Omega-3 fatty acids are considered “essential” fatty acids, which means they are necessary for human health. Essential fatty acids are important because they are required for the optimal function of every cell in the body, including the production of hormones and the regulation of blood pressure, cholesterol and temperature. Because people not have the ability to manufacture them, they must be obtained from the diet or nutritional supplements.
Omega-3′s are required for brain development, central nervous system function including ocular health, and the regulation of chemical processes. These fatty acids are natural blood thinners and can prevent the blood clots which can lead to heart attacks and strokes. Essential fatty acids contain natural anti-inflammatory compounds that have the ability to relieve symptoms of arthritis and autoimmune diseases. In addition, a diet low in essential fatty acids can result in skin problems, such as psoriasis and eczema, and can also cause problems for the nails and hair.
There are three major types of omega-3 oils:
- alpha-linolenic acid (ALA)
- eicosapentaenoic acid (EPA)
- docosahexaenoic acid (DHA)
Once consumed, the body converts ALA to EPA and DHA, the two forms of omega-3′s that are more easily used by the body, and have the greatest importance to human health.
DHA is essential for the growth and development of the fetal and infant brain and visual system. EPA helps in thinning the blood and dilating blood vessels. It is the fatty acid most associated with a healthy cardiovascular system, and it regulates blood pressure and blood clotting. DHA and EPA work together to support heart health by enhancing nitric oxide production in the blood vessels. Both EPA and DHA inhibit the manufacturing of LDL cholesterol in the liver, thereby supporting healthy circulation.
Omega-3 fatty acids have the ability to decrease the inflammation that may be linked to numerous diseases. Inflammation is now recognized as one of the most important underlying causes of a variety of chronic conditions, such as cardiovascular disease, arthritis, vision problems, autoimmune diseases, depression, skin disorders, age-related macular degeneration and even certain cancers.
A study published in the British Journal of Ophthalmology showed that a diet rich in omega-3 fatty acids can significantly reduce the risk of age-related macular degeneration. AMD is an eye disease of the center of the retina. It causes the loss of central vision, leaving one with only peripheral vision. Previous research has indicated that consuming omega-3 fatty acids may decrease a person’s risk of AMD by one-third. In this current study, researchers sought to determine whether a diet rich in omega-3 could also benefit those who already had the disease. They found that “study participants with early AMD who consumed omega-3′s were 25 percent less likely to have their disease progress to the advanced form.”
The AREDS2 (Age-Related Eye Disease Study 2) research supports the beneficial effects of omega-3 consumption for the prevention of age-related macular degeneration. Increased intake of omega-3 fatty acids were shown to “reduce the risk of both the wet and dry form of AMD by 35 and 32 percent, respectively”, according to results published in the American Journal of Clinical Nutrition.
Another study appearing in the Archives of Ophthalmology showed that omega-3 fatty acids, particularly DHA, play an important role in the layer of nerve cells in the retina, possibly protecting against the onset of age-related macular degeneration. These benefits were most evident against the more advanced form of AMD.
Not only does omega-3 protect against eye disease in adults, but it has been shown to be helpful in the development of infant’s eyes, as well. The European Food Safety Authority (EFSA) has recognized that the omega-3 fatty acids DHA and ALA can contribute to eye and cognitive development in babies. Dr. Julian Kleiner of the EFSA wrote, “DHA has a structural and functional role in the brain and retina and maternal DHA intake can contribute to the early development of the eye and normal cognitive development in the fetus and the brain-fed infant.” And a study published this year in the American Journal of Clinical Nutrition confirmed that infants fed DHA had better eye health than the infants who were not given DHA.
Omega-3 fatty acids are among the most important compounds one can take for supporting a healthy heart. Numerous studies over the past decade have shown that omega-3 oils from fish or fish oil supplements can decrease the risk of atherosclerosis and heart attacks. These fatty acids are capable of reducing high cholesterol and high blood pressure, decreasing triglyceride levels, and preventing blood clots. Recently it has been discovered that omega-3′s can lower levels of the protein homocysteine. Elevated levels of homocysteine are believed to be a key risk factor for heart disease.
Howard N. Hodis, MD, director of the atherosclerosis research unit at the University Of Southern California School Of Medicine in Los Angeles states that the omega-3 fatty acids found in fish oil supplements, have shown great promise in supporting regular heartbeat and preventing arrhythmia. “Omega-3 fatty acids appear to be effective in preventing a second heart attack in men who have already had one,” states Dr. Hodis.
