Thursday, July 29, 2010

Most Heart Attacks are Preventable

It is now established that arteriosclerosis is reversible and that most cases of heart attacks are preventable (Journal of Cardiovascular Drugs and Therapy, published online June 15, 2010). Most heart attacks occur in people with known risk factors:

Plaques caused by cholesterol:
Fatty plaques are covered by a fibrous cap that shields the fat inside from the bloodstream. Rupture of this cap releases fats from plaques into the bloodstream. The released fat causes clots that block the arteries to cause a heart attack. Heart attacks are not caused by plaques causing progressive narrowing of these arteries. Since the bad LDL cholesterol causes plaques to form, and the good HDL cholesterol prevents plaques from forming and rupturing, people with high LDLs or low HDLs are at high risk for heart attacks.

Most people could control cholesterol with diet. If this diet does not lower your LDL cholesterol below 100 or raise your HDL cholesterol above 40, your doctor may prescribe medications.

Inflammation:
Your immunity is supposed to be good for you. When bacteria or viruses enter your body, you make proteins and cells to kill them. As soon as the germ is gone, your immunity is supposed to stop making large amounts of these antibodies and cells. However, if your immunity stays active, these white blood cells continue to produce cytokines that are supposed to dissolve the membranes of bacteria. Instead, they dissolve the caps of plaques to release fat from plaques into your bloodstream to cause clots that block arteries to cause heart attacks. Your doctor can diagnose an overactive immunity with blood tests called CRP (above 1) or Sed Rate (above 15).

Any chronic infection can turn on your immunity to increase risk for a heart attack. Check with your doctor if you have symptoms of any infection, such as bladder problems (burning on urination, frequency, night-time urination, urgency when your bladder is full), stomach problems (belching, burping, burning in your abdomen), a chronic sore throat, chronic cough, or chronic joint or muscle pains.

Metabolic syndrome (pre-diabetes) or diabetes:
People with high rises in blood sugar are at high risk for heart attacks and strokes, even if they are not diagnosed with diabetes. A high rise in blood sugar can cause plaques to rupture. You can tell if you have high rises in blood sugar if you store fat in your belly, have small buttocks, a HDL cholesterol below 40, an LDL cholesterol above 100, or triglycerides above 150. When your blood sugar rises too high, your pancreas releases large amounts of insulin (=high insulin) which causes fat to be deposited in your belly (=large belly). Insulin converts sugar to triglycerides (=high triglycerides). Then you use up your good HDL cholesterol to carry triglycerides from your bloodstream into your liver (=low HDL).

If you have metabolic syndrome or diabetes:
1) Check your vitamin D3 level. If it is below 75 nmol/L, you need more sunlight or vitamin D pills. Lack of vitamin D blocks insulin receptors to raise blood sugar levels.
2) Avoid refined carbohydrates. Altered carbohydrates cause higher rises in blood sugar. The worst offenders are flour and sugared beverages.
3) Restrict meat from mammals. The saturated fats in meat may block insulin receptors.
4) Eat plenty of vegetables and fruits. They do not cause high rises in blood sugar.
5) Lift weights. Larger muscles draw more sugar from the bloodstream.
6) Lose excess fat. Full fat cells produce hormones that prevent your cells from responding to insulin.
7) Exercise. Contracting muscles remove sugar from your bloodstream without needing insulin.

Other risk factors to avoid:
• Do not smoke or live with a smoker.
• Do not take more than two alcoholic drinks a day (a drink is a 5-ounce glass of wine, 12 ounces of beer, or 2/3rds of a shot glass of alcohol).

Sunday, July 25, 2010

Sitting is Hazardous to your Health

Researchers at the University of South Carolina found that men who spent more than 23 hours a week watching TV and sitting in their cars had a 64 percent greater chance of dying from heart attacks than those who sat for fewer than 12 hours a week (Medicine and Science in Sports and Exercise, May 2010).

Many of the men who suffered heart attacks also exercised regularly. Their exercise programs did not protect them from the heart attack-causing effects of sitting in cars or while they watched television. This month, a review of the world's literature shows that exercise may not protect you from the life- shortening effects of prolonged sitting (Exercise and Sports Sciences Reviews, July 2010), and many studies show that animals (rats and mice) that do not have exercise wheels in their cages develop insulin resistance, have higher blood fat levels, are fatter, and die earlier than those who have the exercise wheels.

Now we have to explain:

1) Why sitting causes premature death and heart attacks:
• Resting muscles require insulin and respond poorly to insulin in drawing sugar from the bloodstream.
• North Americans eat a lot of refined carbohydrates that cause a high rise in blood sugar.
• A high rise in blood sugar causes sugar to stick to cell membranes, which kills these cells to cause heart attacks, strokes, premature death and nerve damage.

2) How exercise prevents premature death and heart attacks:
• Contracting muscles prevent a high rise in blood sugar by pulling sugar from the bloodstream without needing insulin.

3) Why exercise does not protect many people who spend a lot of time sitting in one place:
• Contracting muscles draw sugar maximally from the bloodstream during exercise and for up to an hour after you finish and tapers until you lose all of its benefit at about 17 hours (Am J Clin Nutr, 2008 July; 88(1): 51-57; Am J Physiol Regul Integr Comp Physiol 1983;245(5):R684-R688; Journal of Applied Physiology, February 2010).
• While you sit, your resting muscles do not draw sugar effectively from the bloodstream and 17 hours after you finish exercising, you have lost this benefit of exercise.

