, leafy greens and berries boost men's minds

  • Researchers looked at data on 27,842 men over the course of 20 years
  • They found those who ate leafy greens and red vegetables had better memories
  • They also found orange juice boosted cognition, despite lacking in fiber 

Middle aged men should drink orange juice and eat plenty of leafy greens and berries to help prevent memory loss, suggests a new study.

Researchers who conducted the 20-year study found that feasting on leafy greens, dark orange and red vegetables as well as berry fruits appeared to lower the risk of memory loss over time in men.

Interestingly, they found the same for orange juice, which has fallen out of favor in nutrition circles for its lack of fiber and high sugar content.  

The study, published online by the journal Neurology, involved 27,842 men with an average age of 51 who were all health professionals.

More research is needed to see if the same is true for women, but the team at Harvard said they feel their findings show dietary tweaks have a profound impact on brain health. 

The study, published online by the journal Neurology, involved 27,842 men with an average age of 51 who were all health professionals

The study, published online by the journal Neurology, involved 27,842 men with an average age of 51 who were all health professionals

The participants filled out questionnaires about how many servings of fruit, vegetables and other foods they had each day at the beginning of the study and then every four years for 20 years.

A serving of fruit is considered one cup of fruit - equivalent to a banana or a small apple or a half-cup of fruit juice. A serving of vegetables is considered one cup of raw vegetables or two cups of leafy greens.

Study author Changzheng Yuan, a doctoral student at Harvard T.H. Chan School of Public Health, said: '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.'

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?'

More than half the men in the study (55 percent) had good thinking and memory skills, 38 percent had moderate skills, and seven per cent had poor thinking and memory skills.

The participants were divided into five groups based on their fruit and veg 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 ate the most vegetables were 34 percent less likely to develop poor thinking skills than the men who consumed the least amount of vegetables.

A total of 6.6 percent of men in the top group developed poor cognitive function, compared to 7.9 percent of men in the bottom group.

The men who drank orange juice every day were 47 percent less likely to develop poor thinking skills than the men who drank less than one serving per month.

The research team said that the association was mainly observed for regular consumption of orange juice among the oldest men.

A total of 6.9 percent of men who drank orange juice every day developed poor cognitive function, compared to 8.4 percent of men who drank orange juice less than once a month.

Yuan said 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 veg 20 years earlier were less likely to develop thinking and memory problems - whether or not they kept eating larger amounts of fruits and veg about six years before the memory test.

Yuan added: 'The study does not show that eating fruits and vegetables and drinking orange juice reduces memory loss; it only shows a relationship between them.'

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