For obese teens, regularly scheduled exercise -- at least 90 minutes, three times a week -- not only helps shed extra pounds, but also improves the health of their arteries. They need your help to get motivated -- that and low perseverance are two of the biggest obstacles for obese teens in sticking to their routines.

"Atherosclerosis - also referred to as hardening of the arteries -- starts during childhood in the presence of such risk factors as obesity and sedentary lifestyle," said Dr. Andreas Alexander Meyer, a pediatric cardiologist at the University of Rostock Children's Hospital in Germany.

At the beginning of a recent study of the effects of regular exercise on preventing heart disease in obese teens, most already had visible signs of artery hardening and thickening of the arterial lining. After six months of exercising at least one hour or more, three times a week, not only had these teens lost significant weight -- the flexibility of their arteries returned, the excess arterial lining shrunk, and their cholesterol and blood pressure levels reduced. Hooray for exercise!

If you eat well usually -- as in low-fat, low cholesterol, balanced, colorful meal eating -- you may think to yourself every now and then "I'm always so good, I can get away with eating this nice big deep-fried fatty piece of red meat, just this once." A new study reveals that eating just one high saturated fat meal, like one full of animal products, can inhibit your blood vessels from properly reacting to stress as well as prevent good cholesterol from keeping vessel inflammation at bay. Without even realizing it, you may have sabotaged all the good work you've done for your heart -- putting you well on the way to hardened artery-ville.

By comparing the effects of eating one meal high in saturated fat versus a meal high in polyunsaturated fat, the study found that the first impaired the anti-inflammatory capabilities of good cholesterol, and the latter aided anti-inflammation. Polyunsaturated fats are primarily plant-sourced. An excellent example is found in soy protein.

High in polyunsaturated fat, soy protein has been found beneficial to heart health by naturally lowering bad cholesterol levels and preventing the arterial plaque build-up that leads to hardened arteries. Soy protein contains all nine essential amino acids and is rich in calcium, iron, B vitamins and fiber. Research on the benefits of soy consumption recommend replacing animal products with soy protein -- with as little as 4 ounces of tofu or tempeh in each meal a day, or by simply replacing cows milk with soy milk. Soy products may be a little weird or scary for some meat eaters, but I assure you with the proper preparation, tofu and tempeh can be just as tasty. Try a BBQ tempeh sandwich or make some tofu jerky -- and I promise not to call you a hippie when you like it.

Magnesium is an important yet overlooked mineral integral to a healthy heart. The average American diet only provides about half of the recommended daily allowance, which is 400 mg. Magnesium helps keep the heart beating smoothly, aides in maintaining healthy blood pressure, and relaxes arterial muscle tissue.

Deficiency of magnesium in heart and arterial tissues can result in a muscular spasm that causes an oxygen-supplying artery to clamp shut, resulting in sudden death. This incidence is known as ischemic heart disease, or a suffocation of the heart.  Hardened arteries, which lead to heart attacks, can also be caused by a lack of magnesium-- without which the body cannot properly assimilate calcium.

Excellent sources of dietary magnesium include dark chocolate, nuts, avocados, milk, spinach and other leafy green vegetables, lentils, wheat germ, bran, and some meat. Dietary supplements, including combo calcium-magnesium capsules, can be found in most health food stores.

A heavy heart is a hard heart. Chronic depression contributes greatly to the development of heart disease.

Depression produces sustained inflammation of the blood vessels, which can lead to hardening of the arteries, or atherosclerosis. This condition causes the heart to pump harder through narrowed vessels, and hardened pieces of the wall can break off forming a clot. Low-serotonin levels associated with chronic depression also come with elevated heart rate, increasing blood pressure. This phenomena also contributes to hardened arteries. In addition, low-serotonin results in thicker blood-- since the neurotransmitter is responsible for platelet activity that keeps the blood pumping smoothly. Sooner or later you've got a heart attack on your hands.

Other effects of depression on the heart include a constant production of cortisol, a stress induced hormone that serves as a key player in 'flight or fight' reaction. Constant high levels of cortisol contribute to high blood pressure, increased bad cholesterol and insulin levels, as well as an excess of abdominal fat.

A daily dose of vegetables helps keep the arteries clear, a new study shows. Researchers tested a vegetable rich diet on lab mice bred to quickly develop the arterial plaque build-up that leads to heart attacks and strokes. The results were obtained based on a diet composed of 30 percent vegetables-- and French fries don't count. After 16 weeks, the veggie mice had 38 percent less atherosclerosis, or hardening and narrowing of the arteries, compared to the mice on the veggie-free diet.

The veggie mice also had lower levels of inflammatory protein. Chronic blood vessel inflammation contributes greatly to atherosclerosis. The study focused on the most commonly eaten vegetables: broccoli, carrots, green beans, peas and corn. These, and other veggies, contain anti-inflammatory and antioxidant plant compounds called polyphenols. Along with other antioxidant-rich vitamins, the polyphenols neutralize cell-destroying molecules. So eat your vegetables and have happy arteries.

Japanese researchers have found a way to effectively prevent heart attacks-- by detecting hardened arteries before symptoms occur.

The study measured blood flow of 27 hypertensive patients using 4-minute periods of stimulation, placing their feet in cold water. Using this test, doctors are able to determine patients with blood vessel dysfunction and place them on early medical treatment of lifestyle modification program. "By measuring the response of coronary blood flow to stress, these researchers were able to detect atherosclerosis [hardening of the arteries] before it became evident clinically," said Josef Machac, cardiovascular vice chairman of the Society of Nuclear Medicine's Scientific Program Committee.

Recent studies show that drinking a daily dose of pomegranate juice prevents hardening of the arteries and improves blood flow. Pomegranates are full of a potent antioxidant called polyphenol, found in smaller quantities in chocolate and blueberries. Polyphenol has been found to help fight cell damage, a preventative aide against heart disease and cancer.

A pomegranate juice study led by Dr. Dean Ornish of the Preventative Medicine Research Institute, published in the American Cardiology Journal, tracked 45 heart disease patients for three months. For those who drank an eight-ounce glass of the deep scarlet juice everyday, blood flow to the heart improved 17 percent. In the placebo group, blood flow worsened 18 percent.

However, health experts and dietitians refuse to tout the stuff as a magic cure-all. Be warned-- one eight-ounce glass contains 160 calories. Positive effects can be gained from a daily dose of as little as one and a half ounces of pomegranate juice.