When muscles shrink
Despite having normal nutrition, many senior citizens actually have low muscle mass, making them more prone to falls and fractures.
MUSCLE loss or sarcopenia is a natural part of ageing and one of the main contributors to musculoskeletal impairments in the elderly.
Strong muscles support the joints as they help absorb the stress placed on the joints when you move.
Without adequate muscles, the joints take a beating, and can cause the individual to become frail and more likely to suffer from falls and fractures.
The 2018 Malaysian National Health and Morbidity Survey (NHMS) reported that 15% of those aged above 60 had fallen at least once over 12 months.
Half suffered injuries, while one in five were hospitalised.
Even if you are active, it is still possible to have some muscle loss beginning in your 30s.
However, there are steps you can take to slow down or prevent losing muscle.
Missing muscles
According to Asia’s largest clinical study of its kind on nutritional outcomes in the elderly, there was a prevalence of low muscle mass among the elderly, despite them being active, healthy and without any chronic medical illnesses.
The two-part Singaporean study, called Strengthening Health in Elderly through Nutrition (Shield), was jointly carried out by Changi General Hospital (CGH), Sing Health Polyclinics and healthcare company Abbott.
Results from the first phase of the study was published in the Plos One journal last year.
This observational phase looked at 400 healthy individuals in Singapore aged 65 and older.
The results revealed that the prevalence of low muscle mass was higher in females (24.9%) than in males (15.5%), with even adults with normal nutritional status at risk for having lower muscle mass. (See Maintaining muscles during menopause on p7) Every one-year increase in age over 65 years was associated with 13% higher odds of having low muscle mass.
And 52% of participants had vitamin D insufficiency despite living on an island where sunshine is available the whole year round.
“The majority (93%) of the subjects were fully independent and self-caring in the community.
“All the subjects were living at home and able to walk independently without any walking aids, and were relatively active prior to the study.
“Participants were not subjected to any exercise programmes before or during the study.
“We assessed their physical activity level using the PASE (Physical Activity Scale for the Elderly) questionnaire.
“The average PASE score of the study participants was 119.45, similar to the norm of older adults,” says principal investigator Dr Samuel Chew, adjunct associate professor and senior consultant at the geriatric medicine department at CGH.
However, the subjects’ daily diet was not collected in this first part of the study.
A combination of physical activity, which includes weights or resistance training, and a balanced diet with an adequate amount of high-quality protein (e.g. chicken breast, fish, eggs, tofu and other soya products), is essential for good muscle health and function.
However, many seniors don’t embark on strength training programmes and cite difficulty in chewing meats and poultry due to deteriorating teeth, so they avoid eating protein or get little of it in their diets.
Assoc Prof Chew says, “We are unable to comment on the possible reasons for the observed low muscle mass, but from the available literature, there is a measurable decline in muscle mass from the age of 40.
“The decline rate increases by about 8% every 10 years and accelerates after the age of 70 to about 15% every 10 years.
“There are many factors that contribute to this loss in muscle mass, such as changes in hormone and endocrine levels, the loss of connections between the nerves and muscle units with the onset of ageing, acute or chronic illness, and inactivity.
“In addition, those above the age of 65 require more dietary protein in order to stimulate the same amount of muscle protein synthesis as a young person.”
Other factors that may impact elderly diets are:
> The lack of knowledge about good nutrition
> The lack of awareness about the high prevalence of low muscle mass and inadequate levels of micronutrients such as vitamin D
> Poor oral health
> Loss of appetite due to physiological and sensory/taste changes associated with ageing
> Living alone
> Other illnesses
> Use of multiple medications
Get some sunshine
As for the lack of vitamin D, it is apparently common in older adults.
“The results from our study are consistent with previous studies performed in Asia.
“Therefore, while the finding is not unexpected, it still poses a cause for concern.
“Vitamin D is produced in the body naturally when the skin is exposed to sunlight.
“It is also found in dietary sources such as dairy products, oily fish, eggs and mushrooms.
“As such, it is likely that the vitamin D insufficiency is related to a lack of exposure to sunlight and/or insufficient intake of vitamin D-rich food sources,” explains Assoc Prof Chew.
To overcome this deficiency, one method is to get 15 minutes of exposure to outdoor sunlight daily.
He asserts, “It is vital for the activity to take place outdoors, as the component of sunlight that stimulates the production of vitamin D in the human skin does not penetrate glass windows very well.
“However, be mindful of direct overexposure to sunlight, which may result in skin damage and other health complications.”
