How Beta Carotene - Vitamin A Can Help You Develop Healthy Eyes And Skin
Vitamins are compounds that you must have for growth and
health. They are needed in small amounts only and are usually available
in the foods that you eat. Beta-carotene is converted in the body to
vitamin A, which is necessary for healthy eyes and skin.
Beta carotene, which is found in plants, is a precursor of vitamin
A. The body converts beta carotene to vitamin A. It occurs mainly in
fruits and vegetables that are deep yellow, orange, or dark green in
color, such as carrots, squash, yams, peaches, apricots, spinach,
collard or mustard greens, and broccoli. It is an antioxidant, a
compound that may prevent cancer-causing substances from damaging DNA.
Epidemiologic studies have linked high intake of foods rich in beta
carotene and high serum levels of the micronutrient to a reduced risk
of cancer, particularly lung cancer. Ordinary cooking does not destroy
beta-carotene.
A lack of vitamin A may cause a rare condition called night
blindness (problems seeing in the dark). It may also cause dry eyes,
eye infections, skin problems, and slowed growth. Your health care
professional may treat these problems by prescribing either
beta-carotene, which your body can change into vitamin A, or vitamin A
for you.
Some conditions may increase your need for vitamin A. These include:
Claims that beta-carotene is effective as a sunscreen have not been
proven. Although beta-carotene supplements are being studied for their
ability to reduce the risk of certain types of cancer and possibly
heart disease, there is not enough information to show that this is
effective.
Beta-carotene may be used to treat other conditions as determined by your doctor.
It is well documented that people who consume diets high in fruits
and vegetables have a reduced risk of heart disease and certain
cancers. Fruits and vegetables are rich in beta-carotene and other
nutrients that may be beneficial.
Vitamins alone will not take the place of a good diet and will not
provide energy. Your body needs other substances found in food, such as
protein, minerals, carbohydrates, and fat. Vitamins themselves often
cannot work without the presence of other foods. For example, some fat
is needed so that beta-carotene can be absorbed into the body.
Daily servings of dark green and deep yellow vegetables and tomatoes
boost immune response, a preliminary study suggests. If the findings
hold up in further research, eating more vegetables rich in beta
carotene and related carotenoids--lutein and lycopene--may help people
ward off a cold or flu as well as protect against cancer.
After three weeks, the volunteers had a 33 percent increase in
immune response as measured by the ability of their T cells to
multiply. This is a good measure of immune system function because T
cells play a vital role in the immune response to foreign organisms and
cancer cells.
As potent antioxidants, these carotenoids are thought to contribute
to the lower rates of heart disease, cancer and other diseases of aging
among populations that eat a lot of fruits and vegetables.
Reported in the Proceedings of the UJNR Protein Resources Panel,
25th Annual Meeting, 1996, the findings suggest that carotenoid-rich
vegetables also stimulate the immune system.
Researchers also found more evidence suggesting carotenes act as
antioxidants to protect the body from harmful oxidation that could
contribute to heart attack, stroke and cancer. During the low-carotene
stints, researchers recorded several biochemical signs of oxidative
damage. For example, they found more carbonyl compounds--breakdown
products of oxidation--in the volunteers' blood and breath.
Older people who get plenty of beta carotene may have a better
chance of preventing virus infections or a cancerous growth. A wealth
of epidemiological evidence has linked a high intake of green leafy and
deep yellow vegetables--both rich in beta carotene--with lower rates of
many types of cancer.
Men over age 65 who took a 50-milligram beta carotene supplement
every other day during the 12-year-long study had natural killer cells
that were more active than those in their counterparts who got a
placebo. Natural killer cells--or NK cells--are the immune system's
sentinels, ever on watch for viruses and cancer cells. They recognize
an enemy immediately and destroy it, using proteins to punch holes in
its outer membrane. This activity is
thought to be an important component of cancer prevention. So ARS
researchers tested NK cell activity in 59 men in the physicians study.
The beta carotene dosage used in the physicians study is equivalent
to eating two regular-size carrots or one and one-half sweet potatoes
daily.
