Broken Knee Cartilage is Forever

A team of researchers at the University of Western Ontario in London, Ontario have shown that arthroscopic removal of loose cartilage and trimming of knee cartilage is no better than doing no surgery at all (NEJM, September 11, 2008). The only other study that also used sham surgery was done at Baylor Medical School and showed the same results (New England Journal of Medicine 2002;347:81-8). The procedure is done when a surgeon inserts small tubes through the skin into the knee joint and trims the edges of cartilage and removes loose pieces of cartilage from the joint.

You hear about many athletes returning to the athletic field after breaking cartilage in their knees and having surgery. However, almost all will have pain in their knees for the rest of their lives and most will eventually have their knees replaced. When you break cartilage in your knee, it will never heal.

If you hurt your knee and the pain persists, your doctor will probably order an MRI. If it shows that you have a crack in your cartilage, you should never run or jump again. When you run, the force of your foot striking the ground is transmitted up to your knee and can extend the existing cracks. Running 6-minute miles exerts a force exceeding three times body weight. Landing from a jump exerts even greater force on your knee joint. You can usually ride a bike safely because you pedal in a smooth rotary motion that exerts little force on your knee joint. Swimming is also usually safe for your knees.

If you extend the cracks in your knee cartilage, you can have pain all the time. Then it is probably time for you to have knee replacement surgery. Surgery is also indicated for a torn anterior cruciate ligament. Your knee is really two sticks held together by four bands called ligaments. You can tear any one of three of these bands and usually do quite well. However if you tear the anterior cruciate ligament, the cartilage of your lower leg is allowed to slip backwards against that of your upper leg and shear off additional cartilage, eventually necessitating a knee replacement. So almost always doctors recommend replacing a torn anterior cruciate ligament.

Contact sports that require running and jumping, such as football and soccer, are the ones that put you at increased risk for knee damage. Once you crack cartilage in your knees, you probably should avoid all sports that require running and jumping. Most people can ride or even race on bicycles and not extend their knee damage.
More on arthroscopic knee surgery

Read more »

Don't Regain Lost Weight

A new study shows that older people who diet without exercising lose huge amounts of muscle. When weight loss was combined with exercise, they did not lose muscle (Journal of Applied Physiology, October, 2008). Loss of muscle slows metabolism even further because larger muscles burn more calories at rest.

In this study, elderly sedentary people were placed in three groups: 1) Diet only, 2) exercise only, 3) diet and exercise. Those who dieted and exercised for four months lost more fat and less muscle than those who only dieted. Most of the exercisers chose to walk on a treadmill, which is not a very vigorous endeavor.

This also explains why losing weight repeatedly through dieting shortens a person's life span. Many people go on diets and lose weight, quickly regain their lost weight and then go on a diet again. These people then become fatter at the same weight because they have lost so much muscle. Therefore at the same weight, they have fuller fat cells. Full fat cells produce immune stimulant called cytokines that turn on a person's immunity continuously to cause inflammation, which increases risk for cancers, heart attacks, strokes, diabetes and other harmful diseases. More

Read more »

Plastic Bottles and Containers: New Concerns

A study from Peninsula Medical School in Exeter, U.K. shows that high levels of urinary Bisphenol-A (BPA), a chemical compound commonly used in plastic packaging for food and beverages, is associated with heart attacks, strokes, diabetes and abnormal liver tests (JAMA, Sept 17, 2008). BPA can break down to form female hormones called estrogens that are linked to breast and uterine cancer in women, decreased testosterone levels in men, and may also cause birth defects.

You are exposed to BPA, primarily through food, drinking water, tooth sealants that you may receive in a dentist's office, and exposure through your skin and lungs from household dusts. Ninety percent of Americans have detectable levels of BPA in their urines.

Although the safety of BPA is still uncertain, you would be prudent to limit your exposure. The primary concerns are plastic water bottles and baby bottles. Each bottle is supposed to have a number in a circle stamped on the bottom. Try to avoid the following numbers:
#1 Most single-use water bottles are made from polyethylene terephthalate (PET or PETE).
#7 This is used for many colorful hard plastic lexan bottles made with polycarbonate plastics.
At a minimum, do not re-use bottles or containers with these numbers. Do not freeze or reheat foods or beverages in them.

Plastic products that bear the following numbers appear to be safe:
#2 HDPE, high-density polyethylene, the most widely recyced plastic,
#4 LDPE, low-density polyethylene) and
#5 PP, polypropylene.

Read more »

Cancer: More Environmental than Genetic

More than 85 percent of the known causes of cancers are environmental, not genetic. Normal cells undergo apoptosis, a process in which each cell lives only so long and then dies. Cancer means that the DNA in cells cannot do its usual job of telling a cell when to die, so the cells grow forever and can spread to other parts of the body to kill you. Scientists have developed drugs and other treatments to destroy the process that makes cancer cells immortal. However, each cancer cell has hundreds, and even thousands, of different pathways that they can use to make them live forever. Pancreatic cancer cells have an average of 63 mutations (Science, September 4, 2008), and a brain tumor called glioblastoma has at least 47.

