Conjugated Linoleic Acid: Sources, Relationship With Weight Loss, Health Benefits, Side Effects and Recommendations

It is found in large amounts in vegetable oils, but also in small amounts 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 actually 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 type of polyunsaturated fatty acid, with cis and trans double bonds. In other words, AL is technically a 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

The main dietary sources of LA 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 around the world, people became more interested in linoleic acid as a possible weight loss treatment .

This has now been fully 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 Really Help You Lose Weight?

Fortunately, we have quite a few studies that have been done on linoleic acid.

In fact, linoleic acid may be the most widely studied weight loss supplement in the world.

Many of the 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, with a reduction in body fat and sometimes increased muscle mass.

But before you start jumping up and down with excitement, keep in mind that many other studies show no effect at all.

Health benefits of linoleic acid

In nature, linoleic acid is mainly found in the fatty meat and dairy products of ruminant animals.

Some studies suggest that people with more linoleic acid in their bodies have a lower risk of heart disease.

This may have something to 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 a number of other reasons, so it’s a good idea 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, c12 type.

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, which is a stepping stone to metabolic syndrome and diabetes.

AL can also cause other 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.


If you disagree and still want to take LA supplements, we recommend that you have regular blood tests to monitor liver function and other metabolic markers, to make sure 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.

There are certainly other better ways to lose fat that won’t give you fatty liver disease and diabetes in the process.