Linoleic acid

Linoleic acid is a colorless to straw-colored, liquid, polyunsaturated fatty acid (C18H32O2) of the omega-6 series. Linoleic and another fatty acid, gamma-linolenic, or gamolenic, produce prostaglandins. Prostaglandins are substances that are found in every cell, are needed for the body's overall health maintenance, and must be replenished constantly. Linoleic acid is an essential fatty acid, which means that the body cannot produce it, so it must be obtained in the diet.

Linoleic acid is an important fatty acid, especially for the growth and development of infants. Fatty acids help to maintain the health of cell membranes, improve nutrient use, and establish and control cellular metabolism. They also provide the raw materials that help in the control of blood pressure, blood clotting, inflammation, body temperature, and other body functions.

Fatty acids are consumed in the greatest quantities in fat. Although many people are encouraged to consume less fat in their diets, fat is still an important component of a healthy body. Fat stores the body's extra calories, helps insulate the body, and protects body tissues. Fats are also an important energy source during exercise, when the body depends on its calories after using up available carbohydrates. Fat helps in the absorption, and transport through the bloodstream, of the fat-soluble vitamins A, D, E, and K.

Linoleic acid is found in fish oil , meat, milk, and other dairy products. It is also a constituent of many vegetable oils, including evening primrose oil , sunflower oil, and safflower oil. Commercially produced linoleic acid is used in margarine, animal feeds, emulsifying agents, soaps, and drugs.

It's now thought that trans fatty acids or those fats which have been hydrogenated commonly found in commercially packaged goods, vegetable shortening, some margarine, commercially fried food such as French fries and onion rings increase LDL (bad) cholesterol while reducing HDL (good) cholesterol. Such an increase causes a decrease in body pH (a more acidic blood plasma), which subsequently creates an environment that is ideal for cholesterol plaque buildup. Evidence suggests that alpha linolenic acid along with the other Omega 3 fatty acids have been associated with decreasing levels of blood cholesterol, preventing against cardiovascular disease and management of chronic disorders.

One particular isomer in CLA, known as cis-9, trans-11, is linked to anticancer benefits. Studies with animals have shown CLA to reduce breast, prostate, stomach, colorectal, lung, and skin cancers. The CLA may slow the growth of cells that give rise to cancer. A human study has shown an association between linoleic acids and a decreased risk for prostate cancer .

Infants with cystic fibrosis (CF) often have poor weight gain and growth and an inability to absorb fats. Some research suggests that infants with CF can benefit from formula with a high linoleic acid content because it optimizes nutrition, growth, and feeding efficiency.

Multiple sclerosis (MS) is a disease in which demyelination, loss of myelin sheath material, occurs. (The myelin sheath is a fatty substance that surrounds and insulates the axon of some nerve cells.) This leads to disruptions in nerve impulse transmission. Linoleic acid is believed to be helpful because myelin is composed of lecithin, which is made of linoleic and other fatty acids.

Many diets recommended for MS patients include supplements. Patients supplementing with linoleic acid show a smaller increase in disability and reduced severity and duration of attacks than those with no linoleic acid supplement. Evening primrose oil is beneficial because of its specialized fatty-acid content, including linoleic acid. Doses of sunflower seed oil or evening primrose oil to provide 17 grams linoleic acid per day may be beneficial.

One study indicated that low doses of linoleic acid and calcium can reduce the incidence of preeclampsia in high-risk women. (Preeclampsia is the development of hypertension with increased protein in the urine or accumulation of watery fluid in cells or tissues or both, due to pregnancy.) Another study showed, however, that linoleic acid consumption can have a negative effect on fetal growth. Pregnant women should talk to their doctors before taking linoleic acid or any other supplement.