The Great Protein Fiasco

The Great Protein Fiasco


“The Great Protein Fiasco” There has been a history
of enthusiasm for protein in the
nutrition world. A century ago the
protein requirements were more than twice what
we know them to be today. This enthusiasm peaked
in the 1950’s with the United Nations
identifying protein deficiency as a serious widespread
global problem. There was a protein gap
that needed to be filled. This was certainly convenient
for the U.S. dairy industry, who could dump their
postwar surplus of dried milk onto
the third world rather than having
to just bury it. But this led to the
great protein fiasco. There was a disease of malnutrition
called kwashiorkor that was assumed to be
caused by protein deficiency, famously discovered by
Dr. Cicely Williams, who spent the latter half
of her life debunking the very condition that
she first described. Turns out there’s no real evidence of
dietary protein deficiency. The actual cause of kwashiokor
remains obscure, but fecal transplant studies
suggest changes in gut flora may be a causal factor. How could the
field of nutrition have gotten it so
spectacularly wrong? A famous editorial
about the profession started with these words. “The dispassionate objectivity
of scientists is a myth. No scientist is
simply involved in the single-minded
pursuit of truth. He or she is also engaged
in the passionate pursuit of research grants and
professional success. Nutritionists may wish
to attack malnutrition, but they also wish to
earn their living in ways they
find congenial.” This inevitably encourages
researchers to “make a case” for
the importance of their own portion of
the field and “their nutrient,” which was protein. Science eventually
prevailed, though, and there was a
massive recalculation of human protein requirements
in the 1970’s, which ‘at the stroke of a pen’ closed the so called
‘protein gap’ and destroyed the theory
of this pandemic of ‘protein malnutrition’. Infant protein requirements went from a recommended 13%
of daily calories, down to 10%, then 7,
then down to 5%. However to this day
there are still those obsessing
about protein. Those promoting Paleolithic
diets, for example, try to make the
case for protein from an evolutionary
perspective. OK, so let’s ask the question: what is the perfect
food for human beings? The food that was
fine-tuned just for us over millions of years to have the perfect
amount of protein? Human breast milk. If high-quality protein was
the “nutrient among nutrients”, helping us build
our big brains over the last few
million years, one would expect
that importance to be resoundingly reflected in the composition of
human breast milk, especially since infancy
is the time of our most
rapid growth. But this is patently
not the case. Human breast milk is one
of the lowest-protein milks in the mammalian world. In fact, it may have
the lowest protein concentration of any animal in the world— less than 1% protein
by weight. This is one of the reasons
why feeding straight cow’s milk to babies can be
so dangerous. The protein content
in human milk is described as
extremely low, but it’s not low at all. It’s right where it
needs to be. That’s the natural,
normal level for the human species
fine-tuned over millions of years. Adults require no more
than 0.8 or 0.9 grams of protein per healthy kilogram of
body weight per day. So that’s like your
ideal weight in pounds multiplied by four and
then divided by ten. So someone who’s ideal
weight is 100 pounds may require up to 40 grams
of protein a day. On average they probably
only need about 30 grams a day, which is 0.66 grams
per kilogram, but we say 0.8 or 0.9
because everyone’s different and we want to capture
most of the bell curve. People are more
likely to suffer from protein EXCESS
than protein deficiency. The adverse effects
associated with long-term high protein diets
may include disorders of bone and
calcium balance, disorders of kidney function,
increased cancer risk, disorders of the liver, and worsening of coronary
artery disease. Therefore, there is currently
no reasonable scientific basis to recommend protein
consumption above the current
recommended daily allowance due to its potential
disease risks.