4) Why intense exercise is more effective than more casual exercise in:
• Preventing and treating diabetes (Circulation, July 2008).
• Preventing heart attacks in obese people without weight loss (MSSE, Oct, 2006).
• Preventing heart attacks than exercising more frequently (MSSE, July, 1997).
• Reducing belly fat (MSSE, November 2008) (storing fat in your belly is a sign of inability to respond to insulin).
• Preventing premature death (Heart, May 2003).
• Preventing metabolic syndrome and heart attacks (Exercise and Sports Sciences Reviews, July 2009).
• Raising HDL (good) cholesterol (Journal of Strength and Conditioning Research, March 2009).

Further data to show that intense exercise is superior to casual exercise:
• The faster aged runners run, the lower their blood pressure, cholesterol, and blood sugar levels (MSSE, October 2008, Arch Int Med, 1999;159(8):882).
• High intensity interval training maximally improves every conceivable measure of heart function and heart strength. (Exercise and Sports Sciences Reviews, July 2009).

Caution: Intense exercise can cause heart attacks in people who already have blocked arteries.

Thursday, July 22, 2010

Why Back Surgery Fails So Often

Researchers from Duke University show that back pain is usually caused by a person's immunity attacking the disc in the same way that it attacks invading germs, not by a broken disc pressing on a nerve (Arthritis & Rheumatism, July 2010). They found that people with back pain associated with damaged discs have high levels of Interleukin-17, produced by your immune lymphocytes and known to cause asthma, rheumatoid arthritis and other autoimmune diseases.

The natural history of back pain from "disc disease" usually starts after you hurt your back. You often appear to recover after several weeks or months of pain. However, the back pain can recur any time later, even many years after your original back problem.

The bones of your spine are separated by pads called discs . When you hurt your back, you can crack the outer layers of a disc, so the softer inner layers protrude through the cracks into the spinal canal. The softer inner layers of a disc normally are not exposed to the immune system. So the human immune system does not recognize it as self and attacks it in the same way that it attacks invading bacteria and viruses. The protruding inner portions of the disc then swell to press against nearby nerves to cause pain. This research implies that the immune reaction that attacks the protruding broken inner portion of the disc causes the disc to swell and press on nerves. The authors feel that the pain is not caused primarily by broken pieces of a disc pressing on nerves so it is incorrect to use the common term "slipped disc".

If this is true, future treatment for disc disease would be to inhibit the lymphocytes that make interleukin-17. This would allow the treatment to reduce pain without blocking the body's ability to prevent infections and tumors. Either way, surgery for "disc disease of the back" has among the highest failure rates of any surgery today.

Tuesday, July 20, 2010

Sodas with HFCS and Caffeine May Be Best Drinks for Endurance

The limiting factor in endurance racing is the time that it takes to get enough oxygen into muscles to burn food for energy. Anything that reduces oxygen requirements allows you to race faster. Sugar stored in muscles, called glycogen, requires less oxygen than fat or protein. Anything that helps you keep sugar in muscles longer gives you greater endurance.

A study from Georgia State University shows that drinks that contain both glucose and fructose burn more carbohydrates than those containing only glucose, and allow cyclists to ride much faster over 60 miles (International Journal of Sport Nutrition and Exercise Metabolism, April 2010).

Most soft drinks are sweetened with high fructose corn syrup (HFCS). Both HFCS and conventional sugar (sucrose) contain a mixture of two sugars, glucose and fructose, in nearly the same concentrations: HFCS has 55 percent fructose/42 percent glucose, while sucrose is a 50/50 mixture. So the relative concentrations of glucose and fructose are not significant. However, the fructose in sucrose from cane or beet sugar is bound to glucose and must first be separated from it, so it is absorbed more slowly into the bloodstream. The manufacturing process for HFCS frees the fructose from glucose to makes it into a free, unbound form that is absorbed more rapidly into the bloodstream. This could cause a higher rise in blood sugar (Pharmacology, Biochemistry and Behavior, March 18, 2010) and provide more sugar for muscles during exercise. We need to wait for more research to know if HFCS drinks improve endurance more those made with cane or beet sugar.

Caffeine increases endurance (Medicine & Science in Sports & Exercise, July 2010) by increasing absorption of sugar by muscles (Journal of Applied Physiology, June 2006). Those who took sugared drinks with caffeine were able to absorb and use 26 percent more of the ingested sugar than those who took the same drinks without caffeine.

On long rides, we drink colas for their sugar and caffeine. However, you should take sugared drinks only when you exercise and for up to an hour after you finish. Contracting muscles remove sugar from the bloodstream rapidly without needing much insulin. Taking sugared drinks when you are not exercising causes higher rises in blood sugar that increase risk for diabetes and cell damage.
More on High Fructose Corn Syrup

Monday, July 12, 2010

18,000 Calories per Day in Race Across America

You need to take in large amounts of food when you exercise for more than a few hours, otherwise you will slow down and eventually have to stop. In the Race Across America, four cyclists alternated shifts as a relay team and completed the race distance of 2800 miles in 6 days, 10 hours and 51 minutes. Each rode up to 10 hours per day in approximately one hour shifts. Even though they cycled only a quarter of the time and distance, they each burned an average 6,420 calories per day, compared to the average for North American men of a little over 2000 calories per day. They ate and drank as much as they could but were able to take in only 4918 calories/day, for a deficit of 1503 calories per day (International Journal of Sports Medicine, July 2010).

Six years ago, a 33 year old bicycle racer used a continuous heart rate monitor to show that he used up more than 18,000 calories per day in the same race. He rode for 20 to 24 hours/day, sleeping no more than 4 hours/day. Yet he could eat only about half that much (9000 calories per day), and he lost 11 pounds of body fat in the nine days of competition (International Journal of Sports Medicine, July-August 2005).

More than 75 percent of North American adults weigh more than they should because they exercise too little and eat too much. These studies show that during long-term continuous intense exercise it is impossible to meet your needs for food, no matter how much you try to eat.