Most people thrive on the idea of staying physically active throughout life, but as we grow older, our skeletal muscle slowly vanishes and our figure changes. This is known as sarcopenia and is one of the main reasons why older people become more fragile and perhaps even disabled. Exercise and diet play a major role, and it seems that the official dietary guidelines are not optimal and should focus more on increased intake of protein as well as lysine, vitamin D, and omega-3 according to a new Canadian study. Earlier research shows that magnesium, selenium, and Q10 are also important for muscle mass and strength.
Sarcopenia slowly sets in around our early forties, and the process accelerates after we reach 65 or 70 years of age. Sarcopenia causes us to lose both muscle mass and strength and it impairs our mobility. This makes us increasingly vulnerable to diseases, hospitalization, and early death. Our figures also change, as we gradually lose our muscle mass, typically causing our arms and legs to become thinner, while our butts become flatter.
Sarcopenia is the result of several different factors such as neuromotor dysfunction, physical inactivity, hormonal changes, and malnutrition. Health authorities underline that exercise and physical activity are the only things that can counteract the loss of muscle mass, but diet also plays a major role.
A team of Canadian scientists from the School of Human Nutrition, McGill University, and the Department of Medicine in Montreal decided to look closer at how protein, lysine, vitamin D and omega-3 affected muscle mass, muscle strength, and physical ability among older citizens living at home that were either healthy or at risk of becoming fragile.
The study showed that a combination of different lysine-rich proteins and supplements of vitamin D and omega-3 might be a useful strategy for preventing sarcopenia and physical decline. Other studies have shown that magnesium, selenium, and Q10 also have an effect. The question is how much of the different nutrients do we need.
Older people need more protein than officially recommended because of their muscle mass
Lack of protein is very common among older people, and it seems that the recommended daily protein intake is lower than it should be. The explanation most likely lies in the fact that muscle-building enzyme processes slow down, as we grow older. The quality of the protein also plays a determining role, and the same goes for physical activity. Not only do we need protein to build muscles, we also need it for our energy turnover and for the production of hormones, antibodies, and neurotransmitters for the nervous system.
Once we reach our forties and fifties, we lose around 0.5 to 1.0 percent of our muscle mass per year
When we are around 65-70 years of age, the process speeds up and may end up costing us more than a third of our skeletal muscle mass.
How much protein do older people need?
The official recommendation for daily protein intake is around 0.8 grams for every kilo of body weight. In recent years, researchers have called for a higher intake and specifically recommend that older people get at least 1.0 to 1.2 grams of protein to maintain healthy muscle mass. In cases of acute or chronic disease (except from kidney ailments), the daily recommendation is 1.2 – 1.5 grams of protein for every kilo of body weight. Older people with serious diseases or signs of severe malnourishment may need as much as 2 grams of protein, which is twice as much as the official recommendations.
Our protein should ideally come from the three daily main meals and should include animal and vegetable protein sources. Older people who are unable to get their calories and nutrition from normal healthy food can resort to special protein drinks.
Protein content (grams) per 100 gram of food
The amino acid lysine is important for building muscle cells
Protein consists of a number of amino acid that work as building blocks. One of them, lysine, is regarded as the most important regulator in the building of muscle mass. As we age, our muscles gradually lose their ability to respond to lysine, whereas increased lysine intake seems to stimulate the protein synthesis. Older people should therefore make sure to get enough of the different amino acids, especially lysine, from sources like eggs, meat, fish, dairy products, and beans.
It is important to stress that vegetable protein sources are less effective than animal sources in terms of their ability to build muscle mass. Animal protein has a more complete composition of amino acids. One can also take lysine supplements, and researchers say that this may be a good idea for older people with limited appetites and those who eat very little food.
Protein, muscle mass, and hip fractures
Epidemiological studies show that a low intake of protein is associated with age-related loss of muscle mass. Low intake of calories, protein, and lysine is also linked to reduced muscle mass in older people, who have sustained a hip fracture.
Vitamin D and its influence on muscle mass and strength
Most cells in the body, including muscle cells, have vitamin D receptors (VDR). Vitamin D influences muscle contraction by affecting insulin sensitivity and calcium regulation.
Studies of vitamin D supplements show different results, depending on the existing level of the nutrient in the blood and the administered dosage. Supplementation with 20-50 micrograms of vitamin D has shown good effects on muscle strength in older, frail individuals.
In Canada, the officially recommended daily intake of vitamin D is 15 micrograms for people aged one to 70 years and 20 micrograms for those aged 71 and older.
These recommendations are far higher than the Danish recommendations, which are 5 micrograms for adults and 10 micrograms for people aged 70 years and older.
Vitamin D is essential for certain interactions with calcium and magnesium that are important for bones, muscles, and the nervous system.
|The sun during summer is our primary source of vitamin D. However, older people and individuals with dark skin do not synthesize the nutrient as effectively and may therefore become deficient.|
Selenium counteracts loss of muscle strength
Selenium is an essential trace element that is of vital importance to our energy turnover, thyroid function, immune defense, and a host of other functions.
