Author: Doug Cook, RD MHSc CDE
For the first 30 or so years of life our bodies are in a state of growth and maintenance; our bones become denser and stronger and our muscle mass and strength increases as well. However, sometime in our 30s, we start to lose muscle mass (sarcopenia), strength (dynapenia) and function.
It’s estimated that we can lose up to 3% of our muscle mass per decade after age 30 or about 0.3% per year. This accelerates significantly after the age of 75; losses range from 0.67 to 0.89% per year. However, the greater impact of aging on muscle is related to a decline in muscle strength. After the age of 75, muscle strength can decrease at a rate of 3.5 to 3.75% per year. Loss of strength occurs up to 5 times faster than loss of muscle mass and declining muscle strength is a better predictor of disability.
While this may not sound like much, the cumulative effects are clear: the hallmarks of aging include loss of coordination, stooped posture, weakness in arms and legs and loss of muscle.
Risk factors include aging itself, with accompanying changes in hormone levels, inactivity, low protein diets, poor diet quality with inadequate intake of supporting nutrients, and not eating adequate amounts of protein throughout the day.
On the upside, our muscles are constantly turning over; old muscle tissue is broken down (catabolism) while new muscle is being built up (anabolism). It’s the net effect, or balance, of muscle turnover which determines whether or not we’re gaining muscle or losing muscle; a negative muscle protein balance results in muscle loss while a positive balance means muscle tissue is being preserved.
Research shows that the best medicine is a nutrient-dense diet that includes more high-quality protein, coupled with resistance and weight-bearing exercise and, it’s never too late to start. Even the elderly are able to gain mass and strength; inevitable frailty, to a large degree, is a myth. While it’s true that the gains for older individuals are less than that of younger adults, research has shown that diet and exercise can help to reverse and preserve functional status, or the ability to maintain our activities of daily living, and independence as we grow older. This brings new meaning to the expression ‘use it, or lose it’. This Lentil & Ground Chicken Shepherd’s Pie is high in protein and great for anyone who needs easy-to-chew recipes.
Regarding dietary protein, it appears on the surface that most Canadians, including the elderly, are eating enough according to the 2004 Canadian Community Health Survey. However, the results of this survey might not be the best way to assess the actual amount of dietary protein consumed. The results, expressed as a percentage of total calories eaten, indicate that essentially all Canadians are falling within the recommended range of 10 to 35% of their calories from protein, albeit at the lower end. The problem though is that this may mean as little as 45 g of protein (10% of calories) a day for an 1,800 calorie intake, an amount that research indicates isn’t enough to maintain muscle mass as we age. Looking for a way to boost your protein in one low-calorie meal? Try something new on the BBQ with these BBQ Chili Drumsticks with Avocado & Tomato Salsawhich feature 22 g of protein per serving.
Studies have shown that when approximately 30 to 40 g of protein is consumed at each main meal, muscle protein synthesis is increased and muscle protein retention is maintained at levels similar to younger adults with an additive effect when coupled with resistance exercise. For another high protein dish that tastes great and can be served at any occasion, try this classic Chicken Cacciatore which provides 36 g of protein per serving.
Most Canadians don’t have a problem with planning for a high-protein supper, but they often fall short of their protein goals with their breakfasts and lunches. What this means in practical terms is that older Canadians may need to increase their total daily protein intake and need to find ways of redistributing their protein evenly throughout the day, versus eating more of it at the evening meal.
Breakfast is often light in protein and carbohydrate heavy with cereals, toasts, and fruit; while lunch may have a little more protein with dinner typically having the most protein of all the meals. For protein rich breakfast ideas click on the breakfast category under recipes at chicken.ca.
As a strategy to increase both total protein intake and to reach the goal of 30 g per meal, portions of protein-rich foods at dinner can be reduced, while increasing the portions of protein containing foods at both breakfast and lunch. This can include relatively affordable foods such as Greek yogurt, cottage cheese, cheese, eggs, fish, meats and chicken. At lunch time pair these very portable Chicken Jerk Wraps with Lime Mayo with a glass of milk and get 32 g of high quality protein.