Some people will do anything to get out of doing exercise, and researchers are scrambling to oblige, showing physical health benefits – in mice and flies, that is – of isolated proteins that could potentially be taken in a pill.
Noting that a naturally occurring protein called Sestrin builds up in muscles after a heavy physical workout, scientists from the University of Michigan were curious to see if boosting Sestrin levels could produce the same health benefits without exercise.
They tested this in three groups of Drosophila flies, two of them bred either unable to produce Sestrin or saturated with it, and a normal group for comparison.
They were all put on a makeshift fly treadmill for three weeks.
“Flies can usually run around four to six hours at this point and the normal flies’ abilities improved over that period,” says researcher Jun Hee Lee.
But the flies without Sestrin showed no improvement with exercise, while those with maxed-out Sestrin levels showed superior abilities to the trained flies, even without working out – and exercising them didn’t increase their endurance.
They note studies with mice also found that Sestrin improved aerobic capacity, respiration and fat burning – all benefits associated with exercise.
Other researchers at Augusta University, US, targeted a different protein, myostatin, that inhibits muscle growth, testing lean and obese mice that couldn’t make the protein.
Both groups bulked up, but the obese mice had similar metabolic and heart health indicators to the lean mice, and better than obese mice that could produce myostatin.
“While much more research is needed, at this point myostatin appears to be a very promising pathway for protection against obesity-derived cardiometabolic dysfunction,” says researchers Joshua Butcher.
Assuming that you can extrapolate these findings to humans – which itself could be drawing a long bow – researcher and sports dietitian Karen Murphy, from the University of South Australia, expresses concern about replacing exercise with a pill.
“There are multitudes of benefits to physical activity beside burning muscle, like heart health, physical health, weight control, mental health and social interaction,” she says. Even cognitive decline can be buffered with exercise, as well as bone density.
And many other nutrients are essential for wellbeing and muscle mass.
“Most people consuming a balanced diet, with foods from all food groups in the right portions, will have little need for a supplement,” says Murphy.
“For some populations an added supplement that boosts muscle synthesis might help such as in elderly populations where muscle wasting is seen. However, to build muscle you also have to work the muscle.”
Essentially, for people who genuinely can’t exercise, there could be some benefits to pills – but they still can’t replace all the other benefits of moving your body.
Even incapacitated people with dementia can derive surprising benefits from personalised movement.
And in a world where people are moving less, getting active is more important than ever.
Since omega-3 fats were discovered in the 1970s, growing evidence has found they have far-reaching benefits for the body and brain, from fighting heart disease and improving cognition, arthritis and eye health to warding off anxiety and depression.
More recently, studies have revealed these active fats may improve protein metabolism in skeletal muscles, which could have implications for loss of muscle mass and strength with aging.
Skeletal muscle comprises 45% of body mass and is critical for physical function, respiratory and overall metabolic health and recovery from illness or surgery.
Yet muscle mass and strength start waning with age as muscle protein breaks down more quickly than it can be regenerated.
This has been linked, in part, to low-level inflammation that often occurs with aging and is linked to frailty. Chronic inflammation has also been associated with abnormalities of mitochondrial function – the cells’ powerhouse – in aging skeletal muscle.
Combined with inadequate physical activity and poor diet, such declines can lead to sarcopenia, a debilitating condition afflicting one in three older adults, increasing risk of falls and fractures with detrimental impacts on health, activities of daily living and quality of life.
Omega-3s are polyunsaturated fats that form vital parts of all cellular and intracellular membranes where they support cell structure and a host of metabolic activities that impact gene expression and mitochondrial function, among other things.
The most studied omega-3s are the long-chain versions EPA and DHA, which also have properties that reduce inflammation and blood clotting and improve blood flow, accounting for much of their health benefits.
Accordingly, growing research has shown that EPA and DHA positively impact skeletal muscle regeneration, suggesting it can help muscles take up protein. This is likely to vary according to protein intake, which is very important to keep up.
Rich plant sources of omega-3s include nuts and seeds, especially linseeds and walnuts, dark leafy greens, and a succulent plant that grows like a weed in hot, dry areas of Australia called purslane or portulaca.
While these have their own health benefits and can be converted into EPA and DHA by the body, it can be more efficient to consume direct sources of these long-chain omega-3s. That includes algae and deep-sea fatty fish like salmon, tuna and mackerel.
In combination with a healthy diet, fish oil supplements can also boost omega-3 levels, with numerous add-on health benefits.
It affects about one in three older adults, it’s debilitating, it fast-tracks mortality, and finally it is gaining greater recognition.
