Chapter List

• Introduction
• Achilles Tendon
• Adrenal Glands
• Ankles
• Appendix
• Arteries
• Back
• Belly Button
• Birth Control
• Birthmarks
• Bladder
• Blood
• Body Hair
• Body Type
• Brain
• Breasts
• Cervix
• Childbirth
• Chin
• Circulatory System
• Clitoris
• Collarbone
• Digestive System
• Ears
• Elbows
• Emotions
• Endocrine System
• Energy
• Esophagus
• Eyes
• Fallopian Tubes
• Fat
• Feet
• Fertility
• Fingernails
• Gallbladder
• Gums
• Gynecological Exam
• Hair
• Hands
• Heart
• Hips
• Hormones
• Intestines
• Jaw
• Joints
• Kidneys
• Knees
• Larynx and Vocal Cords
• Lips
• Liver
• Lungs
• Lymphatic System
• Medical Tests
• Menopause
• Menstrual Cycle
• Moles
• Mouth
• Muscular System
• Neck
• Nervous System
• Nose
• Nutrition
• Ovaries
• Pain Relief
• Pancreas
• Pelvis
• Pregnancy
• Rectum
• Reproductive System
• Respiratory System
• Ribs
• Salivary Glands
• Scalp
• Sex
• Sexually Transmitted Diseases
• Shins
• Shoulders
• Sinuses
• Skeletal System
• Skin
• Skull
• Spine
• Spleen
• Stomach
• Stress
• Sweat Glands
• Tailbone
• Tear Ducts
• Teeth
• Throat
• Thyroid
• Toenails
• Tongue
• Tonsils
• Underarms
• Urinary System
• Urine
• Uterus
• Vagina
• Veins
• Vulva
• Wrists
• Shaping Up
• The Total Body Shaping Workoout
• Abdominals
• Biceps
• Buttocks
• Calves
• Chest
• Forearms
• Neck3
• Shoulders3
• Thighs
• Triceps
• Aerobic Conditioning

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Arteries

Arteries

A mighty red river flows from your heart to all your limbs, branching into creeks, rivulets and estuaries that carry fresh blood to every part of your body.

Each of the arteries that snakes through your system is sheathed and swathed like a muscle-bound snake. From the hefty aorta that leaves your heart to the tiny vessels called arterioles that thread the tips of your hands and toes, the entire network of blood-carrying vessels is well-protected. Two outer layers shield the exterior of each artery and arteriole. Inside those layers is a jacket of muscle and a leotard of elastic tissue. As the vessel surges and subsides with blood, each pulse is regulated by the smooth muscles that help do the grunt work of pushing blood on its way. Speeding its course through the body is the silky-smooth lining of the artery called the endothelium.

It's a great system. But like every mighty river, from the Mississippi to the Monongahela, there's just one problem--silt. In arteries, that silt is composed of free-floating globules of fat (or lipids) and the potential saboteur of the whole system, nasty cholesterol.

Tunnel Damage

No matter how well we treat our arteries--eating low-fat food, getting plenty of exercise, watching blood pressure--nearly all of us eventually get some blemishes on the inner lining of our arteries. These minor aberrations are hardly enough to interfere with the blood flow. But even the smallest of blemishes may eventually throw your blood off course.

What causes these blemishes? "We just don't know precisely what it is," says Malcolm Perry, M.D., professor and chief of vascular surgery at Texas Tech University in Lubbock. "But something happens to the artery lining that results in the conversion of smooth muscle cells to fatty lipid-bearing cells."

There are a number of likely suspects, notes Dr. Perry. Cell-damaging agents in cigarette smoke--called mutagens--may inflict the first damage. Or the cholesterol molecules in high-fat diets could launch a secret assault. High blood pressure could be partially to blame--or the family genes might make it easier for some people to have damaged vessels than others.

"Once that break in the lining happens, whatever the cause, a whole cascade of events occurs," says Edward S. Cooper, M.D., professor of medicine at the University of Pennsylvania School of Medicine in Philadelphia and past president of the American Heart Association. Disklike blood components called platelets rush in to seal the lining shut. As they're repairing the artery, the platelets further roughen the inner surface, causing turbulent blood flow.

Meanwhile, the surface turns knobby, easily snagging fat molecules that hang on and stay within the roughed-up sides like rust in a pipe. That congregation of fat--collectively called an atheroma--eventually makes up a dense, artery-clogging substance called plaque. As plaque narrows the arteries at these points, the result is a condition called atherosclerosis.

The Clot Thickens

In the narrowed artery it doesn't take much of an obstruction to jam up the tunnel and stop the flow. A small blood clot can dam up the works. Though the clot can occur in any part of the body--because arteries are everywhere--certain sites are more vulnerable than others.

