Doc: Cod liver oil treatment OK?
Dear Dr. Roach: About 10 years ago, after a blood test, my doctor noted that my triglycerides were about 450, whereas the norm would be below 150. He didn't seem alarmed, so for the next two years I did nothing and they remained in the 400 range. After moving to Arizona, I visited a naturopath (NMD), who reviewed my blood test. The NMD indicated that the high level could lead to a stroke and that I should start taking a cod liver oil capsule daily. I have seen ads on TV for expensive supplements to combat high triglycerides, but wanted to try the cod liver oil capsule first. The NMD noted that I should look for the supplement with the highest level of omega 3. Mine has 675 mg. Although I've taken vitamin supplements for years, I've never seen any eyeopening results from doing so. I was skeptical, but did as suggested and retested the following year to find that my triglyceride level had fallen to 98. This was pretty amazing — something that actually worked! Please note, your levels will fluctuate with your sugar intake.
Dear E.A.Z.: In addition to cholesterol, there are many other blood factors associated with an increased risk of heart disease. It hasn't been clear, however, whether these substances — such as triglycerides, chylomicrons, low-density lipoproteins (LDL) and high-density lipoproteins (HDL) — are causing heart disease. For this reason, there is intense debate about whether lowering the blood levels of these substances cuts risk for heart attack. There certainly are medications that improve blood levels but don't cut heart disease risk. The only class of medications that definitively improve the numbers and cut risk is the statin class. These cut the risk of heart attack, stroke and overall mortality. The greater the individual's risk, the more the reduction.
Cod liver oil is a type of fish oil that contains omega 3 fatty acids, but unlike other supplements, it contains high levels of vitamins A and D. Some brands of cod liver oil can lead to vitamin A toxicity, and since brands vary in strength, if you choose cod liver oil, you should avoid high doses. The Institute of Medicine recommends no more than 10,000 IU daily, and smokers may have an increased risk of lung cancer at doses as low as 25,000 daily. High doses also increase risk of birth defects if taken by pregnant women.
The benefit of omega 3 fatty acids in preventing disease has been suggested, but not proven for people with known coronary artery disease or at high risk for coronary artery disease. There is no evidence for harm from recommended doses, so it is reasonable for people who don't get omega 3 from eating fish to consider taking a supplement, especially for people with higher-than-normal risk for heart disease.
Finally, as you wrote, sugar or any processed carbohydrate often will hike triglyceride levels. This is another possible pathway to damage from excess sugar.
Dr. Roach Writes: Several readers wrote in about the case of excessive urination at nighttime. One reader wrote that he was diagnosed with sleep apnea, and that treatment cured the problem. This is well-described, and I should have included it in my list of possibilities. Another writer warned of the dangers of excess ddAVP hormone, leading to low sodium levels and seizures. This is very rare if the dose is kept at the recommended level, but a useful warning not to exceed that dose.
Email questions to ToYourGoodHealth@med.cornell.edu.