Omega-3s: The Latest Science on Essential Fats for Health and Longevity

The evidence is growing that eating foods packed with Omega-3s will improve your heart health and extend your life. A June 2016 meta-analysis published in Scientific Reports supports the link between the intake of EPA and DHA Omega-3 fats and a reduced risk of death by any cause.

The general recommendation for an Omega-6 to Omega-3 ratio is from 2:1 to 4:1

The meta-analysis included 11 studies involving 371,965 participants. It showed a 9% reduced risk of death from all causes in people who consumed a diet high in Omega-3s. Those who increased their intake of EPA/DHA to 300 mg per day showed a 6% lower risk of death by all causes.

According to Manfred Eggersdorfer,the study author:

“The meta-analysis of 11 prospective observational studies demonstrates that each 1% increment of Omega-3s in total fatty acids in blood may be associated with a 20% decrease in risk of all-cause mortality. This is an important finding for the potential contribution of adequate Omega-3 intake to public health.”

This latest analysis supports other research findings, including a 2013 study published in the Annals of Internal Medicine showing an association between higher Omega 3s and a lower total mortality, especially death from Coronary Heart Disease.

What are Omega-3s?

While saturated fat has been shown to contribute to heart disease, along with a number of other chronic diseases, Omega-3 polyunsaturated fats are essential to maintaining good health and have many proven health benefits, including improving heart health.

Omega-3s are an integral part of cell membranes throughout the body and affect the function of our cells. They are the building blocks of hormones that regulate blood clotting, contraction and relaxation of the artery walls, and inflammation. Omega-3s also binds to receptors in cells that regulate genetic function.

The body can synthesize most of the fats it needs. However, the body cannot effectively make certain Omega-3 fats. Instead the food we eat or a supplement must be supply them.

To learn more about the importance of Omega-3 fats and good options to obtain then, we recommend our Ornish Living article Omega 3: All Fats are Not Created Equal. 

The Three Main Types of Omega-3s

Alpha-linolenic (ALA)

Sources: flaxseed; soybeans (soybeans/edamame, tofu, tempeh);wheat germ;walnuts; hemp;chia, pumpkin seeds; and rapeseed (canola oil). There are also small amounts in leafy green vegetables.

Eicosapentaenoic acid (EPA)

Sources: fish; small amounts in eggs and seaweed.

Docosahexaenoic acid (DHA)

Sources: fish; small amounts in eggs and seaweed.

ALA: The “Essential” Omega 3

Alpha-linolenic acid (ALA) is the true essential Omega-3. Essential means the body cannot make it and it must be obtained by food or supplements. By consuming ALA (for example, 2 tablespoons of ground flax seeds) it can be converted into the beneficial EPA and DHA by the body. The main problem with ALA, however, is that there is a limited conversion rate to EPA and DHA, especially DHA. It requires large amounts of ALA to produce the optimal amount of DHA. As a result, only a small fraction of ALA can produce the beneficial effects of Omega-3s.

Studies indicate that for men only about 8% of dietary ALA is converted to EPA and 0-4 % to DHA. For women approximately 21 % of dietary ALA is converted to EPA and 9 % to DHA.

Genetic Influence and The Omega 6 Balance

In addition to the limited conversion rate and gender differences, genetics can impact one’s ability to convert ALA to EPA and DHA. Genetics may explain up to 30 % of the variability in blood levels of Omega-3 fatty acids among individuals.

Research has shown that 3 grams (the equivalent of 2 tablespoons of ground flaxseed or about 1-1/2 teaspoons of flaxseed oil) per day of ALA does not increase blood percentages of DHA in the short term, but it may over a longer period of 10 months or more.

