EPA and DHA have been said to assist brain function and support normal growth and development, but fish oil is typically consumed to treat the following:
- Heart disease
- High blood pressure
- Rheumatoid arthritis
- Mood disorders
- Some cancers
The only afflictions that fish oil is clinically proven to relieve: high triglycerides and cholesterol.
Which foods are good sources of omega-3s?
Most experts agree that whenever possible, it’s best to get nutrients from whole foods rather than vitamins. “As is almost always the case with all nutrients, they are better absorbed as food, because that’s what our body was created to process,” says Abrams, “omega-3 from whole fish is better absorbed than from fish oil capsules.” Plus, whole fish provides nutrients fish oil supplements can’t, like protein, vitamin D, and selenium, the last of which helps protect against mercury toxicity.
Dr. Andrew Weil, famous for his writing on holistic health, recommends eating “oily fleshed, wild-caught, cold-water fish” two to three times per week. He lists his favorites as salmon, mackerel, sardines, herring, and black cod. Kressler agrees that this amount, combined with a lower omega-6 intake, would be enough for most people.
Even if you don’t eat animal protein, you can get omega-3s from food. This is where the third omega-3 comes into play — alpha-linoleic acid (ALA). It’s found in vegetable oils, nuts, seeds, leafy greens, and grass-fed animals, and our bodies convert it into EPA or DHA in order to be used. Some of the best sources: chia seeds and flax seeds, which contain 2,600 mg and 2,300 mg of omega-3s per tablespoon respectively.
What are the risks of eating fish?
Fish are only as healthy as the ocean they swim in, and increasingly reflect worrisomely high levels of mercury and plastics. The answer: Eat lower on the food chain. When it comes to toxins, not all fish are created equal. Picture a little fish with low levels of mercury in its system. If a medium-sized fish eats these little fish every day, its body will fill up with mercury. And if a big fish eats those medium-sized fish regularly, its body will be even more stuffed with toxins. This is called biomagnification, and it continues all the way up the food chain, straight to us.
Biomagnification is the reason why Abrams recommends eating sardines, which offer high levels of omega-3s and, because they’re low on the food chain, have very low levels of toxicity. They’re also a more sustainable source, adds Dr. Michael Murray, a doctor of natural medicine and director of product science and innovation at Natural Factors, a Canadian supplement company.
Why take fish oil?
There are a couple of reasons why getting all of your omega-3s from whole fish might not be the best or most practical way to go. Sears cautioned that because fish contain contaminants like PCBs and mercury, eating enough for a therapeutic dose of EPA+DHA could be dangerous. Abrams said that while nutrients may be better absorbed from whole foods, buying all the fish you need could get expensive, too — and, of course, some people just don’t like eating fish.
Can fish oil go bad?
When unsaturated fats, like EPA and DHA, are exposed to heat, light, or oxygen, they can oxidize, or go “rancid.” This can happen during production or even afterward, once the oil has already been packaged, if it’s stored improperly or kept for too long. Because of its molecular structure, fish oil is especially vulnerable to oxidation, so most supplements will come in dark brown or opaque bottles. If they don’t, stay away from them.
Oxidation doesn’t just mean going stale or becoming less effective either. It actually turns a healthy, anti-inflammatory substance into a harmful, pro-inflammatory one that might contribute to the diseases you’re trying to avoid in the first place. Rancid fish oil “increases inflammation, just like rancid cooking oils,” said Abrams. “That’s why you want to make sure you’re taking fish oil that is outside-tested for quality, for purity, for cleanliness, and that has an expiration date on it so it’s pulled off the shelf prior to becoming rancid.”