Nutrition Expert Emily Greenfield explores the secrets to healthy ageing.
Why is nutrition so important for healthy ageing?
A study published in Science journal suggests a drug has been found which can prolong lifespan. While this is exciting news, the drug unfortunately has harmful side effects such as decreasing glucose tolerance and insulin sensitivity. It is true that ageing automatically increases the risk of many chronic diseases due to irreversible physiological changes in the body; however, a healthy diet can increase our lifespan and quality of life without the negative side effects that often come with taking pharmaceutical drugs.
What do we mean by ageing?
Ageing is a progressive deterioration of the body over time, which cannot be reversed. Deterioration includes a steady decrease in lean body mass (particularly in skeletal muscle), an increase in fat mass, and a decline in the function of organs such as the gut, kidneys and skin. These physiological changes can lead to chronic diseases such as diabetes, hypertension, cardiovascular disease, osteoporosis, obesity and dementia.
The main nutrition related issue in ageing is malnutrition, specifically, protein energy malnutrition. Protein energy malnutrition, or PEM, is a form of malnutrition caused by a poor intake of protein which increases the risk of infection, hinders wound healing and makes the risk of fractures more likely. The end result is early residential care and hospital admission, which triggers deterioration in a downward spiral.
PEM is much more common among those living in institutions (up to 68 per cent) compared to people living freely in the community (up to 30 per cent). For this reason, it is very important to recognise PEM in the community, to prevent early admission.
Why is protein energy malnutrition such an issue among the ageing population?
There are many physical changes that can result in a decreased energy and protein intake. These include less energy being expended through physical exercise leading to feeling less hungry and eating less, physical disability, poor dentition, swallowing difficulties and cognitive decline. Other factors affecting energy and protein intake include changes in taste and smell, poor saliva flow and reduced ability to absorb food.
On top of these physical changes are environmental and socio-economic factors such as low income, poor nutrition knowledge, lack of transport, difficulty shopping and inadequate cooking skills. Finally, there may be psychological factors including bereavement, loneliness, depression and a loss of interest in food.
What nutrients are most at risk in this age group?
Protein is high up on the list of at risk nutrients due to a decreased intake and increased need for it in older adults. Ideally, a good portion of ALL meals should be made up of high quality protein to prevent muscle loss. High quality protein comes from lean meat, poultry, fish, eggs, dairy and soy foods.
Due to a decrease in metabolic rate and energy being used up through physical exercise, energy needs are lower in this age group; however, nutrient needs remain high, which can present a challenge. Nutrient-dense foods that are relatively low in energy are to be encouraged and one of the easiest ways to do this is to reduce fat in the diet. Fruit, vegetables, legumes, wholegrains, lean meats and fish are all nutrient-dense foods that are not high in fat, sugar or sodium.
Vitamins and minerals at risk generally include B2, B6, B12, folate, calcium and zinc because as well as physiological changes in the body, medications can interfere with vitamin and mineral uptake. The aged can also be at risk of vitamin D deficiency, due to less sun exposure, impaired synthesis from skin, and impaired metabolism.
Physical activity should also be encouraged, preferably resistance training, to preserve muscle mass. Physical activity also has the advantage of increasing appetite, which is important for preventing PEM.
What can we do?
Preventing PEM in the aged community can be achieved if aged care service providers and health professionals increase their awareness and recognition of the problem, as well as conduct screening to detect those at risk.
Nutrition is a risk factor we can modify to prevent disease and PEM, and improve the quality of life among the aged. The good news is that dietary changes may have an even greater impact on reducing risk factors for chronic disease, among this age group, compared to at any other stage of life.
Disclaimer: This article provides general advice only. Readers should seek independent professional advice from their general practitioner or dietitian in relation to their own individual circumstances or condition before making any decisions based on the information in this article.