Vitamin tidak mencegah kanker

Suplemen vitamin dianggap berperan penting untuk mencegah kanker.

 

Penelitian yang dilakukan terhadap >5000 wanita berusia >42 tahun selama >7 tahun, membandingkan secara random efek suplementasi vitamin (folat, vitamin B6 dan vitamin B12) terhadap plasebo, membuktikan bahwa pemberian folat, vitamin B6 dan vitamin B12 tidak signifikan mencegah kanker.

 

Abstrak

 

Effect of Combined Folic Acid, Vitamin B₆, and Vitamin B₁₂ on Cancer Risk in Women

A Randomized Trial

Shumin M. Zhang, MD, ScD; Nancy R. Cook, ScD; Christine M. Albert, MD, MPH; J. Michael Gaziano, MD, MPH; Julie E. Buring, ScD; JoAnn E. Manson, MD, DrPH

JAMA. 2008;300(17):2012-2021.

Context  Folate, vitamin B₆, and vitamin B₁₂ are thought to play an important role in cancer prevention.

Objective  To evaluate the effect of combined folic acid, vitamin B₆, and vitamin B₁₂ treatment on cancer risk in women at high risk for cardiovascular disease.

Design, Setting, and Participants  In the Women's Antioxidant and Folic Acid Cardiovascular Study, 5442 US female health professionals aged 42 years or older, with preexisting cardiovascular disease or 3 or more coronary risk factors, were randomly assigned to receive either a daily combination of folic acid, vitamin B₆, and vitamin B₁₂ or a matching placebo. They were treated for 7.3 years from April 1998 through July 31, 2005.

Intervention  Daily supplementation of a combination of 2.5 mg of folic acid, 50 mg of vitamin B₆, and 1 mg of vitamin B₁₂ (n = 2721) or placebo (n = 2721).

Main Outcome Measures  Confirmed newly diagnosed total invasive cancer or breast cancer.

Results  A total of 379 women developed invasive cancer (187 in the active treatment group and 192 in the placebo group). Compared with placebo, women receiving the active treatment had similar risk of developing total invasive cancer (101.1/10 000 person-years for the active treatment group vs 104.3/10 000 person-years for placebo group; hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.79-1.18; P = .75), breast cancer (37.8/10 000 person-years vs 45.6/10 000 person-years, respectively; HR, 0.83; 95% CI, 0.60-1.14; P = .24), or any cancer death (24.6/10 000 person-years vs 30.1/10 000 person-years, respectively; HR, 0.82; 95% CI, 0.56-1.21; P = .32).

Conclusion  Combined folic acid, vitamin B₆, and vitamin B₁₂ treatment had no significant effect on overall risk of total invasive cancer or breast cancer among women during the folic acid fortification era.

Omega3 mencegah gagal jantung

Gagal jantung merupakan penyebab morbiditas dan mortalitas kardiovaskuler. Beberapa penelitian menunjukkan manfaat asam lemak tak jenuh n-3 (n-3 polyunsaturated fatty acids disingkat PUFA) dalam menurunkan mortalitas karena efek anti-inflamasi dan aman serta toleransi yang baik. Penelitian GISSI-HF adalah penelitian double blind multicenter yang dilakukan pada 326 pusat kardiologi dan 31 pusat internist di Italia, melibatkan hampir 7000 subyek dan follow-up selama 4 tahun.

 

Hasil penelitian mendukung temuan sebelumnya. Sehingga disimpulkan bahwa pemberian n-3 PUFA 1000mg memberikan benefit dalam hal menurunkan morbiditas dan mortalitas kardiovaskuler pada pasien2 gagal jantung.

 

The Lancet, Volume 372, Issue 9645, Pages 1223 - 1230, 4 October 2008

 

Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebo-controlled trial

 

Background

 

Several epidemiological and experimental studies suggest that n-3 polyunsaturated fatty acids (PUFA) can exert favourable effects on atherothrombotic cardiovascular disease, including arrhythmias. We investigated whether n-3 PUFA could improve morbidity and mortality in a large population of patients with symptomatic heart failure of any cause.

Methods

We undertook a randomised, double-blind, placebo-controlled trial in 326 cardiology and 31 internal medicine centres in Italy. We enrolled patients with chronic heart failure of New York Heart Association class II—IV, irrespective of cause and left ventricular ejection fraction, and randomly assigned them to n-3 PUFA 1 g daily (n=3494) or placebo (n=3481) by a concealed, computerised telephone randomisation system. Patients were followed up for a median of 3·9 years (IQR 3·0—4·5). Primary endpoints were time to death, and time to death or admission to hospital for cardiovascular reasons. Analysis was by intention to treat.

Findings

We analysed all randomised patients. 955 (27%) patients died from any cause in the n-3 PUFA group and 1014 (29%) in the placebo group (adjusted hazard ratio [HR] 0·91 [95·5% CI 0·833—0·998], p=0·041). 1981 (57%) patients in the n-3 PUFA group and 2053 (59%) in the placebo group died or were admitted to hospital for cardiovascular reasons (adjusted HR 0·92 [99% CI 0·849—0·999], p=0·009). In absolute terms, 56 patients needed to be treated for a median duration of 3·9 years to avoid one death or 44 to avoid one event like death or admission to hospital for cardiovascular reasons. In both groups, gastrointestinal disorders were the most frequent adverse reaction (96 [3%] n-3 PUFA group vs 92 [3%] placebo group).

Interpretation

A simple and safe treatment with n-3 PUFA can provide a small beneficial advantage in terms of mortality and admission to hospital for cardiovascular reasons in patients with heart failure in a context of usual care.