Vaccenic acid was discovered in 1928 in animal fats and butter.

The two most common omega-7 fatty acids in nature are palmitoleic acid and vaccenic acid.

Vaccenic acid is also found in human orbitofrontal cortex of patients with bipolar disorder and schizophrenia.

Some of our samples show an increased ratio of the 16-and 18-carbon trans vaccenic acid to the cis isomer.

It is formed along with vaccenic acid by biohydrogenation of dietary polyunsaturated fatty acids in the rumen.

The TFA vaccenic acid, which is of animal origin, poses less of a health risk.

This definition excludes specifically the trans fats (vaccenic acid and conjugated linoleic acid) that are present especially in human milk, dairy products, and beef.

The lipids are vaccenic acid, and Conjugated linoleic acid (CLA) accounting for up to 6% of the human milk fat.

Natural trans fats, which include conjugated linoleic acid (CLA) and vaccenic acid, originate in the rumen of these animals.

The monounsaturated fatty acids oleic acid (18:1n-9) and vaccenic acid (18:1n-7) were also significantly elevated in the red cell membrane phospholipids of the SCD subjects.

Oxidation of omega-7 unsaturated fatty acids on the skin surface, such as palmitoleic acid and vaccenic acid, may be the cause of the phenomenon commonly known as old person smell.

Vaccenic acid, also known as (E)-Octadec-11-enoic acid is a naturally occurring trans-fatty acid found in the fat of ruminants and in dairy products such as milk, butter, and yogurt.

Non-ruminants, including humans, produce certain isomers of CLA from trans isomers of oleic acid, such as vaccenic acid, which is converted to CLA by delta-9-desaturase.

A 2008 study at the University of Alberta suggests that vaccenic acid feeding in rats over 16 weeks resulted in lowered total cholesterol, lowered LDL cholesterol and lower triglyceride levels.

Feeding a sunflower seed and barley diet increased CLA content of beef by 94 per cent, while the content of vaccenic acid, which is a precursor to CLA rose by 394 per cent.

A study by the US Department of Agriculture showed that vaccenic acid raises both HDL and LDL cholesterol, whereas industrial trans fats only raise LDL without any beneficial effect on HDL.

The authors found few studies on fatty acids in milk; all (but for one) were of raw milk, and suggest that raw organic milk may contain significantly more beneficial omega-3 fatty acids and vaccenic acid than raw conventional milk.

Manipulating feeding protocol increases ruminal synthesis of CLA, but more recent research has focused on endogenous synthesis of CLA from ruminally-derived vaccenic acid, which may provide two-thirds to three-fourths of the CLA in milkfat.

Two Canadian studies have shown that the natural trans fat vaccenic acid, found in beef and dairy products, could actually be beneficial compared to hydrogenated vegetable shortening, or a mixture of pork lard and soy fat, by lowering total and LDL and triglyceride levels.

In addition, a seven-fold increase in vaccenic acid was observed and it has now been established that upon consumption, humans can convert the vaccenic acid to CLA which is additive to the CLA in the beef.