Robert Ettinger sent me a copy of The Anti-Aging Zone,
and asked for a review of it. Overall I was not too
impressed with this book. Rather than being a serious
look at interventions on either aging, or disease risk, it
is just a potboiler pushing Sears' high protein diet.
The book is well written, and it is clear that Sears knows
how to write good copy. Although the Zone diet will not win any
support from main-stream medicine, but it is a lot healthier
than some other high protein diets on the market. His diet
is essentially the Mediteranean diet, emphasizing olive
oil, and lots of fruits and vegetables, with an extra dollop
of protein. He recommends cutting the fat off meat, and
consuming only egg whites (which lower cholesterol), and
discarding the egg yolks (which increase cancer risk).
Unlike other high protein diets I doubt the the Zone diet
would increase the risk of cardiovascular disease, as Sears
takes some care to avoid the obvious sins in this regard.
High protein diets generally increase cancer risk, but the
inclusion of tofu, and lots of fruits and vegetables, makes me
think the risks associated with increased meat rations would
probably be largely offset. Others considerations such as
increased kidney stone risk, and weakened bones are harder
to evaluate, with the meat and fruits and vegetables offering
opposing effects. A mineral supplement would likely be a good
idea on this diet.
However the major risk associated with the Zone diet is
increased risk of depression in susceptible individuals. All
high protein diets suffer from this defect, and it is not particular to
the Zone diet alone. This is a consequence of high protein diets
inhibiting tyrosine, and tryptophan transport across the blood/brain
barrier.
Like most diets, significant weight loss will not occur on the Zone
diet, unless dieters are willing to go hungry. The major reason
why obesity is so common, is regarded by scientists as being due
primarily to a combination of the "couch potato" existence now
favoured by many, and the easy availability of a wide variety of
highly palatable foods. With regard to the former factor, lack of
exercise is not the only fattening factor in our remote control
dominated existance. Snacking during television watching,
despite not being hungry is an additional factor. Weight loss has
been induced in children, by restricting the hours of television
watching.
The consumption of a wide variety of highly palatable foods is
referred to in the medical literature as the "cafeteria diet". Feeding
western style human food to rodents for example, in place of rodent
chow, sets the stage for a process of rapid gorging, in which
large weight gains are the net result. The incidence of obesity in Asian
populations is low, despite these diets not being high fiber, high protein,
or even in some cases low fat. It is an unfortunate fact of life that
delicious food encourages many to over-indulge. This is the dietary factor
which is primarily responsible for the obesity epidemic.
If the reader is interested, as a test I suggest temporaily limiting food
intake to just whole meal bread with no toppings for a one day.
Record calorie intake. You may be surprised by the results.
As an anti-aging or anti-disease risk book the Anti-Aging Zone falls
well short of being satisfactory. Sears does not even deal with the
known side-effects of high protein diets, let alone examine the effect
of diet on disease risk. You will not find discussions of
the effect of tomato intake on prostate cancer risk, of nuts on
cardiovascular disease, of carrots on breast cancer risk, why you
should cut garlic cloves open before cooking them and other such
esoterica.
Living longer or in better health is not an important goal with Sears,
despite the title of his book. Rather Sears goes on a confused monolog
in which he discovers the answer to a question that puzzles gerontologists
to this day, why humans age. He has been criticized for trafficking in
falsehoods with his theories concerning eicosanoids. After reading one
scathing review in the medical literature exposing Sears' quackery, I must
come to the conclusion that honesty is one of Sears' strong points.
(Sports Med 27(4): 213-228 Apr 1999)
The Anti-Aging Zone is not recommended.