B Vitamin And/Or Omega-3 Fatty Acid Supplementation And Cancer, Archives of Internal Medicine, February 2012
"We found no beneficial effects of supplementation with relatively low doses of B vitamins and/or omega-3 fatty acids on cancer outcomes in individuals with prior cardiovascular disease."Participants (n=2501) took supplements for 5 years. They were divided into 4 groups:
- B vitamins: Folate (0.56 mg) and Vitamin B6 (3 mg) and Vitamin B12 (0.02 mg)
- Omega-3 fatty acids: EPA (400 mg) and DHA (200 mg)
- B vitamins plus Omega-3s
The lead investigator, Dr. Valentina Andreeva, said:
"People should be very careful when deciding to self-medicate with these dietary supplements because they are active substances. The findings need to be confirmed and should be interpreted with caution, but there is some indication that they might have adverse effects. Taking these supplements without a physician's advice and over the long term might not be a good idea."Five years isn't long for cancer to develop and progress to the point of death, so the cancer was probably there already, small and undetected. If anything, the omega-3 may have hastened its progression.
This adds evidence to the possible connection between omega-3s and cancer. So far I've seen it linked to prostate cancer:
How Much Fish Oil Is Good?
Omega-3 Fatty Acid DHA Found To Increase Risk For Prostate Cancer
And colon cancer:
Fish Oil, Colitis, And Cancer
The mechanism? Who knows. Maybe a reduction in natural killer cells:
Can Omega-3 Fatty Acids (Fish Oil) Predispose Someone To Cancer?
Or maybe it's something about the manufacture of these supplements. How do you keep all that highly processed fish oil from going rancid?