MAF FITNESS NEWSLETTER

Vol. IV, Issue 8, August 1997



In This Issue
Postmenopausal Health
Osteoporosis, A Look
Skeletal-Muscle Structure
Seafood
Chondroitin and Glucosamine
Allergies
T he number of women entering their postmenopausal years is growing by leaps and bounds, and that fact has prompted significant amounts of research on what health habits women should adopt for maximum health benefits during this increasingly long period of their lives. According to the June 1997 issue of the Tufts University Health and Nutrition Letter there are at least seven important issues for late forty-something-and-beyond women to be aware of:

1- Aggressively reduce blood cholesterol. Of particular interest is LDL-cholesterol. Only nine percent of postmenopausal women (That's redundant isn't it, or are there postmenopausal men?) are appropriately under control. A woman with heart disease should have an LDL level below 100. Those without heart disease should be under 130. Many women aren't con cerned about cholesterol levels because they seem to think that heart disease is mostly a men's problem. IT ISN'T.

In fact, coronary heart disease is the number one killer of both men and women (especially those beyond menopause). [Please note that many physicians tend to use drugs for lowering cholesterol, but don't (you) overlook dietary modifications and exercise.]

2- Keep active to increase longevity. A separate study of 40,000 postmenopausal women found that those who exercise live longer than those who don't. Even very modest exercise makes a difference. It is suggested that just one long walk per week could make a difference.

3- Fight the fat. It is often thought by women that menopause, itself, causes weight gain (increased fat), but it seems to be more a function of the aging process. Our metabolic rates tend to slow down roughly two percent each decade after the age of 20, but we don't have to take it lying down. We can cut calories since we don't need as many, or we can get active - it can be especially good to add some weight training (YES, WEIGHTS; those things that most women used to avoid at all costs!) or other weight-bearing strength training activities. The rationale for that suggestion is tied to the observation that aging results in the loss of lean body mass-primarily muscle, which is metabolically active (it burns calories), while fat that often replaces it is metabolically inactive. Strength training is a way to maintain/build muscle tissue, as well as bone mass. In the end, you can profit from eating nutrient-dense foods - especially fruits and vegetables, and small portions of lean meats - doing some regular strength training, and including some aerobic exercise for cardiopulmonary fitness.

4- Get enough calcium. One out of three women in the fifty-something and over category are likely to have a vertebral fracture resulting in stooped posture, back pain, and breathing problems associated with the postural "scrunching" of the chest. Also, thinning bones cause 30,000-plus hip fractures each year. To avoid bone fractures the National Institutes of Health recommends:

Women who don't drink milk may have some trouble getting enough calcium, since milk is a major source; but it can be gotten from calcium-fortified orange juice, hard cheese, green leafy vegetables, and a calcium supplement if needed. And don't forget that vitamin D is needed in order to properly absorb calcium. Postmenopausal women need from 400 to 800 IUs a day - that's two to four times the RDA. Women who live where they are exposed to significant amounts of sun probably have no worry (the body manufactures vitamin D from sunlight), but those in more northern areas might benefit from a multi-vitamin/mineral pill containing 400 IUs. Natural sources include egg yolks, fatty fish, organ meats, milk, and some cereals - the fortified variety. But be aware that over 1,000 units of vit. D per day can be toxic.

5- Soy products might help. You may have heard that there are plant estrogens in soy protein that might help with night sweats, mood swings, keeping down blood cholesterol levels, and maybe affect other symptoms of menopause; and there is some research that now suggests that estrogens in soy may help to maintain bone density (e.g., offset osteoporosis).

A study at the University of Illinois seemed to show that postmenopausal women who ate a diet rich in soy estrogens called isoflavones, had an increase in spinal bone density compared to those who ate a diet deficient in isoflavones. Other studies have shown the same bone-saving characteristic of soy products.

6- Get enough folate. In a recent issue of the MAF Fitness Newsletter, the subject of folate (a B vitamin also called folic acid) was broached, and is reinforced in this article inspired by the Tufts University Health & Nutrition Letter article on postmenopausal health strategies. Folate may help protect against heart disease. It is currently believed that 400 micrograms per day are required. Good sources are chick peas, lentils, and other legumes; orange juice; green vegetables; and the government now requires fortified cereals to contain folate.

