Authors: Jörg Blech
NEW ARTERIES FROM STEM CELLS
One of the most dramatic effects of exercise on the body is to promote the growth of new cells and blood vessels. That was shown in a human trial that involved exercising for eight weeks. New vessels, so-called collateral vessels, established new paths of circulation. This could mean that by getting moderate exercise, you are able to grow natural bypasses in your heart.
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In the past, most researchers thought the growth of collateral circulation was initiated by branches of the vessels that had been dormant or by vessels growing from neighboring areas into the area with the damage. But now they think an even more exciting mechanism is at work: Stem cells from the bone marrow are apparently capable of traveling specifically to blocked areas, where they morph into endothelial cells and start building new vessels.
Two studies performed at the University Hospital in Leipzig, Germany, have shown for the first time that these beneficial stem cells are multiplied by physical training. The hospital combines sports medicine with cardiology and employs not only doctors but also molecular biologists and one researcher with a degree in physical education. Their patients get exercise treadmills and stationary bikes, and their hearts are examined with ultrasound machines.
In one trial, researchers wanted to find out how the sick human heart is affected when patients train on stationary bikes.
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The patients were asked to exercise until their chests started to ache; the pain signaled that the atherosclerotic heart muscle did not get enough oxygen. Two days after this test, the doctors took six blood samples and analyzed them in the laboratory. The results were startling: this
one
dose of exercise had caused a considerable release of stem cells from the bone marrow.
In another study, the physicians prescribed exercise for 18 men who had gotten themselves into lamentable physical shape.
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They were sedentary and chain-smoking to the point of developing peripheral vascular disease, a lack of circulation, in their legs. On the treadmill, these men could not go faster than 2.2 miles per hour. Many of the patients stopped after walking only 50 to 200 meters because they experienced terrible leg aches.
This beneficial—if torturous—program lasted one month. Five days per week, the patients had to walk six times until they felt pain. In the course of their workouts, astonishing things happened inside their bodies. The number of stem cells in the blood tripled, and these cells apparently initiated the renewal of the malfunctioning vessel system for those with peripheral vascular disease in the legs. The investigating cardiologist, Rainer Hambrecht, believes his research tapped into a natural repair mechanism: “The body helps itself and tries, by releasing stem cells from the bone marrow, to promote the growth of new collateral circulation.”
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According to these studies, heart patients do not have to train through the pain threshold to reap these beneficial effects. Whereas moderate training did not immediately cause the release of stem cells, more of them appeared in the blood after three months. Moreover, preexisting stem cells became activated, which “may in fact decelerate disease progression,” as the researchers conclude in the journal
Circulation
.
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How do these effects compare to those achieved by fiddling with the symptoms of arteriosclerosis by using high-tech medicine? This was the subject of yet another landmark study from the center in Leipzig, of 100 men whose coronary arteries had already narrowed.
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Half the patients were treated with angioplasty, the mechanical widening of narrowed or obstructed blood vessels, followed by the insertion of a mesh tube (or stent) to prop open an artery. The other half received a prescription called exercise: every day, these patients trained for 20 minutes on a stationary bike at 70 percent of their maximum capacity.
As with heart failure, physical activity can help to overcome the problems caused by such illnesses as asthma and chronic bronchitis. Asthma is a chronic inflammatory irritation of the air passages that hampers the lungs through recurring attacks. Triggered by allergies as well as physical strain in cold weather, the bronchial tubes can suddenly narrow and start secreting mucus that blocks them. When this happens, a person can still breathe in, but can hardly breathe out, which leads to the frightening symptoms, like fierce coughing and shortness of breath.
Children with asthma are often excluded from physical education and sports and are encouraged to take it easy, which actually makes their troubles worse: Muscles waste away, which makes the children even less able to breathe properly, starting a vicious cycle.
Regular modest exercise would instead improve their bodies’ resilience. Although the illness is not cured, people with asthma can become better at increasing the threshold for attacks, thereby avoiding them. Before starting, people with asthma should consult a specialist to work out an individual training plan.
After one year, the researchers compared the respective outcomes. Eighty-eight percent of the exercising patients avoided clinical events like additional angioplasty or even heart attacks. This was true for only 70 percent of the other patients. Many members of the stent group also needed the insertion of additional stents and on average had to be readmitted more often to the hospital because of recurring chest pain. The gentle exercise regimen, by comparison, was not only more effective but cheaper. On average, the treatment of one active patient necessitated medical costs of $3,429, whereas the average sedentary patient created $6,956 in costs.
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FRESH POWER FOR EXHAUSTED HEARTS
Those who spend time with patients suffering from heart failure might well feel that these patients should have their peace. After tiny bits of exercise, they gasp for breath, they get tired, and their legs become swollen. The underlying condition, cardiac insufficiency, can be caused by infections of the heart muscle, valve defects, and coronary arteriosclerosis. Until the 1970s, the standard treatment was strict bed rest. Too much strain, doctors believed, would further impair the heart, resulting in shortness of breath and swollen legs even at rest.
Today, doctors say the opposite is true. The paradigm began to shift when physicians realized that there is no direct causal connection between heart failure and general physical resilience. Instead, the problem lies with the skeletal muscles; those affected have atrophied muscles and are extremely feeble. Rather than letting their muscles waste away further, they should retrain their bodies.
