Centuries ago, Nordic people used fish liver oil to protect them from the cold. By 1930, scientists had discovered that fish liver oil helped prevent rickets, so it began to be used for diseases caused by vitamin D deficiency and became an essential health product in every household.
Function:
1. Beneficial rheumatoid arthritis
Rheumatoid arthritis is an autoimmune disease with unknown etiology, characterized by chronic, destructive, and debilitating characteristics, accounting for approximately 1% of the adult population. Epidemiological studies have shown that in addition to genetic inheritance, environmental factors such as cigarette smoke, exogenous hormone use, female reproductive factors (irregular menstrual cycle, early menarche, breastfeeding), occupational exposure to silica dust and mineral oil are also factors that affect the onset of the disease. A double-blind placebo-controlled randomized study (9 months, involving 97 patients with rheumatoid arthritis) indicated that the use of fish liver oil (daily dose of 10 g) helped reduce the analgesic drugs (NSAIDs)(but there was no significant difference in clinical indicators).
* Conclusion: For patients with rheumatoid arthritis, fish liver oil can help reduce the dosage of anti-inflammatory and analgesic drugs. However, due to the limited sample size, more studies are still required for confirming this.
2. Beneficial for depressive symptoms
Depression is a significant public health issue that affects patients and society. Its clinical symptoms are called unipolar depression, characterized by low mood, hopelessness, helplessness, intense guilt, sadness, inferiority complex, self-harm, and suicidal thoughts. Statistically, the prevalence of depression in women is higher than that in men. The global annual prevalence rates are 5.5% and 3.2%, respectively. The incidence rate of depression in women is 1.7 times higher than that in men. A population-based cross-sectional study (including 21835 participants) found that compared to nonusers, individuals who took oral fish liver oil were much less likely to experience depressive symptoms (and this persisted even after adjusting for multiple possible confounding factors such as gender, age, alcohol consumption, coffee consumption, physical activity, and education).
* Conclusion: Population observations have found a negative correlation between depressive symptoms and the application of fish liver oil, but randomized controlled trials are still needed to verify their causal relationship.
3. Beneficial for glaucoma
Glaucoma affects over 70 million people worldwide and causing bilateral blindness in 10% of the population, making it the leading cause of irreversible blindness worldwide. Primary glaucoma is common in cases, and the main risk factors include high intraocular pressure, vascular dysfunction, glutamate-mediated toxicity, excessive production of nitric oxide, and oxidative stress. Secondary glaucoma may be caused by trauma, medications such as corticosteroids, inflammation, tumor or pigment dispersion, or pseudoexfoliation. Fish liver oil is considered a beneficial eye health supplement due to its high vitamin A and Omega-3 content. Vitamin A is essential for maintaining normal vision, as it can prevent oxidative damage (the cause of glaucoma). It is also a critical factor in maintaining the integrity of the conjunctiva and corneal surface and can prevent ocular epithelial damage caused by local anti-glaucoma drugs. Omega-3 fatty acids are beneficial for glaucoma patients to reduce intraocular pressure, increase eye blood flow, and improve visual neuroprotective function.
* Conclusion: Fish liver oil is beneficial for glaucoma, but it has not been confirmed by randomized controlled trials in humans and still needs to be verified.
4. Reduce the mortality rate of coronary heart disease
CHD is a kind of myocardial hypoxia, ischemia, and subsequent changes in cardiac function caused by the stenosis (atherosclerosis) of the main arteries of the heart. Possible symptoms include fatigue, shortness of breath, chest pain, and palpitations. If the coronary artery suddenly becomes completely blocked, it can lead to a heart attack (such as heart failure or myocardial infarction). A prospective generational study (with a follow-up period of 22 years and 22035 participants) found that the use of omega-3 polyunsaturated fatty acid supplements (mainly fish liver oil) helped reduce the mortality rate of coronary heart disease by 26% compared to unsupplemented individuals, especially in populations with lower fish consumption and an average age of approximately 60 years old.
* Conclusion: Population observations have found that daily intake of fish liver oil may help reduce the mortality rate of coronary heart disease. However, considering possible interfering factors, more research is needed to confirm this.
Side effects:
For most healthy adults and children, using an appropriate dose of cod liver oil is very safe, and reported side effects or adverse reactions include: oral odor, belching, bad breath, heartburn, loose stools, and nausea (recommended to be taken with meals to reduce these side effects). Please do not exceed the recommended dosage indicated on the product without medical supervision.
* Excessive intake of vitamin A may cause symptoms such as nausea, headache, fatigue, loss of appetite, dizziness, dry skin, peeling, and cerebral edema, with a maximum tolerable intake of 10000 IU or 3000 mcg of retinol activity equivalent per day.
* Excessive vitamin D may cause symptoms such as kidney stones, bone loss, and calcification of organs such as the kidneys and the heart. The maximum tolerated intake is 4000 IU or 100 mcg per day.
Finally, if you have any doubts about supplementing health foods, it is recommended to consult a physician and follow professional advice!
