Supplementing the diet with alpha-tocopherol vitamin E may reduce the risk of certain gastrointestinal cancers, suggests a new Chinese study.
Researchers carrying out a prospective trial to compare blood vitamin E levels with risk of stomach and oesophagus cancers found a significant reduction for those with the highest levels of alpha-tocopherol.
However the vitamin also raised risk of another type of stomach cancer, gastric noncardia cancer, they report in the latest issue of the Journal of the National Cancer Institute.
The study was based on the General Population Trial, a randomised nutrition intervention trial in Linxian, China, which found that those participants who received a combination of selenium, beta-carotene, and vitamin E supplements, had significantly lower cancer mortality rates than those who did not receive the supplements.
Researchers from the Chinese Academy of Medical Sciences in Beijing measured blood alpha-tocopherol, gamma-tocopherol and cholesterol levels in 1072 patients with incident oesophageal squamous cell carcinoma, gastric cardia cancer, or gastric noncardia cancer and compared these to 1053 control subjects.
Those in the highest quartile of alpha-tocopherol saw a risk reduction of 37 per cent for oesophageal cancer. There was also a significant reduction for stomach cancer. Blood levels of gamma-tocopherol had no effect on risk of the cancers studied.
However they also found an association between high levels of alpha-tocopherol and increased risk of another cancer, gastric noncardia cancer. The authors were unable to explain this finding, but concluded : "Our findings provide support for the role of alpha-tocopherol in the etiology of upper gastrointestinal cancers."