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This new understanding of the disease led to studies showing that physical activity turns out to be an excellent remedy against heart failure. More than 25 trials have demonstrated that regular exercise improves the pulse rate, increases the maximum oxygen uptake, and decreases blood pressure. Most participants of these studies also took drugs to prevent heart failure, but the training brought additional benefits, namely an increase of 15 to 20 percent in the amount of exercise they could endure. Often this was critical in making the life of a sick person worth living again.
Heart patients who are not too excited about jogging might consider dancing. Italian researchers invited patients with heart failure to a dancing course that lasted eight weeks. These ladies and gentlemen gathered three days per week in the gym of the local hospital and danced for about 20 minutes. The dancers improved their physical condition to the same extent as volunteer patients in a control group who had trained on stationary bikes and treadmills. Not surprisingly, the dancers were much more motivated than the control-group patients, with more chances to laugh and maybe even flirt a little bit than those stuck on bikes or treadmills.
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Moderate exercise can also bring about changes at the molecular level. Doctors at the heart center of the University Hospital in Leipzig encouraged 12 patients with heart disease to exercise for six months: 20 minutes on the stationary bike every day, plus an hour walking or playing ball games every week. Subsequently, the researchers took samples from the flexor muscles of the patients’ thighs.
The remarkable result, published in the journal
Circulation
, showed that the activity of so-called scavenger enzymes significantly increased in the muscles of the active patients, compared to 11 sedentary individuals with heart disease. These enzymes are beneficial because they remove aggressive substances known as free radicals, which can harm the heart muscle.
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Unfortunately, these discoveries have not yet reached all patients and physicians. Even half a century after the miraculous recovery of President Eisenhower, the healing power of exercise is withheld from many individuals with heart disease. Despite all the clear-cut advantages and benefits, states the cardiologist Paul D. Thompson of Hartford Hospital, “exercise training is rarely prescribed for cardiac patients, as evidenced by the fact that only about 20 percent of qualified patients are referred to formal cardiac rehabilitation programs. Among women and older patients referral rates are even lower.”
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Growing Bones
W
HEN THE JOINTS HURT AND THE BONES ACHE, MOST PEOPLE would rather stay in bed. But as with other problems we’ve discussed, this will only lead to more trouble. Perhaps lying down might spare the cartilage, that smooth and elastic lining of the joints that makes sure bones do not grind painfully on each other when used. Yet it is not only the cartilage that helps your joints. The surrounding muscles also guard and protect joints because they cushion the jolts that damage a moving body. Thanks to muscles, cartilage absorbs fewer shocks.
For that reason, physical inactivity is like poison for the joints. The more muscles waste away, the more bumps and jolts directly affect the cartilage, gradually wearing it down. This way, bones start to ache, people become less active, muscles shrink more, and cartilage gets battered even harder—not a happy trend. A joint may end up being completely destroyed so that it must be replaced with an artificial one. Or the threat looms of being moved to a retirement home. Neither dementia nor problems caused by arteriosclerosis are the most frequent reason for being institutionalized; most people are admitted because they suffer from an ailing musculoskeletal system.
But there’s hope. People can’t reclaim lost cartilage, but they can definitely increase muscle mass. In this way, you can renew the guardians of your joints, preventing future disease, and cure existing ailments.
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STRENGTHENING RATHER THAN REPLACING JOINTS
At about 120 different spots in the body, two bones are connected with joints. Unfortunately, not all of them are perfect links. The term
arthritis
covers more than 100 distinct conditions relating to joint problems, and each one can make life miserable. There are two types of arthritis: inflammatory and degenerative. Common osteoarthritis belongs to the latter one; mechanical forces drive the destruction of cartilage, mainly of the knee and the hip. Among 34-year-old people, about 17 percent suffer from osteoarthritis; among people of age 65 or older, the figure is more than 90 percent. Once the cartilage is gone, the disease can progress rapidly, resulting in bulky joints, thickened bones, muscular atrophy, and inflammations that ravage the capsules that cushion the joints.
People notice this degeneration because of the pain developing over time. Initially, the pain occurs only when the affected joints are moved or touched. After a while, the aches become chronic, and the joints swell. At this point, many patients unconsciously cut down on physical activity—and unwittingly worsen their ailments.
Severely arthritic knees have become a huge and lucrative field within the medical industry: Patients are either instructed to take expensive drugs or to get artificial joints implanted. Yet the researcher Miriam Nelson, at Tufts University in Boston, seems to be convinced there is another way: The best remedy may be for stricken patients to help themselves by strengthening the affected leg muscles.
Nelson and her colleagues have developed a 16-week training program that can be done at home with a stool and light ankle weights.
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The researchers tested their program with 46 volunteers who were in virtually constant pain and were hardly able to walk or climb stairs. The researcher Kristin Baker, part of the Tufts team, visited the patients at home and told half of them how to do the exercises. The other patients also received house calls, but during these visits, Baker just talked in broad terms about the disease and tried to lift the patients’ spirits a little.
Subsequently, the researchers compared the outcomes of the two groups. The patients of the training group reported they had significantly less pain and could perform 17 different physical tasks much better than the inactive patients. The average pain level of the exercising group had plummeted by 43 percent, compared to 12 percent for the inactive patients. The physical performance of the first group improved by 44 percent, nearly twice as much as in the placebo group, which the researchers attribute to muscular resilience; the strength of the thigh muscles increased by 71 percent.