THE IMPROTANCE OF PROTEIN AND YOUR BONES
There is a lot of misinformation out there stating that a “high protein” diet is too “acidic” and can wreak havoc on our bone density. On the contrary, protein, particularly specific amino acids that make up protein like alanine, arginine, glutamic acid, glycine and proline, play an essential role in bone metabolism
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How?
It’s through the production of insulin and insulin-like growth factor 1 (also known as IGF-1), which is a hormone similar to insulin, but plays a role in growth in children and has anabolic effects in adults. There is also the synthesis of collagen and muscle protein that play a role in increasing bone mass density (BMD)
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Collagen is mainly made up of 3 amino acids (glycine, proline and hydroxyproline), 2 in which have been studied for the increase of BMD, where as muscle protein synthesis has been shown to increase primarily with a recommended dosage of 2.2g of leucine per meal. It is interesting how both of these factors directly influence BMD yet also rebuild other parts of our structures, such as our joints and muscles
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IGF-1 is primarily made in the liver and during our bone growing years (up until the age of 30), it is dependent on protein nutrition. Of course, it is at its highest during puberty, but can also be enhanced by exercise and the amount of protein we eat
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The RDI of protein for women is approximately 0.8g per kg of body weight, so for the average woman who weighs 120lbs, which is approximately 54kg, she would only need 43g of protein.
That is WAY too low, and this is why:
1. 43g of protein a day = only 172 calories
2. If we need an average of 2.2g of leucine to grow muscle mass at every meal, the average portion of leucine in a serving of protein is 0.6-1.2g. So, for instance, in one egg, you only get 0.5g of leucine, 70 calories and only 6g of protein.
I don’t think that adds up very well when we are trying to either preserve or grow BMD
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Conversely, putting the first few amino acids aside, alanine and glycine seem to have strong associations observed for higher BMD as well. The standard recommendation for women’s protein threshold should be 25-30% of their daily intake on an average of 2000 calories. That would mean 500-600 calories should be coming from protein, equaling to about 125-150g on average. VERY far off from 43g.
How’s your protein, ladies?