Cod liver oil is a super supplement with some amazing benefits such as helping to relieve joint pain from arthritis, slow down the eye degeneration that comes with age, hear protection and much more (1).
Cod liver oil is an extract from Atlantic cod livers. Such supplements are packed with numerous benefits, due to their wide variety of vitamins and beneficial nutrients — Vitamin A, Vitamin D, and omega-3 fatty acids like EPA and DHA.
Cod liver oil has numerous benefits, and a truly wide range of people who want to supplement their health can take it for a variety of different reasons.
1Cod liver oil helps to reduce joint pain and arthritis. Cod liver oil can dramatically reduce joint pain and inflammation in patients who suffer from it. It’s even an effective supplement for those who have serious medical conditions related to their joints, such as rheumatoid arthritis. A 2013 double-blind study showed that supplementing patients with cod liver oil dramatically reduced their painkiller usage on a regular basis (2).
In another 9 month study, 39% of people who took the cod liver oil supplements were able to reduce their painkiller intake compared to only 10% who took a placebo (3).
Such results are incredibly promising; they show that even though cod liver oil might not have immediate benefits for everybody who takes it, in some cases it can dramatically impact pain management for those who suffer from arthritis.
That’s a huge benefit, especially because many painkillers, though they may be a necessary part of someone’s treatment plan, come with unpleasant side effects. NSAIDs, for instance, or Nonsteroidal Anti-Inflammatory Drugs, often have adverse effects on the gastrointestinal and cardiovascular systems of people who regularly take them, even as they relieve pain at the same time (4).
2Cod liver oil may help improve your cardiovascular system functioning. Daily, regular intake of cod liver oil (in moderate, not extreme amounts) might help prevent atherosclerosis, a cardiovascular condition wherein arteries narrow and get harder because plaque builds up on the insides of the artery walls (5).
The benefits also don’t simply stop at atherosclerosis, either. Science has long supported the intake of omega-3 fatty acids as a factor for lower mortality rates and fewer occurrences of heart failure (6).
Moreover, fish consumption in general has been linked to a much lower rate of cardiovascular disease in all forms (7).
3Cod liver oil is a great source of important vitamins your body needs to function. Besides the omega-3 fatty acids which are responsible for many of cod liver oil’s benefits to the body, it’s also particularly rich in both Vitamin A and Vitamin D.
That’s because unlike normal fatty fish oil supplements, cod liver oil is extracted from, as you might have guessed, the liver. Normal fish oil supplements are taken from the body or the skin of the fish, meaning they’re not quite as nutritious.
As it turns out, that addition of Vitamin A and Vitamin D is quite beneficial. Vitamin A, for instance, can help with everything from healthy teeth to healthy skin. It can also help with vision problems (8).
Vitamin D, on the other hand, helps keep your immune system in shape, regulates blood insulin levels and maintains your skeletal system (i.e., your bones and teeth) (9).
4Cod liver oil helps fight off inflammation in the body. Cod liver oil supplements are a potent source of EPA and DHA – fatty acids shown to have some serious anti-inflammatory benefits (10).
Many chronic conditions, like cardiovascular disease, inflammatory bowel disease (IBD), and cancer are actually conditions that involve inflammatory processes, and cod liver oil could help treat them (11).
The omega 3-fatty acids in cod liver oil may reduce chronic inflammation by suppressing the proteins that promote it (12).
5Cod liver oil could help your eyes stay functional as you age. Age-related macular degeneration, or AMD, is a disease that affects your retinas. As you age, your eyes naturally start to see worse and worse: things that were once sharp, like small text and faraway objects, may appear blurry. Colors may be dimmer than they used to be, and overall vision just deteriorates at a slow rate, though total blindness is unlikely.
This is a normal condition and nothing to be ashamed of, but the fatty acids in cod liver oil could help in a big way. Research involving over 600 participants found that those who ate the most omega-3 fatty acids had a 17% lower risk of early AMD and 41% lower risk of late AMD (15).
In one study in 3,502 people aged 55 and over, researchers found that people who consumed the most vitamin A had a much lower risk of glaucoma than those who ate the least vitamin A (18).
There’s also evidence to support that cod liver oil, and other fatty acid supplements could help not only with age-related macular degeneration but also with dry eye disease (19).
