What is the role of dairy in muscle health?
Dairy foods such as milk, yoghurt and cheese are good sources of calcium and rich in high-quality protein. Calcium has a role in normal muscle function, while protein contributes to muscle growth and maintenance.
Proteins are made up of building blocks called amino acids, with the amino acid leucine being one of the most effective at stimulating muscle growth. The dairy protein whey, which is rich in leucine, particularly seems to benefit muscle growth and repair.
Dairy foods are also recognised as versatile and convenient foods that can be enjoyed as part of a meal or a snack. This makes it easy to include protein at regular intervals, which is recommended to sustain the constant supply of protein needed by active muscles throughout the day.
What can I do to ensure good muscle health?
Maintaining our muscle strength is essential to prevent sarcopenia. Exercise and getting enough good-quality protein are key for keeping muscles strong and healthy. Resistance exercise, which involves weight bearing or impact, is the best type of exercise to stimulate muscle growth. Examples include brisk walking, running, lifting weights or step aerobics.
A balanced diet that includes sufficient protein is also needed. Animal-based foods such as dairy, lean meat, poultry, fish and eggs are the richest sources of these proteins, with legumes such as beans and lentils also providing some protein. Milk proteins obtained from dairy products have a high biological value and quality. Whey and casein proteins ensure a sustained availability of amino acids (protein components). The amino acid leucine in milk is particularly important for building muscle.
Apart from focusing only on the quality of the protein we consume, we also have to consider the timing of protein intake. The best approach is to spread our intake across the day, rather than concentrating a larger amount at one meal. This allows the body to sustain the amount of protein active muscles need throughout the day.
How would I know if I have sarcopenia?
Muscle weakness that interferes with physical activity is a symptom of sarcopenia. However, a medical practitioner has to confirm the diagnosis based on clinical measures of muscle mass and function. Muscle mass can be measured by body composition assessment techniques such as DXA (dual X-ray absorptiometry), MRI (magnetic resonance imaging) and CT (computed tomography) scans or bioelectrical impedance. Physical performance measures include knee extensions, walking speed, hand grip tests and time taken to stand up from a seated position.
How common is sarcopenia?
The prevalence of sarcopenia varies depending on the diagnostic criteria used. It is estimated that 29% of the elderly population suffers from sarcopenia. The prevalence of sarcopenia increases with age. In a recent study involving 1483 South Africans of 65 years or older, about 1 in 8 people were diagnosed with sarcopenia.
What is sarcopenia?
Sarcopenia is the loss of muscle mass and strength as we age. In general, we naturally lose about 1% of our muscle mass per year after the age of 50. These small losses usually go unnoticed, but over time they can accumulate. This may cause your body to lose its strength, which could affect your balance and ability to walk and do daily tasks. Ultimately sarcopenia may reduce your quality of life.