Posted by ProPortion Foods Blog on Dec 5, 2017 in Muscle, Nutrition, Protein, Sarcopenia
Mary and Sylvia might not differ in body weight and appearance, but could be hiding a distinct difference—one may have greater fat mass and the other more lean muscle. Why is this important?
It is well-known that muscles give us strength and mobility, that we need them to walk, run, dance, kick a ball, and hold our bodies upright. Some might know that lean muscle burns more calories, helping to keep excess fat at bay, and helps maintain healthy bone density.
But the humble muscle has secret talents that are not widely flaunted.
Bodily organs like the skin, brain, heart and liver need protein to carry out their unfailing, life-giving duties. Protein continually breaks down in all tissues, which rely on a constant supply.
After a meal, blood vessels absorb and deliver amino acids—protein building blocks—to the organs. Between meals, i.e. when fasting, body tissues rely on lean muscle, their primary amino acid storage facility, to make protein.
Critically, the liver needs lean muscle protein for neogenesis—producing glucose from protein to supply energy when the liver’s stores are depleted during the fasting state.
This operation works well, so long as lean muscle stores are regularly replenished with protein stocks. However, when its protein stores fall below demand, depleted muscle mass has been associated with death from critical illness or starvation.
The body’s demand for muscle protein skyrockets when stressed by infection, burns, cancer or injury, and the stores are raided by the liver, immune system and infected wounds. Even heart disease—the Western world’s leading cause of death—is associated with declining muscle mass, strength and metabolic function.
Muscle bulk naturally declines with age and can cause sarcopenia—age-related loss of muscle mass, strength and function that may result in a vicious cycle of falls, illness, and hospitalisation.
If muscle mass is already low before illness, trauma and forced bed rest, the resulting loss may dramatically exceed an older adult’s recovery threshold. This explains, for instance, why many women over 65 who fall and break their hip never walk again.
There are two simple ways to prevent and reverse accelerated loss of muscle mass and its valuable protein stores.
As previously reported, dietary protein is critical. A day’s supply is best spread over each meal. Whey powder derived from dairy is most easily absorbed—this can be used as a supplement when protein demands are high, and is best taken between meals to maintain a healthy appetite.
Other good protein sources include pea protein, eggs, dairy products, fish, chicken, meat, nuts and seeds.
Physical activity is also important. Any exercise is beneficial, but resistance strength training is most effective for building and retaining muscle mass, which can reduce weakness, frailty and the resulting accelerated decline.
Even two or three days a week of dedicated strength training at an appropriate level, combined with adequate protein intake, can build muscle strength and mass, improve bone density, and improve independence and quality of life with aging.
http://ajcn.nutrition.org/content/84/3/475.full
http://www.gophysiotherapy.co.uk/blog/lean-muscle-mass-important/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3940510/
http://www.sciencedirect.com/science/article/pii/S0749379703001776http://
http://www.proportionfoods.com.au/preventing-age-related-muscle-loss-simple/
Posted by ProPortion Foods Blog on Nov 22, 2017 in Muscle, Nutrition, Protein, Research, Sarcopenia
Unless you are suffering a prolonged midlife crisis, life really does get better after 40—we can start to enjoy the fruits of our labour, care less about what people think, and (hopefully) have life worked out. Physically, things are still okay. But the average person would have lost 3-8% muscle mass since turning 30, and this trend will continue each decade.
Nearly half of our body weight consists of muscles—over 600 different types. Muscles are made of fibres, and more fibres mean greater muscle strength. They all stretch and contract, but distinct muscle groups have very different functions.
Smooth muscles keep organs working behind the scenes (e.g. digesting food, expelling the solid and fluid by-products, maintaining blood flow, delivering babies, and even helping eyes see), and cardiac muscle works 24/7 to keep the heart beating.
Skeletal muscle contains the most tissue and is the body’s largest protein store. Skeletal muscle gives bodies their shape, maintains posture, moves the body on command and generates heat. It even mediates insulin production, supporting evidence that improved muscle tone can help control blood sugar levels.
Severe muscle loss affects 5-13% of people by 60-70 years, increasing to 11-50% of people over 80. As skeletal muscle mass declines with age, so does muscle strength, power and balance. Professor Irwin Rosenberg, of the Jean Mayer USDA Human Nutrition Research Center on Aging, proclaimed, “no decline with age is more dramatic or potentially more functionally significant than the decline in muscle mass.”
Lost muscle mass can increase risk of sudden falls, fractures and mortality. Sarcopenia—age-related loss of lean tissue mass and function—is a serious, multifactorial condition that can creep up unexpectedly. It affects an estimated 29% and 33% of older people living in the community and in long-term care, respectively—and this is likely to increase with our aging population.
