Most people think of fatty foods, overweight people and heart attacks when they hear the word "cholesterol." But some bad things might be good after all.
High cholesterol levels are not necessarily a cause to panic. "You only have to worry when other risk factors are present," says Susanne Bilz, a nutritionist at the Centre for Clinical Studies in Dresden, eastern Germany.
Cholesterol is vital to the production of human cell wall structures, says Achim Weizel of the German Society for Combating Lipid System Disturbances and Related Illnesses in Munich. Gall bile for fat digestion also comes from cholesterol and is an important building block for hormones and vitamins.
The human body creates two thirds of the cholesterol it needs and the remainder comes from diet. Cholesterol is similar to fat. Fat does not dissolve in water, so it has to rely on the blood stream to spread it throughout the body.
"That's why the body adds protein and creates a lipoprotein," says Bilz.
The most important lipoproteins created by the body are the low density lipoproteins (LDL) and the high density proteins (HDL). LDL is usually referred to as bad cholesterol. It's distributed to all body cells by the liver.
"Extra LDL not required in the cell is deposited in the blood vessels," explains Bilz.
That's when HDL starts to play a role. It pulls excess LDL back to the liver, says Elisabeth Steinhagen-Thiessen of the Metabolism Centre of the Charite Hospital in Berlin. For this reason, HDL is known as good cholesterol. Under ideal circumstances, this HDL/LDL cycle functions seamlessly.
If LDL concentrations are too high, it is stored in the blood vessels around the heart, which narrow. Plaque builds up in the vessels. "The vessel surface can rupture or tear, which can lead to blood clots, which can shut down the vessel," explains Weizel. That can lead to a heart attack or a stroke.
Too much LDL means high cholesterol levels. But even if confirmed by a doctor, therapy may not be necessary. "Ultimate risk is decided by looking at all factors, which include smoking, diabetes, high blood pressure, genetic tendencies or being overweight," says Weizel. Only when those factors are present do patients need to worry about their levels.
A "Mediterranean diet" with a lot of fish, fruit and vegetables is often advised. "Fatty ocean fish like mackerel, salmon or herring have a lot of healthy omega-3 fats," says Weizel. On the opposite end of the spectrum, the animal fat in meat can raise cholesterol levels.
Udo Pollmer of the European Institute for Food and Nutrition Science in Gemmingen near Heilbronn has a different opinion. "If cholesterol consumption is decreased with diet, the body just produces more." That means long term cholesterol level changes cannot be controlled with diet.
"Vegetable oils are usually unsaturated. The best are rapeseed and olive oil," says Bilz. "Eat meat twice a week and fish with lots of fruit and vegetables three times a week," says Steinhagen-Thiessen.
Weizel says HDL levels can only be increased with exercise. "Anyone who does endurance training three to four times a week can expect a boost in HDL levels."
Last Mod: 06 Ağustos 2007, 19:05