The right balance of omega-3 and omega-6 fatty acids is crucial to health, but many people may not be aware of challenges in achieving this balance due to insufficient nutrients or genetic predisposition.
Many of us know by now that regularly eating fish, or taking fish oil supplements, has heart-protective and anti-inflammatory effects on our health. This is due to the omega-3 fatty acid content of these foods. Unfortunately, the Western diet has seen a much more pronounced rise in consumption of omega-6 fatty acids. When the ratio of omega-6 and omega-3 fatty acids is so out of whack, bad things happen to our health as we’re witnessing in the steady rise of chronic, inflammatory diseases like heart disease, type 2 diabetes, autoimmune conditions, and more. Many people may not be aware that certain populations have genetic predispositions that increase their need for certain omega-3s because their bodies cannot convert plant forms to the forms needed by the body. Other people may lack the necessary nutrients to perform these important conversions.
Achieving the right balance is so critical because 1) most Americans get way too much omega-6 and 2) too much omega-6 in the diet crowds out metabolism of omega-3s. Most omega-3s in the diet come from plant foods like nuts and seeds in the form of alpha-linolenic acid (ALA), which needs to be converted to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); omega-6s also need to be converted. Both conversions are performed by the same set of enzymes. If you eat a lot of processed foods that are high in omega-6s, when you do eat foods like flax seed oil or walnuts, your body won’t be able to convert them to the anti-inflammatory compounds that benefit health. A diet with a higher proportion of omega-6 will increase inflammation and make you more susceptible to disease.
We need to eat fish or fish oil to get the important long-chain omega-3 fatty acids EPA and DHA. It is possible for the body to synthesize EPA and DHA from ALA found in foods like walnuts, flax seed, and pumpkin seeds, but this conversion is extremely limited: studies have found that about 8 percent of dietary ALA is converted to EPA and 0-4 percent is converted to DHA. EPA and DHA have been shown to protect against many chronic diseases and reduce overall mortality.
This is particularly a concern for vegetarians who do not eat fish and try to get their omega-3 from plant sources. Additionally, the conversion of ALA to DHA depends on iron, among other nutrients, and the bioavailability of iron from plant sources is also quite low compared to animal sources. This is another reason that vegetarians are poor converters of ALA to DHA. The conversion of ALA to EPA and DHA also requires B vitamins, calcium, copper, zinc, and magnesium. Populations who are deficient in these vitamins and minerals will have an impaired ability to convert omega-3s into the useful forms. Certain conditions like Crohn’s disease, celiac disease, HIV, and alcohol use disorder prevent the body from absorbing B vitamins, as are older adults and pregnant women—so these populations may also have an impaired ability to convert ALA to EPA and DHA.
Further, certain single nucleotide polymorphisms (SNPs) in the FADS genes influence how well the body converts ALA into EPA and DHA. Specifically, the enzyme that converts ALA to EPA and DHA has reduced activity in people who carry the minor allele in FADS1 and FADS2, which means they have lower levels of EPA. For these individuals, it is critical to either eat fish regularly or to supplement with fish oil containing EPA and DHA. Research has found that those with African ancestry tend to have efficient conversion enzymes, and those with Native American ancestry have inefficient enzymes.
To get omega fatty acids in balance requires us to reduce intake of omega-6 fats and increase intake of omega-3 fats. Most processed foods contain oils and fats high in omega-6s like sunflower, cottonseed, soybean, and corn oils. Restaurants also commonly use these fats because they are so cheap. It is theoretically possible to increase omega-3 intake without adjusting omega-6 intake, but this isn’t advisable, as it would require eating about 11 ounces of fish a day. Rather, most experts recommend both reducing omega-6 intake by cutting out vegetable oils and other fats high in omega-6, and increasing intake of omega-3s by, for example, eating a 4-ounce portion of salmon twice a week. It’s important to try to get wild salmon, though: the omega-6/omega-3 ratio in farmed salmon is about 14:1, vs 3:1 for wild salmon. Eating farmed salmon will still raise DHA levels, but wild salmon does this without delivering as many omega-6s. This basic principle is true of most other farmed fish compared to wild counterparts: farmed fish have omega-3s, but also more omega-6s. As a side note, this is why farmed salmon is often dyed pink: wild salmon are naturally pink because of the crustaceans and other food they eat in the wild that help impart the higher in omega-3 content. Farmed salmon is naturally gray because they are not fed krill and shrimp.
Grass-fed beef is another source of EPA and DHA; note that grass-fed beef has seven times as much omega-3 fatty acids than conventional beef, which has almost none.
What about foods like avocados, which have an omega-6/omega-3 ratio of about 15:1? Simply put, avocados are still a healthy food because, while it has more omega-6s, the total content of omega fatty acids is relatively low. Most of the fat in an avocado is monounsaturated, and most of that is oleic acid, which has been shown to reduce certain biomarkers of inflammation. If this is all too confusing, an integrative practitioner, nutritionist, or health coach can help guide you to achieve the right balance in your diet.
Anthropological research shows that our hunter-gatherer ancestors consumed omega-6 and omega-3 fatty acids in a ratio roughly of 1:1; they were also free of modern inflammatory diseases like heart disease, cancer, and diabetes. The industrialization of our food supply has disrupted this balance dramatically. Today, our ratio of omega-6 to omega-3 fats is more like 20:1, in some cases 25:1. This is why there are some studies that find no benefit from taking a fish oil supplement: 1,000 mg of fish oil isn’t going to help your heart if you’re also ingesting 20,000 mg of pro-inflammatory omega-6 fats.
Achieving a 1:1 ratio in today’s world is very difficult, so experts generally recommend achieving a range of 1-5:1.
Getting these ratios in balance is a matter of life and death. One study found that replacing corn oil with olive oil and canola oil to reach an 4:1 omega-6/omega-3 ratio led to a 70 percent decrease in total mortality. Elevated omega-6 intake is associated with an increase in all inflammatory diseases that are killing Americans in record numbers. Getting the right balance of omega-3 and omega-6 fatty acids is often over-looked but a critical pillar of health and resilience.