Forced hospital rest can worsen sarcopenia. Some older adults may never recover from extra muscle mass lost from injury and hospitalisation, leading to accelerated breakdown of body tissues, poor clinical outcomes and increased hospital costs. When severe, sarcopenia results in 79% increased risk of disability.
Lifestyle behaviours make up much of the difference between healthy and unhealthy aging: most notably diet quality and exercise. Age-related and severe loss of muscle mass can be reduced with physical activity (especially resistance training) and nutrition.
Protein and amino acids (protein building blocks) from absorbable sources like whey are key nutritional targets for improving muscle mass, strength and physical performance. Adults with protein-energy malnutrition and unintended weight loss also need extra calories from food to prevent their body breaking down muscle protein for energy.
Vitamin D may improve muscle strength, especially in patients over 65 with low Vitamin D (<30 nmol/L). Creatine supplementation, combined with resistance training, might increase upper body strength and reduce muscle aging, and one study reports possible benefits of leucine (an amino acid that stimulates muscle protein synthesis). A recent review further identified a potential role for minerals (particularly magnesium, selenium and zinc) in preventing and treating sarcopenia.
Increased muscle strength can not only enhance treatment outcomes, morbidity and blood sugar control, it may also improve sleep and mental health—hence better quality of life with aging.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3276215/
https://www.ncbi.nlm.nih.gov/pubmed/9164280
https://www.ncbi.nlm.nih.gov/pubmed/29045254
https://www.ncbi.nlm.nih.gov/pubmed/28549707
http://www.sciencedirect.com.access.library.unisa.edu.au/science/article/pii/S8756328217303459
Posted by ProPortion Foods Blog on Sep 13, 2017 in Muscle, Protein, Sarcopenia
Age-related muscle loss is one of greatest health issues for older adults. Up to a third of people over 50 experience sarcopenia – the age-related loss of muscle mass and strength. This can lead to many other health complications. However, it can also be prevented and managed with just a few simple interventions.
Sufficient muscle mass is essential for health and wellbeing at any age. One of the key roles of muscle is utilisation of carbohydrates for energy production. More muscle mass means more is used for energy, instead of being stored as fat.
Muscle mass can protect against conditions such as diabetes, cardiovascular disease, premature ageing and poor cognitive function. Unfortunately, many older adults experience sarcopenia, which increases the risk of illness and injury.
When people are inactive for any reason, muscle can waste away. This is known as muscle atrophy or muscle loss.
One of the most common causes of muscle loss is ageing. There are multiple factors that cause age-related muscle loss. It’s believed that a reduction of testosterone and growth hormone combined with an increase in pro-inflammatory cytokines play a big role (1).
There are other causes of muscle loss aside from ageing. Significant injuries, malnutrition, stroke, long-term steroid use and general inactivity can all lead to atrophied muscles. Conditions that restrict movement can also contribute.
Unfortunately, muscle loss can have a significant impact on health and wellbeing.
Muscle loss can negatively impact on health in a number of ways. By losing muscle mass, people are likely to gain body fat instead. This is due to the reduced carbohydrate usage by the muscles, leading to more energy being stored as fat.
People may also experience stiffer joints with muscle loss. This will make it harder for them to move around, which contributes further to muscle loss and fat gain.
This may lead to other health conditions and complications, including cardiovascular disease, diabetes and arthritis. Many of these can become serious or even fatal if left untreated. It is essential to intervene in the early stages of muscle loss, to slow or even reverse the process.
It’s possible to halt and even reverse muscle loss through simple interventions. By using the right nutrition and exercise, muscles can grow and regain strength.
One of the most important interventions is to consume sufficient protein to meet dietary needs. Research suggests that eating similar quantities at each meal is more effective than a large intake in one meal (2).
Keeping physically active is essential for maintaining muscle mass. Even small, regular movement can help in those with limited movement. Research has demonstrated that even 15 minutes of cardiovascular exercise can stimulate muscle growth (3).
Ideally, resistance exercise is included so that muscle strength can be restored. One study demonstrated that just 3 resistance-training sessions per week for 12 weeks could increase muscle strength (4).
These interventions are inexpensive but highly effective in preventing and reversing age-related muscle loss.
Sarcopenia and muscle loss can cause many health issues. However, simple interventions such as nutrition and exercise provide a safe, easy and effective way to prevent and reverse muscle loss.