6Cod liver oil may fight off cancer. In a study that interviewed 2107 subjects, women who took the most cod liver oil between ages 10-19 were least likely to develop breast cancer. However, the likelihood was not reduced as much with cod liver oil taken between ages 20-29, and not at all with cod liver oil taken between ages 45-54 (20).
7Cod liver oil may help strengthen bones. While cod liver oil and other omega-3 fatty acid supplements are perhaps best known for their role in helping with rheumatoid arthritis, cod liver oil, in particular, can help your skeletal system as well.
That’s mostly due to its status as a Vitamin D supplement. Vitamin D is an essential vitamin for maintaining proper bone health, especially as one ages. Vitamin D deficiencies have been linked to everything from rickets to stress fractures to osteoarthritis (21).
In fact, studies show that when accompanied by a diet high in calcium, taking a vitamin D supplement like cod liver oil can reduce bone loss among adults and strengthen fragile bones in children (22, 23).
Getting enough vitamin D from foods and supplements like cod liver oil is especially important for people who live far from the equator, as their skin doesn’t get enough sunlight to synthesize vitamin D for up to six months of the year (24).
In fact, there are a number of different ways Vitamin D might help regulate bone health, whether through the way it strengthens muscles around bones or through the way it interfaces with your immune system (25).
8Cod liver oil helps combat depression and other mental health issues. If you’re suffering from an inflammatory condition like rheumatoid arthritis, for example, there’s a very good chance that the inflammatory cytokines that characterize that condition are also having an effect on your mental health (26).
Moreover, many studies have also found a link between increased blood levels of vitamin D and a reduction in symptoms of depression. And since cod liver oil is packed with vitamin D, this supplement becomes yet another effective tool in protecting your mental health (29, 30).
There could also be something about cod liver oil that directly treats depression, though the science to date is inconclusive on what exactly that might be. In one study, high levels of depression were negatively associated with cod liver oil intake (31).
In other words, taking cod liver oil either prevented depression in some parts of the study population, or their depressive symptoms abated at least partially after using cod liver oil for a period.
9Cod liver oil may help stomach issues, like ulcers, heal more quickly. It seems likely that this is due, at least in part, to their nature as anti-inflammatory supplements. In one animal study, cod liver oil supplements both increased the healing of pre-existing gastric ulcers in rats and prevented their occurrence altogether (32).
Another animal study found that cod liver oil suppressed genes that are linked with gut inflammation and reduced inflammation and ulceration in the gut (33).
While we haven’t gotten to human trials yet, there’s at least some animal trial evidence for cod liver oil as a stomach ulcer treatment. Further research is necessary to determine whether a suitable treatment for humans can be adapted.
10Cod liver oil can fight off infections and fortify the immune system. In a study of 94 infants and children (6 months to 5 years old) given cod liver oil had fewer pediatric visits for upper respiratory tract infections (1 tsp cod liver oil/day). Children given cod liver oil and a multivitamin also had fewer visits for sinus issues (4 male children with a history of sinus issues) (34).
11Cod liver oil has been shown to protect your organs from damage. One rat study found that cod liver oil reduced liver damage (caused by nitrates) by acting as an antioxidant (35).
1Excess amounts of vitamin D aren’t good for you. Too much vitamin D in your system can actually be toxic; It can impact everything from your weight and eating habits to your cognitive function (36).
Anorexia, inexplicable weight loss, and irregular heart rhythms are all possible side effects of taking too much vitamin D (37).
So as long as you don’t abuse your supplements, this side effect shouldn’t apply.
2Cod liver oil can cause an imbalance of the vitamin A to vitamin D ratio. Some researchers oppose the use of cod liver oil due to a risk of vitamin A overdose with vitamin D deficiency. While this ratio imbalance may explain the discrepancy between data on cod liver oil’s effect on bone mineral density, the vitamin A content in cod liver oil was recently reduced by 75% in Norway (38).
3Eating fish comes with a risk of contaminants. Due to pollution and environmental waste, eating too much fish can actually expose you to environmental toxins, like mercury (39).
Unfortunately, that’s sometimes true for products derived from fish, like fish oil and cod liver oil supplements, as well. When choosing a cod liver oil supplement, make sure to research where and how the supplement is sourced, as well as how it’s processed. That’ll give you a clue as to whether or not it’s sustainably sourced and healthy to consume.
