"RESULTS: No association was observed between multivitamin use and risk of localized prostate cancer. However, we found an increased risk of advanced and fatal prostate cancers (RR = 1.32, 95% CI = 1.04 to 1.67 and RR = 1.98, 95% CI = 1.07 to 3.66, respectively) among men reporting excessive use of multivitamins (more than seven times per week) when compared with never users. The incidence rates per 100,000 person-years for advanced and fatal prostate cancers for those who took a multivitamin more than seven times per week were 143.8 and 18.9, respectively, compared with 113.4 and 11.4 in never users. The positive associations with excessive multivitamin use were strongest in men with a family history of prostate cancer or who took individual micronutrient supplements, including selenium, beta-carotene, or zinc. CONCLUSION: These results suggest that regular multivitamin use is not associated with the risk of early or localized prostate cancer. The possibility that men taking high levels of multivitamins along with other supplements have increased risk of advanced and fatal prostate cancers is of concern and merits further evaluation."
What we can gather from this:
-Excessive intake of multivitamins increases the risk of advanced and fatal prostate cancer.
-Excessive intake of multivitamins doesn't increase the risk of early prostate cancer.
This shows that excessive multivitamin intake is associated with more rapid progression of prostate cancer, not associated with onset of prostate cancer. They don't indicate what 'excessive' use is, nor what was in the multivitamins that were taken.
The researchers themselves say "Differences between heavy users of multivitamins and nonusers that may not be controlled for in a study of this type may obscure the true relationship between multivitamin use and prostate cancer." and "Because multivitamin supplements consist of a combination of several vitamins and men using high levels of multivitamins were also more likely to take a variety of individual supplements, we were unable to identify or quantify individual components responsible for the associations that we observed."
From another recent study "...men with normal baseline prostate-specific antigen (PSA) levels (<3 µg/L), taking multivitamin–multimineral supplements containing a limited number of individual agents (vitamin C, beta-carotene, selenium, and zinc) markedly reduced prostate cancer risk compared with placebo (RR = 0.52, 95% CI = 0.29 to 0.92). However, a reduction in risk was not seen in men with elevated baseline PSA levels (RR = 1.54, 95% CI = 0.87 to 2.72)."
Things we should learn from this study:
- Don't believe the media hype. Epidemiological studies like this are notoriously unreliable as indicated by the conflicting reports. Investigate stuff for yourself.
- Multivitamin is no replacement for a healthy diet and lifestyle.
- Men with family history of prostate cancer should be getting frequent checkups anyway.
- All men should be getting frequent prostate checks.
