Micro Signal | Biotechnology-China
Usually brightly colored mushrooms are mostly poisonous. After eating them, they will be "red umbrella and white pole, lying on the board together"; But colorful fruits and vegetables are of great benefit to the human body. They can not only add luster to physical health, but also protect brain health.
Nowadays, due to the progress of medicine, the life span of human beings has been greatly extended. At the same time, the global population is rapidly aging, and various age-related health problems are becoming more and more serious, among which the most helpless is Alzheimer's disease caused by cognitive decline. Scientists are still at a loss about the disease. Therefore, slowing down cognitive decline has become the top priority in preventing dementia.
Recently, in a new study published in the Journal of Neurology of the American Neurology Association, Professor Yuan of Harvard University and School of Public Health of Zhejiang University conducted a 20-year study on more than 77,000 middle-aged and elderly people. It has been found that people who have more colorful fruits and vegetables in their daily diet greatly reduce the risk of cognitive decline. In other words, simply changing diet can help prevent cognitive decline, thus preventing Alzheimer's disease.
As we all know, besides green, there are many colorful fruits and vegetables, such as red tomatoes and strawberries, orange oranges and carrots, yellow bananas and corn, purple grapes and eggplant. Are fruits and vegetables rich in flavonoids.
Flavonoids are an important class of secondary metabolites in plants, which are widely found in many food-borne plants such as fruits, vegetables, beans and tea in the form of bound (flavonoid glycosides) or free (flavonoid aglycones). At present, more than 8,000 flavonoids have been found.
Previous studies have shown that flavonoids can improve the ability of animals to resist oxidation and scavenge free radicals. Therefore, it is a powerful antioxidant. In addition, more and more evidence proves that flavonoids play a very significant role in preventing the decline of thinking ability with age.
Therefore, it is generally believed that insufficient antioxidants may lead to cognitive decline.
In this study, the researchers investigated 49,493 female participants with an average age of 48 from the Nurses' Health Research (NHS) and 27,842 male participants with an average age of 5 1 from the Follow-up Study for Health Professionals (HPFS). During more than 20 years of follow-up, participants completed five to seven food frequency questionnaires. The researchers calculated the long-term average dietary intake through the food frequency questionnaire. Then, they evaluated the relationship between flavonoids (flavonols, flavonoids, flavanones, flavanone -3- ol, anthocyanins, polymeric flavonoids and procyanidins) and subsequent cognitive decline.
During the research, participants also conducted two cognitive assessments, which involved the following questions: "Is it more difficult for you to recall recent events emotionally than usual?" And "Is it harder for you to remember a short list of things than usual?"
This assessment can capture early memory problems, that is, participants' memory has degenerated enough for them to feel, but it may not be found in screening tests.
After adjusting for age, total energy intake, main non-dietary factors and specific dietary factors, the researchers found that higher flavonoid intake was associated with lower cognitive decline:
Among the participants with the highest intake of 20%, their daily diet contains an average of about 600 mg of flavonoids; Among the 20% participants with the lowest intake, this figure is 150 mg. For example, every 100g of strawberries contains about 180mg of flavonoids, while apples contain about 1 13mg of flavonoids.
Compared with the group with the lowest intake of flavonoids, the risk of cognitive decline in the group with the highest intake of flavonoids decreased by 20%.
In addition, the researchers also studied a single flavonoid. In the summary results, they observed that flavonoids, flavanones and anthocyanins had the strongest correlation. Among them, the dose-response curve of flavonoids is steepest, followed by anthocyanins. Many foods rich in flavonoids, such as strawberries, oranges, grapefruit, oranges, apples, pears, celery, peppers and bananas, are significantly related to the low probability of cognitive decline.
Professor Walter Willett, co-author of the study and professor of the Department of Epidemiology of Harvard School of Public Health, said: "In our study, people with the best long-term cognitive ability eat at least half (about 200g) of fruits and vegetables every day, such as oranges, peppers, celery, grapefruit, grapefruit juice, apples and pears. Although there may be other phytochemicals at work, colorful foods rich in flavonoids, especially flavonoids and anthocyanins seem to be a good choice to promote long-term brain health. In addition, it is never too late to start, because we have observed these protective effects whether we ingested flavonoids in our diet 20 years ago or recently. "
The researchers said that one of the limitations of the study is the frequency of eating reported by participants themselves, and they may not fully remember what they ate and how much they ate.
Paper link:
https://doi . org/ 10. 12 12/wnl . 0000000000 12454