Vitamin C och E-tillskott och risk för cancer

[King Grub]

Background:

Recent posttrial analysis of a completed randomized trial found an increased risk of prostate cancer among healthy men taking high-dose vitamin E supplements. Trials that examined the effect of vitamin C supplements on cancer risk are few.

Objective:

We examined whether vitamin E or vitamin C supplementation affects the risk of cancer events during posttrial follow-up of the Physicians’ Health Study II.

Design:

Beginning in 1997, a total of 14,641 US male physicians aged ≥50 y were randomly assigned to receive 400 IU of vitamin E every other day, 500 mg of vitamin C daily, or their respective placebos. The vitamin E and vitamin C treatment ended in 2007, and observational follow-up continued through June 2011.

Results:

This study included an additional 356 cases of incident prostate cancer and 771 total cancers that developed during a mean (maximum) of 2.8 (3.8) y of posttrial observation. During an overall mean of 10.3 (13.8) y, there were a total of 1373 incident prostate cancers and 2669 total cancers documented. In comparison with placebo, vitamin E supplementation had no effect on the incidence of prostate cancer (HR: 0.99; 95% CI: 0.89, 1.10) or total cancers (HR: 1.02; 95% CI: 0.95, 1.10). There was also no effect of vitamin C supplementation on total cancers (HR: 1.02; 95% CI: 0.94, 1.10) or incident prostate cancer (HR: 1.03; 95% CI: 0.93, 1.15). Neither vitamin E nor vitamin C supplementation had effects on other site-specific cancers overall. Stratification by known cancer risk factors, history of cancer, other randomized treatment, and follow-up time showed no significant interactions.

Conclusion:

In this large-scale randomized trial in men, vitamin E and C supplementation had no immediate or long-term effects on the risk of total cancers, prostate cancer, or other site-specific cancers.

Vitamin E and C supplementation and risk of cancer in men: posttrial follow-up in the Physicians’ Health Study II randomized trial. Am J Clin Nutr July 9, 2014.

http://ajcn.nutrition.org/content/early/2014/07/09/ajcn.114.085480.full.pdf+html

[maqan]

"Men det skadar ju inte i alla fall" :).

[Sverker]

200 mg alfa-tokoferol och 500 mg askorbinsyra varje dag är rätt stora doser. Främst ifall man ser det över en längre tid.
Att askorbinsyra är lockande att ta, m a p förkylning kan jag förstå men varför ta >> 10 mg tokoferol varje dag:confused:

[whuddafuks]

200 mg alfa-tokoferol och 500 mg askorbinsyra varje dag är rätt stora doser. Främst ifall man ser det över en längre tid.
Att askorbinsyra är lockande att ta, m a p förkylning kan jag förstå men varför ta >> 10 mg tokoferol varje dag:confused:

Det var dock 200 mg varannan dag, inte varje (inte för att 100 mg är lite direkt)!

Och är 500 mg c-vitamin verkligen en giftig mängd? http://ods.od.nih.gov/factsheets/VitaminC-Consumer/#h8 Påstår att 2000 mg är den övre gränsen för vuxna.

[Sverker]

assigned to receive 400 IU of vitamin E every other day, 500 mg of vitamin C daily, or their respective placebos..

Jag minns att 1 mg alfa-tokoferol är 1 IU.



Lite konstigt att räkna IU eftersom alla tillskott är alfa-tokoferol. Mer förnuftigt att räkna IU på naturliga, mixade källor som vetegroddsolja eller palmolja.