There is a lot of talk about protein these days. In fact, most people agree we need protein in our diets. Whether it comes from plants, like the “all the rage” Beyond Meat burgers, or more traditional avenues, it’s agreed there are many benefits to consuming protein-rich foods. But with Keto diets in full swing, some people have raised the question:
“Is there such a thing as too much protein?”
Well… just like fat and cholesterol used to be considered bad in large amounts, surprisingly, scientists have claimed that it’s more complicated than initially thought and that high levels of protein in your diet might not be as bad as originally perceived.
Interesting, isn’t it?
But wait, there’s more to it than meets the eye. And to understand that, we have to go back to the basics.
What is protein anyway?
Here’s a simplified overview of this macronutrient:
Protein, together with fat and carbohydrate, is one of the 3 macronutrients the body needs to carry out certain functions.
It can be derived from various sources such as meat, fish, yogurt, beans, nuts, and soy products. However, protein isn’t just a big chunk of material. If we look at it from a sophisticated microscope, it’s made up of amino acids, which are its main building blocks.
Think of them like your childhood favorite toy, Lego. Lego houses are made up of individual pieces that once disassembled and assembled, can form various objects. So is protein and amino acids. Once a protein-rich meal enters your GI tract, digestive enzymes will break these houses apart into individual blocks (amino acids). Then, your body takes all those loose pieces and rebuilds them into hormones, tissues, and organs.
If you want to learn more about protein, check out this article.
Why is protein important?
There are 5 main reasons why it’s vital for your body:
1. Acts as a messenger
Messengers send signals between one internal organ to the other to begin or halt certain functions.
An example of this is when high blood sugar is detected and messenger proteins relay a signal to increase insulin (a hormone that indirectly lowers down blood sugar) secretion.
2. Serves as a transport medium
Proteins act as transport systems (pretty much like tunnels) thereby allowing molecules to move through cellular structures, such as the passage of ions like sodium, chloride, or calcium through cellular membranes.
3. Function As Enzymes
Enzymes are the body’s small catalysts. Meaning, they make reactions occur. And without them, well… no chemical reaction will happen to keep cells functioning. Some examples are Lipases (responsible for digestion of fat), Insulin (for redirecting blood glucose to its appropriate storage) or Amylase (for converting starch into sugar).
4. Builds up the Immune System
Antibodies are part of the immune system that act by binding to invading cells (i.e. bacteria) and release an alarm signal that notifies white blood cells (WBC) to aggregate and begin their defensive mechanisms. This leads to an enhanced immune system.
5. As Structural Components
Proteins bind together on a small scale to provide structure to our cells, making them firm yet flexible. While on a large scale they make up our tendons, muscles, and skin.
How much protein do we need in order to function?
The World Health Organization recommends about 0.83 grams of protein for every kilogram of body weight. So for a 70 kg person that would be 58.1 grams of protein daily (roughly 200 grams of chicken breast).
Not so much, is it?
That is the amount required for the average adult to avoid malnutrition. However, this requirement was formulated as a guideline in order to prevent malnutrition, not as an optimal upper limit.
Remember, surviving is not the same as thriving.
But you may be asking, “but I’ve heard health gurus talk about meat being linked to cancer and a myriad of diseases?”
Well…that’s what the last section is all about: Does excess protein lead to cancer? Kidney injury? Or even osteoporosis?
Let’s find out.
Osteoporosis and Protein
It used to be a belief that eating large amounts of protein can lead to osteoporosis. This was connected to the increase in calcium secreted in the urine of individuals eating high protein diets.
Why would that be?
The logic behind this was that when protein is broken down, acidity levels rise. And in order to normalize the acidity calcium must be borrowed from bone, eventually leading to some calcium excreted in the urine, thus weakening the bones.
But as it turns out, research says the opposite. In fact, more recent and long ranging studies have shown a decrease in the number of hip replacements in those with high protein diets and an overall increase in bone health as well.
Well… that’s what research has to say.
Kidney and Protein
Not long ago there was a belief that high protein diets might overtax the kidneys and lead to acute kidney injury (AKI). This was due to the fact that one role of the kidney was to act as a remover of metabolic byproducts (e.g. urea, uric acid, etc.), especially nitrogen (a byproduct of protein metabolism). And the common thought was, the more protein you eat, the more taxing it’ll be for your kidneys, hence, causing AKI.
It all sounds logical, but then when we look at the studies things begin to take a turn.
For one, among the population who eat a very large amount of protein (i.e bodybuilders), no study has shown that bodybuilders have an increased rate of kidney disease related to protein intake.
Don’t get it wrong…
Athletes and bodybuilders do have a bigger risk for kidney injury, but it’s mainly from steroid use (a pathology called drug-induced interstitial nephritis), not excess protein as it was initially thought.
Some of you may ask, “if that is all true, then why is protein intake decreased in people with kidney injury?
Obviously, you can’t just overload a sick kidney. The same way you don’t prescribe strenuous exercises on an injured limb, so it is with a damaged organ.
Cancer and Protein
And finally cancer – the last and most notorious issue we have among the health community.
But is it true? Will your favorite Angus Steak lead to cancer?
We can’t deny the fact that studies have shown cancer being linked to meat consumption nowadays. However, there are two caveats people tend to always overlook:
One, in a society where easily accessible and quick to cook canned meal predominate, food consumption is comprised mostly of processed meat (e.g. sausage, bacon, salami) instead of whole, fresh, organic, free-range products we used to obtain decades ago.
Second, for some reason, the majority of avid meat eaters avoid fiber rich foods like the plague (the same population studied by researchers to find out if meat causes cancer).
So what does all of this mean?
It means that despite the association of meat with cancer, evidence is still inconclusive. And this is because studies related to the problem not only show meat as a possible cause, but lack of fiber too. Thereby leaving us with more questions rather than answers:
“So which causes cancer? is it the excess meat? The lack of fruits and veggies? Or is it the processed meat? Or perhaps both?”
As the saying goes, “correlation doesn’t imply causation”, and unfortunately, there is still lack in supporting evidence to prove that theory.
Why would that be?
Because it’s just too plain difficult to isolate the “suspect” given the fact that cancer is caused by various factors such as genetics and environment. While it might be easier experimenting with mice in a lab and keep these factors constant, things work differently for human beings in the real world: smoking, alcohol, stress, genetics, sedentary lifestyle are variables quite hard to keep an eye on in acceptable forms of studies (unless someone is willing to isolate himself in a laboratory for 20-50 years).
So where does this leave us? Does it mean you can now enjoy an orgy of sausages and steaks?
That wouldn’t be an intelligent way to live.
All we know for now is that cancer is multifactorial, hence it’s safe to assume that meat, particularly processed meat and a diet lacking in fruits and vegetables may increase tumor growth, the same way smoking increases the risk of lung cancer and lack of exercise heart disease.
A sedentary lifestyle, stress, alcohol, and an unbalanced diet – these are factors that are far more important rather than obsessing over excess protein. In the end, it’s all about keeping things in balance. It’s the safest route towards optimal health.
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