by Braddock Ray

Most Americans associate dietary fat with heart disease, certain

cancers, and overweight. But, in truth, certain fats can help prevent

all three conditions. Conjugated linoleic acid, more commonly known as

CLA, is one such "healthy" fat that has been attracting attention from

researchers--for good reason.

Rather than a single substance, CLA is actually several

polyunsaturated fatty acid compounds that occur naturally in meat,

particularly grazing cows and sheep, as well as in cheese, milk, and

yogurt that have been heat-treated. While US rates of cancer, heart

disease, and obesity have been increasing, American consumption of

grass-fed animal protein has substantially declined. "Unfortunately,

today's cattle are fed an amalgam of chemically altered grain-based

feeds rather than their traditional grass feed," says Ann Louise

Gittleman, CNS, author of Eat Fat, Lose Weight. "This has left CLA in

short supply in its once natural sources."

In preliminary studies, CLA holds promise for halting the

proliferation of cancers in breast, colorectal, lung, and prostate

tissue, as well as of melanoma, the most aggressive for of skin cancer.

while the way CLA fights cancer is not yet clearly understood, this fat

seems both to weaken cancer-causing agents and to protect certain

tissues from carcinogens.

Based on his research with rats, Clement Ip, PhD, considers CLA

the most powerful natural fat to inhibit tumor growth. Other research

has shown that diets high in conjugated linolenic acid can reduce the

number of terminal end buds (containing rapidly dividing cells), from

which mammary cancer develops. CLA also promotes the programmed death,

or apoptosis, of cancer cells, according to one in vitro study; while

another study points to enhanced T-cell function in the immune system.

"CLA has also been found to have positive effects on serum

cholesterol levels," says nutritionist Gittleman. "Research subjects

treated with healthy doses of CLA experienced a reduction of harmful

LDL

levels without a reduction in healthy HDL levels." Animal studies also

find that CLA slows the buildup of fat in blood vessels, preventing

hardening of the arteries.

This healthy fat can significantly lower triglyceride levels,

normalize glucose tolerance, and improve insulin levels. Based on

investigations with prediabetic rats, researchers find "CLA may prove

to be an important therapy for the prevention and treatment of NIDDM,"

also known as Type II diabetes. One safety investigation of CLA's

effects on a patient with Type II diabetes suggests that these benefits

also apply to humans. However, more research is clearly needed.

Currently 61 percent of all Americans are overweight, a condition

that's linked to diabetes, heart disease, and some cancers. Not only

does CLA help protect against these conditions, but it also helps

control body fat. Or as one researcher puts it: "CLA makes big fat

cells get little and stay that way." The latest research suggests that

CLA keeps fat from being deposited in the body. "As it reduces body

fat, it increases lean tissue," says Delbert Dorscheid, MD, PhD, a

researcher at the University of British Columbia who reviewed a study

of the use of CLA by individuals who exercise regularly.

A double-blind, randomized, placebo-controlled Swedish trial

recently discovered that CLA reduces body fat, while preserving muscle

mass, in men with "beer bellies," without their changing any exercise

or dietary habits. A larger, earlier clinical trial, in which

participants lost an average of six pounds over 12 weeks, found similar

results. "Repeated analysis showed significantly greater reduction of

fat amoung the CLA group than in the placebo group," says researcher

Ola Gudmundsen, PhD, making CLA "quite effective as a fat-fighting

supplement."

"CLA may be a valuable weight management supplement to any diet

regime," adds study coauthor Jan Wadstein, MD, PhD, associate professor

of medicine at Sweden's Lund University. "Keeping lean body mass and

speeding up fat loss are the keys to a successful weight loss program."

Conjugated linoleic acid is available in a growing number of

dietary supplements and will probably be added to functional foods.

Until long-term safety data is available, CLA is not advised for

children or for pregnant or nursing women.

This supplement is best taken before meals, unless directed

otherwise. Typical dosages range from 1 to 2 grams daily; 3.4 grams of

CLA daily has been found sufficient for weight loss. For health

problems, larger doses may be required, so consult a complementary

medical practitioner.

Selected Sources

*"Conjugated Linoleic Acid and Atherosclerosis in Rabbits" by Kisun N.

Lee

*"Conjugated Linoleic Acid (CLA) Reduced Abdominal Adipose Tissue in

Obese Middle-Aged Men..." by U. Riserus

*"Conjugated Linoleic Acid Reduces Body Fat in Healthy Exercising

Humans" by Earling Thom

*"Conjugated Linoleic Acid Reduces Body Fat Mass inOverweight and Obese

Humans" by Henrietta Blankson

*"Conjugated Linoleic Acid Suppresses Mammary Carcinogenesis..." by

Clement Ip

*100 Super Supplements by Frank Murray

*PDR for Nutritional Supplements