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Nutritional Factors Critical to Preserve Muscle
 In
physically inactive people there is a loss of about [-0.5%] of lean
muscle mass every
year between age 25 and 60, and a corresponding decline in muscle
strength.
From age 60 on, the rate of loss doubles, to about 1%. It doubles again at
age 70; again at age 80, and then again at age 90.
With age we are losing muscle mass, and that muscle mass is being replaced
by fat cells.
Typically an individual wonders why they develop a "pouch" gut, or why their thighs or buttocks are
becoming larger. We realize we are not gaining muscle mass in these areas,
but losing muscle mass and fat cells are gaining in size. Most people can
envision this process occurring in their body from the age of 30 on. As
strength goes, so does physical functioning---the ability to do chores, take
walks, climb stairs, or the accomplishment of other activities. This loss of strength can
create a vicious cycle. Since it takes a great deal of physical effort and
discomfort to perform daily tasks, one naturally avoids it, which creates
even more weakness.
The most obvious intervention against sarcopenia is exercise in the form of
resistance training. A recent review by
the International Osteoporosis Foundation (IOF) Nutrition Working Group has
identified nutritional factors that contribute to loss of muscle mass, or
conversely, can prove beneficial in the maintenance of muscle mass.
The IOF Group reviewed evidence from worldwide studies on the role of nutrition in sarcopenia (gradual
loss of muscle mass), and identified the following important nutritional
factors that have been shown to be beneficial to the maintenance of muscle mass
and the treatment and prevention of sarcopenia:
-
 Protein:
Protein intake plays an integral part in muscle health. The authors propose
an intake of 1.0–1.2 g/kg of body weight per day as optimal for skeletal
muscle and bone health
in elderly people without severely impaired renal function. Vary your protein sources
so you get the full range of amino acids. Good sources include fish,
chicken, lean red meat, turkey, skim milk, low-fat cottage cheese, Greek
yogurt, eggs and whey protein.
-
Vitamin D:
Role of vitamin D is critical in the develop-
ment and preservation of muscle
mass and function. Older people are prone to develop vitamin D deficiency
because of various risk factors: decreased dietary intake, diminished
sunlight exposure, reduced skin thickness, impaired intestinal absorption,
and impaired hydroxylation in the liver and kidneys. Muscle weakness due to vitamin
D deficiency is
predominantly of the proximal muscle groups and is manifested by a feeling
of heaviness in the legs, tiring easily, and difficulty in mounting stairs
and rising from a chair; the deficiency is reversible with supplementation.
Adequate vitamin
D should
be ensured through exposure to sunlight and/or supplementation if required.
Vitamin D supplementation in seniors, and especially in institutionalized
elderly, is recommended for optimal musculoskeletal health. Getting adequate
amounts can depend on regular exposure to the sun’s UVB rays. In addition to
being photoconverted in the skin,
vitamin D can be obtained from the diet through ingestion of vitamin
D–containing products (eg, fatty fish), from vitamin D–fortified milk or
margarine, and from the use of multivitamins. The vitamin D ingested via
this route is metabolized in the same manner as is endogenously produced
vitamin D.
-
Avoid dietary acid loads: Modify
your diet to include more fruits
and vegetables in
order to benefit both bones and muscles. Excess intake of acid-producing
nutrients (meat and cereal grains) in combination with low intake of
alkalizing fruits and vegetables may have negative effects on
musculoskeletal health. Acid - base homeostasis is critical to health and
it is well documented that extracellular fluid pH remains between 7.35 and
7.45. A major requirements therefore of our metabolic system is to ensure
that hydrogen ion concentrations are maintained between 0.035 and 0.045 m Eq/L.
Acid-forming foods (protein and carbohydrates) drain calcium from the bones;
alkalizing foods (fruits, vegetables, seaweeds) neutralize the acids and
prevent calcium drain.
-
 Vitamin
B12:
plays a role in improving muscle function and strength. Vitamin B12 is only
found in animal products, such as meat, dairy, eggs, and seafood. Studies
have shown that people in their older years (50 an older) lose the ability
to absorb adequate amounts of vitamin B12 from meat or dairy products. This
is where vitamin B supplements can be required. Clams are an excellent
source of vitamin B12 and copper. These nutrients may help maintain good
blood status for delivering oxygen to working muscles.
-
Folic acid: Necessary
for DNA & RNA synthesis, which is essential for the growth and reproduction
of all body cells. It is essential to the formation of red blood cells by
its action on the bone marrow. It also aids in amino acid metabolism. An
excellent source of folic acid are cereals that have been fortified with
100%DV (400 mcg) of folic
acid.
Along with proper nutrition, a powerful intervention in the prevention and
treatment of sarcopenia is resistance
training (weight-lifting
or strength training). Resistance training works to build muscle by forcing the
body to heal the damage to muscle cells that occur with use. When the intensity
is high enough, microscopic tears occur in the muscle, which then rebuild
protein and make the muscle stronger.
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