Many people can tolerate small amounts of
substances that contain the sugars for which they
are lacking enzymes. Avoiding larger amounts
keeps symptoms in check. It is important for peo-
ple who have carbohydrate intolerance to make
sure they receive adequate intake of other NUTRI-
ENTSin foods for which they have intolerance or to
take supplements that supply them.
See also AGING, NUTRITION AND DIETARY CHANGES
THAT OCCUR WITH.
cholesterol, dietary A sterol substance found in
animal-based foods such as meats and dairy prod-
ucts. Dietary cholesterol under scrutiny in the
1970s when research connected high BLOODcho-
lesterol levels with increased risk for CARDIOVASCU-
LAR DISEASE (CVD), notably ATHEROSCLEROSIS and
CORONARY ARTERY DISEASE(CAD). However, subse-
quent research has determined the true culprit is
endogenous cholesterol—the cholesterol the LIVER
synthesizes from the components of dietary satu-
rated fats and trans fats. The liver makes about 80
percent of the cholesterol in the blood circulation,
and it continues to make cholesterol as long as it
receives the source materials (dietary fats) to do
so. Dietary cholesterol has almost no role in this
process.
Furthermore, researchers recognized it is not
the cholesterol itself that is the problem. Choles-
terol, which is important to health because it is
essential for cell membrane repair and HORMONE
production, has the consistency of a waxy liquid
and does not dissolve in water or blood. Carrier
proteins called lipoproteins, which the liver also
produces, bind with cholesterol molecules so they
can travel through the bloodstream. The more
cholesterol molecules in the blood circulation, the
more lipoproteins required to transport them
through the blood. When there are high levels of
lipoproteins in the blood some tend to “fall out”
against the sides of the arteries, eventually form-
ing plaques (hardened patches) that narrow and
stiffen the arteries. These plaques are the early
stages of ATHEROSCLEROSIS, the foundation of CAD.
There is very little correlation between the cho-
lesterol in foods and the cholesterol in the blood
circulation. Rather, the amounts of saturated fats
and trans fats in the diet determine blood levels of
cholesterol in most people. Cholesterol and satu-
rated fats co-exist in many animal-based foods,
however, so a diet heavy in these foods con-
tributes to higher-than-healthy cholesterol and
lipoprotein levels in the blood. Health experts rec-
ommend limiting dietary cholesterol to 200 mil-
ligrams a day for people who have no increased
risk for CVD. Doctors may recommend a lower
limit for people who have, or have increased risk
for, CVD.
See also CARDIOVASCULAR DISEASE PREVENTION;
CHOLESTEROL BLOOD LEVELS; DIET AND HEALTH; HYPER-
LIPIDEMIA; LIFESTYLE AND HEALTH; NUTRIENTS; TRIGLYC-
ERIDE BLOOD LEVEL; TRIGLYCERIDES, DIETARY.cholesterol, dietary 181