People who are emotionally invested in avoiding protein often state that protein damages the kidneys, particularly when that protein comes from animals. Where did this theory come from? Not from studying humans. On the podcast I share with ultra-endurance world-record holder, Zach Bitter, I was talking with Dr. Stuart Phillips, one of the world’s leading protein experts, and we got into this topic. The misconception about this issue evolved from some work researchers did on rats, but no research on humans has ever shown the same results.
Protein doesn’t damage kidneys, but damaged kidneys tend to leak protein, which is something that contributes to the confusion about the relationship between protein and the kidneys. Many physicians have bought into this myth that protein damages kidneys even though the assertion has almost no scientific support. As with other misconceptions, you can look at the treasure trove of nutritional epidemiology and find some relationship between a high-protein diet and an increased incidence of kidney disease, but, as always, you have to ask the question, “Does it apply to all people in all situations?”
In my experience, people who eat a high-protein carnivore diet aren’t finding that their kidneys are compromised. I’m not saying that no one who follows the carnivore diet will ever have kidney problems; they can occur for many reasons. But I do not think that an all-meat diet causes kidney issues. I know of some cases where chronic kidney dysfunction has started to get better for several people.
Let’s put this in perspective. Humans evolved in an environment where eating copious amounts of meat was likely a common occurrence. We have several historical accounts of humans consuming very large amounts of meat, and those accounts show no evidence that the people experienced kidney problems. As I mentioned earlier, the explorers on the Lewis and Clark expedition were noted to have eaten as much as 9 pounds of meat per day. Modern-day competitive eaters have sometimes eaten more than 20 pounds of meat in one sitting without damaging their kidneys. If protein did indeed damage our kidneys, humans would not have made it this far through history.
Another common myth about the consumption of meat is that it leads to the development of gout. This perception goes back to the days when gout was considered a “rich man’s” disease. Because the financially well off were diagnosed with gout more frequently than the less affluent population, and the rich also were the people who could afford to eat meat, the assumption was that meat was the cause of gout. However, what do you think we find when we look at people who eat only meat? They don’t get gout, and if they had it before they start the carnivore diet, the gout generally clears up.
One of the beautiful things about a carnivore diet is that it tends to make some things crystal clear. You can wallow around in pointless epidemiology or use some questionably applicable animal studies to try to interpret something about the effects of eating meat, or you can take the simpler route and look at people who eat only meat. When we look at populations of meat eaters, such as the Maasai, Mongols, or Sámi, we see that there’s no indication that they were hobbled by gout. Today I routinely observe people with gout who go on an all-meat diet; for them, gout becomes a distant memory within months.
So, what about those rich dudes from a few hundred years ago? Why did they have gout? Because they had access to something that the common folk did not. Sugar! The wealthy also had more access to alcohol, and both sugar and alcohol are strong drivers of gout. The traditional view of gout is that it’s caused by an increase in uric acid because we can see uric acid crystals when we view gouty tissue under a microscope. I’ve taken care of plenty of gout patients over the years, and I’ve even removed large gouty tophi (which are basically giant blobs of crystal deposits in the skin that resemble toothpaste when cut open) from all parts of the body. None of my gout-afflicted patients has said he was a pure carnivore.
We know that purines form as food breaks down, and they can lead to increased uric acid production. Meat is often high in purines, and thus experts concluded that meat was the reason for the rich man’s disease. The problem is that most food leads to purines being produced, and high uric acid levels do not always lead to gout. As with all things, the path to gout isn’t a simple route. Is uric acid more of a problem when an underlying inflammatory state exists?
If so, what drives the inflammation? What about hyperinsulinemia (excess insulin)? Because of the complex system that comprises the human body, we have to look at issues like gout from all angles. Fructose is a vital component of table sugar, making up 50 percent of the sucrose molecule; the other 50 percent is glucose. We’ve seen that as fructose consumption goes up, the incidence of gout also goes up. Coincidentally, markers of inflammation and uric acid levels also rise as fructose consumption increases. Alcohol is another major contributor to higher uric acid levels. Like fructose, higher alcohol consumption tends to increase the incidence of gout.
One caveat is that if someone already has gout or is strongly predisposed to it, that person may experience a flare up during the transition phase into a ketogenic or carnivore diet. The flare-up is likely a result of a preexisting inflamed state combined with entering into a state of nutritional ketosis, or it’s because a transient uric acid elevation is a likely reason for the short-term occurrence of gout. After a person has fully transitioned to an all-meat diet, the gout generally subsides for good.
Excerpted from The Carnivore Diet, By Dr. Shawn Baker.
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