Aging and Muscle Loss
/We all know that as we age, we become more susceptible to a loss of muscle mass, muscle strength, fractures, and a decrease in physical function. What many of us may not know is that these elements are associated with a condition known as sarcopenia.
Sarcopenia, described as a decline in skeletal muscle mass, strength and physical function, has become so prevalent with our aging population, that in 2016 the World Health Organization classified it as a disease.
Is it preventable?
We know our bodies change as we age, but this disease is preventable - and it will come as no surprise that nutrition and physical activity are two of the key factors in its prevention. NOTE: these two factors are critical for everyone regardless, not simply as a "prevention" of a disease.
We need to eat more protein
From a nutrition perspective, think protein. As we age, we need more protein. Evidence is suggesting that this triggers more muscle growth. We also need to eat our protein over the course of a day, instead of just at dinner. Studies suggest that we can process only 30g of protein at one time, and that excess can't be stored (1).
The problem is that the existing guidelines for protein intake (and physical activity) are obsolete, especially when it comes to the aging population.
So how much protein do we need?
As of now, protein recommendations are fairly general for the population as a whole, at 0.8g/kg/day (*refer to the end for what this looks like, as well as the protein content of common foods).
But new and updated research is ongoing, suggesting older adults need more. Specifically, recent studies recommend between 1.0 and 1.5g/kg/day. In fact, this study found that older adults eating 1.2g/kg/day of protein lost 40% less muscle over a three year period than those eating the recommended 0.8g/kg/day.
More research needs to be done, especially between the sexes and age categories. For example, menopausal women lose muscle more rapidly and their protein requirements may reflect this. As well, it's common knowledge that too much protein can be detrimental.
Finally, we need to ensure we get high quality protein sources. Animal proteins such as meat, fish, eggs and dairy tend to pack a bigger punch than plant proteins, which can make it challenging for vegetarians and vegans.
Get physical: Use it or lose it!
Physical activity is critical, and yet we tend to become more and more sedentary the older we get. There is much truth to the saying, "Use it or lose it." Muscle mass and strength are essential for bone health, mobility and vitality, and we need to exercise to avoid the inevitable decrease in the mass of our skeletal muscles.
But don't think this information is only for "aging" people! As per the ROAD study, physical exercise in middle age seems to reduce the development of sarcopenia in older adults. So no sitting around until your 50's, thinking this all can wait ;-)
Separately, as we know, women of menopausal age need to be especially vigilant, as it's felt that without the protective effects of estrogen, our susceptibility to sarcopenia (and osteoporosis) increases significantly.
Current guidelines are 150 minutes per week (30 minutes 5x/week) of moderate to vigorous intensity, with a focus on aerobic activity. But we need more focus on resistance training. The guidelines do incorporate resistance training, but without much emphasis or direction, and yet it is of paramount importance - essential for our muscle integrity and bone health.
Suggestions:
If you can afford it, hire a trainer. Even once a month is helpful - they can give you a routine and you can build on it monthly
Go online. There are a variety of home workouts as well as gym workouts available
Walk more! Any weight bearing exercise is excellent. Walking, jogging, stair repeats, tennis and golf are examples of activities to incorporate (just don't forget your upper body).
In summary...
From a nutritional focus, protein plays a critical role. There are also other nutritional elements at play when it comes to sarcopenia, such as vitamin D, certain antioxidants (vitamins E and C, selenium and carotenoids) and omega-3 fatty acids. So as a baseline, start with maintaining a balanced diet of whole foods, and ensuring it includes enough healthy protein (*see below) throughout the day.
And of course, "move" as much as possible, including aerobic AND resistance training.
In the meantime, happy summer! Feel free to reach out if you feel you might be "overindulging" this summer and are looking to get back on track, now or in the fall ;-)
Thanks for reading.
gillian
*For protein amounts in different foods, this chart lays it out nicely. Note that 1 oz of nuts is approximately 1/4 cup; 3 oz meat/fish is approximately a deck of cards. All the other amounts in the chart are fairly straightforward.
140lb female = 63.5kg x 0.8 = 50.8g protein/day (existing recommendation - low)
170lb male = 77.1kg x 0.8 = 61.68g protein/day (existing recommendation - low)
Ensure you are getting at least this as a minimum, and consider up to 25g protein per meal.
(1) Burford-Mason, The Healthy Brain, (Toronto, Ontario, 2017), 135.