Scientists who conducted a study published in the Journal of the American College of Cardiology are suggesting that everyone should consume omega-3′s daily. This analysis extensively reviewed data from a broad range of studies in thousands of patients over the last 20 to 30 years. According to the lead author of the study, EPA and DHA work by “getting into the membranes of cells and, in doing so, may help improve the heart’s electrical activity, vascular tone, plaque stabilization and blood pressure, among other benefits.”
And in a paper published in the Journal of Clinical Endocrinology and Metabolism, 1123 subjects were examined and those with the highest intake of omega-3 fatty acids had the lowest rate of death from cardiovascular disease.
A study conducted at Albany Medical College and published in the American Journal of Medicine found that omega-3 fatty acids seemed to assist with keeping blood vessels open in a number of people with Raynaud’s disease. Raynaud’s disease is a circulatory disorder caused by insufficient blood supply to the hands and feet resulting in discoloration, numbness and pain. In the study, symptoms of the disease disappeared in five of 11 people taking 12 fish oil capsules daily for two consecutive six-week periods. In a similar group of nine people with Raynaud’s taking olive oil, only one person showed any substantial improvement.
According to findings published in the September, 2009 Journal of Hypertension, omega-3 oils decrease blood pressure and heart rate in kidney disease patients. The study showed that omega-3′s “lowered blood pressure and may reduce cardiovascular risk in non-diabetic patients with moderate-to-severe kidney disease.”
It has been found that dementia in the elderly has been associated with low levels of essential fatty acids. The relationship between omega-3 oils and cognitive function is not new. Some of the more promising data has been reported for the DHA component of omega-3′s. A study in the Journal of Neuroscience found that DHA may improve memory and learning in healthy older adults with a decline in cognitive functions. Such degeneration is said to precede diseases such as Alzheimer’s, the most common form of dementia, currently affecting over 30 million people worldwide.
Studies have shown that children with attention deficit hyperactive disorder (ADHD) may have insufficient levels of EPA and DHA, while supplementation can improve cognitive functioning and may reduce distractibility, hyperactivity, and impulsivity. Alex Richardson, senior research fellow at the University of Oxford in the UK, has done extensive research linking omega 3-deficiency to behavior, learning, and mood disorders.
A growing amount of research seems to support the notion that the omega-3 fatty acids found in fish such as salmon and mackerel play a role in combating the symptoms of depression. And this has been shown to be the case whether the omega-3′s come from the diet or supplements. In addition, other studies have shown that individuals with abnormally low levels of omega-3 oils are more likely to suffer from depression.
An important clinical trial published in the Archives of General Psychiatry reveals that fish oil supplements may help protect against mental illness. The study involved 81 people regarded to be at high risk for psychosis. Fish oil supplements were supplied to half the study participants for 12 weeks, while the other half received a placebo. While 11 people in the placebo group developed a psychotic disorder, only two in the fish oil group did.
Given that essential fatty acids play such a vital role in health, many experts in the field of nutrition believe that a deficiency in omega-3 oils is one of the leading causes of the high rates of cancer occurring today.
Studies have found that men who eat fish more than three times a week have a lower risk of getting prostate cancer. Analysis of more than 6,000 men over 30 years found that consuming omega-3 oils as part of one’s diet had the potential to reduce prostate cancer risk by two or three times.
In a 2009 study appearing in the journal Clinical Cancer Research, scientists evaluated the diets of 466 men diagnosed with aggressive prostate cancer and compared them with the diets of 478 men without the disease. Those who ate fish containing the highest amounts of omega-3 fatty acids one to three times a month had a 36 percent lower chance of developing aggressive prostate cancer than those who ate it infrequently, while those who ate fish once a week or more had a 63 percent lower risk.
A recent study in the American Journal of Epidemiology shows that Omega- 3 fats have the ability to reduce precancerous growths in those prone to bowel cancer. The authors of the study examined the relationship between omega-3 intake and colon cancer, and it was shown that increased consumption of omega-3′s is associated with a reduced risk of the disease.