4Cod liver oil may increase the risk of thyroid cancer. A study of 60,000 Norwegians found that consumption of fish and cod liver oil may increase the risk of thyroid cancer. Since thyroid follicle cells are sensitive to vitamin D, the improper ratio of vitamin A to D is a possible factor (40, 41).
5Cod liver oil may increase blood pressure during pregnancy. A study of 549 pregnant women found that slightly higher intakes of the omega-3 fatty acids found in cod liver oil (more than 0.87 g/day or 1 tsp/5 mL of cod liver oil) in the early stages of pregnancy increased incidence of high blood pressure. The dosage associated with the lowest risk was 0.6-5.0 mL of cod liver oil (42).
As stated above, too much cod liver oil really can be a bad thing for you. That’s not a result of the omega-3 fatty acids that it’s often touted for, however; it’s actually a result of cod liver oil’s high vitamin D content. For that reason, daily dosage should focus on the EPA/DHA and Vitamin A/D dosage, not necessarily the liver oil itself.
A proper dosage of EPA/DHA is around 300-500mg per day, while a proper dosage of Vitamin D is around 500 IU, not to exceed 1000 IU. Again, different cod liver oil supplements will vary in the exact amount of either EPA/DHA or Vitamins A/D they have per pill or per mL, so this is one time when reading the label will be your best bet.
Is cod liver oil safe? Yes! As far as dietary supplements go, cod liver oil is relatively safe and well-researched. In normal daily amounts, it’s totally safe to take, even for children. That said, it can be dangerous if abused because of its high Vitamin D content, so don’t overprescribe yourself and be careful when measuring dosages for children or young adults.
Can pregnant women take cod liver oil? Unfortunately, no. Pregnant women should abstain from taking cod liver oil while they’re pregnant, though they can certainly start back up again once they give birth. That’s because cod liver oil contains high levels of Vitamin A in the form of retinol, which can be dangerous to your unborn baby. If you’re concerned about getting the proper amount of omega-3 fatty acids while pregnant, it’s best to simply eat fish.
Are cod liver oil and fish oil supplements the same thing? No! Cod liver oil and fish oil are actually pretty different, even though they sound quite similar. Both offer omega-3 fatty acids, with all of the associated benefits listed above. But while fish oil supplements are extracted from whole fish, cod liver oil is made using only the liver. This gives cod liver oil a higher Vitamin A and Vitamin D content, making it more nutritious.
Is cod liver oil better than a normal fish oil supplement? That depends upon your needs. If you only want omega-3 fatty acids, then either would suffice. However, if you want to get a proper Vitamin A or Vitamin D supplement at the same time that you’re getting those fatty acids, then cod liver oil would be a better choice.
Can I take both cod liver oil and fish oil supplements at the same time? Technically, yes, you could, though it might not necessarily make much sense to do so. Cod liver oil will give you much the same benefits as a fish oil supplement, but with the added benefits of Vitamin A and Vitamin D supplementation.
Where does cod liver oil come from? Cod liver oil is extracted specifically from the livers of Atlantic cod. It doesn’t come from other types of fish or other parts of fish. If a label says so, then you’re probably looking at a more general type of fish oil supplement.
Are there any drug interactions I should know about? While there aren’t any serious, totally threatening drug interactions associated with cod liver oil, users who take it along with a blood thinner like Aspirin or other blood pressure medications should exercise caution. That’s because cod liver oil may lower blood pressure or prevent clotting, leading to either low blood pressure or to bruising.
Can I take cod liver oil as a medication for mental illness? Cod liver oil should not be seen as a standalone solution for mental health conditions. If you suffer from depression or another serious mental health issue, talking with your doctor or psychiatrist is your best bet. That said, if you’re already on medication or seeking some other kind of therapy, then cod liver oil may be able to supplement said treatment.
As far as dietary supplements go, cod liver oil is one of the best bets you can make. It has a whole host of benefits associated with the omega-3 fatty acids, EPA and DHA, that it carries, helping patients with everything from rheumatoid arthritis to age-related macular degeneration. It can even help with certain cardiovascular diseases and may have a positive impact on mental health. Whether you’re concerned with aging joints or heart health, cod liver oil may be a good supplement to add to your daily routine.
As always, consult with your doctor or physician before starting a new supplement to see if it’ll interfere with any current course of treatment you may be going through.