In this first chapter of the Health Section, we'll discuss some basics about protein.
We'll talk later about the relationship between animal protein and our health,
but for this first chapter, let's start with some general information.
As Dr. Walter Willett, the chair of Harvard's Department of Nutrition,
explains, "To the metabolic systems engaged in protein production and repair,
it is immaterial whether amino acids come from
animal or plant protein. However, protein is not consumed in isolation...
...it is packaged with a host of other nutrients" that vary depending on the source.
He therefore recommends to "Pick the best protein packages
by emphasizing plant sources of protein rather than animal sources."
Although meat has long been touted as a "basic food group,"
and many people assume it's a necessary part of a healthy diet,
there's a broad body of scientific literature and studies that lead physicians
like Dr. Willett and myself to recommend
plant protein over animal protein.
First, it's important to note that proteins are abundant in both animal sources,
like meat, fish, dairy, and eggs, as well as plant sources,
like vegetables, grains, legumes and nuts. Proteins are chains of organic compounds called
amino acids, which are joined together by peptide bonds.
The term "essential amino acid" refers to nine amino acids that our bodies do not synthesize
and we therefore need to get from food. With few exceptions, such as
gelatin, most protein from both
animal and plant sources are complete proteins,
meaning they contain all of the essential amino acids our bodies need.
The fact that plants have protein is for some reason
not always well known. But just as an example,
according to the USDA, broccoli has
more protein per calorie then beef.
Specifically, beef has 14.63 grams of protein
in 204 calories, whereas broccoli has
17.15 grams of protein
in 207 calories. This equates to about 15.5%
more protein per calorie in broccoli
then in beef. This well cited review in the American Journal of Clinical Nutrition
addresses protein in plant foods, noting that most animal
and plant foods not only meet, but
exceed the required concentration of essential animal acids.
A joint panel of the Food and Agriculture Organization,
World Health Organization, and United Nations University
estimated our nutritional amino acid requirements.
When those requirements are compared with the
amino acid patterns of plant and
animal sources of protein, the amount of amino acids
in all these foods was found to be
"much higher (per-unit of protein) than required."
"Thus," the review concludes, "all usual food proteins would readily meet and even
exceed the requirement for indispensable animo acids."
To be clear, this means we can get more than enough,
and even exceed our protein requirements, including all other essential amino acids,
from either animal foods or
a purely plant-based diet. So, if we can get
adequate protein from either plants
or animals, which one should we use?
Well, Harvard's Healthy Eating Plate
states, "Go with plants. Eating a plant-based diet is healthiest."
And, as I mentioned earlier, the chair Harvard's Department of Nutrition
recommends that you "Pick the best protein packages by emphasizing
plant sources of protein rather than animal sources."
Also, physicians from Kaiser Permanente
have recently suggested the same thing, noting in their medical journal
that, "Further research is needed
to find ways to make plant-based diets
the new normal for our patient and employees."
And, as I mentioned earlier, that's what I recommend to my patients.
So, let's talk more about animal protein and health,
which we'll do in the next video chapters.