DHA is an essential polyunsaturated fatty acid that has no side effects in the right dosage.DHA is abundant in fish oil and is an important constituent of brain cell membranes, involved in brain cell formation and development, has an important role in nerve cell axon extension and new synapse formation, can maintain normal physiological activities of nerve cells, participate in the formation process of brain thinking and memory, and can also promote Nerve cell growth. Some studies suggest that DHA has an antioxidant effect, can inhibit platelet aggregation, thrombosis is blocked, blood viscosity decreases, thus improving blood circulation, lowering blood pressure, preventing cerebral thrombosis, lower limb occlusive arteriosclerosis, hyperlipidemia, atherosclerosis, etc.. However, excessive intake of DHA may lead to low immunity. In addition, because DHA may increase the burden on the liver and kidneys after taking it, people suffering from bleeding disorders, cirrhosis of the liver and declining kidney function should control the intake of DHA to avoid aggravating the original disease.