Sarcopenia Australia Day was officially launched just last year in July 2018 by the Australian Institute for Musculoskeletal Science, the University of Melbourne and Western Health to increase awareness, detection and treatment of this muscle wasting disease.
In November 2016, Sarcopenia was dubbed the “‘new’ disease on the block” by SBS news, shortly after it was recognised by the World Health Organisation and given its own ICD-10 (International Classification of Diseases) code in October that year.
Its label as a disease may be new, but the condition certainly isn’t.
Irving Rosenberg first devised the term sarcopenia (sarx = flesh; penia = loss) in 1988 to describe the disease, saying, “no single feature of age-related decline (is) more striking than the decline in lean body mass.”
Despite this, the disease didn’t gain traction until more recent years. Professor Gustavo Duque from the University of Melbourne is pushing for greater recognition of the condition.
He told SBS news that “People progressively lose the capacity to do the things that they usually do and they don’t know why.”
The disease is “to muscles what osteoporosis is to bones”, but doctors are often unaware of the condition, he said.
It can be particularly tricky to detect if patients are not visually wasting away; low muscle mass can even coexist with obesity.
Some muscle wasting is normal with ageing, but thousands of older Australians have accelerated muscle loss, leading to increased risk of falls, fractures, and hospitalisation.
And it affects more than just muscles. Muscle mass makes up more than half of overall body tissue, and so far research suggests its degradation has widespread ramifications including poor wound healing, increased risk of insulin resistance, type 2 diabetes, poor lung function and even breast cancer.
Diet and exercise become increasingly important as we age, and our body’s ability to repair and regenerate muscle is not what it used to be.
Physical activity helps to maintain muscle mass and strength – especially resistance training. But any activity can help, even small, regular movements or 15 minutes of cardiovascular exercise can promote muscle growth.
The importance of protein cannot be underestimated. Protein has numerous functions for maintaining the body’s metabolic processes and is important for maintaining lean muscle mass and healthy bone density.
Other nutrients can also help, including Vitamin D, creatinine supplementation (combined with resistance training), and minerals such as magnesium, selenium and zinc.
Importantly, the best results come from combining movement with good nutrition for stronger muscles and better, longer quality of life.
Animal protein – particularly whey powder – is popularly endorsed as the best source of amino acids for boosting muscle strength. But a closer look at the research suggests that plant proteins could be just as effective for building and maintaining lean muscle mass.
Whey protein contains more of the amino acid leucine than plant proteins. Extensive research shows that leucine activates muscle protein synthesis – i.e. helps muscle to use the protein. This is thought to explain its superior benefits for building lean muscle and strength after resistance training.
However, the evidence derives from studies of whey protein’s short-term impact over 3 to 4 hours. A recent meta-analysis combined nine studies that compared soy protein with various animal proteins over 6 weeks or more (5 studies tested whey and 4 used beef, milk or dairy protein).
Overall, the analysis found that combining protein supplementation with resistance training exercises (bench press and squat) increased muscle strength. But the effects of soy protein did not differ from whey powder or the other animal proteins.
Looking at whole dietary patterns, the Framingham Third Generation Study found last year that people with lower protein intakes had lower lean mass and muscle strength. But they also found no difference between the different types of protein.
According to Health.com, lead author Kelsey Mangano says, “As long as a person is exceeding the recommended daily allowance for protein, no matter the source in their diet, they can improve their muscle health.”
Losing muscle mass is one of the biggest health challenges of aging. Lean muscle does so much more than endow our bodies with a shapely physique.
Older adults need to maintain lean muscle mass to prevent falls, a major problem in aging that results in physical injury, reduced quality of life, and death.
Muscles store glucose to provide energy and can protect against diabetes and heart disease. Age-related loss of muscle mass can lead to sarcopenia, also associated with reduced quality of life, hospital admissions and chronic conditions like poor lung function and breast cancer risk.
Proteins are made from 20 amino acids arranged in thousands of different combinations. Nine amino acids are “essential” – i.e. we need to get them through dietary sources.
Animal proteins include meat, fish, chicken, eggs, and dairy foods. Protein also derives from abundant plant foods including nuts, legumes, seeds, lentils, grains, and even hemp.
Most plant protein sources are incomplete – i.e. they don’t contain all essential amino acids. Proteins derived from animal sources are complete; hence animal protein was deemed to be superior.
However, eating combinations of plant sources provides a complete protein, and it’s now established that the body can store amino acids, so a whole amino acid contingent doesn’t need to be eaten in one meal.
Most importantly, regardless of the source, research suggests that older adults who eat 1 gram of protein per kg of body weight each day are less likely to suffer disability. Combining this with regular physical movement will yield the greatest benefits.