Update on Fish Oil
Updated: Aug 30, 2018
Certain fats in our diets are important nutrients for health and others should be avoided as risk factors for disease. In general, saturated fatty acids from animals (such as beef) and animal products (butter) are considered unhealthy and polyunsaturated fats from vegetables promote health. There is a unique class of polyunsaturated (healthy) fats found ironically in marine animals, most notably oily fish. These fats are contained in fish oil and as a class are known as omega-3 fatty acids (O-3FA). The human body can synthesize (manufacture) most types of fats that it needs from other fats or raw natural materials. This isn’t the case for O-3FA’s. These are called essential fats because the body cannot synthesize them from scratch but must obtain them from dietary sources. There are three main O-3FA’s: EPA, DHA, and ALA. ALA is the most common O-3FA in the Western diet and is found in leafy veggies, vegetable oils, flax seed, eggs, nuts (especially walnuts), and some animal fats. The body can convert some ALA into EPA and DHA, but the main source of the latter two is fish; thus, they are frequently referred to as marine omega-3’s. If a traditional western diet is consumed, deficiencies in O-3FA’s is very rare.
So, what ignited the fish oil craze? In the early 1970’s, two Danish researchers visited remote villages in Northern Greenland. According to these scientist, residents in these areas (called Intuits, formerly Eskimos) ate mostly fish, whales, and seals. This diet was obviously rich in fish oil containing O-3FA’s. Since this was animal fat, it was assumed that these people would be at increased risk for cardiovascular disease. Paradoxically, reports of heart attacks were rare and blood samples from the residents revealed low levels of cholesterol and triglycerides, known risk factors for heart disease. Subsequently, the two investigators hypothesized the low incidence of heart disease was likely the result of their high fish oil consumption resulting in high levels of O-3FA’s.
The first major study to test this idea was published in the well-respected British medical journal, The Lancet, in 1989. This investigation involved following over 2000 Welsh men who had previously suffered a heart attack. One portion of the participants were instructed to eat a diet high in oily fish and the remainder consumed their “normal” diet. The group that increased their fish consumption was found to be 29% less likely to die from heart disease over a follow-up period of 2 years. Subsequently, the American Heart Association issued a statement that omega-3 fatty acids from fish oils have been proven to reduce the risk of cardiovascular disease. No fish oil supplements were involved in the study, but the demand for these products exploded. Fish oil supplements and related products are currently the 3rd most widely used supplements in the USA. Some studies estimate the number of Americans using fish oil as high as 23% and people are spending approximately $1.2 billion annually on fish oil pills.
However, in 2003 some of the same investigators who conducted the original study on the Greenland population published the results of a follow-up investigation. Over 3000 participants with known coronary artery disease were prescribed either a diet high in oily fish or given fish oil supplements to compare with people who pursued a traditional diet. This time, the fish group patients were much more likely to die from cardiac disease and the incidence of death was much higher in those who were taking the fish oil supplements (capsules). Subsequent observational studies have been conflicting, but review of fish oil supplement research published in major journals between 2005 and 2014, reveals no health benefit in 22 of the 24 studies. More currently, the vast majority of published research provides no solid evidence of a significand health benefit from these products.
Based on what is known today, consuming adequate amounts of O-3FA’s is important, but rather than supplements, consider eating fish and other sea foods as a healthy strategy. If we could prove that the benefits of eating fish comes entirely from O-3FA’s, then downing fish oil pills might be an acceptable alternative. It seems more likely that to get the health benefits, one needs the entire ‘orchestra’ of fish fat: vitamins, minerals, and other supporting micronutrients rather the ‘solo notes’ of O-3 FA’s. This holds true for other foods as well. Taking a handful of supplements is no substitute for the wealth of nutrients obtained by eating fruits, veggies, and whole grains.
In general, it is wise to avoid supplements unless you have been diagnosed with a true deficiency.
Dr Tippett is the founder of CQHP, a concierge internal medicine practice, located at 1210 Commerce Dr. Suite 106 Greensboro, Ga. 30642. He can be reached at 706-510-3659. Visit his web page at drtippett.com