Recent evidence suggests that choline is an essential
nutrient in humans. Small quantities are synthesized in the liver with the
help of vitamin B12, folic acid and the amino acid, methionine; but the
amounts made may not be sufficient to meet daily needs.
What it does in the body
Fat metabolism - Choline is involved in
fat metabolism and in the transport of fats from the liver.
Cell membranes - Choline is a component of cell membranes
and plays a role in the transmission of signals inside cells. Myelin, the
insulating sheath around the nerves, and platelet activating factor
Neurotransmitters - Choline accelerates the synthesis and
release of the neurotransmitter acetylcholine, which is involved in many
nerve and brain functions. Dietary intake of choline seems to affect body
levels of acetylcholine.
Absorption - Choline may be absorbed
better in the form of lecithin.
Choline deficiency symptoms in humans include fatty
liver and liver damage. These symptoms have been demonstrated only
recently in humans fed choline- deficient diets.1
This means that choline fulfills one of the criteria for being an
essential nutrient. Patients on long-term parenteral nutrition who are not
given choline develop fatty infiltration of the liver and other signs of
dysfunction. This condition can be improved, and possibly prevented, with
Choline deficiency in animals also leads to nerve
degeneration, senile dementia, high blood cholesterol, and liver cancer -
possibly by affecting cell signaling or by generating free radicals and
Nervous system disorders - Uptake of circulating choline
into the brain decreases with age. Choline is important for nerve
structure and function; and this change may contribute to the type of
dementia in which cholinergic nerves are lost.
Good sources of choline in the form of lecithin include
eggs, organ meats, lean meat, brewer's yeast, legumes such as soybeans,
grains, and nuts. It is found in green leafy vegetables as free choline.
Adequate intake levels for choline have recently been
set in the US. The average daily diet supplies around 1000 mg.
Men 550 mg
Women 425 mg
Pregnancy 450 mg
Lactation 550 mg
The tolerable upper intake limit has been set at 3 g
Research shows that if you don't have enough choline
during pregnancy, the brain doesn't develop normally and babies are born
either with defective memory or lower memory capabilities that lasts
throughout their lives. Giving choline in utero has been shown to lead to
better than average memory for life. Choline is actively transported from
mother to fetus across the placenta and from mother to infant across the
mammary gland. Thus, during pregnancy and lactation, dietary requirements
for choline are increased.
Alcoholics, diabetics and anyone who has deficiency
symptoms may benefit from supplements either of lecithin or of choline.
Supplemental choline is often in the form of lecithin. The choline content
of supplements varies widely.
Toxic effects at high doses may include reduced
appetite, nausea, gastrointestinal problems and a 'fishy' body odor.
Therapeutic uses of supplements
Choline supplements have been used to treat the
symptoms of brain diseases such as Alzheimer's disease and Huntington's
chorea, in which acetylcholine levels are low due to the reduced activity
of the enzyme which synthesizes it. Some studies have detected
improvements in mental performance after choline treatment.2
However, results of studies have been mixed. Choline and lecithin may only
be useful in the initial stages of the disease. In a 1994 study,
lecithin was given to patients with Alzheimer's disease in daily doses of
1000 mg for one month. Results showed slightly improved mental
performance, and enhanced cerebrovascular blood flow.3
Choline helps to lower cholesterol levels, as a
choline-containing enzyme helps to remove cholesterol from tissues. In a
1995 study, researchers gave lecithin supplements to 32 patients with high
cholesterol and triglyceride levels. The dosage used was 3.5 g three times
daily before meals. After 30 days of treatment, total cholesterol and
triglycerides levels decreased significantly, and beneficial HDL
cholesterol levels rose.4 Choline has also been used
to lower homocysteine concentrations, another risk factor for
cardiovascular disease. (See page 560 for more information.)
Choline supplements (in the form of lecithin) have been
shown to bring some benefits in the treatment of bipolar disorder (manic
depression).5 Choline and lecithin are also used to
treat liver damage and hepatitis. Supplements have also been used to treat
Severe folic acid deficiency causes secondary liver choline deficiency,
and vice versa, in rats. Choline supplements reduce urinary excretion of