Headlines can Drive you Crazy! Today’s Rant is Vitamin E
Headlines. They are seductive. They are memorable. Unfortunately, the details beneath the headline may be different. In an insightful article (The media wails about money wasted on Tamiflu – but we were the ones who demanded it), Oliver Wright tracks headlines last week in Great Britain condemning their government for wasting taxes to stockpile the anti-flu drug Tamiflu. Then he cites 2005 headlines when the media criticized government for failing to protect its citizens, leaving 500,000 defenseless. Mr Wright makes the argument that media pressure led to the British government decision to buy and stockpile the drug Tamiflu in 2005. The case being made: policy decisions by controversial headlines are not synonymous with good governance.
Media can distort understanding of nutrition too. On March 17, a systematic review and meta-analysis of dietary fat and coronary risk was published which generated headlines like “Daily Fish Oil Supplement May Not Help Your Heart: Studies”, and “Omega-3 Fatty Acids: Studies Don’t Support Heart Benefit”. Unfortunately, the correction a few days later was not covered by the media. Most people will not know that there was an error in the original publication. Chowdhury and colleagues had miscalculated the association between circulating omega -3 fatty acids and risk of coronary disease (CHD). Althought they originally reported significant beneficial relationships of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and DHA+EPA concentrations with CHD risk, they drew their conclusions based on total omega-3 fatty acids. Presumably because it was exciting to suggest that current scientific opinion with respect to omega-3 fatty acids and heart health was wrong. Except, it isn’t. The original calculations were wrong. The corrected manuscript reports statistically significant (beneficial) associations for all four circulating concentrations (total omega-3 fatty acids, DHA, EPA, and DHA+EPA). Did you see headlines correcting the record? Not likely, unless you regularly read TalkingNutrition.dsm.com for perspective on new studies.
Today the Wall Street Journal has a press release referencing a prostate cancer intervention study (SELECT) which was ended in 2008. The secondary analysis reports an interaction between treatment randomization (vitamin E supplementation) and baseline selenium status (toenail selenium concentrations). A medical physician advises people to avoid using vitamin E supplements. In an interview released by Yahoo Finance, Dr David Samadi cautions men about “adding supplements or unusual dietary changes without the counsel of a medical professional. What are the facts with regards to vitamin E and prostate cancer?
The Alpha-Tocopherol Beta-Carotene (ATBC) trial reported a 35% reduction for prostate cancer in men supplementing with vitamin E. The SELECT trial did find a 17% increased risk in prostate cancer with vitamin E supplementation (620 cases vs 529 cases in placebo group). This equates to an absolute increase in risk of prostate cancer of 1.6 per 1000 person years. Why the different outcomes between the ATBC and SELECT trials? The SELECT trial only evaluated randomization to treatment (placebo vs supplementation). Vitamin E concentrations in blood were measured in the ATBC trial but not the SELECT trial. Unlike drug studies, everyone has some level of nutrient status.
A recent meta-analysis of prostate cancer intervention trials reported that every 25 mg/L (5.8µmol/L) increase in blood α-tocopherol levels is associated with a 21% decrease in prostate cancer risk. This is consistent with the ATBC trial which reported a significant decrease in mortality rate with serum α-tocopherol concentrations increasing to 30 µmol/L. 70% of US males 51-70y having serum α-tocopherol concentrations below 30 µmol/L. Almost 100% are not consuming the vitamin E RDA (15 mg daily).
Advice on vitamin E supplementation should be based on nutrient status not randomization codes. At this point, it is known that most vitamin E intervention trials were conducted in people with much better vitamin E status than the average American. To have evidence-based guidance, medical professionals should be calling for more research on the relationship between vitamin E status and health.
Kristal AR, Darke AK, Morris JS, Tangen CM, Goodman PJ, Thompson IM, Meyskens Jr FL, Goodman GE, Minasian LM, Parnes HL, Lippman SM, Klein EA. Baseline selenium status and effects of selenium and vitamin E supplementation on prostate cancer risk. 2014 JNCI doi: 10.1093/jnci/djt456
Chowdhury R, Warnakula S, Kunutsor S, Crowe F, Ward HA, Johnson L, Franco OH, Butterworth AS, Forouhi NG, Thompston SG, Khaw K-T, Mozaffarian D, Danesh J, Angelantonio ED. Association of dietary, circulating and supplemental fatty acids with coronary risk: A systematic Review and meta-analysis. 2014 Ann Intern Med doi:10.7326/M13-1788
Klein EA, Thompson IM, Tangen CM, Crowley JJ, Lucia MS, Goodman PJ, Minasian LM, Ford LG, Parnes HL, Gaziano JM, Karp DD, Lieber MM, Walther PJ, Klotz L, Parsons JK, Chin JL, Darke AK, Lippman SM, Goodman GE, Meyskens FL, Baker LH. Vitamin E and the risk of prostate cancer: The Selenium and Vitamin E Cancer Prevention Trial (SELECT). 2011 JAMA doi: 10.1001/jama.2011.1437
The Alpha-Tocopherol Beta Carotene Cancer Prevention Study Group. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. 1994 NEJM doi 10.1056/NEJM199404143301501
Cui R, Liu Z-Q, Xu Q. Blood α-tocopherol, γ-tocopherol levels and risk of prostate cancer: A meta-analysis of prospective studies. 2014 PloS ONE doi: 10.1371/journal.pone.0093044