|Questions About Natural Products|
CLA and The BTD
Recently we have read a lot of health related articles that promote the use of CLA (conjugated linoleic acid) for weight loss and muscle gain. This supplement is not mentioned in any of your books. As an O, is this something I would be OK taking or should I avoid it?
The term "conjugated linoleic acid" refers to a group of several variants of linoleic acid (also called octadecadienoic acid), an essential fatty acid. Variants of linoleic acid differ from one another in the type and arrangement of their chemical bonds. The specific structure of CLA's chemical bonds is crucial to the compound's ability to fight cancer; at high levels, linoleic acid, whose chemical structure is slightly different, increases cancer growth in lab animals. Researchers are excited about CLA because it is anticarcinogenic at much lower dosages than are many other naturally occurring anticarcinogens. It is effective in animals at dietary levels as low as .05 percent. Findings include potential usefulness in colon and prostate cancer and some findings suggestive that CLA may help decrease body fat (but not body weight.)
In a review of the literature my colleague Greg Kelly examined the science on CLA and felt the results on body composition were ambiguous, and indeed that the bad effects of CLA supplementation on HDL (the 'good cholesterol') needed better understanding before wholesale supplementation could be advised.
Most dietary substances protective against cancer originate in plants, but CLA is found almost exclusively in animal products. Dairy products are the main source of CLA for humans. Meat, particularly beef, is another major source. The meat of ruminants - cows, sheep, and other animals that chew the cud - contains more CLA than nonruminant meats, such as turkey, chicken, and pork.
Because CLA is a fatty acid, its concentrations in food are generally measured against the fat in the food: milligrams (mg) of CLA per gram (g) of fat. According to one study that used this measure, lamb, beef, and veal - in descending order of concentration - contain more CLA than other meats. The study also showed that seafood is very low in CLA and that plant oils contain much less CLA than animal fats.
For types O and B, findings on CLA demonstrate again that it is the current methods of production that makes meat products deleterious for all individuals, When raised properly (grass-fed, no antibiotics or hormones) animal proteins can have beneficial effects for some individuals, especially thes two blood types.
For types A, increasing consumption of fatty foods to increase CLA intake is ill-advised - not only because researchers have not demonstrated CLA's effectiveness against cancer in humans, but also because high fat intakes may have adverse health effects, such as increasing one's risk of heart disease and certain types of cancer.