cron-web.org

[A1CR]

A new issue of J Am Coll Nutr has been published, can be
accessed for the
citations and most abstracts of the papers at the
http://www.jacn.org/current.shtml URL and pdfs are avail.

1. Metabolic Advantage of Low-carbohydrate Diets
Anssi H. Manninen and Carol S. Johnston
J Am Coll Nutr 2006. 25: 436-437.

The recent review by Johnston published in the Journal
suggested, quite
incorrectly, that the success of
low-carbohydrate/high-protein diets may
simply reflect increased thermogenesis and greater satiety
afforded by
higher intakes of protein rather than the low-carbohydrate
nature of the
diets [1]. However, the author did not provide any evidence
supporting this
contention. Indeed, it is becoming increasingly clear that
low-carbohydrate
diets provide a "metabolic advantage", i.e., induce greater
fat loss
compared to isocaloric
high-carbohydrate/moderate-carbohydrate diets [2-4],
and this advantage does not simply relate to dietary
protein-induced
thermogenesis. In fact, there is some evidence suggesting
that calorie
content may not be as predictive of fat loss as is reduced
carbohydrate
consumption [3]. Contrary to what some believe, the
"metabolic advantage"
certainly does not violate the first law of thermodynamics
[3,4]. Recently,
Volek et al. encouraged a more unbiased, balanced appraisal of
low-carbohydrate diets [5]. To look at the evidence and go
away unconvinced
is one thing. To not look at the evidence and be convinced
against it
nonetheless is another.

[1] Johnston CS
Strategies for healthy weight loss: from vitamin C to the
glycemic response.
J Am Coll Nutr24 :158-65,2005. [Abstract/Free Full Text]

2. Book Review
David Kritchevsky
J Am Coll Nutr 2006. 25: 439.

Diet, Life Expectancy and Chronic Disease: Studies of
Seventh Day Adventists
and Other Vegetarians, edited by Gary E. Fraser, New York,
Oxford University
Press, 2003, 392 pp.

Since the early epidemiological reports of the late Roland
Phillips we have
known that, in contrast to their neighbors, Seventh Day
Adventists enjoy
relative protection from coronary disease and most types of
cancer. This
book is an epidemiological treatise intended to expand and
explain the
findings for health professionals.

The book contains sixteen chapters, thirteen of which have
been written by
Dr. Fraser, two of which he co-authored and one by a
nutritionist. In the
first 4 chapters the author compares health and life style
of Seventh Day
Adventists and their neighbors. Chapters 5-8 discuss the
role(s) of diet and
life style vis-a-vis the risk of cancer, heart disease,
hypertension and
diabetes as well as aging. Chapter 9 is devoted to health
promoting effects
of social support, religiosity and other psychological
factors. Chapters
10-13 concern themselves with cancer, heart disease and
all-cause mortality
in vegetarians who are not Seventh Day Adventists and in
Vegans. The next
two chapters provide guidelines for changing to a vegetarian
diet. The last
chapter reviews the author's views which strongly endorse
the Adventist life
style and suggest that the dietary factors which are most
influential are
avoidance of meat and increased intake of nuts. The
contributions that a
vegetarian diet makes to increased intake of health
promoting phytochemicals
may add to the lowered risk of degenerative disease and
increased life
expectancy enjoyed by Seventh Day Adventists.

The author stresses that meat avoidance may be a key to
protection from
cancer but only 3-5% of Adventists are true vegans and fewer
than 30% are
lacto-ovo vegetarians. The cancer literature is rife with
publications
purporting to prove that meat eating is or isn't a major
risk factor for
cancer. The data are equivocal-there is certainly no
unanimity. A review of
the universal dietary data might dissect out some hitherto
unconsidered diet
or lifestyle characteristics which could influence the
dietary observations.

The Mormons (Latter Day Saints) constitute another religious
group that
lends itself to studies of diet and degenerative disease.
The Mormons do not
limit meat intake but their rates of breast and colon cancer
are
considerably lower than those of their non-Mormon neighbors
and approach
those of the Adventists. Two behavioral traits that Mormons
and Adventists
have in common are avoidance of alcohol and tobacco.

Educational level has been shown to provide health
advantages in many
societies and Adventists, as the author points out, have a
higher
educational level than the average Californian. Higher
educational level
suggests a better understanding of health and nutrition
guidelines but also
suggests an economic level which makes a "healthful" diet
more accessible.

The chapter on social support and religiousity is of
interest but, as the
author points out, church attendance had very little
influence on estimated
effects of vegetarianism or traditional risk factors. It
shows more what
might be a moderating influence of church attendance on
stress, which can be
a risk factor.

In the past quarter century we have increased our overall
longevity and
health status. Between 1970 and 2000 total deaths (age
adjusted) in the
United States have decreased by 29% and deaths from
cardiovascular disease
and stroke have fallen by 48 and 59% respectively. It would
be interesting
to know if the same has happened in the Seventh Day
Adventist community or
if they were just ahead of the curve.

This book provides a summary of salient points at the end of
each chapter, a
glossary of terms and 46 pages of references. It is clearly
written and easy
to read. It would be a useful reference text in the average
epidemiology
library.