There is some compelling new evidence that omega-3 fatty acids may prevent breast cancer and may even be a useful treatment for this disease. A 2010 study appearing in the journal Cancer Epidemiology, Biomarkers & Prevention followed 35,000 healthy women between 2000 and 2007. The women who were consuming fish oil when the study originated had a decreased risk of invasive ductal carcinoma, the most common form of breast cancer.
Recent studies show that omega-3 oils help with inflammatory disorders such as osteoarthritis. Several laboratory studies of cartilage-containing cells have shown that omega-3′s help reduce inflammation and decrease activity of enzymes that break down cartilage. A study appearing in a recent issue of the British Journal of Nutrition showed that increased intake of DHA may increase bone mineral content and produce healthier, stronger, bones.
Recent research performed at Brigham and Women’s Hospital in Boston demonstrated that omega-3′s have the ability to convert into compounds that are thousands of times more potent than the original fatty acids themselves. These new compounds include resolvins, which have the ability to reduce cellular inflammation. In a strong and healthy immune system, inflammation acts to repair damage and protect the body from infections. But in arthritis and other inflammatory diseases, an overactive immune response leads to tissue destruction. The study’s research showed that “omega-3′s convert into these more powerful compounds, putting the brakes on this active (inflammatory) process.”
According the most current research, people with eczema seem to have low levels of omega-3 oils, and several studies have shown that getting more omega-3′s in the form of fish oil capsules leads to a reduction in the severity of eczema inflammation and other symptoms. In a Finnish study, 80 people with psoriasis took two capsules consisting of omega-3 fatty acids three times a day for 8 weeks. At the end of the study, the lesions on seven people were completely healed, and 13 participants stated 75 percent healing.
A study appearing in the August, 2010 issue of The Journal of Nutrition found that Omega-3 supplements may be capable of improving blood fat levels in people with metabolic syndrome, a risk factor that increases the chance of developing coronary artery disease, stroke and type-2 diabetes. This data “suggests a place for higher omega-3 intake in people with metabolic syndrome, and supports previous research that suggests…fatty acids can have a positive effect on blood lipid levels.”
New research published in the Journal of the American Medical Association demonstrates that adding omega-3′s to the diet can offer protection from cellular aging. Telomeres, structures at the end of chromosomes, are indications of biological aging. Shortened telomeres are believed to contribute to the aging process. This study showed that omega-3 oils are instrumental in slowing down the shortening of telomeres, which means they may guard against aging on a cellular level.
The scientists found that the research subjects with the least amount of DHA and EPA had the fastest pace of telomere shortening. However, those with the highest levels of the omega-3 oils were subjected to the slowest rate of telomere shortening.
Recommendations for Omega-3 Consumption
Studies measuring the effects of omega-3′s on HDL indicate that regularly adding fatty fish to your diet at least two times a week is a good way to reduce saturated fat intake. For instance, a recent study done at the Harvard School of Public Health reported that the death rate from heart disease was 36 percent lower among people who ate fish twice a week compared with people who ate little or no seafood.
Some examples of foods that contain omega-3 fatty acids are flaxseeds, salmon, tuna, sardines, avocado, walnuts, pumpkin seeds, and wheat germ.
Presently, there are no dietary intake recommendations for omega-3 oils. However, nutrition experts believe that people should consume approximately 4% of their total calories as omega-3 oils, which would translate to about 4 grams of omega-3 oils per day, based on a 2,000 calorie per day diet.
What to Look For When Purchasing an Omega-3 Supplement
Because fish from many sources can be dangerous to eat due to high mercury levels and other toxic compounds, consuming it to receive the benefits of natural fish oils can be a difficult choice. That’s why adding omega-3 in the form of supplements is a sensible option.
Deep-water fish that live in the least polluted waters are the best sources of omega-3, but even then, these fish can still contain high levels of toxins. These toxins can be removed with proper processing techniques, such as distillation and cold-vacuum processes. Look for a product that lists the fish that the oil is pressed from. Some fish are higher in omega-3s than others.
To make sure you get the full benefit from omega-3 supplements, all eight omega-3 fatty acids should be present. These are EPA, DHA, ALA which are the primary omega-3s, and SDA, ETA, ETA(3), HPA and DPA, which will usually be listed as “other omega-3s” on the label. So look for supplements that have a balanced ratio of all eight omega-3 fatty acids. When the total of the nutrients are combined together, they should equal the amount of fish oil in each serving.