Multivitamins–big money, no effect on cardiovascular disease

A few months ago, I wrote about the role of supplements, mainly vitamins and other nutrients, in preventing cancer. Conclusion: they didn’t. To quote Martinez et al., who published a review of dietary supplements and vitamins in cancer prevention

Nutritional supplementation is now a multibillion-dollar industry, and about half of all US adults take supplements. Supplement use is fueled in part by the belief that nutritional supplements can ward off chronic disease, including cancer, although several expert committees and organizations have concluded that there is little to no scientific evidence that supplements reduce cancer risk. To the contrary, there is now evidence that high doses of some supplements increase cancer risk. Despite this evidence, marketing claims by the supplement industry continue to imply anticancer benefits. Insufficient government regulation of the marketing of dietary supplement products may continue to result in unsound advice to consumers. Both the scientific community and government regulators need to provide clear guidance to the public about the use of dietary supplements to lower cancer risk. 

All those expensive supplements, most of which have broad and unproven claims made about them, do precious little for cancer. And some actually increase the risk of certain types of cancer. Continue reading “Multivitamins–big money, no effect on cardiovascular disease”

Ginkgo biloba and neurological disorders–Myth vs. Science

I’m trying out a new series, looking at some popular myths (mostly in medicine, but maybe we’ll wander outside of it when something interesting shows up) and determining if there’s any support or not in science. I’m going to link mostly to science articles and high-quality blogs, just so you have all the back-up evidence that you need. One way or another.

Background

Ginkgo biloba is actually an interesting plant because it has been relatively unchanged for nearly 270 million years. It is considered a living fossil, an informal term used for species like G. biloba that appear to be the same as a species otherwise only known from fossils and which has no close living relatives. The genus Ginkgo was fairly widely distributed until about 100 million years ago. It slowly disappeared from the fossil record until it was found only in one small part of China about 5 million years ago, where it is found today.  

The tree is native to China and is known to have been widely cultivated early in human history. It is used as a food source by various Asian cultures, with the Chinese eating the meaty gametophytes and the Japanese the whole seed. Unfortunately, the seed contains a chemical, 4′-O-methylpyridoxine, that can be poisonous if consumed in enough quantity.  Continue reading “Ginkgo biloba and neurological disorders–Myth vs. Science”

Cancer prevention–supplements

Potential causes for cancer are numerous. Infections. Radon gas. Cigarette smoking. Sun exposure. Obesity. With over 200 types of cancer, each with a different pathophysiology, there may be an equal (and probably greater) number of causes. Although many causes can be easily eliminated, such as stopping smoking, testing your house for radon, getting an HPV vaccine to prevent human papillomavirus infections, and wearing sunblock to reduce the risk of melanomas, the sheer complexity and number of types of cancer means that there is probably not going to be any simple panacea to preventing (or even curing) cancer. In fact, some hereditary cancers, such as those individuals who carry genes that are implicated in breast and ovarian cancers, may not be preventable at all. Continue reading “Cancer prevention–supplements”