Globally we have an increase in ageing populations. In the UK in 2016, 18% of the population was aged 65 years or older (1), this is estimated to increase to nearly a quarter of the population by 2046. Add to this that normal ageing is associated with a gradual decline in muscle mass, known as sarcopenia (2) which can impair muscle function and strength, and we, therefore, have a current and future need to prolong people’s health span, ability to be active and independence of living.
It’s estimated that from the third decade of life we begin to lose our muscle mass and, scarily, losses of between 30 to 50% (3) have been reported between the ages of 40 and 80. Loss of muscle function and strength reduces the ability to perform everyday tasks and also increases the risk of falls.
So what can we do about it? Current UK dietary recommendations for protein intake in adults is set at 0.75g/kg of body weight, meaning 60g daily protein for an 80kg adult. However, this requirement doesn’t account for physical activity; those who are less active tend to have a greater protein requirement, meaning older adults may need a relatively greater dietary protein intake.
Evidence suggests that from mid-life, adults may benefit from a greater intake than the average recommendation to slow the ageing of muscles.
Looking at the current UK intakes of protein, there seem to be key areas for improvement:
· Amount of protein - protein intake tends to decline with age, partially attributed to what is termed the anorexia of ageing (4) where older adults sometimes inadequately regulate food intake. The latest NDNS data (5) shows an average protein intake of 76.9g per day in those aged 19 to 64, dropping to 62.7g per day in the over 75-year age group.
· Distribution of protein intake – consumption of two to three meals or snacks each containing 25 to 30g protein (6) throughout the day is estimated to be required for optimal muscle protein synthesis. However, estimates of protein intake in adults in mid-life indicate protein-rich meals tend to be eaten towards the end of the day (7), at lunch or dinner time.
· Type of protein – in the UK the main source of protein in the diet is from animal sources such as meat, dairy and fish. Increasing the intake of plant-based proteins (8) (e.g. pulses, cereal products, nuts) might be a more sustainable dietary pattern.
Taking the biscuit
The research we have been carrying out is part of the Protein For Life (9) project, a recent academic and industry partnership, aiming to address this issue of malnutrition-related sarcopenia.
As part of this project exemplar, higher protein biscuit products were formulated containing different amounts of protein (~12% protein from energy and ~20% protein from energy). To put this in perspective, a typical digestive biscuit contains around 6% protein from energy. Products were also enriched with different sources of protein; animal protein (from whey powder) or plant protein (from peanut butter, soya protein and wheat crispies).
Higher protein biscuits offer a handy on-the-go snack helping to support protein intake anywhere at anytime; potentially helping to spread protein intake throughout the day and also tapping into the current ‘snackification’ trend.
According to current legislation for front-of-pack labelling these products could also be labelled as a ‘source of protein’ or ‘high in protein’ for the 12% and 20% protein biscuits respectively, directing consumers to their ‘protein power’.
Sensory analysis in a population of older adults (≥40 years) was performed to ascertain which level of enrichment was preferred and also whether the products are actually enjoyable to eat. Biscuit tasting at the trial site in Aberdeen (one of 4 across the UK) revealed that the source of protein biscuits (12%) was favoured over the high protein biscuits (20%). This suggests that consumers might favour a more subtle approach to the reformulation of much-loved products.
Although there was some division of opinion over the type of protein used for enrichment more people indicated they generally prefer plant sources of protein over animal. This potentially identifies a niche for food products enriched with plant proteins specifically, which would help to reduce the environmental impact of the protein-enriched product.
The future..?
This proof-of-concept study raises important points over how what we eat, affects the environment and also our long-term health. The future reformulation of current products or production of protein-enriched products suitable for increasing the intake of protein in an older population may help contribute to prolonged health, independence and quality of life.
Looking for enjoyable, more sustainable ways to increase your protein intake throughout the day, from an earlier age, might be beneficial to support healthy ageing.
References
(1) https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/articles/overviewoftheukpopulation/july2017
(2) https://www.youtube.com/watch?v=LkXwfTsqQgQ
(3) Lonnie et al. (2018). Protein for Life: Review of Optimal Protein Intake, Sustainable Dietary Sources and the Effect on Appetite in Ageing Adults.Nutrients. 2018 Mar 16;10(3). pii: E360. doi: 10.3390/nu10030360.https://www.mdpi.com/2072-6643/10/3/360
(4) Morley(2017). Anorexia of ageing: a key component in the pathogenesis of both sarcopenia and cachexia. Cachexia Sarcopenia Muscle. 2017 Aug; 8(4): 523–526. Published online 2017 Apr 27. doi: 10.1002/jcsm.12192https://onlinelibrary.wiley.com/doi/abs/10.1002/jcsm.12192
(5) NDNS: results from years 7 and 8 (combined) 2018. Results of the National Diet and Nutrition Survey (NDNS) rolling programme for 2014 to 2015 and 2015 to 2016. Available at: https://www.gov.uk/government/statistics/ndns-results-from-years-7-and-8-combined
(6) Donaldson et al. (2018). Role of protein in healthy ageing. Eur J Integ Med. https://www.sciencedirect.com/science/article/pii/S1876382018306309?via%3Dihub
(7) Almoosawi et al. (2012). Daily profiles of energy and nutrient intakes: are eating profiles changing over time? Eur J Clin Nutr. 2012 Jun;66(6):678-86. doi: 10.1038/ejcn.2011.210. Epub 2011 Dec 21.https://www.nature.com/articles/ejcn2011210
(8) https://www.bbc.co.uk/news/science-environment-45814659
(9) https://research.ncl.ac.uk/proteinforlife/
Stevenson et al. (2018). Protein for Life: Towards a focussed dietary framework for healthy ageing. https://doi.org/10.1111/nbu.12312