Posted by ProPortion Foods Blog on Jul 3, 2017 in Sarcopenia
Sarcopenia can be described as a loss of skeletal muscle mass, muscle function and strength that occurs with aging. Sarcopenia can significantly impact on quality of life and lead to other chronic disease states. Lack of a clinical definition of sarcopenia means that its prevalence in Australia is difficult to determine. However, it is estimated that up to 29% of the community-dwelling population and up to 33% of those in long term care are affected (1). Whilst sarcopenia is often associated with the elderly in aged care, those requiring assistance and frailty, the reality is that muscle decline and sarcopenia begin much earlier in life and often goes unnoticed.
Age is the major determining risk factor for sarcopenia; muscle mass can begin to decline by the 4th decade of life and by the 8th decade total muscle may have declined by up to a 50%. Genetics, lifestyle and the presence of other chronic disease are also contributing factors to loss of muscle mass (2, 3).
As we age the number of muscle fibres, most notably the type 2 fast twitch muscle fibres, begin to decline. Additionally, the precursor or satellite cells – which are activated to repair and build muscle after weight bearing exercise or trauma – also begin to reduce in concentration. These physiological changes make the muscle building and repair process less effective and together with a decline in physical activity and nutritional status contributes to the progression of sarcopenia (2).
When overweight or obesity is present sarcopenia may not be as noticeable, yet it is equally as detrimental to health. This is referred to as sarcopenic obesity, the presence of obesity and sarcopenia together (4). This paradox is often characterised by fat infiltration of muscle; the increase in adipose tissue and decrease in muscle mass drastically alters metabolic processes and is closely associated with insulin resistance and diabetes (5).
As muscle mass makes up 60% of overall body tissue the structural and metabolic consequences of muscle loss are significant (2). This dramatic change in body composition can impact on mobility and lead to frailty, increased risk of falls and fractures, insulin resistance, fatigue and mortality. Sarcopenia can, of course, occur concurrently with other diseases such as rheumatoid arthritis or osteoporosis; when this is the case there is an even greater increase in the risk of fracture, illness and decreased quality of life.
Fortunately, with diet and lifestyle interventions the progression and severity of sarcopenia can be reduced.
Nutrition and diet are the gold standard for the management or prevention of sarcopenia. Older adults generally have a greater relative protein requirement than younger adults. This is due to changes over time in ability to digest protein and, in the case of muscle, decreased sensitivity in older adults of muscle protein synthesis (‘MPS’) pathways. Whilst the current RDI is 0.8g/kg of body weight, recommended intake for older adults often ranges from 1.0 to 1.2g/kg of body weight. This may increase further in the case of chronic disease. The essential amino acid leucine is strongly associated with MPS and consumption of protein sources rich in this amino acid may help improve muscle strength and function (1 2, 6).
The aim should be to include 25-30g of protein with each main meal. Timing these meals post exercise may help increase muscle mass. Exercise programs focussing on resistance exercises, or a blend of both aerobic and resistance or compound exercises, can improve muscle strength and function as well as potentially increasing muscle mass in sarcopenic individuals (1).
Maintenance of overall physical activity, inclusion of resistance exercise and a diet containing sufficient energy and protein can be helpful in the prevention of sarcopenia and should be the cornerstone of a healthy lifestyle as we age (2, 6).
1. Cruz-Jentoft AJ, Landi F, Schneider SM, Zúñiga C, Arai H, Boirie Y, et al. (2014) Prevalence of and interventions for sarcopenia in ageing adults: a systematic review. Report of the International Sarcopenia Initiative (EWGSOP and IWGS). Age and ageing; 43, 748-59.
2. Walston JD (2012) Sarcopenia in older adults. Current opinion in rheumatology; 24, 623.
3. Scott D, Blizzard L, Fell J, Jones G (2011) The epidemiology of sarcopenia in community living older adults: what role does lifestyle play? Journal of cachexia, sarcopenia and muscle; 2, 125-34.
4. Cleasby ME, Jamieson PM, Atherton PJ (2016) Insulin resistance and sarcopenia: mechanistic links between common co-morbidities. Journal of Endocrinology; 229, R67-R81.
5. Stenholm S, Harris TB, Rantanen T, Visser M, Kritchevsky SB, Ferrucci L (2008) Sarcopenic obesity-definition, etiology and consequences. Current opinion in clinical nutrition and metabolic care; 11, 693.
6. Steffl M, Bohannon RW, Sontakova L, Tufano JJ, Shiells K, Holmerova I (2017) Relationship between sarcopenia and physical activity in older people: a systematic review and meta-analysis. Clinical interventions in aging; 12, 835.
Image from pixabay.com