Protein intake is a hotly debated issue in the nutrition community for all stages of development. However, there seems to be the least amount of agreement as to what constitutes adequate protein intake as we progress into adulthood. There are some experts that argue the importance of protein especially as we age and who believe that most adults aren’t getting an adequate supply. On the other side of the issue there are those experts who argue that high amounts of protein in the diet can actually be detrimental to the body, especially to the kidneys and the liver both of which deal with the strain of breaking protein down into its amino acid constituents.
The main argument for those who support additional protein in the diet for older adults is that the ability to process protein declines with age meaning that as we get older we need more of it to get the same benefits we once did. The RDA for protein for younger and older adults is 0.8 g/kg of body weight and many experts believe that this fails to reflect our increasing protein needs as we age. They instead support the idea that increasing protein in the diet to between 1.2 and 1.5 g/kg of body weight as we progress into adulthood could be extremely beneficial in helping to maintain lean muscle mass and stave off age related muscle wasting.
The main argument on the other side of this issue is that even though protein does have myriad benefits for muscle development and maintenance, it is not without its detriments to the body. Protein is difficult for the body to process and it requires an acidic environment in order to be broken down, which is contraindicated to the alkaline environment many experts recommend for optimal health. The breakdown of protein also creates increased pressure in the kidneys as well as an increase of urea and creatinine, which can strain the kidneys if sustained over time leading to chronic dehydration and mineral loss.
While I see the points of both sides, my personal thinking is that it is myopic to consider just protein intake. Recent studies have explored the idea that it might not actually be protein intake that is the most important factor as we age, but rather amino acid balance and this more holistic approach makes the most sense to me. Traditionally high protein foods such as meat and eggs are complete proteins but they provide our bodies with the same amino acids, giving us very little variety if we are relying solely on them. There have been many findings that support the idea that eating a wide range of amino acids, especially a healthy mix of those found predominantly in plant sources, is the best protocol for optimal health. I try to implement this approach in my own diet and rely on a mix of complete proteins such as lean fish and eggs and amino acid rich food sources such as quinoa, chickpeas, and lentils.