Fish oil supplements offer certain healthy fats and other nutrients that may help to reduce the risk of heart disease. Sardines are a healthy source of omega-3 fatty acids, vitamin B-12, vitamin D and calcium. Compared with other fish, sardines have among the highest concentrations of omega-3 fatty acids -- about 2.8 g per 6 oz. -- and lowest concentrations of mercury. Fish oil supplements may provide higher dosages of specific nutrients than sardines do, but consult your physician before taking them.
Omega-3 Fatty Acids
Eicosapentaneoic acid, or EPA, and docosahexaneoic acid, or DHA, are long-chain omega-3 fatty acids found in cold-water fatty fish such as sardines, salmon, tuna, herring and halibut. Fish oil supplements often contain one or both of these omega-3 fatty acids. Obtaining EPA and DHA either from tablets or from eating sardines can lower your blood levels of triglycerides and cholesterol, slow the buildup of plaque in your arteries, lower your blood pressure and reduce the risk of abnormal heart rhythms, heart attack, stroke and death. However, taking high doses of omega-3 fatty acids can increase your risk of internal bleeding.
Vitamin B-12, also called cobalamin, is a water-soluble nutrient you need to develop red blood cells and DNA and to support nerve function. The recommended dietary allowance for vitamin B-12 for adults is 2.4 mcg per day. Vitamin B-12 is only found in animal products, particularly shellfish, fish and organ meats. Sardines are an excellent source of the vitamin, providing 8.22 mcg per 3.75-oz. serving. Fish oil tablets, on the other hand, do not contain vitamin B-12.
Fish oil is one of the few sources of vitamin D in the human diet. Sardines provide 178 IU of vitamin D per 3.75-oz. serving. People between the ages of 1 and 70 years of age require 600 IU of vitamin D daily, and people older than 70 require 800 IU. Your body produces vitamin D after your skin is exposed to the ultraviolet rays of the sun. In fact, you can meet between 80 and 90 percent of your vitamin D requirements through exposure to sunshine. People who do not get sufficient skin exposure to sunlight each day or eat foods that contain sufficient amounts of vitamin D can obtain the nutrient daily by taking fish oil supplements.
Fish can often come in contact with toxic chemicals, such as mercury, that it retains and can pass on to those who consume it. Although sardines are comparatively low in mercury, fish oil tablets may still carry less risk. Research by scientists at Massachusetts General Hospital and Harvard Medical School in Boston and published in the "Archives of Pathology and Laboratory Medicine" in December 2003 analyzed five brands of fish oil supplements for mercury and found negligible amounts. The scientists concluded that fish oil supplements may provide a safer alternative to fish consumption.