7- Battle Depression. Many of our older citizens suffer from depression, which often results in eating problems - loss of appetite, or loss of interest in a healthy diet. Kind of a nutritional malaise. It is interesting that Tufts researchers discovered that strength training often had a significant positive affect on attitude after only a couple of months.

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The subject of bones was discussed in the February 1997 issue of the MAF FITNESS NEWSLETTER. Following is a minor adjunct. We talked about how bones are not solid, as they look, but are constructed to provide strength without too much weight. A solid outer layer covers the inner "spongy" bone that is constructed of a network of needle-like pieces of bone called trabeculae. Look at Figure 8-1a, a normal bone (highly magnified); and compare it to Figure 8-1b, which shows what the ravages of osteoporosis can do. From these two pictures (sorry about the poor quality), you can easily see (I hope) how someone's hip bone, for instance, can break and result in a fall. That's right, a bone often breaks and causes a fall, rather than a fall causing a broken bone.

    [IMAGE]         [IMAGE]    
Figure 8-1a Figure 8-1b

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Now let's take a look at the structure of a muscle (striated skeletal muscle - see Figure 8-2).


Figure 8-2

At the top of the figure is a cross-section of a skeletal muscle. (One of the three muscle cell types in the human body: 1) skeletal (striated), 2) cardiac (heart muscle, also striated, and very similar to skeletal muscle), and 3) smooth - makes up walls of organs with cavities (like arteries and intestines); and functions to move the contents along to their final destinations.

For our purposes, only skeletal muscles are addressed.

It should be clear that muscles are bundles of bundles. The largest bundles are fascicles, which contain bundles of muscle fibers (also known as muscle cells), that consist of myofibrils which are, in turn, made up of protein structures - primarily actin and myosin - that are ultimately the contractile components of muscles.

Now let's look at Figure 8-3 and decipher what all that mess is.


Figure 8-3

We are looking at myofibrils, specifically sarcomeres, which are the con tractile units in a muscle. There are many sarcomeres (arranged end-to-end) in each myofibril. They are bounded on each end by T-tubules, whose function is to receive nerve impulses that trigger muscle contractions. You will note that next to each T-tubule (on each side) is what is called a terminal cisternae, and is part of the sarcoplasmic reticulum (which looks a little like an asymmetrical tennis or volley ball net. The nerve impulse sent through the T-tubule results in the release of calcium, which is stored in the terminal cisternae, into the reticulum and down into the muscle being activated. There are more gory details involved in the act of muscle contraction, but I don't want to put anyone to sleep, so I'll try to keep it simple without too much distortion. The calcium released into the muscle ultimately results in its contraction.

The intensity of a muscle contraction varies, of course, according to the task at hand. Fibers are combined into "motor units" - a nerve connected to one or more muscle fibers (see Figure 8-4).


Figure 8-4

This arrangement allows us to tailor muscle strength to specific tasks; like picking up a piece of paper as opposed to an iron frying pan, or walking as opposed to running. Speaking of muscle fibers, there are two fundamentally different types: 1) slow twitch, (ST, type I), and 2) fast twitch (FT, type II). Motor Units do not mix fiber types. ST fibers work aerobically - not so powerful, but with endurance; while FT fibers are basically anaerobic - for heavy lifting, jumping, sprinting - more intense activities for shorter durations. ST fibers are always recruited first, with FT fiber recruitment added as needed.

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Following is a bit of information from the June 1997, Harvard Health Letter about nutrition - specifically, seafood.

About seafood. You have probably heard about cold-water fish and omega-3 fatty acids. There is some evidence that omega-3 (polyunsaturated) fat reduces heart attacks, but not by diminishing atherosclerosis. It seems that fish oils may reduce the development of blood clots that can reduce the occurrence of both heart attacks and strokes; and reduce high blood triglyceride levels, which can lead to coronary disease. And maybe help prevent heart rhythm deviations. So far, numerous studies have been done, but with inconsistent results; so fish may not help avoid heart disease, but it is still recommended that we have at least two fish meals per week. It at least avoids the high saturated fat and cholesterol of other meats.

