Cancer Prevention Research: Does Vitamin E Prevent or Promote Cancer?

Abstract

The cancer preventive activity of vitamin E has been suggested by many epidemiologic studies. However, several recent large-scale human trials with α-tocopherol, the most commonly recognized and used form of vitamin E, failed to show a cancer preventive effect. The recently finished follow-up of the Selenium and Vitamin E Cancer Prevention Trial (SELECT) even showed higher prostate cancer incidence in subjects who took α-tocopherol supplementation. The scientific community and the general public are faced with a question: “Does vitamin E prevent or promote cancer?” Our recent results in animal models have shown the cancer preventive activity of γ- and δ-tocopherols as well as a naturally occurring mixture of tocopherols, and the lack of cancer preventive activity by α-tocopherol. On the basis of these results as well as information from the literature, we suggest that vitamin E, as ingested in the diet or in supplements that are rich in γ- and δ-tocopherols, is cancer preventive; whereas supplementation with high doses of α-tocopherol is not. Cancer Prev Res; 1–5. ©2012 AACR.

Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases - The Cochrane Library ((beta-carotene, vitamin A, vitamin C, vitamin E, and selenium)

Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases - The Cochrane Library

 Abstract

"The increased risk of mortality was associated with beta-carotene and possibly vitamin E and vitamin A, but was not associated with the use of vitamin C or selenium. The current evidence does not support the use of antioxidant supplements in the general population or in patients with various diseases."

Background

Our systematic review has demonstrated that antioxidant supplements may increase mortality. We have now updated this review.

Objectives

To assess the beneficial and harmful effects of antioxidant supplements for prevention of mortality in adults.

abstract: Effects of vitamin E on bone turnover markers among US postmenopausal women.

Abstract

Increased oxidative stress and inflammation resulting from aging and declining estrogen levels can lead to increased bone loss in postmenopausal women. Alpha- and gamma-tocopherol, the two predominant isomers of vitamin E, have antioxidant and anti-inflammatory properties, but their effects on bone metabolism have not been well studied in humans. We examined the associations between dietary and total (diet and supplements) alpha-tocopherol intake, serum alpha- and gamma-tocopherol levels and their ratio, and bone turnover markers (BTMs) among postmenopausal women aged ≥45 years........

EvidenceUpdates - Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND:
Cisplatin and several related antineoplastic agents used to treat many types of solid tumors are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought.


AUTHORS' CONCLUSIONS:
At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxycarbazepine, or Vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients.

Cochrane review: Interventions for preventing neuropathy caused by cisplatin and related compounds

AUTHORS' CONCLUSIONS: At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxycarbazepine, or Vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients.

Vitamin E neuroprotection for cisplatin neuropathy: A randomized, placebo-controlled trial -- Neurology

Conclusions: This phase III study confirms the neuroprotective role of vitamin E against cisplatin peripheral neurotoxicity. Vitamin E supplementation should be adopted in patients receiving cisplatin-based chemotherapy.