gamma -Tocopherol is the major form of vitamin E in many plant seeds and in
the US diet, but has drawn little attention compared with alpha -tocophero
l, the predominant form of vitamin E in tissues and the primary form in sup
plements. However, recent studies indicate that gamma -tocopherol may be im
portant to human health and that it possesses unique features that distingu
ish it from alpha -tocopherol. gamma -Tocopherol appears to be a more effec
tive trap for lipophilic electrophiles than is alpha -tocopherol. gamma -To
copherol is well absorbed and accumulates to a significant degree in some h
uman tissues; it is metabolized, however, largely to 2,7,8-trimethyl-2-(bet
a -carboxyethyl)-6-hydroxycluoman (gamma -CEHC), which is mainly excreted i
n the urine. gamma -CEHC, but not the corresponding metabolite derived from
alpha -tocopherol, has natriuretic activity that may be of physiologic imp
ortance. Both gamma -tocopherol and gamma -CEHC, but not alpha -tocopherol,
inhibit cyclooxygenase activity and, thus, possess antiinflammatory proper
ties. Some human and animal studies indicate that plasma concentrations of
gamma -tocopherol are inversely associated with the incidence of cardiovasc
ular disease and prostate cancer. These distinguishing features of gamma -t
ocopherol and its metabolite suggest that gamma -tocopherol may contribute
significantly to human health in ways not recognized previously. This possi
bility should be further evaluated, especially considering that high doses
of alpha -tocopherol deplete plasma and tissue gamma -tocopherol, in contra
st with supplementation with gamma -tocopherol, which increases both. We re
view current information on the bioavailability, metabolism, chemistry, and
nonantioxidant activities of gamma -tocopherol and epidemiologic data conc
erning the relation between gamma -tocopherol and cardiovascular disease an
d cancer.