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.
A new study has found that adults over 84 years who eat more protein are less likely to suffer disability, which is a significant problem in this growing age group.
Researchers took food diaries from 722 community-dwelling adults in the UK and measured disability according to difficulty performing daily activities like moving around the house, getting in and out of a chair, shopping, walking and climbing stairs.
Progression of disability, followed up 18 months, 3 and 5 years later, fell into four distinct categories, from very low to severe.
Results showed that adults who ate more protein were less likely to become disabled over the 5-year follow-up than those with lower protein intake, after factoring in gender, education, physical activity, cognition and chronic diseases.
Lead author of the study, Dr Nuno Mendonca, told Nutrition Insight, “We believe that the largest benefit of protein consumption is due to delaying muscle mass and strength loss.”
Protein is critical for maintaining lean muscle mass, needed for strength and mobility, and healthy bone density. Not only that, if protein stores are low, the liver will draw on the muscle’s protein stores to maintain energy levels between meals.
Dietary protein also has a multitude of other important bodily functions including formation of enzymes and hormones, transporting molecules through the bloodstream, manufacturing antibodies and regulating acid-alkaline levels.
Adults in the study who consumed 1g protein per kg of body weight each day were more likely to have lower disability, supporting calls to increase recommended protein intakes.
For a 58 kg person, that could easily be met by eating 2 eggs for breakfast, 100g yoghurt with lunch and a 100g serve of salmon for dinner – all soft foods for people with dentition or swallowing difficulties.
For adults with poor appetite, eating small meals with protein shakes for morning and afternoon tea will help boost protein intake.
It’s important to note that protein needs increase when the body is stressed by infection, burns, cancer or injury.
And to maximise muscle mass and strength, the benefits of regular physical activity in conjunction with protein intake cannot be underestimated.