Alpha Lipoic Acid
The Free Radical Theory of Aging Matures
KENNETH B. BECKMAN AND BRUCE N. AMES
Department of Molecular and Cell Biology, University of California, Berkeley, California
Beckman, Kenneth B., and Bruce N. Ames.
The Free Radical Theory of Aging Matures. Physiol. Rev. 78: 547-581, 1998. — The
free radical theory of aging, conceived in 1956, has turned 40 and
is rapidly attracting the interest of the mainstream of biological
research. From its origins in radiation biology, through a
decade or so of dormancy and two decades of steady phenomenological research,
it has attracted an increasing number of scientists from
an expanding circle of fields. During the past decade, several lines
of evidence have convinced a number of scientists that oxidants play
an important role in aging. (For the sake of simplicity, we
use the term oxidant to refer to all "reactive oxygen species," including
O—2·,
H2O2 , and ·OH, even though the
former often acts as a reductant and produces oxidants
indirectly.) The pace and scope of research in the last
few years have been particularly impressive and diverse. The
only disadvantage of the current intellectual ferment is the difficulty
in digesting the literature. Therefore, we have systematically reviewed
the status of the free radical theory, by categorizing the
literature in terms of the various types of experiments that have
been performed. These include phenomenological measurements of
age-associated oxidative stress, interspecies comparisons, dietary
restriction, the manipulation of metabolic activity and oxygen
tension, treatment with dietary and pharmacological antioxidants, in
vitro senescence, classical and population genetics, molecular genetics,
transgenic organisms, the study of human diseases of aging,
epidemiological studies, and the ongoing elucidation of the
role of active oxygen in biology.
PHYSIOLOGICAL REVIEWS - Vol. 78 No. 2 April 1998, pp. 547-581
Copyright ©1998 The American Physiological Society