Beta-Carotene has been reported to produce regressions in patients
with oral leukoplakia, a premalignant lesion. In this multicenter,
double-blind, placebo-controlled trial, subjects were given
beta-carotene, 60 mg/d, for 6 months. At 6 months, responders were
randomized to continue beta-carotene or placebo therapy for 12
additional months. Nutritional intake was assessed using food frequency
questionnaires. There was no change in carotenoid intake during the
trial. Responders had a lower intake of dietary fiber, fruits, folate,
and vitamin E supplements than did nonresponders. In conclusion, the
activity of beta-carotene in patients with oral leukoplakia was
confirmed. The responses produced were durable for 1 year.
Known Hazards: Use of beta-carotene has been associated with
an increased risk of lung cancer in people who smoke or who have been
exposed to asbestos. One study of 29,000 male smokers found an 18%
increase in lung cancer in the group receiving 20 mg of beta-carotene a
day for 5 to 8 years. Another study of 18,000 people found 28% more
lung cancers in people with a history of smoking and/or asbestos
exposure. These people took 30 mg of beta-carotene in addition to
25,000 Units of retinol (a form of vitamin A) a day for 4 years.
However, one study of 22,000 male physicians, some of them smokers or
former smokers, found no increase in lung cancer. These people took 50
mg of beta-carotene every other day for 12 years. If you smoke or have
a history of smoking or asbestos exposure, you should not take large
amounts of beta-carotene supplements for long periods of time. However,
foods that are rich in beta-carotene are considered safe and appear to
lower the risk of some types of cancer and possibly heart disease.
The results from the ATBC Study and the Beta-Carotene and Retinol
Efficacy Trial (CARET) suggest that smokers should avoid taking
beta-carotene supplements. The best advice for smokers who want to
reduce their risk of lung cancer and many other cancers is still the
most direct: Stop smoking.
Yellowing of palms, hands, or soles of feet, and to a lesser extent
the face (this may be a sign that your dose of beta-carotene as a
nutritional supplement is too high).
Vitamins are compounds that you must have for growth and
health. They are needed in small amounts only and are usually available
in the foods that you eat. Beta-carotene is converted in the body to
vitamin A, which is necessary for healthy eyes and skin.
Beta carotene, which is found in plants, is a precursor of vitamin
A. The body converts beta carotene to vitamin A. It occurs mainly in
fruits and vegetables that are deep yellow, orange, or dark green in
color, such as carrots, squash, yams, peaches, apricots, spinach,
collard or mustard greens, and broccoli. It is an antioxidant, a
compound that may prevent cancer-causing substances from damaging DNA.
Epidemiologic studies have linked high intake of foods rich in beta
carotene and high serum levels of the micronutrient to a reduced risk
of cancer, particularly lung cancer. Ordinary cooking does not destroy
beta-carotene.
A lack of vitamin A may cause a rare condition called night
blindness (problems seeing in the dark). It may also cause dry eyes,
eye infections, skin problems, and slowed growth. Your health care
professional may treat these problems by prescribing either
beta-carotene, which your body can change into vitamin A, or vitamin A
for you.
Some conditions may increase your need for vitamin A. These include:
- Cystic fibrosis
- Diarrhea, continuing
- Illness, long-term
- Injury, serious
- Liver disease
- Malabsorption problems
- Pancreas disease
Claims that beta-carotene is effective as a sunscreen have not been
proven. Although beta-carotene supplements are being studied for their
ability to reduce the risk of certain types of cancer and possibly
heart disease, there is not enough information to show that this is
effective.
Beta-carotene may be used to treat other conditions as determined by your doctor.
It is well documented that people who consume diets high in fruits
and vegetables have a reduced risk of heart disease and certain
cancers. Fruits and vegetables are rich in beta-carotene and other
nutrients that may be beneficial.
Vitamins alone will not take the place of a good diet and will not
provide energy. Your body needs other substances found in food, such as
protein, minerals, carbohydrates, and fat. Vitamins themselves often
cannot work without the presence of other foods. For example, some fat
is needed so that beta-carotene can be absorbed into the body.
Daily servings of dark green and deep yellow vegetables and tomatoes
boost immune response, a preliminary study suggests. If the findings
hold up in further research, eating more vegetables rich in beta
carotene and related carotenoids--lutein and lycopene--may help people
ward off a cold or flu as well as protect against cancer.
