Introduction
Correct protein intake is a highly controversial topic due to the “hypothetical” possible risks of consuming too much protein in the diet; however in the current state of scientific knowledge, many of those problems that are attributed to high protein intake are actually real distortions .
They hurt?
By carefully analyzing the theme of excess protein , it is first of all necessary to define the concept of “too much”: this term is not a precise measure and in fact there is no precise quantity that justifies the adjective “too much”, which certainly varies from person to person but which is constantly mentioned, if not even abused, by phantom nutrition experts, who too superficially generalize the concept by saying that ” too much protein is bad for you “. The reality is that by analyzing all the main risks that excessive intake is accused of, based on what the scientific literature demonstrates, it turns out that none of the dangerous ailments generally mentioned have ever really been proven.
Proteins and bone decalcification
By scientifically analyzing these problems we can argue that, according to some scholars, a high consumption of proteins leads to a reduction in bone calcification . This effect is related to the fact that animal proteins contain many sulfur amino acids , which increase the release of calcium from the bones ; however, there are studies showing that this theory needs to be revised, as various studies have shown that the bone density of protein consumers is similar to that of moderate consumers, and that the former are less prone to fractures than the latter.
Protein and kidney health
Some believe that excessive protein consumption leads to kidney damage. What has been demonstrated is that protein consumption modifies renal function , but this is considered by the most accredited scholars of the matter to be a natural physiological adaptation . The hyperfiltration observed in patients and animals fed high protein diets is only a natural adaptive process, which carries no additional risk.
Some studies on athletes who usually have a higher protein consumption, also associated with the use of amino acid and creatine supplements , do not show a higher incidence of kidney pathologies compared to individuals subjected to diets with a lower protein intake. One of these studies analyzed the effects of a daily intake of 2.8 g/kg of weight without highlighting particular consequences at the renal level (Poortmans et al.). For this reason, many scholars believe that the high protein intake does not lead to a greater risk of incidence of kidney disease. According to various research institutes, there is not enough data to state that protein consumption in healthy people should be limited to 15% of the total intake ofcalories , as generally suggested by the media and some nutritionists. According to these institutions, the protein intake can reach 35% of the amount of calories ingested. Some studies show that people with kidney disease have difficulty eliminating nitrogen , so they must reduce their protein intake . In the case of overt pathologies there is a real risk that the excess of proteins will lead to a worsening of the renal condition. However, this does not mean that proteins damage the kidneys in healthy people, because the available data find little correlation between the two. In them, the increase in protein consumption may simply require an increase in water consumption to promote healthdiuresis .
Protein and liver health
Possible liver damage from protein consumption has not been found in any scientific study. Obviously those suffering from liver diseases such as cirrhosis , liver failure , hepatitis , etc., must follow a particular diet and must reduce the consumption of proteins as the diseased liver is not able to metabolize them correctly. People who do not have liver tissue damage do not have these problems.
Protein, uric acid and gout
The possible risk of gout is not strictly related to the excessive intake of proteins but to the excess of purines ( nucleic acids ), abundant in offal , fish and meat – but not only. The cause of this pathology is due to an accumulation of uric acid , abundant in the cells but not in the proteins themselves. Taking proteins from milk , eggs or supplements prevents the accumulation of metabolites of nucleic acids.
Protein and heart health
Other presumed negative effects linked to excessive protein consumption are the risk of incidence of cardiovascular pathologies identified in large consumers of red meat . In reality, the problem is closely related to the presence of saturated fats in these meats and not to their protein intake, so also in this case it is not the proteins that pose health risks. In practice, all the possible risks attributed to the intake of high quantities of protein are not found in the scientific literature. Finally, it is important to remember how much research shows that increasing protein consumption to the detriment of carbohydrate and fat intake promotes weight lossand how important it is to increase protein intake in the event of intense physical activity , as the body consumes and damages these molecules during activity.
