As the most popular dietary supplement in the United States, fish oil has been linked to increased longevity by combatting a series of chronic diseases such as breast cancer. Among 6,000 Americans who take dietary supplements on a daily basis, fish oil ranked first, followed by multivitamins, vitamin D, calcium, and coenzyme Q10 (CoQ10), reports a survey conducted by ConsumerLab.com. Fish oil's omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are the two main fatty acids that are considered to be vital nutrients that can aid the immune system. The American Heart Association (AHA) recommends patients without a history of coronary heart disease (CHD) to eat omega-3 fatty fish oils at least two times a week, while patients with a history should consume 1 gram of fish oil. An increase in fish oil production is largely due to the numerous health benefits associated with the heart-healthy oil. It is important to consume fish in moderation to prevent exposure from contaminants.

Fish Toxins And Pregnancy

The amount of contaminants or toxins — mercury, dioxins and polychlorinated biphenyls (PCBs) — in a fish depends on the type of fish, its age, and where it was originally caught. Large fish such as shark, tilefish, swordfish, and king mackerel have higher levels of mercury than smaller fish, says Mayo Clinic. Generally, the health benefits of consuming omega-3 fatty acids outweigh the risks, but the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) advises women who are pregnant or trying to become pregnant, breast-feeding mothers, and children under the age of 12 to limit consumption.

The mercury levels attained from fish oil can be detrimental to brain development and the nervous system of unborn and young children. In an article published in Current Problems in Pediatric and Adolescent Health Care, a scientific study on the effect of a high mercury diet in pregnant women and their 1,022 Inuit children from the Faeroe Islands was discussed. The expectant mothers had a diet high in pilot-whale blubber and meat, which contains large amounts of methylmercury. Researchers measured the MeHg levels in the pregnant women's hair at the end of their pregnancy and found large amounts of MeHg. When the children of the mothers turned seven, researchers performed cognitive and motor skills tests and found that the high level of MeHg during the mothers' pregnancy was directly related to greater Impairments of language, attention, and memory in the children.

Cooking With Fish

With a moderate amount of omega-3 consumption, it is important to know the basics of cooking with fish. Tilapia and catfish are said to not be as heart-healthy as other fish because they contain higher levels of unhealthy fatty acids. The key to cooking fish is how it is prepared. If a fish is deep-fried, it can lose a lot of its nutritional value and can increase the risk of cardiovascular disease, says the University of California Berkeley Wellness. Fish that is broiled or baked is a healthier alternative and can still preserve the fish's original nutrients.

Fish Oil And Its Prevention of Chronic Diseases

Fish's main beneficial nutrient — omega-3 — contains EPA and DHA, which have been linked to combatting a series of health issues that affect the body. EPA and DHA can fight cardiovascular disease and reduce triglyceride levels in the blood, especially in those with type 2 diabetes, says American Diabetes. Fish oil can provide a solution for increased longevity for those suffering from chronic diseases.

Breast Cancer

A high intake of fish oil can reduce a woman's breast cancer risk by 14 percent, says a study published in British Medical Journal (BMJ). Chinese researchers analyzed 21 studies of 16,178 breast cancer occurrences in 527,392 patients and found fish oil prevented breast cancer in 96 percent of the patients even though the patients were originally predisposed to the disease. The reduction rate — 14 percent — of breast cancer occurrence later in life was in postmenopausal women.

Cardiovascular Disease

Fish oil can lower the levels of bad cholesterol (LDL) and increase the levels of good cholesterol (HDL). These omega-3 fatty acids can decrease triglycerides, lower blood pressure, and reduce blood clotting, says the AHA. Fish oil is especially effective for aiding atherosclerosis, a slow disease in which the arteries become blogged and hardened. This disease is a risk factor for cardiovascular disease and has the potential to cause blood clot that can block blood flow to organs in the body, says the University of Maryland Medical Center. Omega-3 can reduce inflammation in the body; inflammation can damage blood vessels that lead to the heart.

Kidney Disease

Kidney failure or renal failure refers to the scarring of the kidneys or no kidney function. In a paper published in the Journal of the American Society of Nephrology, James Donadio examined the long-term use of fish oil by patients with IgA nephropathy, a kidney disorder when IgA — a protein that helps the body fight infections — stays in the kidney. The participants of the study were followed for approximately seven years, and 85 percent of the patients who took fish oil were said to have a functioning kidney eight years after the study began. While high fish oil consumption and its relation to kidney disease require further research, scientists reveal that it can alleviate the disease.

Osteoporosis

The bone disease that will affect one of every two women and one in every five men older than 50 years of age can be aided with omega-3, says the International Osteoporosis Foundation (IOF). Four grams of fish oil per day can help keep and even increase bone mass, says the University of Maryland Medical Center. The fatty acids have been linked to an increased amount of calcium that the body absorbs, and can get rid of the calcium lost in urine while improving bone strength and stimulating bone growth.

Asthma

Omega-3 that is derived from New Zealand green-lipped mussel has been linked to improved lung function and reduced airway inflammation in those who experience exercise-induced asthma, says the University of Indiana. The study conducted at the University found a "59 percent improvement in lung function, after an airway challenge, and a reduction in airway inflammation, asthma symptoms and the use of emergency medication," says the IU News Room. "Not only does it reduce symptoms, which will make you feel better, but it potentially could improve athletic performance," said Timothy Mickleborough, professor at the University of Indiana School of Public Health in Bloomington and researcher of the study. "Any time you can reduce medication is good."