What they are
Fat molecules have a long backbone of carbon atoms bound to hydrogen atoms. When a particular carbon is “saturated,” it forms a single bond with two other carbon atoms, and two hydrogen atoms. When consecutive carbons are “unsaturated,” they’re each only bound to a single hydrogen atom, allowing the neighboring carbon atoms to form a double bond with each other. This typically causes a bend in the carbon backbone.
Omega-6 fats are polyunsaturated fats with at least three pairs of unsaturated carbons, and multiple bends in the carbon backbone of the fat. These bends in the carbon backbone make the fat molecules less likely to stack up in an orderly fashion, thus making omega-6 polyunsaturated fats liquids at room temperature.
Omega-6 fats all have a double bond between the 6th and 7th carbons from the end of the carbon backbone.
What they do
The vast majority of omega-6 intake comes in the form of linoleic acid (LA). LA is an essential fatty acid, meaning it’s necessary for human health, but the body can’t synthesize it.
LA, and omega-6 fats more broadly, get a bad rap because they’re generally pro-inflammatory. When your body generates an inflammatory response, that inflammatory response is generally mediated through a group of compounds called eicosanoids. The pro-inflammatory eicosanoids are primarily made from arachidonic acid. You can consume arachidonic acid in your diet, but most arachidonic acid in the body is synthesized from LA.
Concerns about the pro-inflammatory effects of omega-6 fats are probably overblown. Omega-6 fats don’t cause inflammation. They merely allow for the creation of molecules that mediate inflammatory responses that are generated for other reasons. So, if you’re doing things that should generate an inflammatory response, the molecules created from omega-6 fats allow that inflammatory response to occur. Contrary to the current fear-mongering about omega-6 fats, omega-6 fat intake is not associated with all-cause mortality, and it’s associated with some positive cardiovascular health outcomes.
The recommended intake of linoleic acid is 17g/day for younger men (below 50 years old), 12g/day for younger women, 14g/day for older men (above 50 years old), and 11g per day for older women.
Likelihood of tracking completeness: Very low
Omega-6 fats are not nutrients food manufacturers are required to disclose on nutrition labels. The vast majority of food manufacturers do not voluntarily list omega-6 fat content on nutrition labels, so most branded products in the MacroFactor database lack information on omega-6 fats. So, if you’d like to accurately track your omega-6 fat intake, you’ll need to make a point of mostly tracking “common foods,” which come from research-grade databases that have full nutrient reporting.
For more on when you can track using branded foods versus common foods when you’re trying to accurately monitor your intake of particular nutrients, you should check out this article.
Likelihood of insufficient intake: Very low
Most adults in developed countries consume adequate amounts of omega-6 fats.
For more on nutrients with a greater likelihood of insufficient or excessive intake, you should check out this article.
Signs of deficiency/insufficiency
Though rare, LA deficiencies can cause scaly skin lesions, a reduction in blood platelet levels, poor wound healing, and an increased susceptibility to illness and infections.
The best sources of omega-6 fats are typically nuts, seeds, and seed oils. Safflower oil, grapeseed oil, and sunflower seed oil are especially high in omega-6 fats.
If you’d like to learn more about micronutrients generally, there’s a five-part series on the MacroFactor website you might enjoy.