ALA levels do increase, however, if the ratio of Omega-6s to Omega-3s is low. Omega-6s, which are another type of essential fats that comes from sources such as oils, nuts, seeds, poultry and eggs compete with Omega-3s for the same enzymes. Therefore, how many Omega-6s we ingest will impact the levels of our Omega-3s. Human beings evolved on a diet with a 1:1 ratio of Omega 6 to Omega 3 essential fatty acids (EFA). The ratio is close to 15 Omega-6s to 1 Omega-3s in today’s standard American diet . Excessive amounts of Omega-6 polyunsaturated fatty acids (PUFA) and a very high Omega-6/Omega-3 ratio have been found to promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases.

On the other hand, a lower ratio of Omega-6 to Omega-3 fatty acids has been shown to reduce inflammation and the risk of chronic disease such as cardiovascular disease, cancer, and inflammatory and autoimmune diseases.  The general recommendation for an Omega 6 to Omega 3 ratio is from 2:1 to 4:1, but most health experts advocate 2:1 and even lower.

A 2003 study published in Circulation originally established the benefits of Omega 3s for cardiovascular health and the prevention of arrhythmias and sudden cardiac death. Dr. Alexander Leaf, one of the leading researchers, noted that the findings supported the theory that an imbalance of Omega 3s and Omega 6s may promote arrhythmias in some people. For those with a personal or family history of heart disease, it’s suggested to include Omega-3s as a supplement or to add Omega -3 rich foods to an already healthy diet. At the same time, it’s recommended to reduce Omega-6s (which are abundant in plant seed cooking oils such as corn, safflower, and sunflower seed oils).

Toxins in Fish

Fish contain significant levels of toxins including methylmercury, polychlorinated biphenyls (PCBs), dioxins and other environmental contaminates. PCBs are absorbed into the bodies of fish. Bigger fish that eat smaller fish accumulate greater and greater concentrations of PCBs in their flesh, which can reach levels that may be many thousands of times higher than the PCB levels in the water itself.  PCBs are dangerous because they act like hormones, wreaking havoc on the nervous system and contributing to a variety of chronic illnesses such as cancer.

The CDC reports that toxic poisoning from fish and seafood is under-recognized and at risk to increasing as a result of climate changes and other factors. A number of studies show that farmed salmon accumulate PCBs from the fishmeal they are fed. The feed is often designed to have high amounts of fish oil and is made largely from ground-up small fish. PCBs concentrate in oils and fat, and previous tests of salmon feed have consistently found PCB contamination at high levels, even more than wild caught fish. Six of every ten salmon sold in stores and restaurants are raised in high-density fish pens in the ocean, compelling evidence of industry-wide contamination with unacceptably high levels of PCBs. On average farmed salmon have 16 times the dioxin-like PCBs found in wild salmon.

Research is beginning to examine the idea that these dangerous pollutants in fish may overshadow the health benefits of the Omega-3s . A 2014 study published in the Journal of Internal Medicine showed that fish pollution increases the risk of strokes in women.

What if I Don’t Eat Fish?

A 2010 study in the American Journal of Clinical Nutrition found that the blood levels of EPA and DHA in vegans and vegetarians were approximately the same as regular fish eaters. This finding indicates that the bodies of vegetarians and other non-fish-eaters can perhaps respond to a lack of dietary Omega-3 EPA and DHA by increasing their ability to make them from Omega-3 ALA.

Omega 3 Supplements

There are several options to ensure beneficial levels of DHA and EPA on a low-fat, plant-based diet such as Ornish Lifestyle Medicine (Intensive Cardiac Rehabilitation) If you are looking for a vegan option, a plankton/algae supplement is an excellent alternative. If you’re not a strict vegan, a high quality, purified fish oil supplement can be a great option. It is important for supplement manufacturers to have a Certificate of Analysis (COA). COA is an analysis performed by an independent lab to measure the ingredients of a product and confirm whether it lives up to the claims made by the manufacturer.

For more information about choosing an Omega 3 supplements, see Ornish Living article, Omega 3: All Fats are Not Created Equal 

Have you noticed a difference by adding Omega 3s?