Nutrient needs in adults change with age, and it's increasingly recognised that elderly – and also possibly middle-aged – people need more protein than younger adults. Because of changes in your metabolism, you need a larger 'dose' of protein to stimulate the muscle building process. Inadequate protein is linked with loss of bone mass (osteopenia and osteoporosis) and muscle wastage (sarcopenia), and also affects immunity and wound healing.
How much do middle-aged and older adults need?
The Nutrient Reference Values for Australia and New Zealand recommend 0.75 g/kg for adult women and 0.84 g/kg for adult men. At 70, however, this increases to around 1 gram (1.07 grams per kilogram for men and 0.94g per kilogram for women).
But it's likely the optimal protein intake for adults over 50 may be higher than the current recommendations, with research suggesting that levels of 1 to 1.3g/kg would meet the protein needs of middle aged and older adults while avoiding issues of too much protein, such as kidney and liver problems, and loss of calcium.
However, just as protein needs of older adults increase, the amount of food eaten tends to decrease: less physical activity and changes in taste and smell reduce appetite, food may be harder to chew and swallow, and cooking habits may also change, especially for those living alone. Unless a conscious effort is made to ensure there's adequate protein, people may not get enough to meet their needs.
Marketers have cottoned on to this, and are promoting protein powders as a way for older people to ensure they're getting enough.
Added nutrients, added complexity
Some added nutrients may interfere with medications commonly taken by older people. Potassium, for example, interferes with ACE inhibitors (taken for blood pressure and heart failure), while vitamin K interferes with warfarin (a blood thinner). Other nutrients including iron, calcium and magnesium may interfere with certain antibiotics, thyroid medication, osteoporosis medication and/or other drugs if taken at the same time, so the advice is to take them several hours apart.
It's important to talk to your doctor when taking any supplements in addition to prescription medication.
Healthy ageing and sarcopenia
Sarcopenia is the loss of the amount and strength of muscle as we age. Starting from middle age, it accelerates at around 70 years of age.
Loss of muscle strength can impact heavily on quality of life, affecting mobility, increasing the risk of falls and fractures and making it difficult to perform daily activities – dressing, personal care, household tasks, shopping and so on. It's also linked with diabetes, because muscle plays an important role in blood glucose regulation.
However, it isn't inevitable and it is reversible – a program of strength training combined with adequate protein means you can successfully maintain and rebuild muscle mass.
Bottom line for 50-plus
Taking protein supplements isn't as effective as eating whole foods high in protein, because there are other nutritional benefits in whole foods that you don't get from protein alone. Most people get enough protein from a balanced diet.
However, for some people – especially frail elderly people who have little interest in eating – supplements could be the best option. Your doctor can give you a referral to a dietitian, and you may be eligible for a Medicare rebate.