Eating protein in older age may help keep you strong and fit. Not only can it preserve muscle mass and maintain physical functioning, but it can also improve the global well-being. And in a win-win situation, choosing the right protein-rich foods can also help protect the environment, the authors of this research reveal.
That’s because production of certain protein-rich foods is associated with higher greenhouse gas emissions (GHGEs) than others, and so potentially has a greater impact on climate change. Shifting toward a more diverse plant-based diet with small amounts of certain types of meat can provide the suggested higher protein requirement of older adults and lower GHGEs, say the authors.
Finding the best diet
This Dutch study looked at dietary data for 1,354 older adults (aged 56–101 years) from the Longitudinal Aging Study Amsterdam cohort. Starting with the average diet, the researchers designed high-protein diets (≥1.2 g protein/kg body weight/day) that took into account nutritional adequacy, the Dutch food-based dietary guidelines (FBDG), and GHGEs. For each modelled high-protein diet, they worked out what changes were needed to the average food intake to achieve a healthy sustainable diet.
A high-protein diet in line with Dutch FBDG, but without considering GHGEs, involved eating more vegetables, legumes, nuts, whole grains, meat/dairy alternatives, dairy and eggs, and less meat (men only) and ‘discretionary’ foods such as dressings, sauces, sweets. The authors estimated that this diet would increase GHGEs by 5% in men and 9% in women.
Changing the type of meat to benefit the environment
In order to halve GHGEs – a European goal by 2030 – the FBDG-aligned high-protein diet needed to be adapted. This meant further increases in whole grains, nuts and meat/dairy alternatives and decreases in discretionary foods. It didn’t involve much change in the total amount of meat. But it did involve avoiding beef, lamb and processed meat, instead eating more poultry and pork.
About half the protein in this environmentally-friendly FBDG-aligned high-protein diet came from plant-based foods. Including animal-based foods in the diet is important to provide enough omega-3 fatty acids, calcium and iron, say the authors.
What about protein quality and acceptability?
Protein quality – measured through nine essential amino acids – wasn’t compromised in the environmentally-friendly FBDG-aligned high-protein diet.
The dietary changes required were likely to be acceptable to most people, say the authors.
‘A high-protein diet aligned with FBDG can be achieved in concert with reductions in GHGEs in Dutch older adults by consuming no more than the recommended 500 g meat per week while replacing beef and lamb and processed meat with poultry and pork and increasing intake of diverse plant-protein sources.’ – Grasso, 2021.
Find out more: read the original article
Grasso AC, Olthof MR, van Dooren C et al. Protein for a Healthy Future: How to Increase Protein Intake in an Environmentally Sustainable Way in Older Adults in the Netherlands. J Nutr. 2021;151(1):109-119.
