Plant-based vs. animal protein: the debate that endures
Originally published on Medium.
An all too common concern among those contemplating a plant-based diet is whether they’ll consume the necessary amount of protein to be healthy. It’s not a silly concern. Protein, that all-important factor in a healthy diet, is arguably the single most crucial thing to consume. Our bodies can’t function without it, and the consequences for not eating enough can be severe.
But it’s also true that not all proteins are equal. We’ve long surpassed the falsehood that the only protein worth consuming is animal protein. Plant protein does exist and it is beneficial to consume. But the debate over which protein is better for us lingers largely because animal proteins offer things that plants don’t and vice versa.
To begin, it may be helpful to understand what protein is. By way of a simple definition, protein is compiled of strings of amino acids. There are twenty amino acids in total carrying out a wide array of functions throughout the body. The means by which they do this is fascinating and better explained by someone with a medical degree. But for a general overview, amino acids do a number of jobs in our bodies we don’t appreciate. These include breaking down food, making hormones and brain chemicals, providing energy, building muscle, boosting our immune systems, and maintaining a proper digestive system, among other things.
Should we not receive the correct amount of protein, our systems naturally won’t function as they should. Those with protein deficiency can experience weakness, brittle hair and nails, more frequent illnesses, and possibly muscle weakness should the deficiency continue for some time.
Of the twenty amino acids necessary for our health, eleven are produced by the body. The remaining nine are obtained through food sources. This is where the debate over animal protein versus plant protein gets interesting.
Animal protein is what dietitians and nutritionists would call a “complete protein”. What this means is that any animal protein (i.e. meat, dairy products, eggs, fish, etc.) that someone consumes has all remaining nine amino acids. It’s efficient. Should you choose to eat nothing but a chicken breast, you’ll at least have received all the necessary amino acids to carry out your important bodily functions.
Most (though interestingly not all) plant-based proteins are considered “incomplete”. That is to say, they contain some amino acids, though not all. For a complete set of the required amino acids, a plant-based eater would need to eat a wider variety of protein sources. This isn’t as difficult as it sounds. Have some lentils (a plant-based protein) with some whole grain bread and you’re all set. There is a little more work involved, but not so much so that it’s impossible.
Plant protein can be found in many ingredients. Most well-known of these perhaps is beans, of which there are several varieties. Nuts and seeds also are well known plant-based protein sources. Whole grains, lentils, peas, and vegetables can also qualify. Though we don’t always see vegetables as being ‘rich’ in protein, they certainly have it. Mushrooms, asparagus, spinach, broccoli, Brussel sprouts, and corn each have quantities of protein that shouldn’t go unnoticed.
Finally, we must not forget that there are some plant-based protein sources that qualify as ‘complete’. Quinoa, tofu, tempeh, buckwheat, Ezekiel bread, spirulina, chia seeds, and edamame are some examples that contain all the necessary amino acids.
For reasons unknown, health experts haven’t universally declared one protein to be better than the other. Animal proteins have of course, been the lords of the house when it comes to protein sources. Unquestionably, there are some benefits. For one, meat contains heme iron, an iron that is more readily absorbed than the iron found in plant foods and which plays a central role in carrying oxygen throughout the body. They also have B12, a nutrient that is commonly found lacking in vegan diets, and which would require additional sources for those on a plant-based diet. Eating fish has been known to slow cognitive decline and reduce the risk of heart disease. Eating meat also promises to increase lean muscle mass, which naturally declines as we age.
This isn’t to say that there aren’t benefits to eating plant-based proteins. Significantly, consuming plant-based proteins can reduce blood pressure, lower cholesterol, help towards maintaining weight and reducing obesity, and lowering the risk for stroke, cancer, or heart disease. What’s more, those things that are missing in a plant-based diet, Vitamin B12 and heme iron for instance, are easily ingested via over-the-counter supplements.
There are also more than a few eyebrow-raising facts about eating animal protein. Meat and dairy are famously devoid of fiber for instance. If protein is the most important thing for us to consume, fiber is in second place. A diet high in fiber has been linked with lower risk of cancer, ulcerative colitis, Crohn’s disease, and diverticulitis. Animal foods have proven also to be rather high in TMAO (trimethylamine N-oxide), a substance that causes inflammation and helps to produce cholesterol blockages in our blood vessels. Too much animal protein and our bodies will produce an overflow of this to a worrying degree.
And to be ruthless for a moment, many meat dishes aren’t even healthy in the slightest. Steak, hamburgers, chicken nuggets, etc. are all foods high in saturated fat and cholesterol. While they can make our mouths water, the cons from eating high-fat meats far outweighs whatever protein benefits we’re getting when we consume them.
All of this may make one wonder why the debate is still raging, despite the overwhelming evidence that plant-based protein sources have the clear lead. Undoubtedly, some of this is due to human nature: it’s not easy to change one’s diet, even if a doctor tells you to. Medicos probably wouldn’t win any popularity contest by stating that one protein is best and the rest should be forgotten.
I’m also willing to bet however, that many don’t understand the nature of protein itself or the role plants can play in providing a balanced diet. Many animal product consumers fail to understand that protein is found in a variety of other plants, legumes, grains, and nuts. And on the flip side of the coin, not all plant-based eaters understand that eating ‘impossible’ meat also comes with its own side-effects.
Ultimately, the choice is a highly personal one. If there is any lesson to take away from this, it’s that despite the strides we’ve made in understanding protein and its numerous sources, we’re still learning. Only time will tell how our protein sources will change in the future.