A new
study points to a very big effect of regular nut consumption — for me almost
too big to be believed.
by Theodore Dalrymple in PJ MEDIA
Some years ago a medical paper was published that caused a run on
Brazil nuts throughout the western world. For a time they disappeared entirely
from supermarket shelves; for Brazil nuts contain a high level of selenium and
the medical paper had suggested that the high rate of heart attacks in a
certain province of China was caused by the exceptionally low level of selenium
in the inhabitants’ diet.
But of course for every panacea there is an equal and opposite
health scare. Brazil nuts concentrate radium and give off more radiation than
any other food; they also often contain relatively high levels of aflatoxin,
produced by a fungus of the Aspergillus genus. Aflatoxins are very
carcinogenic, leading to cancer of the liver.
So where Brazil nuts are concerned, the question boils down to
whether you would prefer to die of heart attack or cancer.
A paper in a recent edition of the New England Journal of
Medicine suggests that, overall, nuts are very good for you. The authors
compared the death rates among female nurses and male health nurses according
to their self-reported consumption of nuts. They divided nut consumption into
true nuts and peanuts, the latter being legumes rather than nuts.
I never cease to be amazed at the organizational feat of such
studies: 76,464 women and 42,498 men were followed up between 1980 and 2010 and
1986 and 2010, respectively. After various statistical manipulations which 99
percent of the readership of the NEJM would not understand it was found
that the more nuts people ate (including the false nuts known as peanuts), the
lower their all-cause mortality. They didn’t just die less of such illnesses as
heart attack, stroke and cancer, but of all illnesses whatsoever.
At last, then, the panacea!
People who ate nuts more than seven times a week(!),
hunter-gatherer style, had a 20 percent less chance of dying in the period of
follow up than those who never ate nuts. This is a very big effect, for me
almost too big to be believed.
As everyone knows, nuts are fattening, or at least of high caloric
content. But strangely enough those who ate nuts more than seven times a week
were not fat, and this suggested to me that something more than the mere
consumption of nuts accounted for their low death rate. People who lie on
couches at the first opportunity watching television are not the kind of
people, on the whole, who nibble nuts rather than guzzle hamburgers, but the
authors claim that the protective effect of nuts still exists even when they
controlled for weight.
This is far from the first study that indicates the healthfulness
of nuts. Indeed, so persuasive have these studies been that the Food and Drug
Administration says a daily consumption of one and a half ounces of nuts might
reduce the risk of heart disease. Nuts are said to reduce inflammation, fat
deposition round the viscera, the level of sugar in the blood, blood pressure
and damage to the lining of the blood vessels, among other desiderata.
Increased nut consumption is “associated with” (weasel words) a reduction in the
rate of colon cancer, gallstones, diverticulitis and type II diabetes.
The authors warn that “epidemiological observations establish
associations, not causality, and not all findings from observational studies
have been confirmed in controlled, randomized clinical trials.” But I would not
be at all surprised if nut consumption rocketed with the publicity given to
this paper – and perhaps nut allergy too. At the moment, only about 100 people
a year die in the United States of nut allergy, but who knows what the future
may hold?
In the meantime, I suggest the following notice at the entrance to
every hospital: May contain nuts.
*****
Theodore Dalrymple, a physician, is
a contributing editor of City Journal and the Dietrich Weismann Fellow
at the Manhattan Institute. His new book is Second Opinion: A Doctor's Notes from the Inner City.
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