Palmitoleic acid, or (Z)-9-hexadecenoic acid, is an omega-7 monounsaturated fatty acid that is a common constituent of the glycerides of human adipose tissue. It is present in all tissues, but generally found in higher concentrations in the liver. It is biosynthesized from palmitic acid by the action of the enzyme delta-9 desaturase.

Sources

Dietary sources of palmitoleic acid include a variety of animal oils, vegetable oils, and marine oils. Macadamia oil (Macadamia integrifolia) and Sea Buckthorn oil (Hippophae rhamnoides) are botanical sources with high concentrations, containing 22 and 40%^[1] of palmitoleic acid, respectively.

In a recent study examining the effects of diets high in various fatty acids, total cholesterol and low density lipoprotein (LDL, "bad cholesterol") concentrations were similar with palmitoleic and palmitic acids and significantly higher than with oleic acid.^[2] High density lipoprotein (HDL, "good cholesterol") was significantly lower with palmitoleic than with palmitic acid. The study confirms that, at least in hypercholesterolemic men, a modest increase in palmitic acid raises LDL cholesterol relative to oleic acid, even when dietary cholesterol is low. Palmitoleic acid behaves like a saturated and not a monounsaturated fatty acid in its effect on LDL cholesterol.

Aging

In the April 2001 issue of the Journal of Investigative Dermatology, Shinichiro Haze et al published an article suggesting that omega-7 unsaturated fatty acids, such as palmitoleic acid and vaccenic acid found on the skin surface were oxidatively decomposed to 2-nonenal, which may be the cause of the phenomenon commonly known as old person smell.^[3]

A scientist in Japan, Shoji Nakamura is devising products for a cosmetic line to meet the market.^[4] He says, "Over time, this fatty acid is broken down by bacteria inhabiting the skin or by lipid peroxides (which are present in larger quantities in older people), producing a substance called nonenal that 'has an unpleasant... smell... closely approximating... that of old books'."

References

de:Palmitoleinsäure fr:Acide palmitoléique pl:Kwas oleopalmitynowy