Both EPA and DHA are important intermediate metabolites in the metabolism of α-linolenic acid, and play a very important physiological role in human life activities. After α-linolenic acid enters the human body, EPA and DHA are sequentially formed under the action of enzymes. This process is irreversible, that is to say, α-linolenic acid has more effects than DHA, and the effect is more comprehensive. Moreover, when α-linolenic acid enters the human body, the human body can rationally carry out metabolism according to its own needs. As long as the amount of α-linolenic acid is sufficient, how much DHA can be supplemented by the body, and the excess α-linolenic acid is also It can be metabolized into other substances such as EPA to complete other physiological functions. DHA does not have such characteristics, and supplementing excessive DHA will have negative effects, such as low immunity.