The elderly have a higher need for leucine to build muscle proteins, and milk-based proteins (e.g. milk and whey) are a good source for this. Image by Shutterstock.

The minimum protein requirement for healthy adults has been set almost 15 years ago but there is a growing body of evidence that this recommended dietary allowance (RDA) is not sufficient for older persons.

— By Hedwig Ens

You can find the recommended dietary allowance (RDA) on the nutrition labels of all your processed food. Food manufacturers are obliged to list the nutritional value of their products, and therefore must mention the percent daily value of the RDA their product meets for certain nutrients.

These RDA guidelines are put together by the Food and Nutrition Board of the National Academy of Sciences’ Institute of Medicine. They inform you how much of a specific nutrient your body minimally needs every day. They are set to meet the requirements of 97.5% of the healthy individuals older than 19 years.

The RDA you will find on the nutrition labels on your food, however, were set in 1968, and the ones used by researchers and professionals were set in 2003. A recent review published in Frontiers in Nutrition points out that both these values do not do justice to the protein needs of the elderly and critically ill.

“A big disservice is being done. The prescribed 0.8 g/kg/day just isn’t enough protein for the elderly and people with a clinical condition. This shouldn’t be communicated as what is ‘allowed’ or even ‘recommended’ to eat.”, author Stuart Phillips of McMaster University in Canada explains.

In his review, he points out that the quality of proteins should be considered when setting the RDA guidelines and recommending protein supplements. He argues that there should be a stronger focus on leucine; an indispensable amino acid and building block for proteins. The elderly have a higher need for leucine to build muscle proteins, and milk-based proteins (e.g. milk and whey) are a good source for this.

Moreover, it may be highly beneficial for the critically ill patients that rapidly lose lean body mass (i.e. the body weight minus body fat) to increase their protein intake. Again, elderly ill patients would benefit the most from this. “I think it’s clear we need some longer-term clinical trials with older people on higher protein intakes. These trials need to consist of around 400 – 500 people.”, Phillips argues.

He is not the first researcher to challenge the current protein RDA, and hopes his message does not fall on deaf ears. That is also why he chose to publish Open Access: “I love to publish work that everyone can read. The days of publishing a paper that only people in academic institutions can read are over. I think it is essential that everyone and not only your scientific colleagues can read the work we do.”

At his own dinner table, Phillips also puts the focus on proteins. “But not at the expense of other macronutrients. I enjoy a variety of foods, and the only thing I specifically focus on is limiting my intake of sugar and refined carbohydrates. But of course, given the benefits of proteins, they are a big part of what I think about when planning my meals.”