How much protein do we need after 50? Probably more than you think, as it turns out.
But no need to take my word for it – I brought along one of the top experts in the world on protein metabolism and utilization in older adults:
Sara Oikawa, PhD, Senior Scientist in nutrition and exercise physiology research for the Gatorade Sports Science Institute at IMG Academy in Bradenton, Florida.
Sara earned her Honours Bachelor of Science Kinesiology, Masters of Science in Kinesiology, and her Ph.D. in Kinesiology at McMaster University in Hamilton, Canada (note: which by the way is pretty much the top research center in the world on protein metabolism). Sara’s Masters focused on resistance training-load mediated muscle hypertrophy in trained young adults. Her Ph.D. work focused on dietary protein quality and alterations in protein metabolism, specifically muscle protein synthesis, in both inactivity and resistance training models. In her spare time, Sara enjoys travelling, hiking, cooking, and watching Toronto based sports teams. (From the GSSI website)
I had the pleasure of meeting Sara at the 2021 Resistance Exercise Conference, where she delivered one of the finest presentations I have ever heard at a fitness seminar (and I’ve heard hundreds).
So grab a beverage, sit back and learn some cutting edge nutrition information that YOU can apply RIGHT NOW to improve your health and fitness results.
How much protein do we need after 50? My interview with Sara Oikawa, PhD
Can you tell us a little about you and your background?
My Ph.D. research was focused on the effects of differing levels of physical activity (resistance exercise, and step reduction- disuse) on rates of muscle protein synthesis in healthy older adults. However, I’ve been very fortunate to work with a variety of populations such as young adults, elite athletes, pregnant women, and with individuals with cardiovascular disease.
Currently, I work at the Gatorade Sports Science Institute in Bradenton, Florida supporting our research and innovation platforms primarily.
You’ve been involved in some of the top research on protein utilization and consumption. How did you become interested in protein research?
I was very lucky to be exposed to research early in my undergraduate career and I was extremely lucky that my research exposure occurred with one of the top protein metabolism researchers in the world, Dr. Stuart Phillips. It was in working with Dr. Phillips and his phenomenal lab group that I first became interested in protein research, mainly in young adults, however through my time in the lab my interests shifted to how protein may protect muscle mass with aging. In particular, I became more familiar with how detrimental periods of disuse are in older adults, and the additive understanding that they often do not mount a full recovery is quite troubling.
How much protein per day would you recommend for people over 50, especially those who strength train regularly?
At present we don’t have a specific differentiation for protein recommendations for older adults who strength train and those who do not. In general, it’s been recommended for older adults to consume 1.2-1.6 g/kg/day of total protein with the recommendations to try and achieve 0.4 g/kg of protein at each eating occasion. For older adults specifically, we believe that the timing of protein ingestion may be more important where protein should be consumed post exercise to help potentiate the synergistic responses of both stimuli.
(NOTE from Dave: to figure out your own personal protein needs in grams per pound, divide your weight in pounds by 2.2, the multiply that number by 1.2 to 1.6.
For example, I weigh 170 pounds. 170 divided by 2.2 = 77.27. I multiply that by 1.2 to 1.6 = 92.72 to 123.63 grams of protein per day that I need. Personally, I try to get 125 to 135 grams per day).
Does consistent strength training increase a person’s protein requirements?
In general, strength-based athletes are recommended to consume protein over the recommended daily allowance, anywhere between 1.6-2.0 g/kg/day. The reason that protein recommendations are augmented for individuals who are resistance training are to support muscle growth but also to make sure there is an adequate supply of amino acids to help with muscle remodeling and repair.
(NOTE from Dave: to figure out 2 grams of protein per kilogram of bodyweight in pounds, take your weight and divide by 2.2, then double that number. For example, I weigh 170, divided by 2.2 = approximately 77, double that = 154 grams of protein per day.)
It seems protein intake recommendations have increased in recent years. Why do you think older adults need to ingest more protein?
