The Importance of Protein in the Diet of Boomers and Seniors - Part I

We get a bit over excited sometimes educating people about protein. It is not just because we have our own protein product either. There are so many implications to not having enough protein in our diet, particularly as we age, that people need to prepare now or pay the price later.

As the body ages it becomes naturally less able to absorb protein effectively. Whey protein is the most easily absorbed protein available. This is extremely important for boomers and seniors. For example, evidence already supports whey protein’s ability to maintain lean muscle mass. If we can maintain lean muscle mass as we age, our coordination/balance is better (strength in muscles) as is our ability to move and get up from stationary positions. Thus if we can encourage boomers and seniors to add whey protein to their diet and initiate some level of weight-bearing exercise, they should be able to maintain their lean muscle mass longer and therefore remain independent for a longer time.

Muscle loss associated with aging (sarcopenia) is a widespread syndrome with an accompanying increase in illness and death and a profound effect on quality of life and ultimately survival.

Chronic muscle loss (sarcopenia) is estimated to affect 30% of people over the age of 60 and may affect more than 50% of those over 80. That means that you should be preparing now to prevent or minimize issues later. For boomers, some are already into their sixties and many more are in their 50’s already, so you need to be aware of these statistics and what you can do about it.

Sarcopenia is associated with a three- to four-fold increased likelihood of disability in elderly people, regardless of age, sex, obesity, ethnicity, socioeconomic status, chronic morbidity, and health behaviours that might also increase the likelihood of disability. This makes it an important public health issue, as well as an economic issue for even retirement communities. Progressive sarcopenia leads to the development of frailty, an increased likelihood of falls, and impairment of the ability to perform routine daily tasks.

Can chronic muscle loss be stopped or reversed?
Yes. Insufficient protein intake is one of a number of factors that lead to sarcopenia (and increasing protein intake is one factor in treatment). Resistance exercise is also recommended to prevent muscle loss. While it is not easy to reverse sarcopenia, it is possible to at least maintain and somewhat improve muscle strength, even into your nineties.

What is the current RDA for protein?
Currently the recommended protein intake in elderly individuals is the same as for all adults aged 19 years and older (0.88 g/kg/day). The RDA or Recommended Daily Allowance for protein however is only an expression of the minimum value needed to prevent deficiency.

The RDA for more mature individuals does not take into account the significant changes in body composition, food intake, physical activity level, and the frequency of disease that often occurs with aging. More current research indicates these levels for protein should be re-evaluated and should include using muscle mass, strength and metabolic function endpoints in relation to protein intake in determining protein requirements.

Several studies have suggested that the dietary protein requirements for mature adults are greater than the currently recommended 0.8 g/kg/day. This would make sense given the original method of determining protein requirements (as a threshold to prevent disease rather than optimizing muscle strength). Do you really want to have just the minimum required to prevent disease? Or should you target your protein requirements at a level to optimize muscle strength and metabolism, and thereby improve health – allowing you to maintain function longer?

Now, because this article is getting much longer than I planned, I am going to have to break this into two articles. So watch your inboxes for “Part 2” of “Boomers – prepare now or pay later, it’s your choice”. In part two, I’ll finish the discussion on the implications of muscle loss (Did you know? >50% of women older than 65 years who break a hip in a fall never walk again. True! Usually because of pre-existing muscle loss before the fall!)

References:
Baumgartner R, Koehler K, Gallagher D et al. Epidemiology of sarcopenia among the elderly in New Mexico. Am J Epidemiol 1998;147(8):755-63.
Campbell W, Trappe T, Wolfe R et al. The recommended dietary allowance for protein may not be adequate for older people to maintain skeletal muscle. J Gerontol A Biol Sci Med Sci 2001;56:M373-80.
Janssen I, Shepard D, Katzmarzyk P et al. The healthcare costs of sarcopenia in the United States. J Am Geriat Soc 2004;52:80-5.
Doherty T. Physiology of Aging. Invited review: Aging and sarcopenia. J Appl Physiol 2003;95:1717-27.
Wolfe R. The underappreciated role of muscle in health and disease. Am J Clin Nutr 2006;84(3):475-482.
Kerstetter J, O’Brien K, Insogna K. Dietary protein, calcium metabolism, and skeletal homeostasis revisited. Am J Clin Nutr 2003;78(suppl):584S-92S.
Vellas B, Hunt W, Romero L et al. Changes in nutritional status and patterns of morbidity among free-living elderly persons: a 10-years longitudinal study. Nutrition 1997;13:55-19.
Boyd C, Xue Q, Simpson C et al. Frailty, hospitalization, and progression of disability in a cohort of disabled older women. Am J Med 2005;118:1225-31.
Campbell WW, Barton ML Jr, Cyr-Campbell D et al. Effects of an omnivorous diet compared with a lactoovovegetarian diet on resistance-training-induced changes in body composition and skeletal muscle in older men. Am J Clin Nutr 1999;70:1032-9.
Campbell W, Crim M, Dallal G et al. Increased protein requirements in elderly people: new data and retrospective reassessments. Am J Clin Nutr 1994;60:501-509.
Lemon P. Is increased dietary protein necessary or beneficial for individuals with a physically active lifestyle? Nutr Rev 1996;54:5169-75.