Healthy ageing and the role of nutrition
9 January 2017 by Julie Howell
Whilst ageing is an inevitable biological process, recent scientific studies have shown that nutrition status and dietary interventions can slow the ageing process and increase healthy lifespan (1-3).
The relationship between diet and ageing is a complex interaction of biological, environmental and nutritional factors. Furthermore, ageing influences, and is influenced by nutrition (4). Our understanding of how ageing influences the nutritional status of an individual is well reported, particularly from disease states. Whilst, the influence of nutrition on ageing is an area of active research, the deleterious effects of poor nutrition on health are well known. Poor dietary intake has been found to be associated with increased risk of overweight, obesity, Type II diabetes, hypertension, heart disease and some cancers (5). Conversely, a healthful diet that meets the nutritional requirements of older adults is likely to have a beneficial effect on age-related decline and may help reduce the risk of these conditions.
The pace at which the global population is ageing is accelerating according to the UN World Population Ageing report 2015 (6). Driven by declining fertility and increasing longevity, the proportion of elderly persons ≥60 years will reach 32% worldwide by 2050 (6). These changes in population trends are expected to have significant economic, social and public policy implications. Therefore, maintaining health and wellbeing among older adults should be a major public health priority, as well as a personal goal.
Consistent with projected ageing population trends and related public health issues, a global strategy on healthy ageing was announced at the 69th World Health Assembly (WHA) in 2016 (7). The WHA report on ageing and health defines healthy ageing as "the process of developing and maintaining the functional ability that enables wellbeing in older age". Nutrition is one of the most prominent and modifiable lifestyle factors that can impact healthy ageing.
The role of nutrition in healthy ageing
Lifespan and health are influenced by nutrition via the nutrients obtained from food and by their influence on growth, metabolism, energy balance and cellular repair. Ageing is typically accompanied by functional changes in the body, which makes the nutritional requirements of older adults different to younger adults, with greater emphasis on supporting metabolism and repair.
Commonly, extrapolations of nutrient requirements for younger adults are used for older adults (4). However, this is inappropriate as the nutritional needs of adults > 50 years can be very different to those of a 20 year old. Even in a healthy adult age-related changes in metabolism, physical activity levels, appetite and dentition can lead to weight gain or loss, micronutrient deficiencies and malnutrition if not balanced with age-appropriate nutrition. For example, daily energy expenditure typically declines with age, which needs to be balanced by energy intake to maintain a healthy body weight. Dietary patterns not only affect energy balance and weight, but also play a role in healthy ageing. The reduced efficiency of the ageing gastrointestinal tract to absorb some nutrients necessitates increased intake of nutrient-dense foods to avoid micronutrient deficiencies. As nutrition requirements change with age dietary intake needs to adjust accordingly.
As we are living longer, the challenge is to live healthier and disease-free for longer. Whilst biological, environmental and nutritional factors all play important roles in health and the ageing process, good nutrition in older adults is vital to support metabolism and repair, thereby delaying age-related decline. Ongoing research will continue to help us better understand how nutrition can influence and alter the ageing process.
I dedicate my time and energy to helping people choose nutritious food and follow healthy eating habits. I promote healthy ageing based on current dietary knowledge and verifiable evidence-based information. For further individual advice feel free to contact me at julieh@healthyageing.com.au
References
1. Longo VD, Antebi A, Bartke A, Barzilai N, Brown-Borg HM, Caruso C, et al. Interventions to slow aging in humans: are we ready? Aging Cell 2015; 14 (4): 497-510.
2. Levine ME, Suarez JA, Brandhorst S, Balasubramanian P, Cheng CW, Madia F, et al. Low protein intake is associated with a major reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not older population. Cell Metab. 2014; 19(3): 407-417.
3. Fontana L, Partridge L, Longo VD. Extending healthy life-span from yeast to humans. Science 2010; 328(5976): 321-326.
4. Dato S, Bellizzi D, Rose G, Passarino G. The impact of nutrients on the aging rate: A complex interaction of demographic, environmental and genetic factors. Mechanisms of Ageing and Development 154 (2016): 49-61.
5. World Health Organisation. Intervention on diet and physical activity: what works: summary report 2009. Available from: http://apps.who.int/iris/bitstream/10665/44140/1/9789241598248_eng.pdf
6. United Nations, Department of Economic and Social Affairs, Population Division (2015). World Population Ageing 2015. Available from: http://www.un.org/en/development/desa/population/publications/pdf/ageing/WPA2015_Report.pdf
7. World Health Organisation, 69th World Health Assembly 2016. Global strategy and action plan on ageing and health. Available from: http://who.int/ageing/global-strategy/en/
