The Myth of Cholesterol - Seafood?
Written by Gloria Tsang, RD
Published in November 2004
Myth 1: I have high blood cholesterol. I should avoid seafood because it's high in cholesterol.
Many think that cholesterol in seafood will increase the cholesterol in blood. Indeed, cholesterol found in seafood or other meats has little effect on blood cholesterol in MOST people. Saturated fats and trans fattty acids are the most
important factors that raise blood cholesterol, not dietary cholesterol!
Saturated fats are found in some pre-packaged food or other processed
foods containing shortening or partially hydrogenated vegetable
oil. Trans fatty acids, on the other hand, are also found in packaged snack foods, deep-fried foods or firm margarine containing hydrogenated oil.
Myth 2: All cholesterol in my body is bad!
Our body does need cholesterol to make
bile salts, hormones and vitamin D. It is mainly produced by
our liver. Cholesterol will build up on the artery walls when
the level of cholesterol in the blood is too high. There are
2 main types of blood cholesterol: LDL (the "Bad" cholesterol)
and HDL (the "Good" cholesterol).
High amounts of the bad LDL will deposit cholesterol on the artery walls forming plaques. More and more plaques will narrow the arteries lumen and may eventually block blood flow. Therefore LDL is considered the "Bad" cholesterol. Monounsaturated fats and polyunsaturated fats found in nuts and fish for instance, can lower the LDL level. In addition, soluble fiber found in fruits, oats, barley, and legumes can also lower LDL.
The good HDL, on the other hand, takes
excess cholesterol away and carries it back to the liver to be
excreted. It can also remove some of the cholesterol already
attached to the artery walls. Therefore HDL is considered the
"Good" cholesterol as high levels of HDL in the blood
can decrease the risk of heart disease. Physical activity can
also raise HDL level.
There are many factors affecting your blood cholesterol level,
including your family history, age, gender, eating habits, body
weight and shape, level of physical activity as well as concurrent
diabetes conditions. Consult with your Registered Dietitian for
a more detailed eating plan.