"They most commonly involve the coronary arteries that serve the heart, the carotid artery to the brain and the femoral artery to the lower legs," says Dr. Perry. If the clot occurs in one of the arteries that feeds the heart muscle, you're at risk for coronary artery disease.

"It's critical when a clot suddenly closes one of those narrowed arteries to the heart or brain," says Dr. Perry. "Heart attack and stroke are the most common causes of sudden death, next to trauma." Because it sets the stage for these life-threatening occurrences, arterial disease indirectly claims half of all the citizens of the Western world.

Going with the Flow

For many people, risks rise with age because the arteries begin to get stiff and less flexible. The result is the condition called arteriosclerosis, better known as hardening of the arteries. When atherosclerosis teams up with arteriosclerosis, you have a life-threatening conspiracy--because the clogged up artery doesn't have the flexibility to expand when it needs to.

Often arterial disease pads stealthily into place before you have an inkling of trouble. "It begins in childhood--even adolescents have fatty streaks forming on their arteries," says JoAnn E. Manson, M.D., associate professor of medicine at Harvard Medical School and co-director of women's health at Brigham and Women's Hospital in Boston.

With a few precautions arterial disease doesn't have to catch you by surprise. Here are some things you can do to prevent it.

Favor fresh veggies. "There have been decades of studies that showed without fail the protective effects eating vegetables has on the arteries," says Dr. Perry.

Among the substances that seem to lend protective power are vegetables that contain the so-called antioxidants--most prominently, vitamin C, vitamin E and beta-carotene. The antioxidants have a protective effect on cells, helping capture "free radicals," chemically unstable oxygen molecules that can do a lot of cell damage. It has been shown that the antioxidant vitamins also help prevent arterial damage.

Many fresh fruits and vegetables are good sources of one key antioxidant, vitamin C. If you choose fruits and vegetables that are orange, yellow or dark green, you're also getting the benefit of beta-carotene, which turns to vitamin A in your body. True, you could take supplements, but researchers have found that you don't get the same beneficial effects. Fruits and vegetables contain other micronutrients that are healthful.

"It doesn't seem to be as simple as taking one beta-carotene capsule or a vitamin C tablet," says Dexter L. Morris, M.D., Ph.D., vice chairman and assistant professor of emergency medicine at the University of North Carolina at Chapel Hill School of Medicine. "It's more complicated than that."

"Nothing's really proven for sure, but the message is to eat five to nine servings of fruits and vegetables every day," says Dr. Manson.

Leaf through your menu. You'll get another benefit beyond vitamin C and beta-carotene from dark green, leafy vegetables, researchers say. These valuable leafy greens also give you a B vitamin called folate. (The supplement form is called folic acid.)

folate isn't an antioxidant, but it lowers levels of an amino acid called homocysteine that has shown up in the blood of people with arterial disease. When the Centers for Disease Control and Prevention in Atlanta sponsored a review of 38 studies on the subject, researchers found that people who had arterial health problems often had high homocysteine levels and low folate levels. They also discovered--in 11 of the studies--that folic acid lowered homocysteine levels.

Some of the investigators who did the study found it so convincing that they now take the recommended 400 micrograms of folate in supplement form, says investigator Carol J. Boushey, R.D., Ph.D., assistant professor of food and nutrition at Southern Illinois University at Carbondale. "I drink orange juice and fix legumes for dinner to get mine." Just a cup of orange juice and a cup of raw spinach will get you halfway to your folate goal. Add a bean-and-broccoli salad, and you've met your daily requirement for folate.

Stub out cigs. "Smoking is turning out to be even more important than we thought 20 or 30 years ago," says Dr. Cooper. "It's very likely that even passive smoke might be harmful."

It's never too late to stop, however, according to Dr. Manson. When you do, your blood pressure and carbon monoxide levels immediately drop. After three to five years you reduce your risk of coronary heart disease to the level of a person who never smoked.

Tone up for your arteries. You firm up your arms and tighten your abs when you weight train, and you help your body burn fat when you do aerobics. For your arteries, either kind of exercise can help keep the red pipelines toned, flexible and fat-free.

Exercise is famous for elevating HDLs, or high-density lipoproteins, the "good" cholesterol that protects against artery-clogging plaques. Exercise also helps lower blood pressure. "But the good effects of exercise go even beyond what we can measure--like blood pressure and HDLs," says Dr. Cooper. "It can probably unclog at least some of the fat from our arteries."

Counter claudication. Exercise is also turning out to be better therapy than surgery for the arterial bad news known as claudication. The word comes from the Greek word for limp. People who have claudication must often stop to rest their aching calves. The pain comes from narrowed, clogged-up arteries in the legs, and surgery is sometimes needed to clear up the condition.

But exercise may be a good alternative. "There have been several good studies showing that people with this condition get better on exercise therapy than they do with surgery to clean out the artery," says Dr. Perry.

 

See also Circulatory System