Finally a clue to explain why you should avoid red meat
Finally, a Clue to Explain Why You Should Avoid Red Meat
June 22, 2013
by Gabe Mirkin, MD
Several years ago, Professor Ajit Varki of the
University of California, San Diego discovered a
molecule called Neu5Gc that appears in the tissues of
every mammal except humans (Proceedings of the National
Academy of Sciences, September 29, 2003). Now he has
put together the pieces of a puzzle that may explain
why humans evolved with large brains and why, if we
want to live into old age, we should probably avoid
eating meat from any other mammals (Science, October
His theory depends on evolution. Living creatures on
earth started as one-celled organisms, progressed to 2
cells, and eventually to fish and birds. A mutation
occurred in progressing to mammals, who developed the
gene to make Neu5Gc. Mammals progressed to apes and
Neanderthals, and as humans evolved, Neu5Gc added a
single oxygen atom to become a different molecule
called Neu5Ac. So Neu5Gc is found in all mammals and
their milks except humans. It is not in fish or birds.
Interestingly, the Neu5Ac molecule explains why humans
are the only mammal to suffer from malaria. The malaria
parasite cannot enter a cell until it grabs onto the
Neu5Ac on the surface of human cells.
Many epidemiological studies show that people who eat
red meat are at increased risk for heart attacks,
strokes, at least 17 different cancers, diabetes,
autoimmune diseases, arthritis and asthma. Scientists
have blamed saturated fats or burnt fats, but this does
not explain why red meat is linked to all of these
diseases while poultry, fish or saturated fats from
plants are not.
Dr. Varki proposes another theory. When humans ingest
the flesh or milk of any mammal, they absorb Neu5Gc and
treat it the same way as an invading germ, so they make
antibodies against it. This turns on their immunity and
keeps it active so it eventually attacks the host
itself, the human body. This is called chronic
inflammation, which can lead to heart attacks, strokes,
cancers and so forth.
Since humans cannot make Neu5Gc, any amount found in
human cells come from the mammals that they have eaten.
Neu5Gc is found in high levels in tumors, with the
highest levels in metastasizing tumors. In our food
supply, Dr. Varki found very high levels of Neu5Gc in
beef, pork, lamb and goat, and moderately high amounts
in milk and cheese. Low levels are found in turkey,
duck, chicken and eggs; and negligible amounts occur in
plants and seafood.
I stopped eating meat many years ago, and this report
makes me even more convinced that it should be avoided.
I eat lots of fruits, vegetables, whole grains, beans
and nuts, as well as fish and shellfish. Eggs, long
thought to be a harmful high- cholesterol food, now
appear to be a healthful dietary staple. While poultry
appears to be a healthful food according to Dr. Varki’s
theory, I still do not eat it. I do not drink milk and
now plan to limit cheese as well.