Source of this article: Consumer Reports Author: Liao Yuting
On May 15, there are only 22 days left before the 2024 college entrance examination.
At this moment, you are strategizing, ready to wave the pen in your hand in the examination room, and turn the cold window of several years into every answer in the pen? Still anxious, facing the gap between the white horse and the mountains of uneaten learning materials, looking forward to having a piece of Doraemon's memory bread.
The anxiety of candidates and parents has given birth to a valuable business. Approaching the high school entrance examination, the DHA products on the market that advertise "strong brain supplementation", "unforgettable" and "top students are eating" arrived as scheduled.
So, what exactly is this DHA, known as "brain gold"? Does it really work?
“脑黄金”DHA，补还是不补？
DHA, whose Chinese name is docosahexaenoic acid, is a type of Omega-3 polyunsaturated fatty acids. DHA, commonly known as "brain gold", is particularly high in the retina, brain and sperm of the human body, of which DHA accounts for 20% of all fatty acids in the human cerebral cortex.
How does DHA continue throughout our lives?
First of all, DHA plays an important role in cognitive function, visual development and immune function in infants and young children during pregnancy and infancy. The mother begins to consume DHA in the body during pregnancy to meet the development needs of the fetus, and after the fetus is delivered, breast milk provides a certain amount of DHA for the baby.
Zhang Yiming mentioned in "The Source and Rational Application of DHA" that if a woman lacks DHA in her diet during pregnancy, it will also affect the normal development of the fetal brain and nervous system, as well as her acquired IQ index.
With the implementation of the new national standard for milk powder (increasing the DHA addition requirement in infant and older baby food: from 0-0.5mg/100kJ to 3.6-9.6mg/100kJ), more and more consumers have begun to pay attention to supplementing DHA to their babies, and there are even maternal milk powders containing high doses of DHA on the market.
Secondly, because DHA is an essential fatty acid, it means that the body cannot synthesize it on its own, but must be consumed from food. Studies have shown that high levels of DHA play an extremely important role in maintaining the integrity and fluidity of nerve cell membranes, so adding exogenous DHA to the diet can delay the loss of DHA in brain tissue, thereby improving the cognitive function of the brain.
It is worth mentioning that direct access to DHA from the diet is the most effective way to obtain DHA in the human body. The amount of DHA varies from food to food, but it is found in deep-sea cold-water fish, especially cold-water fish fat. In fact, the reason why fish contain DHA is because fish eat DHA-rich seaweed, and the DHA in seaweed is passed through the food chain before accumulating in the fish.
Due to concerns about nuclear radiation in marine water, many of the DHA supplements available for babies on the market today are extracted from DHA-rich algae such as Schizochytrium, Cryptodinoflagellates and Chytridora Ukkeni, rather than deep-sea fish oil.
However, whether an adult needs additional DHA supplementation depends on the individual's nutritional needs. Under normal circumstances, consumers normally eat fish 2-3 times a week, and one egg a day can basically meet the DHA intake needs, and generally do not need special supplements. For consumers with DHA supplements, fish oil, krill oil and algae oil can be chosen, as well as DHA-fortified foods including eggs, yogurt and milk.
The highest difference in the content of commercially available DHA products is more than 6 times
"Consumer Reports" investigated 5 popular DHA products on the market, such as "study and test preparation", "high score God of War" and "improve memory", from the source of DHA, 3 products came from algal oil, and 2 products came from fish oil.
For the labeling of DHA content, only 1 Zhilingtong brand Di'er soft capsule clearly indicates the actual DHA content of each capsule, and K-Max Yiliqing capsule is labeled with DHA content per 100g, which can be converted to contain about 244mg of DHA per capsule, which is the highest among the 5 products.
Some businesses take DHA as the main selling point, but they are vague about the DHA content, not mentioning the actual DHA content of the product, and ordinary consumers may have to do "arithmetic problems" when buying products.
Among them, sorlife brain nutrient capsules and Beijing Tong Ren Tang DHA algal oil walnut oil gel candy claim to add DHA algal oil, which are 100mg and 150mg respectively, but it should be noted that the content of DHA algal oil is not equal to the content of DHA. Referring to the algae oil of Zhilingtong brand Di'er soft capsules "39.6g of DHA per 100g of algal oil", it can be estimated that the DHA content of sorlife brain nutrient capsule and Beijing Tong Ren Tang DHA algal oil walnut oil gel candy are 39.6mg and 59.4mg respectively. The softgels in Golden Partner Giant Brain Gold weigh 250mg per capsule, while DHA accounts for 30%-50%, that is, the DHA content per capsule is 75-125mg.
In general, there is a huge gap between the DHA contained in the 5 DHA products, the DHA content range of 39.6-244mg per capsule, a difference of more than 6 times, and the price per capsule is about 0.7-6.4 yuan in terms of price, among which Beijing Tongrentang DHA algal oil walnut oil gel candy has the lowest price, 0.7 yuan per capsule, and the price of gold partner Giant Brain Gold (assuming the same price as capsules and oral liquid) is the highest, at 6.4 yuan per capsule.
According to the recommendations of the Food and Agriculture Organization of the United Nations (FAO), each person should consume no less than 250-500mg of n-3 long-chain polyunsaturated fatty acids (of which 220mg per day is DHA) to maintain the daily needs of adults.
According to the conversion, if you consume the above products, you need to consume about 1-6 capsules per day, of which sorlife brain nutrient capsules need to consume 5.6 capsules to achieve the recommended intake of DHA, but consumers must pay a "cost" of 33 yuan for this.
Consumer Reports reminds that the level of DHA reached in the brain depends not only on the concentration of DHA in the diet, but also on the form of DHA ingested. The DHA sold on the market mainly includes ethyl ester DHA extracted artificially, triglyceride DHA in natural fish oil and algal oil, and lecithin DHA in Antarctic krill, deep-sea fish eggs and DHA eggs. Among them, lecithin-type DHA is relatively more stable (lower content is a shortcoming), and triglyceride DHA is more popular because it is more natural.
理性看待dhai,补充dhai≠提高智商
Perhaps it is the importance of DHA to the human body, I don't know when DHA has been linked to "IQ". In this intensive college entrance examination season, DHA products have attracted more and more attention.
What has to be poured cold water is to ensure the development of the brain and nervous system and improve IQ, which are two concepts that cannot be equated at all. This relationship can be compared to calcium and vitamin D can promote bone development, because calcium and vitamin D are nutrients that the body needs, but supplementing them does not make everyone grow to 180cm tall.
In fact, the effect of DHA on children's cognitive ability has been widely concerned by the academic community, but it is still difficult to conclude the absolute effect of additional DHA on the development of neurocognitive function in infants and young children, and how to supplement DHA and the amount of supplementation is still a challenge.
In 2013, the Swiss journal Nutrients published a review of 15 previous literature on the "effects of DHA on children's cognitive ability and behavior", on the one hand, it affirmed the physiological effect of DHA on brain activity, and on the other hand, did not find any difference in the results of standard cognitive ability tests in children. This result is consistent with the findings of recent studies.
In addition, the best source of DHA is natural food, and an appropriate increase in seafood intake can provide the body with a high-quality source of DHA. In addition, the supplement should have a "degree", because DHA is a fatty acid after all, which will accumulate in the body when the body consumes too much, resulting in health risks such as increased blood lipids and weight gain.