It is found in large amounts in vegetable oils and small parts in various other foods.
It is the most common Omega-6 fatty acid. The word conjugated has to do with the arrangement of the double bonds in the fatty acid molecule.
There are 28 different forms of linoleic acid (AL), but two of the most important are “c9, t11” and “t10, c12”.
The difference between the AL shapes is that the double bonds (seen as a double line in the image) are arranged differently, but it is important to note that something as tiny as this can make a big difference in our cells.
So basically, AL is a polyunsaturated fatty acid with cis and trans double bonds. In other words, AL is technically trans fat, but it is a natural type of trans fat found in many healthy foods.
Numerous studies show that industrial trans fats are harmful, while trans fats found naturally in animal foods are not.
Linoleic acid sources
LA’s primary dietary sources are ruminant animal feeds, such as cows, goats, and sheep.
The total amount of AL in these foods varies greatly depending on what the animals ate.
Most people already get some LA from their diet; the average intake in the US is about 151 mg per day for women and 212 mg for men.
The biological activity of linoleic acid was first discovered in 1987 by a team of researchers who showed that it could help fight cancer in mice.
Later, other researchers found that it could also lower body fat levels.
As obesity increased worldwide, people became more interested in linoleic acid as a possible weight loss treatment.
This has now been thoroughly studied, and LA has been shown to have several different mechanisms against obesity.
This includes reducing food intake (calories), increasing fat burning (no calories), stimulating the breakdown of fat, and inhibiting fat production.
Can It Help You Lose Weight?
Fortunately, we have quite a few studies that have been done on linoleic acid.
Linoleic acid may be the most widely studied weight loss supplement globally.
Many studies are so-called randomized controlled trials, the gold standard of scientific experimentation in humans.
Some studies have shown that linoleic acid can cause significant fat loss in humans.
It has also been shown to improve body composition, reducing body fat and sometimes increasing muscle mass.
But before you start jumping up and down with excitement, keep in mind that many other studies show no effect.
Health benefits of linoleic acid
In nature, linoleic acid is mainly found in ruminant animals’ fatty meat and dairy products.
Some studies suggest that people with more linoleic acid have a lower risk of heart disease.
This may do with LA or other protective components in grass-fed animal products, such as vitamin K2.
Of course, grass-fed beef and dairy are healthy for several other reasons, so it’s good to consume them regularly.
Serious side effects
There is considerable evidence that linoleic acid found naturally in food is beneficial.
However, as I mentioned before, the AL found in supplements is produced by chemically altering the linoleic acid in unhealthy vegetable oils.
The AL in supplements is usually of a different form than the AL in food, being much higher in the t10 and c12 types.
As is often the case, some molecules and nutrients are beneficial when found in natural amounts in real food but become harmful when we start taking them in large doses.
According to some studies, this appears to be the case with AL supplements.
These studies have shown that large doses of supplemental AL can cause increased fat accumulation in the liver, a stepping stone to metabolic syndrome and diabetes.
AL can also cause less serious side effects such as diarrhea, stomach pain, nausea, and flatulence.
Most of the studies used doses ranging from 3.2 to 6.4 grams per day.
The risk of side effects is proportional to the dose.
Suppose you disagree and still want to take LA supplements. In that case, we recommend that you have regular blood tests to monitor liver function and other metabolic markers to ensure you are not harming yourself.
Although linoleic acid from meat and dairy is beneficial, taking “unnatural” types of AL made from chemically altered vegetable oils seems like a bad idea.