Muscle tissue health by Ray Sahelian, M.D. Maintaining muscle mass as we age

Muscle is a contractile tissue of the body whose function is to produce force and cause motion, either locomotion or movement within internal organs. Much of muscle contraction occurs without conscious thought and is necessary for survival, like the contraction of the heart or peristalsis, which pushes food through the digestive system. Voluntary muscle contraction is used to move the body and can be finely controlled, such as movements of the finger or gross movements like the quadriceps muscle of the thigh.

Muscle and Protein Metabolism
Muscle plays a central role in protein metabolism by serving as the principal reservoir for amino acids to maintain protein synthesis in vital tissues and organs in the absence of amino acid absorption from the gut and by providing hepatic gluconeogenic precursors. Furthermore, altered muscle metabolism plays a key role in the genesis, and therefore the prevention, of many common pathologic conditions and chronic diseases. Nonetheless, the maintenance of adequate muscle mass, strength, and metabolic function has rarely, if ever, been targeted as a relevant endpoint of recommendations for dietary intake.

Muscle and Creatine
Creatine is an essential player in the primary energy source used for muscle contraction. It exists in two different forms within the muscle fiber: as free (chemically-unbound) creatine and as creatine phosphate. This later form of creatine makes up two-thirds of the total creatine supply. When your muscles contract, the initial fuel for this movement is a compound called ATP. ATP provides its energy by releasing one of its phosphate molecules. It then becomes a different compound called ADP. Unfortunately, there is only enough ATP to provide energy for about 10 seconds, so for muscle contraction to continue, more ATP must be produced. Creatine phosphate comes to the rescue by giving up its phosphate molecule to ADP, recreating ATP. This ATP can then be burned again as fuel for more muscle contraction.

Skim milk better than soy milk for muscle growth
Weightlifters who drink skim milk after a workout build more muscle than those who drink a soy beverage. Consuming protein after "pumping iron" is known to help build muscle mass, Quickly digested or "fast" proteins, including whey and soy, cause a temporary flood of amino acids into the blood, they explain, making more of these protein "building blocks" available for uptake by muscle. Proteins that take longer to digest, such as casein that is found in milk, produce a more gradual and long-lasting increase in blood levels of amino acids. While these "slow" proteins don't promote muscle formation, they do prevent muscle breakdown. Researchers hypothesized that a combination of "slow" and "fast" proteins like casein and whey, both found in cow's milk, would be most effective for building muscle. Eight men who regularly lifted weights were given a soy beverage or skim milk after performing a series of exercises with one leg. For three hours after the workout muscle uptake of amino acids was significantly greater when the men drank milk than when they consumed soy. The current study was funded by the National Dairy Council, along with the Canadian Institutes for Health Research. American Journal of Clinical Nutrition, April 2007.

Muscles strengthen bones, not fat tissue
Dr. Vicente Gilsanz and colleagues from Children's Hospital Los Angeles and colleagues used a technique called dual X-ray absorptiometry and CT scanning to precisely measure body fat, lean body mass, bone density and mineral content in 300 people between 13 and 21 years of age. Half were female and half were male. The researchers found strong associations between lean body mass and bone size and density. But the amount of fat mass either had no relationship to measures of bone strength or a negative one, meaning the more fat mass, the less dense the bone.
The findings back up the idea that "bone strength is primarily determined by dynamic loads from muscle force, not static loads, such as fat mass," Gilsanz and his colleagues write in the Journal of Clinical Endocrinology & Metabolism. Fat may also secrete substances that affect bone metabolism, they add. The Journal of Clinical Endocrinology & Metabolism, January 2007.
   Comments: Perhaps those who have more muscle mass may be more physically active and thus the physical activity itself may strengthen bones?

Muscle training reverses muscle aging
Strength training may not only make older adults' muscles stronger, but younger as well. It's well known that resistance exercises improve muscle strength and function in young and old alike, but strength training also affects older muscles on the level of gene expression -- essentially turning back the clock on muscle aging.

Muscle recovery after exercise
After a long bout of physical activity, eating a bowl of healthy cereal with skim milk may help muscle tissue recover at least as well as, if not better, than drinking a specialized sports drink. Heavy exercise damages muscle tissue, and milk and a 100-percent whole-wheat cereal, which contain protein and carbohydrate, help rebuild damaged tissue. Twelve athletes (8 men and 4 women) fasted for 12 hours, then cycled for 2 hours at least 5 days apart on a stationary bicycle. The subject did not ride to exhaustion. Immediately after each ride, the athletes ate either a 100-percent whole-wheat flake cereal with nonfat milk or drank a typical carbohydrate-packed sports drink. During recovery, cereal blunted the rise in blood lactate compared with the sports drink. The cereal and milk, and the sports, drink helped the body replenish depleted glycogen -- a fuel the body uses during exercise -- but the cereal and milk displayed greater glycogen storage potential. Tests showed the tired muscles were ready to store additional glycogen after the cereal-and-milk regimen, even after glycogen had already been synthesized.

Flexible muscles lead to stronger muscles
Most physically active people probably do a little stretching or know that they should. There is a correlation between muscle flexibility and muscle performance. Flexible muscles are stronger muscles. Flexibility training may help prevent knee injuries. It's important to regularly stretch not only the hamstrings, but other muscle groups as well. Clinical Journal of Sports Medicine, July 2007.

Muscle tissue and acid base balance, the role of diet
An alkaline diet favors lean tissue mass in older adults. Metabolic acidosis promotes muscle wasting, and the acid load from diets that are rich in net acid–producing protein and cereal grains relative to their content of net alkali–producing fruit and vegetables contribute to a reductions in lean tissue mass in older adults. Higher intake of foods rich in potassium, such as fruit and vegetables, may favor the preservation of muscle mass in older men and women. American Journal of Clinical Nutrition, March 2008.

Whole body vibration training is good for muscle fibers
Standing on a vibrating platform helps muscles and bones, particularly in older or sedentary adults. Whole body vibration training involves standing on a platform that sends mild vibratory impulses through the feet and into the rest of the body. These vibrations activate muscle fibers more efficiently, it is claimed, than conscious contraction of muscles during regular exercise. Whole body vibration training is often promoted as a way to improve muscle power, jump higher or sprint faster.

Women like men with muscles
Muscular young men are likely to have more sex partners than their less-chiseled peers. Muscles in men are akin to elaborate tail feathers in male peacocks: They attract females looking for a virile mate. Prior studies indicated a man's desirability was influenced more by his earning potential and commitment. Women were more physically attracted to brawny men, especially for a fling. But when it comes to finding a long-term partner, they tend to pick a regular man over a mate with huge biceps.

Diseases involving muscles
Duchenne Muscular dystrophy disease

Muscle Questions
Q. In your opinion, what is the best supplement for muscle growth?
   A. Creatine and protein powders are the best supplements to increase muscle growth.

Q. Does tongkat ali lead to muscle tissue increase? What about LJ100?
   A. I doubt it.

Q. I would like to find out about herbs that will help muscle spasms. The Dr. gave me valium and told me to take some muscle relaxing pills with them. When I take the pills I am always feeling sick. Could you recomend some herbs that can muscle spasms in my back.
   A. Kava may occasionally be used for muscle spasms but not more than 3 days a week. Have approval by your doctor.