It has now been well documented that the ability for older adults to mount the same muscle protein synthetic response to protein ingestion is attenuated compared to younger adults. In other words, if a young adult is able to maximally stimulate muscle protein synthesis with 20 g of protein, we likely would see that this is not a sufficient amount to maximally stimulate muscle protein synthesis in an adult > 60 years. This has led to some research that has shown that older adults require >60% more protein per dose/meal in order to mount the same anabolic response as young adults.
Does the source of the protein consumed matter? Or should we just worry about how many grams we get per day from all sources?
The source of a protein often dictates the quality of the protein source. We consider high quality proteins to contain a full complement of the essential amino acids, to be rapidly digestible and bioavailable, and to be higher in the essential amino acid leucine. For older adults, we believe the threshold for which leucine helps to stimulate muscle protein synthesis is higher, and therefore, proteins of higher quality with higher levels of leucine will be more beneficial to help maximize muscle protein synthesis. Interestingly, a recent meta-analysis showed that consuming protein at 1.6 g/kg/day is likely to contribute to muscle growth when combined with resistance training, irrespective of the protein source. However, for older adults, I think protein quality is just as important as achieving total daily protein goals.
What is your opinion of low carbohydrate diets for people over 50? Are they ok as long as a person’s protein intake is sufficient?
Low carbohydrate diets are likely not detrimental in adults over the age of 50 if the low carbohydrate intake does not result in energy restriction. We know that cutting calories as little as 300 from habitual intake is sufficient to decrease rates of muscle protein synthesis. Given that older adults are less sensitive to protein and resistance exercise to increase rates of muscle protein synthesis, we ideally want to avoid any decrease in rates that might occur with caloric restriction.
Is protein supplementation necessary for people over 50 who want to build muscle mass? Are there any guidelines you would recommend for supplementation?
It is always best to get protein from whole food sources as this likely means you’ll receive the other nutritional benefits from that food matrix. However, where supplementation can be helpful is if individuals are having a difficult time achieving protein recommendations. For example, consuming 0.4 g/kg of protein at a meal if you weight 85 kg would equate to about 34 g of protein. If an individual ate 20 g of protein from their meal, they could use a protein supplement to consume the other 14 g without having to eat a whole food source. In general, we recommend that adults over 60 aim to consume 1.2-1.6 g/kg/day of total protein, using their body mass to calculate how much protein per meal they should have (0.4 g/kg/meal).
At the Resistance Exercise Conference, you discussed “Disuse Events” and their effect on muscle mass and muscle strength. Can you elaborate on what “Disuse Events” are, and their consequences, and what we can do to overcome those consequences?
A disuse event can present in a number of ways. A more overt example is something like bed rest where you are not weight bearing however, a disuse event can also apply to single limb casting or immobilization, similar to what would occur after elective surgery for a hip or knee replacement. Importantly a disuse event can also manifest as an event that is much more benign like a cold of the flu, where we see drastic decreases in physical activity from normal. So although you are not bed-ridden, you are really only weight bearing to use the washroom or perhaps get something to eat or drink infrequently, and in a limited capacity throughout the day. These drastic periods of step reduction or physical activity reduction are still harmful and may occur with greater frequency than bed rest or casting. We know that older adults often do not fully recover lost muscle mass with disuse, so the concern is if individuals do not perceive the benign periods of disuse as harmful, they may not take action to try to recover (ex. Participating in rehabilitation or exercise). Regarding muscle loss with disuse, we know that nutritional interventions play a minimal role in attenuating muscle loss in healthy older people. However, we have seen that exercise during periods of inactivity, can significantly protect muscle loss. If you are unable to exercise while experiencing a period of disuse, as is common with many individuals, getting moving and exercising as quickly as possible (and is safe) following a disuse event is critical for recovery. This recovery period is also where getting adequate protein may prove to be beneficial.
Do you have any parting advice for our Strength After 50 audience regarding protein intake?
Do you best to eat a well-rounded diet and aim to consume adequate protein as mentioned above, ideally from a source that is high quality. It is also incredibly important to stay physically active and in particular to resistance train, and dietary protein can help to support your muscles as you are training. Maintaining muscle strength and power is crucial to maintaining independence as you age.