diet rich in vitamin E could protect smokers from the oxidative stress
linked to cancer development, US-based scientists reported this week.
«This suggests that while working toward the goal of quitting smoking,
which is the very best way to prevent development of smoking-related
cancers, it could be helpful to eat a diet rich in vitamin E,» said
Frederica Perera, senior investigator from Columbia University School of
Public Health. «We don’t yet know why this relationship was not found
in women, but a good diet is beneficial to health in many ways.» Vitamin
E, an antioxidant, actually refers to a group of eight compounds: four
types of tocopherols and four tocotrienols. The most common form
consumed in the American diet is gamma-tocopherol, while
alpha-tocopherol is the form mostly found in supplements. Perera and
colleagues reported that increased plasma alpha-tocopherol levels were
associated with lower levels of oxidative damage, according to 8-OHdG
levels, but only among men. The data was presented at the American
Association for Cancer Research’s Frontiers in Cancer Prevention
Research meeting earlier this week. The researchers also investigated
possible interactions between vitamin E and GSTM1, a gene variant known
to produce enzymes that efficiently detoxify carcinogens in tobacco
smoke. The apparent protective effect of vitamin E was greatest among
the men with the GSTM1 gene variant, said the researchers. A diet rich
in antioxidants like vitamins C and E, and beta-carotene has been
reported to protect certain sub-populations, particularly smokers,
against prostate cancer, a disease that is becoming more common, with
incidence rates haven risen by almost two per cent over 15 years.
Indeed, the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer
Screening Trial, (Journal of the National Cancer Institute, Vol. 98, pp.
245-254), and the Alpha-Tocopherol, Beta-Carotene Cancer Prevention
(ATBC) study (1998), have both reported protective effects of vitamin E
against prostate cancer amongst smokers.