We can get protein from plants or animals. Which is better?

Let's define our terms: What do we mean by “better?” How can we measure the effectiveness of a protein molecule?

First, some quick biochemistry. Proteins break down into amino acids when they are consumed, There are 20 types of amino acids in total, classified as either “essential” or “non-essential.” The essential are the ones your body cannot produce except by breaking down the proteins in your food.  You want your proteins to be as “complete” as possible; that is, contain as many of the 20 amino acids as possible, and in the right ratios.

If we define “better” as “having the most amino acids in the best ratio,” then plant proteins come up short. Vegans point to beans, nuts and lentils as good sources of protein, but in truth they are incomplete by this amino acid calculus. Each lack one or more of the essential amino acids. Even soy, which, as tofu, is often positioned as meat surrogate in vegan versions of burgers and turkey, has two essential amino acids in only very small amounts. Most of the time, plant proteins fall short of methionine, tryptophan, lycine and isoleucine. As a result, eating animal protein is linked with increased lean muscle mass and a reduction in the muscle loss that occurs with age.

On the other hand, if we define “better” as “less likely to kill you,” then plant proteins win, hands down. The highest quality protein source, red meat, has been linked to an increased risk of heart disease, stroke and early death. To be fair, there are many indicators that it is the processing of the meat which contribute to its elevated risk level. In various studies, unprocessed meat showed no association with any kind of disease or early mortality. So stay away from red meat, unless you are eating what you are catching and killing and preparing it yourself. Or stick with the proteins found in fish and poultry, which are 27 percent less likely to give you a stroke compared to red meat.

But what may be the biggest indictment of animal protein has just been published in the Journal of the American Medical Association. The study had over 130,000 participants, and the results showed that every 10 percent increase in animal protein from total calories was linked with a 2 percent higher risk of death from all causes and an 8 percent increased risk of death from cardiovascular disease.

The takeaway here is that vegans need to eat a wide spectrum of food to ensure that they are getting all the essential amino acids that carnivores can take for granted. Meat-eaters, in turn, should be eating a diet that is low in processed red meat. One study concluded that the optimal diet would be rich in plant protein, with some animal sources such as grass-fed meat, fish, poultry, eggs and dairy included.