Are high protein diets really as safe as they say?

(Video transcript follows)

High-protein diets are increasingly common, as well as particularly popular; almost invariably these are low-carb approaches, i.e. diets in which carbohydrates are sacrificed in favor of proteins and fats, and the mind can only run rapidly following the trend of these years, the ketogenic diet. If you think about it, it is not difficult to find the reasons for this success:

• Abatement of the sense of appetite after just a few days,
• Extremely significant weight loss in the short term.

And it doesn’t matter if in the long run they aren’t actually more effective than more balanced and more sustainable approaches, it is clear that an effective and, at least initially, easy to follow approach can enjoy all this appreciation.

I’ll tell you, if once I too was more critical, today I have developed a tendentially neutral approach: I still don’t consider the ketogenic diet an ideal regimen, but if it can work for patients who have not obtained results with healthier diets, why no? The benefit-risk ratio, but I repeat, only in some patients, it might be worth it.

Yet there is one topic that always comes up when it comes to proteins: their impact on the kidneys, and it is natural that this doubt arises, because when a kidney problem is diagnosed it becomes very important to pay particular attention to specific aspects of your diet , including sodium, potassium, phosphate and protein intake, however preferring those of vegetable origin.

But if instead you are in perfect health, is it useful to apply the same degree of attention to the origin and amount of protein?

This is a legitimate question, because if it is known that in the most advanced states of renal disease a hypoproteic diet, i.e. low in protein, is a cornerstone of treatment, what do we do in the healthy patient? Is an excess of protein a danger?

The doubt arises thinking about the fact that during their digestion the body produces urea, a compound that is eliminated in the urine. When the kidneys don’t work properly, urea builds up in the blood causing various symptoms, including nausea, fatigue and loss of appetite. The more protein waste that needs to be removed, the harder the kidneys have to work to get rid of it and this can be downright stressful for already struggling kidneys in the long run.

That’s why a low-protein diet is necessary when the kidneys are not working enough, an approach that is necessary not only for immediate well-being, but also to benefit from a slowdown in the progression of chronic kidney disease in an advanced state. In other words, in severe nephropathic patients, the low-protein diet lengthens the time interval before starting dialysis.

In healthy subjects, however, there are no major problems, the kidneys are also able to take charge of a possible and occasional excess of protein, but in this regard I would like to focus your attention on some important aspects:

1. Based on what we know today, following a high-protein diet, i.e. with more protein than recommended by the guidelines, does not appear to be a risk for healthy subjects in the short term, while in the long term we still don’t have this certainty. And yes, I’m also talking about keto diets, which are unlikely to compensate for the cut in carbs with only the increase in fat.
2. By now essentially all medical and scientific societies agree on the fact that vegetable sources of protein are preferable to animal ones. I’m not telling you that you have to become vegan by force, I’m not telling you that meat can’t find space in a healthy and well-balanced diet, I’m telling you that we Westerners generally eat too many animal derivatives and therefore we should recalibrate our animal/vegetable distribution.
3. Third point, perhaps the most important of all: “When the wise man points to the moon, the fool looks at the finger” and so do we, trying to cure not the body but blood tests or the number read on the scale. I tell you this because more than the numerical value what must matter to us is the long-term goal, and more and more convincing evidence accumulates that exaggerating with proteins is linked to a reduction in longevity, above all, again, when the sources are mostly animals. The professor. In this sense, Fontana was one of the first researchers I’ve heard dealing with the problem, but obviously he’s not the only one.

In fact, there are several authors who hypothesize that high-protein diets followed for long periods can be a direct cause of kidney damage even in healthy subjects and that the difference between animal and vegetable sources can lie in factors such as

• acid load of the diet,
• phosphate content,
• alterations of the intestinal microbiome and consequent inflammation,
• in addition of course to the other substances that animal sources bring with them, first of all saturated fats.

In short, to make it short, many pieces are certainly still missing, but I invite you to be cautious: a correct intake of proteins is undoubtedly fundamental, but if the advice I always give you to prefer vegetable sources remains valid, I take the liberty of inviting you to caution even with quantities if we are talking about a time span of months or even years, because high protein diets (and the Western diet is already in itself more often than one thinks high protein) may not be as safe as it always is thought.