Life Extension Magazine®

Issue: May 2000

Q and A

Differentiating among CLA products and more.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, on January 2021.


Q: I've noticed that there are now several supplement companies offering CLA products. Are these products the same as the one offered by Life Extension Buyers Club?

A: We checked out some companies offering CLA supplements and found that the prices were considerably higher than what Foundation members pay. We then inquired about the quality of the CLA sold by these commercial companies and found that these CLA products do not contain the same active isomers as the pharmaceutical-grade Japanese product offered by the Life Extension Buyers Club. Here is a comparison of the percentage of the most important isomers from CLA: For the moment, the Japanese CLA product is clearly superior, and that is what the Life Extension Buyers Club exclusively uses. The Europeans have approached us to offer their product, but it does not contain the high percentage of active isomers that is found in the Japanese product we currently offer. The good news is that the public has learned about the benefits of CLA and there are now many companies competing for market share. In the long-term, this will mean lower prices for consumers. Based on the above published comparisons of active ingredients, we look forward to other companies seeking to match the high standards the Japanese have set for CLA.

Q: I had breast cancer several years ago, and underwent chemotherapy and radiation treatment. I am now taking tamoxifen. Can I also take I3C?

A: Studies done at the University of California suggest I3C enhances the ability of tamoxifen to prevent the recurrence of breast cancer. However, these studies were only done in the test tube, and no human studies have been done. According to the authors, "Combinations of I3C and the antiestrogen tamoxifen cooperate to inhibit the growth of the estrogen-dependent human MCF-7 breast cancer cell line more effectively than either agent alone." While I3C and tamoxifen share some of the same properties, I3C has anticancer actions that tamoxifen does not possess. Accordingly, I3C can stop the growth of some cancer cells that tamoxifen cannot. Whereas tamoxifen is generally prescribed in estrogen receptor positive cases, I3C can be used in both receptor-positive and negative cancers. While we cannot give you a definitive answer because clinical studies have not been done, there is strong evidence that I3C, either alone or in combination with tamoxifen, will reduce the incidence of breast and other cancers. We know of no contraindication. Be aware, however, that I3C is powerful: do not take more than the recommended dose.

Q: Will 250mg/day of BHT prevent Vitamin K from being absorbed?

A: Good question. It won't keep it from being absorbed, but it may keep it from working. Some antioxidant vitamins (vitamin E and co-enzyme Q10) interfere with vitamin K's ability to do its job of carboxylating proteins, including coagulation proteins. This accounts for the "blood thinning" characteristics of these antioxidants. There is evidence that the synthetic antioxidant, BHT, also interferes with K's ability to carboxylate, the net effect being that instead of being utilized, vitamin K is excreted. You didn't say how much you weigh, but to a male of average weight, 250 mg of BHT will probably have a minor, transient effect on the utilization of vitamin K in your body. Large amounts of BHT on a consistent basis, however, could cause bleeding problems and osteoporosis due to its negative impact on vitamin K. It may also cause kidney damage. This is why it is so important for antioxidant supplement takers to consume 10 mg a day of low-cost vitamin K.

Q: I am currently using stinging nettle leaf extract for prostate symptoms and am considering switching to stinging nettle root extract. Can you tell me what the leaf extract is used for, as well as what the root extract's intended use is?

A: Nettle root extract and nettle leaf extracts are used for different purposes. Nettle root extract aids with reducing the binding of DHT to prostate cells. Nettle leaf extract aids with reducing TNFa (Tumor Necrosis Factor alpha), which is involved with the development of arthritis and other aging-related degenerative processes. Nettle root helps to alleviate symptoms of prostate enlargement, not nettle leaf. Q:You mention in the book review that appeared in the January 2000 issue ("Knowledge is Power," p. 49) that the authors of Formula for Life, Eberhard and Phyllis Kronhausen warn against using a blender in preparing whey protein drinks and smoothies. That "blending impairs the bioactive properties of whey." Please explain how.

A: It has to do with what the process may do to disable absorption. The heat involved in the electrical blending of proteins may denature them, rendering the proteins less viable for absorption.