SARCOPENIA
Sarcopenia refers to the loss of muscle mass and strength, and is a disease associated with the aging process. Balance, walking gait and the overall ability to perform tasks of daily living are hallmark signs of this disease. After the age of 50, we naturally lose about 1% of muscle mass per year. These small losses go mostly unnoticed, but over time they can accumulate, resulting in decreased strength and function, which can lead to an increased risk of falling, physical disability, frailty and poor quality of life.
The prevalence of sarcopenia is estimated to be around 29% among the elderly population. In one study, the prevalence of sarcopenia increased dramatically with age: from 4% of men and 3% of women aged 70–75, to 16% of men and 13% of women aged 85 or older. In a recent study of 1483 people over 64 years in South Africa, 12.9% were diagnosed with sarcopenia and 10.3% with sarcopenic obesity.
Muscle weakness that interferes with physical activity is a symptom of sarcopenia. However, a medical practitioner should be consulted to diagnose sarcopenia according to clinical measures of muscle mass and function. Muscle mass can be measured by body composition assessment techniques such as dual X-ray absorptiometry, magnetic resonance imaging and computed tomography, or bioelectrical impedance. Physical performance measures include knee extensions, walking speed, hand grip tests and time taken to stand from a seated position.
Maintaining muscle health is essential to prevent sarcopenia. Exercise, combined with the intake of good-quality protein, are key considerations for strong, healthy muscles. The best exercises to stimulate muscle growth are ‘resistance’ types, which are weight bearing or involve impact. Examples include running or brisk walking, lifting weights or step-aerobics. A balanced diet that includes sufficient protein is also needed. Animal-based proteins, which include dairy, lean meat, poultry, fish and eggs, are the richest sources, with legumes such as beans and lentils also providing some protein. Timing and quality are important when it comes to the consumption of protein and the optimal approach is to spread intake across the day, rather than concentrating a larger amount at one meal. This enables the body to be efficient in supplying the constant amounts needed by active muscles throughout the day.
Dairy foods such as milk, yoghurt and cheese are good sources of calcium and rich in high-quality protein. Calcium plays a part in normal muscle function, while protein contributes to muscle growth and maintenance. Proteins are made up of building blocks called amino acids, with an amino acid called leucine being one of the most effective at stimulating muscle growth. The dairy protein whey, which is rich in leucine, has been shown to be particularly beneficial for muscle growth and repair. Dairy foods are also recognised as versatile and convenient foods that can be enjoyed as snack or incorporated into meals during cooking and baking. This makes it easy to include protein regularly throughout the day, which is recommended to supply the constant amounts needed by active muscles. It is recommended that elderly people include at least three servings of milk and dairy in their diet to help prevent sarcopenia.