Alpha-Tocopherol Reduces Upper GI Cancer Risk 32830

Alpha-Tocopherol Reduces Upper GI Cancer Risk

BETHESDA, Md.Serumalpha-tocopherol levels, but not gamma-tocopherol levels, may be associated witha reduced risk of upper gastrointestinal (GI) cancers, according toinvestigators at the Cancer Prevention Studies Branch of the Center for CancerResearch at the National Cancer Institute (NCI). Philip R. Taylor, M.D., Sc.D.,and colleagues published their findings in the Sept. 17 issue of the Journalof the National Cancer Institute (95, 18:1414-16, 2003) (http://jnci.oupjournals.org).

According to the researchers, a prior studythe GeneralPopulation Trialindicated subjects in Linxian, China, taking beta-caroteneand vitamin E supplements had significantly lower cancer mortality rates thanthose who did not take supplements. To further explore this data, Taylor andcolleagues conducted a case-cohort study to investigate whether pre-trial serumvitamin E levels were associated with the risk of upper GI cancers, as Linxianresidents have extraordinary rates of esophageal and gastric cardia cancers.

Researchers reviewed serum alpha- and gamma-tocopherol levels,as well as cholesterol levels, for 1,072 case participants and 1,053 controlsubjects. An analysis indicated those in the highest quartile of serumalpha-tocopherol levels were less likely to develop esophageal squamous cellcarcinoma and slightly less likely to develop gastric cardia cancer than thosein the lowest quartile. However, higher alpha-tocopherol levels were actuallyassociated with an increased risk of gastric noncardia cancer than those in thelowest quartiles. The researchers also learned gamma-tocopherol was notassociated with the incidence of any of the cancers studied.

For the broader scientific community and the world, we haveto be cautious in generalizing the results from these studies, including thecurrent study, to the rest of the world, Taylor told INSIDER. We donot know for sure that supplementation with these micronutrients in awell-nourished population such as is found in the Westas opposed to thepoorly nourished population of Linxianwould provide similar reduction inrisk. These data do, however, provide strong proof-of-principle evidence thatnutrition is related to cancer overall, and they establish the paradigm thatimproving nutrition status in selected undernourished populations can reducecancer rates.