After three weeks, the volunteers had a 33 percent increase in
immune response as measured by the ability of their T cells to
multiply. This is a good measure of immune system function because T
cells play a vital role in the immune response to foreign organisms and
cancer cells.
As potent antioxidants, these carotenoids are thought to contribute
to the lower rates of heart disease, cancer and other diseases of aging
among populations that eat a lot of fruits and vegetables.
Reported in the Proceedings of the UJNR Protein Resources Panel,
25th Annual Meeting, 1996, the findings suggest that carotenoid-rich
vegetables also stimulate the immune system.
Researchers also found more evidence suggesting carotenes act as
antioxidants to protect the body from harmful oxidation that could
contribute to heart attack, stroke and cancer. During the low-carotene
stints, researchers recorded several biochemical signs of oxidative
damage. For example, they found more carbonyl compounds--breakdown
products of oxidation--in the volunteers' blood and breath.
Older people who get plenty of beta carotene may have a better
chance of preventing virus infections or a cancerous growth. A wealth
of epidemiological evidence has linked a high intake of green leafy and
deep yellow vegetables--both rich in beta carotene--with lower rates of
many types of cancer.
Men over age 65 who took a 50-milligram beta carotene supplement
every other day during the 12-year-long study had natural killer cells
that were more active than those in their counterparts who got a
placebo. Natural killer cells--or NK cells--are the immune system's
sentinels, ever on watch for viruses and cancer cells. They recognize
an enemy immediately and destroy it, using proteins to punch holes in
its outer membrane. This activity is
thought to be an important component of cancer prevention. So ARS
researchers tested NK cell activity in 59 men in the physicians study.
The beta carotene dosage used in the physicians study is equivalent
to eating two regular-size carrots or one and one-half sweet potatoes
daily.
Beta-Carotene has been reported to produce regressions in patients
with oral leukoplakia, a premalignant lesion. In this multicenter,
double-blind, placebo-controlled trial, subjects were given
beta-carotene, 60 mg/d, for 6 months. At 6 months, responders were
randomized to continue beta-carotene or placebo therapy for 12
additional months. Nutritional intake was assessed using food frequency
questionnaires. There was no change in carotenoid intake during the
trial. Responders had a lower intake of dietary fiber, fruits, folate,
and vitamin E supplements than did nonresponders. In conclusion, the
activity of beta-carotene in patients with oral leukoplakia was
confirmed. The responses produced were durable for 1 year.
Known Hazards: Use of beta-carotene has been associated with
an increased risk of lung cancer in people who smoke or who have been
exposed to asbestos. One study of 29,000 male smokers found an 18%
increase in lung cancer in the group receiving 20 mg of beta-carotene a
day for 5 to 8 years. Another study of 18,000 people found 28% more
lung cancers in people with a history of smoking and/or asbestos
exposure. These people took 30 mg of beta-carotene in addition to
25,000 Units of retinol (a form of vitamin A) a day for 4 years.
However, one study of 22,000 male physicians, some of them smokers or
former smokers, found no increase in lung cancer. These people took 50
mg of beta-carotene every other day for 12 years. If you smoke or have
a history of smoking or asbestos exposure, you should not take large
amounts of beta-carotene supplements for long periods of time. However,
foods that are rich in beta-carotene are considered safe and appear to
lower the risk of some types of cancer and possibly heart disease.
The results from the ATBC Study and the Beta-Carotene and Retinol
Efficacy Trial (CARET) suggest that smokers should avoid taking
beta-carotene supplements. The best advice for smokers who want to
reduce their risk of lung cancer and many other cancers is still the
most direct: Stop smoking.
Yellowing of palms, hands, or soles of feet, and to a lesser extent
the face (this may be a sign that your dose of beta-carotene as a
nutritional supplement is too high).
- U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894. Beta-Carotene (Systemic)
- U.S. Department of Agriculture Agricultural Research Service. -
Carotenoids Show Their True Colors - Beta Carotene Boosts Immunity in
Elders - Garewal HS; Katz RV; Et al. Beta-carotene produces sustained
remissions in patients with oral leukoplakia: results of a multicenter
prospective trial. Arch Otolaryngol Head Neck Surg 1999
Dec;125(12):1305-10
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