In a study, Italian researchers found that older people with low selenium intake are considerably more likely to lack muscle strength in their hips, knees, and hands, and that increases their risk of fall injuries. According to the scientists, selenium supports certain proteins (selenoproteins) that are involved in muscle cell activity and they also counteract deterioration of muscle tissue caused by free radicals. Their study is published in the American Journal of Clinical Nutrition.
Compensating for the declining selenium intake and saturating selenoprotein P
We get most of our selenium from fish, shellfish, eggs, dairy product, and nuts (Brazil nuts are the best source), but European crops generally contain very little selenium. The average European gets less than half the recommended amount of selenium, and the intake is too low to effectively saturate selenoprotein P, which is used as a marker for the body’s selenium status. It takes around 100 micrograms of selenium daily to saturate this selenoprotein, which is nearly twice the officially recommended amount. When taking selenium as a supplement, it is a good idea to choose a selenium yeast that contains a variety of different organic selenium compounds, as this provides the same variety of selenium types, as you would get from eating a balanced diet with many different selenium sources.
Omega-3 helps you walk faster and counteracts inflammation
The omega-3 fatty acids are important for our nervous system, cardiovascular system, and immune system. Linseed oil and certain other plant oils contain omega-3 in the form of ALA (alpha-linolenic acid) that is converted into the active forms of omega-3 known as EPA and DHA. Many people have difficulty with converting ALA and are therefore better off eating oily fish or taking fish oil supplements that are rich in EPA and DHA.
There are no specific recommendations for omega-3 fatty acids, only that they should be included in the daily diet. Many experts believe that a daily intake of 250-500 mg of EPA and DHA is beneficial for good cardiovascular health. In a study, scientists gave 126 people aged 65 years and older a daily fish oil supplement with 1.2 grams of omega-3 (720 mg EPA and 480 mg DHA) for six months. As a result, the participants were able to walk faster, but the supplements did not increase their muscle strength. Other studies suggest that it requires as much as three grams of fish oil per day. This dosage is even able to counteract inflammation and aching joints, something from which many older people with sarcopenia suffer.
Coenzyme Q10, muscle strength, and ageing processes
It is commonly known that coenzyme Q10 holds a key role in the energy turnover of cells and as a powerful antioxidant that protects against oxidative stress. Two independent cohort studies have shown a link between the body’s Q10 status and muscle strength. A study has demonstrated that Q10 supplements given to older people can “rejuvenate” muscles by shifting the composition of different muscle fibers in a more youthful direction. This is most likely because Q10 counteracts oxidative damage to the mitochondrial DNA of muscle cells. The effect is clearly increased in those who are physically active at the same time and use their muscles.
Compensating for the reduced or inhibited endogenous production of Q10
Our primary source of Q10 is our endogenous production, but this starts to decrease in our early twenties. Many people really notice when they reach their 40s and 50s and they begin to lose vitality. Cholesterol-lowering medicine can also inhibit the body’s own production of Q10.
It is possible to compensate for the decreasing Q10 levels with help from high-quality Q10 supplements. Q10 is a lipid-soluble compound and tends to forms large, insoluble crystals. They are quite difficult for the body to absorb, unless the raw material has been through a special technique with heat and oil that changes the Q10 crystals in such a way that they are able to dissolve entirely at normal body temperature. That way, they can pass through the intestinal wall and into the bloodstream.
Ageing processes and sarcopenia is largely due to a lack of nutrients
Sarcopenia is a part of the normal ageing process. According to the American biochemist, Bruce Ames, ageing is a process that is largely due to lack of nutrients. A very important reason for this is that our uptake and utilization of nutrients decreases with age. This causes many enzyme processes to slow down, and our cells become increasingly fragile and vulnerable.
Anne-Julie Tessier and Stéphanie Chevalier. An Update on Protein, Leucine, Omega-3 Acids and Vitamin D in the Prevention and Treatment of Sarcopenia and Functional Decline. Nutrients august 2018
Van Dronkelaar et al. Minerals and Sarcopenia. The Role of Calcium, Iron, Magnesium, Phosphorus, Potassium, Selenium, Sodium, and Zinc on Muscle Mass Muscle Strength, and Physical Performance in Older adults: A systematic review. J Am Med Dir Assoc Jan 2018
Francesco Landi et al. Protein Intake and Muscle Health in Old Age: From Biological Plausibility to Clinical Evidence. Nutrients 2016
Jens Kondrup. Underernæring. Det skjulte samfundsproblem Kost- og ernæringsforbundet. 2014
Association of low plasma selenium concentrations with poor muscle strength in older community-dwelling adults: the InCHIANTI Study. Am J Clin Nutr 2007
Linnane et al. Cellular redox activity of coenzyme Q10: effect of coQ10 supplementation on human skeletal muscle. Free Rad Res 2002
Pernille Lund. Sund og smuk hele livet. Ny Videnskab 2016
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