The
"Eat Right for Your Blood Type!" diet, by naturopath
Dr. D'Adamo, is to dieting as astrology is to astronomy. In
fact, every time I pick up "Eat Right for Your Blood Type!",
I am seized by a very powerful urge to tear my hair out. Never
have I read such an unsubstantiated mound of pseudoscience diet-babble.
In fact, it's first on my list of all-time most ridiculous diets.
Why review a diet that I feel so negatively about? Two reasons...
First,
it's important to recognize that even a diet founded on pure nonsense
can work for a surprisingly large percentage of people. Second,
it will provide a good basis of how to analyze a particular diet
for credibility.
The
crux of "Eat Right for Your Blood Type!" is quite simple:
D'Adamo postulates that your blood type is the determining factor
in what you should be eating. Each of the 4 diet plans specific
to each blood type (O,A,B, and AB), are carefully formulated to
avoid foods containing the "protein lectins" incompatible
with it. According to D'Adamo...
"...
when you eat a food containing protein lectins that are incompatible
with your blood type antigen, the lectins target an organ or
bodily system (kidneys, liver, brain, stomach, etc.,), and begin
to agglutinate blood cells in that area".
Unfortunately,
D'Adamo offers no proof or documentation (no references to peer
reviewed medical journals), to validate this argument. The best
he can do is state his theory is valid because he himself has
done tons of research to prove it so. In other words, we are
not to question this theory, but to accept it at face value
(the almost total lack of footnotes in the book, especially
to validate the many general statements, is particularly alarming).
Yeah,
right.
Perhaps
even more disturbing is the fact that the symptoms attributed
to "lectin agglutination" mirror the symptoms of many
other diet-related disorders -- yeast overgrowth, nutritional
deficiencies, bowel toxicity, allergies, heavy metal toxicity,
hyperinsulinemia, prostaglandin imbalance and so on. In other
words, this is at best, only a theory.
Aside:
Believe it or not, D'Adamo even goes as far as to predict personality
traits and establish exercise programs on the basis of blood type.
For instance, he indicates blood type A's exceed psychologically
at planning and networking, and are decent, and law abiding people.
Yeah OK, Dr D'Adamo (remember the reference to astrology I mentioned
earlier?).
The
problems don't end here; there are some serious issues with
D'Adamo's theory linking blood type with diet. For instance...
D'Adamo
postulates that blood type A evolved sometime between 25,000-15,000
B.C. in response to the domestication of livestock and farming.
Blood type A, for example, apparently allowed people to "better
tolerate grains and other agricultural products".
What's
the problem with this? There are two...
First,
most experts agree that mankind made the jump from hunter-gatherer
to farmer about 6-10,000 years ago. On the outside, this switch-over
began no earlier than 15,000 years ago, at which time the last
ice age was drawing to a close.
The
significance of this?
Well,
geneticists theorize that it takes many thousands of generations
to bring about any sort of significant genetic evolutionary response.
In other words, our switch from hunter gatherer to farmer happened
much too recently in our history for it to have resulted in the
evolution of a new blood type. Since blood type A obviously evolved
as a result of some other stimuli, D'Adamo's theory is a bust.
As
a reader, one can feel D'Adamo grasping at straws as he develops
his theory for blood type B, which evolved in the Himalayans
"perhaps" as a result of climactic change. Here's
another BIG problem... if blood type mutation and evolution
is not consistent with dietary changes (and by D'Adamo's own
admission clearly it is not), why would it make sense to use
blood type to best determine what we eat?
When
it comes to actual diet advice itself, D'Adamo doesn't fare much
better. In fact, he consistently provides recommendations that
are totally incorrect; Type B's are encouraged to eat rice cakes
(pure carbohydrate with a glycemic rating of pure glucose), which
are perhaps the dieter's worst enemy. Peanuts, on the other hand,
are said to cause hypoglycemia for type Bs. Interesting, since
peanuts have a very low G.I. (glycemic index) rating, and don't
generate fluctuations in blood sugar levels. Believe it or not,
the entire book is jam-packed with similar misinformation, generalities,
and information that is just plain wrong.
Despite
this, around 50% of those trying "Eat Right for Your Blood
Type!" will experience positive results, but certainly
not because D'Adamo's theory is correct. Here's why...
In
North America, the predominant blood type is type O. Just under
50% of the Black/People Of African descent population is type O, while the Caucasian population
comprises just slightly less (about 45%).
D'Adamo's blood type
O diet focuses on restricting breads and grains, while increasing
lean meat, poultry, and fish. This will effectively place the
dieter on the "cusp" of ketosis, similar to Protein
Power's Phase 2 diet. It will also eliminate vacillating blood
sugar levels, encourage lean muscle growth, and stimulate weight
loss. In short...
The
plan for type O will work, simply because it sticks to proven
diet fundamentals.
If
your blood type is anything other than type O, you'll be lucky
to achieve anything on this diet.
In
summation, I heartily recommend you avoid this diet (unless you
wish to read it for its comedic value). There is so much nonsense
in this book that I for one find it insulting that this thing
is actually sitting on the bookshelves. Instead, investigate more
credible diets like the Zone
diet, and the recently exonerated Atkins
diet.
