Sarcopenia is loss of muscle mass and strength that happens with aging. But certain things like eating more protein and resistance training can prevent or slow this process.
What Causes Muscle Loss?
Muscle loss is caused by not eating enough protein, and in older adults, a reduced ability of the body to digest it along with a sedentary lifestyle. Other factors though to be involved include changes in hormone levels, not consuming enough calories overall and inflammation.
Some studies show that 15-30% of adults over 65, living in the community, could have muscle loss and this goes up to 50% for adults over 80 years. It can also be more common in people with certain diseases such as cardiovascular disease, dementia, diabetes and respiratory diseases.
What happens with Sarcopenia (muscle loss)?
With ageing muscles atrophy or shrink (see image 1), they lose strength and that can increase your risk of falls and fractures, reduce your mobility and lead to a loss of independence. Our muscle mass shrinks by 3-8% per decade after the age of 30 and even faster after the age of 60.
Image 1- Normal muscle versus wasting muscle
Source: https://www.bgs.org.uk/blog/bgs-raising-the-profile-of-sarcopenia-and-frailty
Is there anything I can do to prevent muscle loss?
There are things you can do to prevent loss of muscle mass including:
- Getting enough protein which is one of the building blocks of muscle.
- Spreading your protein intake out throughout the day is optimum for muscle building, not just eating it with one main meal.
- Including resistance exercise or weights 2-3 times per week.
- Checking your vitamin D levels and supplement if necessary (combined with exercise and protein intake)
- Omega 3 fatty acids reduce inflammation and may reduce or help prevent muscle loss.
Taking a closer look at these points:
1. Eat more protein
One study, which looked at 2066 adults aged 74.5 years for 3 years, found that the group with the highest protein diet lost 40% less muscle than the group with lower protein in their diet. Research shows that increasing protein intake above the current recommended dietary intakes (RDIs) can improve muscle mass and reduce muscle loss, as the current recommendations may not take into account the extra protein needs of older people.
There are many healthy protein sources from foods such as lean meats, eggs, fish, poultry, nuts, seeds, and legumes. You can find the serving sizes here, too. The current recommendations are between 0.75-1.07g protein/per kg of body weight per day. However, it is recommended to get this protein intake up to 1-1.5g/kg/day to enhance muscle synthesis.
2. Spread your protein intake over the day
If possible, spreading your protein intake over your three meals of the day has been shown to improve muscle mass synthesis ( or growth) by 25%. For example, eating 30g of protein at breakfast, lunch and dinner rather than having 10g at breakfast, 10g at lunch and 70g at dinner is better for muscle production.
Examples of protein content in different foods:
- Raw chicken 150g - provides 33g protein
- Tuna can 95g - provides around 19g of protein
- Eggs x 2 50g each - provides around 12g protein
- Legumes ½ cup - provides 7g of protein
- Tofu 100g - provides 12g protein
- High protein yoghurt 170g tub - provides 15g protein
Breakfast is commonly the meal with the least protein for older people, so start with breakfast. Then, using healthy protein sources, try and add protein to each meal and snack.
3. Add resistance training
Lack of physical activity either through a sedentary lifestyle or because of another health condition can be a cause of muscle loss. Particularly if there is a period of bed rest then muscle levels can decline quickly. Strength activities or resistance exercise should be performed a minimum of two times per week.
Some strength building activities include:
- Climbing stairs
- Lifting and carrying (children or groceries)
- Using weights, or resistance bands
- Garden work that includes digging or lifting
Another study, that included 100 women 60-90 years of age, found combining resistance exercise with a high protein diet for 4 months increased muscle mass and strength considerably in comparison to a group that did the exercise but had no added protein intake.
4.Vitamin D deficiencies can lead to muscle wasting
Deficiency of Vitamin D is common around the world and in Australia, with more than 1 in 3 Australian adults having mild, moderate or severe vitamin D deficiency. Vitamin D helps regulate the functioning of many body systems including skeletal muscle. Research shows that older people with vitamin D deficiency might be at higher risk of sarcopenia (muscle loss). The research on whether just supplementing with Vitamin D will treat sarcopenia (muscle loss) though is controversial.
However, a meta-analysis (one of the most esteemed type studies) has found that combining Vitamin D supplementation with increased protein intake and exercise can significantly improve grip strength and increase muscle mass.
5.Omega 3 fatty acids
Omega 3 fatty acids may also be beneficial in reducing muscle loss as emerging evidence shows Omega 3 supplementation may improve protein metabolism. A recent review also found Omega 3 to reduce muscle loss associated with ageing or associated with a disease. However, these results came about even when inflammatory markers weren’t reduced, which was one of the mechanisms it was thought to work by. Other studies have shown that maybe Omega 3 might enhance muscle growth directly.
Key take-away messages
- Muscle mass starts declining in your 30s
- The main symptoms of sarcopenia (muscle loss) are reduced muscle mass and strength, frailty, balance problems, falls, loss of independence
- Causes can be lack of exercise, lack of protein/overall calories, hormone changes and inflammation
- Treatment and prevention includes; increasing protein intake and distribution throughout the day, increased resistance training, increasing vitamin D status and increasing Omega 3 fatty acids.
