Doc: Nobel or no, vitamins don’t treat the common cold
Dear Dr. Roach: I cannot believe you would talk people out of vitamins as the flu season is approaching. You have some nerve to not quote studies to back up your false premises. Have you never heard of Dr. Linus Pauling? He got the Nobel Prize.
Dear H.R.: Dr. Linus Pauling won the Nobel Prize in chemistry in 1954 for his work on the nature of the chemical bond, work instrumental in understanding molecular biology. He won the Nobel Prize for Peace as well in 1962 for his work to reduce nuclear arms. (I haven’t even won one Nobel Prize, but I did study chemistry, physics and molecular biology before medical school.)
Dr. Pauling was a proponent of high-dose vitamin C as a preventive and treatment for many conditions, from colds to cancer. However, the majority of evidence has demonstrated that Dr. Pauling’s claims are not supported: Vitamin C supplementation neither prevents nor treats cancer. (Dr. Pauling felt that vitamin C didn’t “cure” cancer, only that it stopped cancer from spreading.) Further, it is generally accepted that vitamin C supplementation does not treat colds, but it may reduce cold incidence in individuals exposed to extreme physical exercise.
Vitamin C has little potential for harm. Kidney stones in people with too much oxalate is one exception. Although one study showed vitamin C increased risk of heart disease and death in women with diabetes, I think this is not likely to be a true risk.
A fair summary of vitamin C, with a hundred references, can be found at ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/.
The data on multivitamins (as opposed to just vitamin C) are becoming irrefutable that a daily multivitamin does not confer any health advantages large enough to be seen in a population study.
Dear Dr. Roach: I am a breast cancer survivor currently taking tamoxifen (20 mg). I had a bilateral mastectomy with no chemo or radiation. I have read several articles regarding the benefit of turkey tail mushroom capsules and also vitamin B-17. Do you think it is a good idea or waste of money?
Dear S.G.: Several trials of Trametes versicolor (also called turkey tail mushroom) have shown that, in combination with chemotherapy, an extract from the mushroom increased immune cells in breast cancer patients. Tamoxifen, which opposes some activities of estrogen, does reduce recurrent cancer risk in women with estrogen-receptor positive breast cancer. One older study suggested this mushroom might have similar activity to tamoxifen, but the data are not strong. Turkey tail mushroom has very few side effects. The data are insufficient for me to recommend it, but given possible benefit and probable safety, it is reasonable for a person with breast cancer to discuss this with her or his oncologist, either during therapy or to prevent recurrence.
Amygdalin, misnamed “vitamin B-17” by those who sell and promote it, is also called laetrile, and is an extract of apricot or other fruit pits. It’s broken down into cyanide in the intestines. There have been no studies showing any benefit to it, and it’s banned by the Food and Drug Administration. It is unsafe and ineffective. You should run away from anyone recommending it.
Email questions to ToYourGoodHealth@med.cornell.edu.