A follow-up study of 80,000 people for more than 20 years revealed that a variety of fruits and vegetables can reduce the risk of cognitive decline!

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These phytochemicals have powerful antioxidant properties, so people hope that they can reduce oxidative stress in the brain

Oxidative stress is an important factor that leads to age-related cognitive decline and ultimately to dementia, which affects a person's memory, thinking and reasoning abilities

A large amount of scientific evidence shows that long-term oxidative stress contributes to the development of a series of chronic diseases

In 2014, in the United States alone, about 5 million adults aged 65 and over suffered from dementia

Although there are some treatments that can temporarily relieve the symptoms of dementia, there is currently no cure

However, previous studies on the possible link between eating flavonoid-rich foods and reducing the risk of cognitive decline in later life are still inconclusive

Recently, a new study prospectively studied the association between long-term dietary flavonoids and subjective cognitive decline (SCD)

Even after adjusting for other risk factors (such as physical exercise), people with the highest dietary intake of flavonoids were 20% less likely to experience subjective cognitive decline compared with those who ate the least.

Long-term Dietary Flavonoid Intake and Subjective Cognitive Decline in US Men and Women.

Some flavonoids seem to be better at preventing cognitive decline than others

Some flavonoids seem to provide stronger protection than others to prevent cognitive decline

Flavonoids are flavonoids found in yellow and orange fruits and vegetables, which can reduce the risk of cognitive decline by 38%

The anthocyanins present in blueberries, blackberries and cherries are associated with a 24% reduction in the risk of cognitive decline

Although other phytochemicals may be at work, a diet rich in flavonoids—especially flavonoids and anthocyanins—seems to be a good choice for long-term brain health
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And research shows that whether people took flavonoids in their diet 20 years ago or only recently started taking them, they have seen these beneficial protective relationships
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Subjective cognitive decline

In their study, the researchers used data from two large longitudinal studies, one for men and one for women, which monitored the life>
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The Nurses’ Health Study (NHS) started in 1976 and is one of the largest studies of risk factors for women’s chronic diseases
.

In this study, there are data on 49,493 women who completed seven questionnaires on diet between 1984 and 2006, and conducted follow-up surveys of cognitive decline in 2012 and 2014
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The researchers also obtained data on 27,842 men from a follow-up study of health experts who completed five dietary questionnaires between 1986 and 2002
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Their subjective cognitive decline was investigated during follow-up in 2008 and 2012
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Investigations of cognitive decline include questions such as:

- Are more difficult than usual when you recall recent events?

- Due to the memory, you are more difficult than usual in the collective memory of the conversation or TV show episode?

-Do you have trouble finding your way on a familiar street?

The results of the study showed that after adjusting for age, total energy intake, major non-dietary factors, and specific dietary factors, a higher total flavonoid intake was associated with a lower chance of SCD
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Comparing the highest and lowest quintiles of total flavonoid intake, the aggregate multivariate adjusted odds ratio (OR) of SCD 3 unit increments was 0.
81
.
In the summary results, the strongest correlations were observed between flavonoids (OR=0.
62), flavanones (OR=0.
64) and anthocyanins (OR=0.
76)
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The dose-response curve of flavonoids is the steepest, followed by anthocyanins
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Many foods rich in flavonoids, such as strawberries, oranges, grapefruit, citrus juice, apples/pears, celery, peppers, and bananas, are significantly associated with a lower chance of SCD
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Research results support that higher intake of flavonoids is beneficial for maintaining the cognitive function of American men and women
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When analyzing the relationship between dietary flavonoids and subjective cognitive decline, the researchers took into account the participants' intake of other nutrients, such as vitamins and omega-3 fatty acids
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They also considered a number of non-dietary factors, including physical activity, body mass index, smoking, alcohol consumption, and family history of dementia
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After adjusting for all major non-dietary and dietary risk factors for cognitive dysfunction, the results of the study remain robust and consistent during long-term follow-up
.

In this study, there is no doubt that randomized controlled trials comparing the intervention group and the control group are needed to prove that flavonoids can prevent cognitive decline and determine the effective amount
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However, in such studies, it is challenging to ensure that a large number of participants adhere to a specific diet for a long time
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Researchers believe that the results of current research can be used as a basis for future research to further understand the role that flavonoids may play in cognitive decline
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Previous short-term randomized controlled trials have shown that flavonoid supplements may be beneficial to cognitive ability, but there is more work to be done to confirm this
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At the same time, eating foods rich in flavonoids seems to be the best choice, partly because ingredients other than flavonoids in these foods may provide some benefits
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In addition, we have extensive long-term evidence for the safety and additional benefits of these foods
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Limitations of the study

Experts expressed their encouragement to the new research findings, but the research results should be treated with caution
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The study relied on the dietary survey results recorded by the participants, rather than monitoring their food intake
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More importantly, this study did not directly study the effect of diet on dementia.
We cannot know from this study whether a diet rich in flavonoids has any effect on preventing or delaying the onset of the disease
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Experts point out that in addition to diet, other life>
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Therefore, more research is needed on the possible benefits of different foods to the brain, especially in the prevention and/or management of dementia
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Of course, there is evidence that the Mediterranean diet -in addition to fish, green leafy vegetables, fruits, nuts, and olive oil, but also a small amount of meat and dairy products-is good for brain health
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