Seafood in general; however, isn't always healthy, but many of the problems are from eating raw or improperly cooked seafood - especially shellfish. Also, contaminated water may result in viral or bacterial infections; not to mention naturally occurring toxins and bacteria found in water off our coasts. Mollusks, like clams or oysters, feed by filtering water through their systems to get their food; but they can also pick up contaminants that can make us sick, especially if we eat them raw or undercooked. Also, some contaminants can build up in some species of seafood. [Thus the common suggestion to eat a wide variety. By eating the same fish, supplements or mollusk, or whatever; you may, over time, end up poisoning yourself.]

People who already have some kind of ill-health; like, liver disease, diabetes, AIDS, or alcoholism; are more susceptible to problems from eating seafood. There are also some other factors that can increase your risk of getting sick from seafood consumption; like taking either prescription antacids or other drugs that block gastric acid production.

On the positive side, heat kills most viruses and bacteria, so eating only completely cooked seafood is pretty safe.

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In the July/August 1997, issue of HEALTH magazine, is another article about the book: The Arthritis Cure. Well, not about the book so much as the two supplements recommended in the book - chondroitin and glucosamine.

A relatively short story goes like this: A woman having debilitatingly painful arthritis, and without substantial help from her doctor; turned to a remedy that her veterinarian husband used with some success on dogs, and found some relief for herself. The claim (as does the book The Arthritis Cure) is that these supplements stimulate growth of cartilage, thereby preventing it from wearing down - ARTHRITIS. Chondroitin sulfate and glucosamine are produced in the body (and some comes from our diet) to build cartilage. It is thought that some bodies either don't produce it, or at least not in sufficient quantities.

Studies on glucosamine dating from the 1980s, seemed to show positive results, and without side effects worse than nausea and heartburn; although it took about a month to show results.

Condroitin, in a study of its own, and using material extracted from cows, interfered with enzymes which function to break down cartilage. This was a test tube experiment, that suggests similar results in humans; thus suggesting that it improves movement.

In an interview with the author of The Arthritis Cure, he admitted that he used the word "Cure" very loosely. [Maybe it could more accurately be described as "pain relief therapy," rather than an actual cure.]

Rheumatologist Roland Moskowitz at Case Western Reserve University says the supplements seem safe, although a bit costly at about $1.75 per day.

There are enough sales of these supplements at healthfood stores, including repeat customers, to suggest that they work - there are at least some veterinarians who think they are a real cure.

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Following is a brief response to a question that I was asked about allergies and allergy shots. I will use nasal allergies ("hay fever") as an example. There are four basic causes (called allergens): 1) pollen; 2) house dust, including dust mites; 3) mold - likes dark, damp areas like bathrooms, basements, refrigerators, and even house plant soil; and 4) animals (e.g., house cats). Also, there are a number of irritants that don't cause allergies, but aggravate them - like cigarette smoke, perfume, smoke from fires, car exhaust, etc.

All of us are exposed to allergens, most of us with no significant reaction; but those with allergies perceive allergens as an enemy that has to be destroyed (via the immune system). Antibodies (immune cells) are deployed to eradicate antigens (allergens). During this process, a chemical (histamine) is released that causes swollen sinus tissues and extra mucous that plugs air passages, resulting in a "runny nose."

In addition to nasal allergies, there are a number of allergic reactions - eye inflammation, nasal polyps (basically a sac that can block passages), ear problems, asthma, rashes, sneezing and more, including anaphalactic shock and death.

There are a number of antiallergy weapons, but because I was specifically asked about "shots," I'll stick to that topic. The shots that you take are a small dose of whatever you are allergic to - pollen, or whatever. Shots are typically given in a series, potentially over a number of years. Each shot contains slightly more of your specific allergen, and is intended to decrease or eliminate your sensitivity to it. The shot therapy has to be regular, or it won't work.

There are a number of allergens in addition to those already mentioned: food additives, insect stings, food - like cow's milk, eggs, some peas and beans, peanuts, and shrimp. You can be allergic to almost anything that you can eat, smell, or touch.

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_____________________________________
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