Atherosclerosis is a gradual narrowing and hardening of the arteries that occurs when cholesterol and other substances build up on the inner wall of blood vessels, forming a hard substance that is called plaque.

Preventing atherosclerosis means preventing strokes, heart attacks, and peripheral vascular diseases (such as poor circulation in the legs).

Diet and exercise are your two best protections against this dangerous condition. However, there are special cases in which diet and exercise may not be enough to help.

For instance, people with high exposure to toxic metals such as aluminum, lead, mercury, copper, iron, and cadmium are at a very high risk for developing atherosclerosis.

But for the majority of people, the most important thing is to avoid oxidized oils. The most common oxidized oils people in the West are exposed to are polyunsaturated vegetable oils, including:

• Corn oil

• Safflower oil

• Sunflower oil

• Soybean oil

• Peanut oil

• Canola oil

Americans consume about 50 times the amounts of these oils that they need for good health.

Another type of fat, called trans fats, should be avoided at all cost. If you see the words partially hydrogenated oil on a food label, that means it contains trans fats — even if it doesn’t say so on the label.

On the other hand, saturated fats rarely oxidize. The major danger involved with animal fats (saturated fats) is that they commonly contain traces of pesticides, herbicides, and fungicides, which can lead to inflammation — the main cause of atherosclerosis. Conventionally raised cattle eat grasses and grains that are saturated with these chemicals.

Organic farm-raised animals consume far less of these dangerous chemicals, and therefore are healthier food sources.

In addition, animals allowed to graze on wild grasses have higher levels of omega-3 oils in their tissues (meat). A diet high in omega-3 oils reduces atherosclerosis.

However, you should never cook with an omega-3 oil. When heated, such oils rapidly oxidize.

They also oxidize when used as a salad dressing. For this reason, you should always check the label of your salad dressing very carefully — even the ones advertised as containing olive oil.

Another thing to beware of is clear bottles of olive oil in restaurants. You should avoid these, as sunlight oxidizes the oil and ruins it beneficial effects.

You should also limit your intake of red meats to no more than once a week. Red meats have at least two things that can cause atherosclerosis — high levels of absorbable iron and high levels of glutamate.

In combination, they powerfully stimulate atherosclerosis.