Nowadays, there are many kinds of health products, and many people will buy them for themselves or their loved ones, such as deep-sea fish oil, believing that it has the effect of preventing cardiovascular disease. There are many names related to "fish oil" on the Internet, such as cod liver oil, deep-sea fish oil, fish oil supplements, etc., which makes people confused when choosing. However, although the names are similar, they are actually different.
There are differences in ingredients
Cod liver oil is a fat extracted directly from the liver of shark, cod and other marine fish, generally yellow or orange-red clear liquid, the main components are fat-soluble vitamin A and vitamin D.
Deep-sea fish oil is a general term for all oils and fats in deep-sea fish, including brain oil, liver oil and body oil. Although the source is all fish, the composition of deep-sea fish oil is completely different from cod liver oil. High-purity deep-sea fish oil is rich in omega-3 unsaturated fatty acids, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
Common fish oil supplements are the more common health supplements on the market that contain omega-3 unsaturated fatty acids of different purity.
There are differences in effects
Vitamin A in cod liver oil has the effect of maintaining normal vision, can prevent night blindness, can also promote the differentiation of bone cells, strengthen bones, promote cell growth, and prevent rough skin. Vitamin D can maintain blood calcium and phosphorus levels, effectively preventing rickets in children and osteoporosis in the elderly. Taking cod liver oil in moderation can help reduce the risk of heart disease.
Deep sea fish oil contains two nutrients, DHA and EPA. DHA is known as "brain gold" and is an important component of the brain and retina; EPA is found in cells and blood vessels throughout the body and has a reputation as a "vascular scavenger". Studies have found that high-purity deep-sea fish oil can reduce platelet aggregation, thereby reducing the risk of thrombosis, and can reduce inflammatory mediators, as well as triglycerides, total cholesterol and LDL cholesterol in the blood, which has the effect of reducing the risk of atherosclerotic cardiovascular and cerebrovascular diseases.
Most of the common fish oil supplements available on the market are of low purity and have less obvious results.
Applicable to different people
Cod liver oil is mainly suitable for young children, pregnant women and lactating women who need vitamin A and vitamin D supplementation. For healthy adults, vitamin A and vitamin D can be supplemented with food. β-carotene is the main source of dietary vitamin A for mainland residents, in order to ensure sufficient supply, it is recommended that the daily intake of dark vegetables should account for more than 1/2 of the total intake of vegetables. We can also get vitamin A from animal liver, dairy products, eggs and other foods. As for vitamin D, the simplest and most direct way to obtain it is to properly bask in the sun, and ultraviolet rays can promote vitamin D synthesis. If you're afraid of getting sunburned by ultraviolet rays, you can also choose a natural vitamin D supplement.
The suitable population for deep-sea fish oil is more complex. The relevant expert consensus published by the American College of Cardiology (ACC) in 2021 pointed out that there are two types of people suitable for high-purity deep-sea fish oil preparations, the first is adults aged 20 years and older with severely elevated triglycerides; The second group is people aged 20 years and older, although triglycerides are mildly to moderately elevated, but already have atherosclerotic cardiovascular disease or diabetes, or are at high risk of cardiovascular disease. The consensus recommends that high-purity fish oil preparations can be used in both groups of people to control blood lipids. It should be emphasized that fish oil preparations recommended by consensus are "prescription drugs" and not general health supplements.
Of course, deep-sea fish oil can not replace commonly used lipid-lowering drugs, for patients with elevated LDL cholesterol or cardiovascular atherosclerosis, domestic and foreign guidelines recommend the first choice of statin therapy.
Not everyone is suitable for taking deep sea fish oil, and some people may experience mild discomfort after taking it, such as hiccups, diarrhea, nausea and other gastrointestinal adverse reactions, which can generally be alleviated by taking it with meals. Recent studies have shown that taking 4 grams of high-purity fish oil daily increases the risk of atrial fibrillation (atrial fibrillation). Therefore, fish oil products are not recommended for patients with atrial fibrillation.
How to choose fish oil products
Source: Public Health magazine
Author: Liu Jian, Chief Physician, Department of Cardiology, Peking University People's Hospital
Review: Wang Fang, expert of the National Health Science Expert Database and chief physician of the Department of Cardiology of Beijing Hospital
Curator: Wu Weihong Yu Yunxi
Editor: Chen Xiuchao