Heart Disease Risk Factor #1: Nitric Oxide

The role of nitric oxide in cardiovascular health.

The same chemical responsible for men's erections (and, indirectly, for the success of Viagra) also plays a vital role in the health of your arteries, and thus your heart.

The chemical is nitric oxide (NO), which is primarily produced in the blood vessels' endothelium, or lining. There it increases blood flow, prevents fatty deposits from sticking to blood vessel walls, keeps walls from getting too thick and stiff, and prevents the arteries from narrowing.

"The lining of the vessel is very important for cardiac health," says John P. Cooke, M.D., Ph.D., head of Stanford University's vascular unit and one of the first researchers to pinpoint the role of NO in cardiovascular health. "When the endothelium is healthy it's like Teflon, and things don't stick." When it's unhealthy, it becomes more like Velcro, attracting blood-borne gunk like flies to flypaper.

All of the major culprits in heart disease -- overweight, lack of exercise, smoking, high cholesterol, high blood pressure, high levels of homocysteine and lipoprotein (a) -- damage the endothelium. And a damaged endothelium doesn't make enough NO, which results in more damage in an increasingly dangerous spiral. "But we can restore endothelial health and the lining of the vessel through exercise and nutrition," Dr. Cooke says. Certain nutritional supplements (like arginine) and drugs used to treat heart disease (like aspirin and statins) can also help.

By the Numbers

If doctors could measure endothelial function -- how blood vessels behave -- they would have a good indication of your nitric oxide production, and in fact, your overall risk for coronary heart disease (CHD). Measuring endothelial function is like asking your arteries, "How's it going?" If the answer is "well," your arteries are happy with the composition of the blood and are probably relatively free of plaque.

Doctors can measure endothelial function in various ways, most of which involve using ultrasound to measure changes in the diameter of certain arteries. This testing is usually used for research purposes only. But soon there may be a way to test endothelial function right in the doctor's office. In late 2000 the FDA approved a new, noninvasive instrument called CVProfilor DO-2020 that can measure the elasticity of your arteries, an indication of NO production. Normal ranges vary depending on your age and sex. The test isn't in routine use yet, but that day may be coming.

Quick Tips

• Eat more foods that contain the amino acid arginine, from which NO is produced. This includes beans, soy, almonds, walnuts, oats, and such cold-water fish as salmon, tuna, and mackerel.


• Cut your intake of saturated fat. Just one meal high in saturated fat can temporarily cut endothelial function almost in half.


• Exercise. The increased blood flow that occurs during exercise encourages the endothelium to make more NO. Over the long term, if you exercise every day, your endothelial cells not only release more NO but also make more of the enzyme that converts arginine into NO.

From Cut Your Cholesterol

 

• Healthy Heart
• Cholesterol
• • Heart Disease

• Heart Disease Risk Factor #2: Inflammation
• When your white blood cells work against you.
• 
• Heart Disease Risk Factor #3: Germs
• The consequences of bacteria and viruses can last well past the immediate symptoms.
• 
• Heart Disease Risk Factor #4: Homocysteine
• A potentially deadly amino acid.
• 
• Heart Disease Risk Factor #5: Metabolic Syndrome and Diabetes
• The possible cause for at least half of all heart attacks.
• 
• Heart Disease Risk Factor #6: High Blood Pressure
• The symptom-less cause of damaged arteries.
• 
• Heart Disease Risk Factors You're Stuck With
• Know your inborn risks to better manage cholesterol.
• 

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In good weather, my friend Mark always let his yellow-naped Amazon parrot, Nicky, sit on the balcony of his tenth-floor apartment. One morning, Nicky flew away, much to Mark’s dismay. He searched and called for the bird, with no luck. The next day when Mark returned from work, the phone rang. “Is this Mark?” The caller asked. “You’re going to think this is crazy, but there’s a bird outside on my balcony saying, ‘Hello, this is Mark.’ Then it recites this phone number and says, ‘I can’t come to the phone right now, but if you will leave a message Read More

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