It’s well-known that a healthy diet – one that’s plentiful in vegetables, fruit, whole grains, pulses (e.g., beans and lentils), nuts and fish – delivers many health benefits.
Eating a high-quality diet is tied to a lower risk of obesity, heart disease, stroke, type 2 diabetes, certain cancers and premature death.
What’s lesser-known, though, is that a healthy eating pattern in midlife can also help preserve muscle mass and muscle strength in older age.
That’s important since the gradual loss of both can lead to sarcopenia, a skeletal-muscle disorder that can significantly impact the quality of life.
What is sarcopenia?
Sarcopenia is a skeletal-muscle disorder defined by the progressive loss of muscle mass, strength and function.
Symptoms include muscle weakness, slow walking speed, trouble climbing stairs and difficulty performing normal daily activities. Poor physical performance is an indicator of sarcopenia severity.
Sarcopenia is associated with poor health outcomes, including a greater risk of falls and fractures, frailty, hospitalization, complications after surgeries and mortality.
The most common cause of sarcopenia is aging. After age 30, muscle loss is estimated to be 3 to 8 per cent per decade, increasing after age 60. Muscle strength declines more quickly. Studies suggest that at age 75, muscle strength is lost at a rate of 3 to 4 per cent per year in men and 2.5 to 3 per cent per in women.
Risk factors for sarcopenia include physical inactivity, chronic illness, loss of mobility, hormonal changes, inflammation and poor nutrition.
Why nutrition matters
Dietary factors can influence a number of underlying causes of sarcopenia. For example, an adequate intake of calories and protein can minimize muscle loss by supporting muscle protein synthesis.
Anti-inflammatory nutrients and phytochemicals can combat inflammation, which plays a role in developing sarcopenia.
As well, dietary antioxidants defend against free radicals, molecules that contribute to sarcopenia by damaging muscle cells.
A healthy diet can also improve the composition of the gut microbiome which, in turn, may benefit muscle mass and function by reducing inflammation and enhancing muscle protein synthesis.
What the research says
According to an evidence review conducted by researchers from Newcastle University in the United Kingdom, adopting a healthy diet in adulthood can enable better physical performance and independence in older age.
The review, published in advance online in The American Journal of Clinical Nutrition, evaluated evidence on the relationship between diet, single foods and nutrients consumed during mid-adulthood (40 to 60) and younger-older adulthood (60 to 70) and future risk of sarcopenia.
The findings suggest the following strategies can help keep muscles strong as you age.
Over 65? Pay attention to your protein intake
Adopt a healthy dietary pattern
Eating a higher quality diet throughout mid-adulthood is linked to better physical performance 10 to 20 years later. A more inflammatory diet at age 50, though, has been associated with a greater loss of muscle mass and slower physical performance at age 65.
Physical performance is measured by chair rise speed, standing balance time, gait speed and/or TUG (Timed-Up-And-Go) speed. For the TUG test, individuals are asked to rise from a seated position, walk eight feet, turn around, walk back and sit down again.
Following a healthy diet during younger-older adulthood has also been shown to protect muscles.
Compelling evidence comes from the Baltimore Longitudinal Study of Aging published in 2022. Among 1,358 participants, average age 68, higher (versus lower) adherence to the MIND diet was tied to better physical performance six years later, as well as a slower decline in muscle function. Findings were consistent for males and females.
What is the anti-inflammatory diet plan?
Don’t skimp on fruits and vegetables
A 2014 study from the U.K. found that among 5,761 males and females, average age 49 at study onset, eating fewer than two daily servings of fruit and vegetables throughout the 17-year study was associated with slower walking speed at follow up.
The results indicated stronger effects with a longer duration of low fruit and vegetable intake. The researchers accounted for other unhealthy lifestyle habits.
Include vegetables and fruit at each meal. Eat leafy green vegetables, plentiful in beta-carotene and lutein, daily; higher intakes of these phytochemicals have been tied to smaller losses in physical performance.
Meet daily protein needs
To maintain muscle mass and function, healthy older adults are advised consume 1.2 g of protein per kilogram body weight each day, an amount that’s higher than the official recommended daily intake (0.8 g protein/kg/day). With age, adults turn protein into muscle less efficiently and need to eat more of it to support muscle health.
A 2022 review of 18 randomized controlled trials concluded that an increased protein intake likely increases muscle mass and muscle strength but only when combined with resistance training, which is the most potent stimulus of muscle protein synthesis.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on Twitter @LeslieBeckRD
Leslie Beck