High-protein diet and loss of bone mineral 🆙

Introduction

Culture, tradition (religious, mystical, superstitious, folkloristic, etc.) are spatial-temporal cases that weave a large part of the plot of the relational-social aspects of the individual, conditioning their fate. High-protein diet and loss of bone mineral If you add the "False information" (as an orphan of scientific literature) promulgated by some professional and academic figures of who knows what training (vehicle of false and / or outdated information) with a high media and social impact, due to the role of reference figures they cover within their fields, here is the birth of the "myth".
Unfortunately, there are many "myths" of our sector ...
"A lie told enough times becomes a truth" - reads a quote attributed to the Russian revolutionary Lenin. The efficacy and power of such a claim has been recognized by political leaders for eons, as it is such as to do to hold in the minds of the people the beliefs that they want to be assimilated as truth.
But as Kennedy said in 1962 to the "Commencement Address" at Yale University, the greatest enemy of truth is not the lie but the "myth", as persistent, persuasive and unrealistic. And the most serious problem occurs when the myth, permeating the classes of scientific rank, automatically becomes a law, in reference to which public opinion relates and, therefore, behaves! And here the "mythological" examples would follow in extensive review.
In this "Pseudo-truth Dossier" we will try to bring to the attention of readers the main issues most debated within body-building and sport in general, related to nutritional aspects and not only, to highlight - through the appropriate literature reported in the extensive bibliographical references - like many of the not only popular but also medical (media) -scientific beliefs are unfortunately dictated by opinions, convictions, hearsay, hypotheses and anything else that has no connection with science , with concrete facts and statistical significance ... - e however they represent the most widespread and permeating knowledge of the masses and (pseudo) specialists!

High-protein diet and loss of bone mineral

It is now well known on a large scale that protein can be bad for bone health, on the basis of the association that thehypercalciuria - induced by their intake - is the result of bone calcium mobilization (1, 2).

He later came to scientific knowledge that the main source of hypercalciuria is the intestine. Subsequent studies revealed that reduced protein intake induces a reduced intestinal absorption of calcium, an event associated with increased levels of parathyroid hormone (3, 4). Therefore, the assumption that hyperprotein diet-induced hypercalciuria was associated with bone mineral loss was revisited. And even the opposite emerged.
Studies in menopausal women aged 50 to 75, and another study in men and women aged 50 and over, were conducted to evaluate the effect on calcium levels and bone metabolism caused by an increase in protein (from meat) from 0,94 to 1,62 and 0,78 to 1,55g per kg of body weight respectively after 5 and up to 9 weeks. The results of the two studies did not report any hypercalciuria, much less any decrease in calcium retention (5, 6).
In the first study, the initial renal acid excretion reported by the hyperprotein group decreased significantly over time and no markers of bone metabolism changed. In the second, on the other hand, there was a decreased urinary excretion of N-telopeptide (bone resorption marker) and an increase in IGF-1 (somatomedin favoring anabolism, also of a bone nature).
If yesterday losing weight was the prerogative of the caloric counting, recently it was the glycemic index, whereas very recently it was a virtue of the glycemic load; today the PRAL (“Potential Renal Acid Load”, or renal acid load potential) has become a reference for monitoring food quality selection, in order to avoid renal acid loads responsible for bone mineral loss. Beyond the nutritional fads and recent scientific discoveries - which instead of adding to the known baggage of knowledge seem to almost suppress it to excel, as if they represented absolute and indisputable truths -, the body-builder tipo It "does not lie" about the correctness and healthiness of the lifestyle choices undertaken, since its morphological structure is nothing more than the mere phenotyping of full organic health in its entirety.
A recent publication, which comes to further confirmation and validation of the aforementioned studies, is that of 2011 in the "Journal of Nutrition". The study aimed to determine the effects of a high-protein and high PRAL diet on calcium absorption and retention levels, as well as on bone metabolism markers. To this end, the hyperproteic diet with high PRAL (HPHP) was compared with the hypoproteic diet with low PRAL (LPLP). The HPHP diet showed higher IGF-1 values and decreased parathyroid hormone values compared to the LPLP diet.
Furthermore, the HPHP diet reported higher values in calcium absorption and also in excretion compared to the LPLP diet, but the net difference between absorbed and excreted calcium values did not differ between the two approaches. The HPHP protocol did not result in changes in bone metabolism markers. And the increased calcium absorption observed in HPHP compensates for its excretion. In addition to this, the increased levels of IGF-1, the decreased concentrations of parathyroid hormone and the simultaneous stability of bone metabolism markers indicate that the high-protein approach is not responsible for negative effects on bone health (7).

Another recent study conducted on 8 elite bodybuilders denies the absoluteness of the causal relationship "high-protein approach and metabolic acidosis" (72). The eight athletes, aged between 18 and 25, were recruited from those who had at least a training period of more than 2 years behind them in preparation for competitive events and who have also achieved several victories in within the national championships (therefore these are not novice subjects included in the study, but athletes with high protein turnover).
Their protein intake consisted of 4,3g ± 1,2g of protein per kilo of body weight per day, in a caloric context of 5621,7kcal +/- 1354,7 kcal per day. Their supplementary plan also included quantities of vitamin and mineral supplements (calcium and potassium) significantly higher than the normally recommended doses.
The proportion of the ratios between macronutrients within the daily calorie body was set as follows: 34% carbohydrates, 30% proteins, 36% fats. The proportions of the ratios between the macronutrients deriving solely from the supplements were the following: 14% carbohydrates, 66% proteins, 20% fats; and 28% of the total daily protein intake came from protein supplements.
At the beginning of the study it was assumed that the protein intake five times higher compared to that recommended for the general population (0,8g per kilo of body weight) could induce serious homeostatic alterations in the delicate acid-base balance.
At the end of the study, the obviousness in finding phenomena of metabolic acidosis in response to high protein loads has failed.
This study confirms to what extent the effects of a macronutrient (in this case proteins) they cannot be given for absolute and in every circumstance, but must always be contextualized and above all verified in a cause-effect relationship as a sine qua non for the knowledge of their real metabolic impact.
Any other way of observing and conceiving is skimmed of objective feedback it remains indifferent, speculative and sterile with respect to the real effects induced by precise stimuli, in this case biochemical-nutritional.
The authors hypothesize that, most likely, physical exercise in combination with "buffers" such as potassium and calcium helped prevent the phenomena of acidosis resulting from high protein consumption.
So it is not the proteins that are primarily responsible for effects ... but the nutritional context and it overall lifestyle in which they are inserted represents the determinant of the ultimate effects, positive or negative respectively.