The Shield study compares to a similar European ageing study that was carried out in Berlin, Germany, where the prevalence of sarcopenia was 24.3%.
“Many factors can affect the results, such as the characteristics of the study participants, methods used to measure muscle mass and cut-off criteria used to define low muscle mass, and participants’ nutritional status.
“The study conducted in Europe included generally healthy community-dwelling older adults who may have had normal nutritional status or were at risk of malnutrition, which is a risk factor for low muscle mass.
“Therefore, the true prevalence of low muscle mass in the general population aged 65 years and above in Singapore is likely going to be higher than the prevalence observed in our study, as they would include individuals who are at risk of malnutrition,” says study co-investigator and Abbott Scientific & Medical Affairs divisional vice-president Dr Low Yen Ling.
While no similar studies
have been carried out in Malaysia, it is believed that our elderly could also be having low muscle mass.
Statistics from the Global Burden Disease Study 2010 shows that the lifespan of Singaporean men is 78.8 years, and for women, 83.3 years. So, even with lower muscle mass, women are living longer.
Dr Low reflects: “Biological, behavioural, and environmental factors can all contribute to this topic.
“One possible explanation is that men smoke more often than women.
“Some evidence also suggests that although both men and women are living longer as the burden of infectious diseases falls, such reduction may disproportionally benefit women.
“This is an ongoing effort and researchers are still studying how all these potential factors influence life expectancy and ways to improve longevity.
“What we know is that scientific evidence has shown that low muscle mass is associated with negative outcomes such as higher risk of functional impairment, fractures, complications, and even mortality.”
Less muscles, poorer immunity
Skeletal muscle accounts for about 40% of total body weight and contains at least half of all body proteins.
Data suggests that loss of muscle mass is associated with compromised immunity and infections.
Research in older adults has shown increased markers of inflammation associated with low muscle mass and muscle function.
Immunity is affected if an older adult loses more than 10% of their lean body mass, while a decrease of more than 30% can make them susceptible to pneumonia.
This is probably because muscles produce and release compounds that play an important role in the proliferation, activation and distribution of certain immune cells.
Assoc Prof Chew says, “Hospitalised patients with pneumonia may have poor outcomes, and this is often associated with very low muscle mass and poor nutrition – two factors that are also linked to a weakened immune system.
This is because muscles are a natural reservoir of amino acids, which are required for proper functioning of the immune system.
“Decreased muscle mass, together with the associated loss of physical strength and function, can lead to an impaired recovery from critical illness.
“Infection in an individual with deficient muscle mass causes further inflammation in the body, which can cause further loss of muscle mass and impairment of the immune system, resulting in a vicious cycle that may ultimately result in poor health outcomes.”
To help preserve muscles, Dr Low provides these tips:
> Engage in regular exercise
Aim for at least 150 minutes of moderateintensity exercise a week, and include resistance training to maintain muscles and strength.
> Eat enough protein
Incorporate chicken, seafood, eggs, beans or dairy into your diet, and aim for about 20-30g per meal.
Adults 65 years and above may need up to 50% more protein than younger adults.
To further amp up protein intake, snack on proteins between meals or supplement your diet if needed with protein powders or shakes.
> Follow a balanced diet
Choose a balanced diet full of vegetables, fruits, whole grains, proteins, healthy fats, and key vitamins and minerals like calcium and vitamin D.
> Consider HMB (beta-hydroxy-betamethylbutyrate)
HMB is a metabolite of the essential amino acid leucine and a naturally-occurring compound that has been shown to preserve muscle mass in healthy older adults when taken as a supplement.
While HMB is naturally found in very small amounts in foods such as avocados, grapefruit and catfish, it’s hard to get enough from food sources alone to achieve the desired health benefits.
Having healthy muscles is critical to ensure that the elderly can continue to retain their mobility, strength, energy levels and independence as they age – the Shield study reinforces that.
There is also a correlation between skeletal muscle and bone health – healthy muscles link to healthy bones, but strong bones do not necessarily mean that the muscles are strong.
Dr Low suggests: “It is important to perform early screening to identify those who have low muscle mass, so that appropriate interventions can be implemented.
“Muscle health can be determined by using a handheld dynamometer (to test hand grip), measuring calf circumference or measuring muscle mass using the bioelectrical impedance analysis (BIA).”
The second phase 2 of the Shield study, to be completed this year, will involve 800 elderly participants at risk of being malnourished, who will be placed on oral nutritional supplements.
The aim is to find out how the supplement will affect their nutritional status, and their rates of hospital admission and re-admission.