So when scientists develop a drug to kill a cancer, the drug acts on one or more pathways and may temporarily inhibit the cancer, but drugs never block all the pathways that can go wrong. Therefore cancer can always come back. That is why doctors often use as many as five different drugs to treat some cancers because they want to block as many of the different pathways as possible.

At this time, I believe that the best approach is to avoid or limit your exposure to known or suspected environmental triggers for cancers, which include:

- meat, particularly beef (eating red meat is associated with increased risk for 17 different cancers)
- barbecued, grilled or deep-fried foods (browning or burning foods, particularly fats or starches, forms carcinogens)
- BPA (Bisphenol A) in some plastics
- PCB's
- lead in any form
- molds such as aflatoxin from rotten peanuts or grains
- arsenic in well water
- asbestos in old buildings
- sexually transmitted diseases such as hepatis C that causes liver cancer or HPV, the human wart virus that causes cervical cancer
- formaldehyde or carbon tetrachloride
- Helicobacter pylori (bacteria that cause stomach burning and ulcers) which can cause stomach cancer
- unnecessary X rays, particularly CAT scans
- heavy exposure to pesticides
- radon from the ground leaking into your house
- tobacco in any form
- second-hand smoke
- alcohol (more than three drinks a day increases cancer risk)
- exposure to uranium
- excessive UV radiation (too much sunlight)
- not enough sunlight (lack of vitamin D)
- night shift work (depresses melatonin, a cancer-preventing hormone)

Other cancer risk factors include lack of exercise, excess weight, lack of fiber in the diet, a diet that is low in vegetables, early puberty in women (before age 12), late menopause (after age 55) or taking estrogen after menopause. In 2008, cancer will take the lives of about 230,000 more Americans than it did in 1971. Try not to be one of them.

Read more »

Limit All Sugared Drinks, Not Just HCFS

High-fructose corn syrup (HFCS) contains approximately 59 percent fructose and 41 percent glucose, while fruits juices contain a ratio of 50 percent glucose to 50 percent fructose. There really is no difference. HFCS is no better and no worse than any sugared beverage or fruit juice, it is just cheaper. When manufacturers process corn for oil, the residue is a sugary liquid that used to be thrown away. In the 1950s, soft drink makers discovered that HFCS could be added to sweet drinks at a fraction of the cost of cane sugar. Then scientists noticed that Americans have gotten progressively fatter from the 1950s to the present. This is the same period that HFCS was added to the American diet.

In the following years, many respected scientists tried to link HFCS to the obesity epidemic. However, we now have multiple studies showing that any kind of sugar in liquid form can make you fat (American Journal of Clinical Nutrition, May 2008). When you eat sugar in solid form, such as in a cookie, you eat less of other foods because the solid food fills you up. However, in liquid form, sugar supplies calories without making you feel full. When you drink any liquid containing sugar, you do not reduce your intake of food to compensate. Sugar in liquid form is not recognized by your brain as extra calories and therefore does not suppress appetite.

Today almost all researchers agree that HFCS is no worse than any other liquid sugar. All forms of sugar-water can make you fat. That includes fruit juices, sugar added to your coffee or tea, and any other sugared drinks.
Newsletter

Read more »

Burning Feet while Cycling

Many cyclists suffer from "burning foot syndrome", pain on the bottom of the feet, particularly during a long ride. After years of this problem, I tried a simple tip from RoadBikeRider, a free weekly newsletter from some of America's best long distance bicycle riders: Ed Pavelka, Fred Matheny, and Lon Halderman. They suggest moving the cleats back as far as possible toward the arch of the foot. All of the other articles I have read and all of the experts I have consulted recommend that you set your cleats on your shoes so that the ball of your big toe is exactly aligned with the axle of the pedal. Following Lon Haldeman's advice, I moved my cleats back last week and my feet have stopped burning. I also think I am riding faster.

This flies in the face of what other experts claim: the further back your cleat, the less power you get from your calf muscle. That's just not true. More than 90 percent of the pressure on your pedals comes from your thighs, not your lower leg (calf) muscles. The pain is caused by the front part of the foot pressing on the pedals. Moving the cleat backward takes the pressure of the forefoot and relieves the pain. As Haldeman states, you actually can be in better shape when you don't have burning feet, and you can train further and ride faster. (To subscribe to their free newsletter go to http://www.roadbikerider.com)

Read more »

Cracked skin on your heels

If you have painful cracks in the skin on your heels, try applying tape across the split skin to limit movement of the cracked edges. Let the tape fall off, as pulling it off may tear the skin even more. Friction irritates the cracks, causing more pain, so avoid loose slip-on shoes, sandals or any other footwear that causes friction. Do not file the skin as this can cause even greater thickening (called the Koebner phenomenon) that leads to cracking.

Your podiatrist can prescribe topical medications, such as urea-based creams or cortisone creams, to help heal the cracks. Cortisone creams should be used with caution since they can cause permanent thinning of the skin. If your symptoms are severe, your doctor may recommend cortisone injections, but again be aware of the side effects of too much cortisone. More

Read more »