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Carotenoids are organic pigments that are found in plants and some particular types of fungi and algae. Carotenoids are what give the vivid yellow-orange coloring to things like carrots, egg yolk, corn, and daffodils. There are more than 750 naturally occurring carotenoids, but we only see about 40 in our normal human diet.
The most common dietary carotenoids include alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, zeaxanthin, and lycopene.
Alpha-carotene, beta-carotene, and beta-cryptoxanthin can all be converted into vitamin A in the body and are referred to as provitamin A carotenoids. The rest of the carotenoids listed cannot be converted into vitamin A. Instead, they are called non-provitamin A carotenoids. For most people, beta-carotene is the main source of vitamin A.
Health Benefits
Many of carotenoids' benefits come from their antioxidant abilities.
Vision Benefits
Carotenoid supplements can help reduce the risk of developing age-related macular degeneration. According to the National Institutes of Health, taking carotenoid supplements containing carotenoids with antioxidant properties, such as beta-carotene, lutein, and zeaxanthin, might be helpful to treat and prevent age-related macular degeneration.
Lutein and zeaxanthin supplements are sometimes prescribed to reduce the risk of developing eye diseases and to improve eye function.
Cardiovascular Benefits
Some studies have shown that carotenoids can help reduce your risk of developing atherosclerosis (the buildup of plaque in your artery walls that eventually narrows your blood vessels). Hypertension, glucose intolerance, and abdominal obesity are all risk factors for atherosclerosis, and studies have shown that carotenoids help to improve these risk factors.
Carotenoids may also help improve early atherosclerosis that hasn't yet progressed to full-on cardiovascular disease. However, it seems that these cardiovascular benefits can only be reaped when carotenoids have been consumed over a long period of time (nine to 20 years, as suggested by one study).
Skin Aging Protection
Most skin aging is caused by UV radiation (sunlight). Studies have shown that carotenoids, when consumed, are stored up in your skin and serve as a line of defense against skin damage from UV radiation. It’s suggested that lycopene and beta-carotene, specifically, provide this skin protection.
Lycopene and beta-carotene supplements are also effective at preventing skin redness caused by UV radiation. This effect is even more pronounced when a lycopene or beta-carotene supplement is combined with vitamin E.
Skin Cancer Protection
Many studies have shown that carotenoids help protect against the development of skin cancer and pre-skin cancers. One way they do this is by promoting cell differentiation and inhibiting cell cycle progression. They also protect against skin cancer by modulating apoptosis (cell death). Carotenoids are able to induce cell death in melanoma cells.
Potential Health Benefits
In addition to the known health benefits of carotenoids, there are additional potential benefits some studies suggest.
- Bone health: A study suggests that carotenoids, particularly lycopene, have a positive effect on bone health. Another study suggests that taking beta-carotene and beta-cryptoxanthin can help lower the risk of developing osteopenia (a condition in which your bones are weaker than normal).
- Slowing rate of mental decline: A medical article published in the Journal of American Medical Association showed that long-term beta-carotene supplementation may provide cognitive benefits.
- Boosting immunity: It is widely thought that carotenoids boost immunity, especially the provitamin A carotenoids, because vitamin A is in itself necessary for good immune system function.
- Breast cancer and prostate cancer risk reduction: While still under investigation, many studies have suggested that carotenoids, especially lycopene, have anti-cancer effects on sex-hormone-dependent cancers like breast cancer and prostate cancer.
Possible Side Effects
Increased Risk of Lung Cancer with Supplements
Many studies have shown that high intake of carotenoids (beta-carotene) in supplement form significantly increases the risk of developing lung cancer in current and former smokers. One study, in particular, gave current smokers 20 milligrams per day of beta-carotene supplements for five to eight years.
The results showed a higher incidence in lung cancer in those receiving the supplement. However, the incidence of other major cancers wasn't affected. A similar study conducted with asbestos workers showed that they, too, may have a higher risk of developing lung cancer with high intake of carotenoid supplements.
However, remember that consuming ample fruits and vegetablesas part of an overall healthy diet has many benefits. In fact, dietary intake of carotenoids—as opposed to in supplement form—is associated with lower lung cancer risk.
Carotenemia
This is a condition in which the skin becomes yellowish because of a high amount of beta-carotene in the body.
Carotenemia is reversible, and while it is usually caused by intake through food, excessive intake via supplements can cause it, too.
Canthaxanthin Retinopathy
This condition is characterized by yellow-golden flecks in the eye, and sometimes vision field defects and problems with vision clarity. It is caused by taking high doses of a carotenoid called canthaxanthin. Fortunately, it is reversible: your eyes and vision will go back to normal once you stop consuming canthaxanthin.
Lycopenodermia
Taking high amounts of lycopene can cause your skin to temporarily become a deep orange color.
Allergic Reaction
As with many other substances, it is possible to have an allergic reaction to carotenoid supplements. You should see your physician immediately if you suspect you are having an allergic reaction. Itching, swelling, and rashes are typical signs of this.
Interactions with Medications
If you’re currently taking any medication, it’s best to consult with your physician before starting carotenoid supplements. Beta-carotene supplements, in particular, may have negative interactions with cholesterol-lowering drugs.
Dosage and Preparation
The U.S. Food and Nutrition Board advises against taking beta-carotene supplements except to treat a vitamin A deficiency. Daily limit guidelines for beta-carotene to follow:
- For teenagers and adults, 6 to 15 mg of beta-carotene supplements (10,000 to 25,000 Units of vitamin A) every day is safe
- For children, 3 to 6 mg of beta-carotene supplements (5,000 to 10,000 Units of vitamin A activity) daily is safe
Vitamin A deficiency, while rare in the United States and other developed countries, is significantly more prevalent in developing countries, especially in children.
What to Look For
Foods that naturally contain carotenoids include:
- • Carrots
- • Mangoes
- • Tomatoes
- • Plums
- • Sweet potatoes
- • Kale
- • Spinach
- • Cantaloupe
- • Winter squash
- • Apricots
- • Tangerines
- • Plantain
- • Turnip greens
- • Red peppers
- • Yellow corn
A Word From Verywell
While there are many potential health benefits from carotenoids, taking them in high-dose supplement form may be harmful. It is generally unnecessary to supplement carotenoids and should be avoided in smokers. The best way to get your carotenoids is from a healthy diet that includes plenty of carotenoid-containing fruits and vegetables. However, if you think you want to use carotenoid supplements, discuss it with your doctor first.
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Increased Risk of Lung Cancer with Supplements
Many studies have shown that high intake of carotenoids (beta-carotene) in supplement form significantly increases the risk of developing lung cancer in current and former smokers. One study, in particular, gave current smokers 20 milligrams per day of beta-carotene supplements for five to eight years.
The results showed a higher incidence in lung cancer in those receiving the supplement. However, the incidence of other major cancers wasn't affected. A similar study conducted with asbestos workers showed that they, too, may have a higher risk of developing lung cancer with high intake of carotenoid supplements.
However, remember that consuming ample fruits and vegetablesas part of an overall healthy diet has many benefits. In fact, dietary intake of carotenoids—as opposed to in supplement form—is associated with lower lung cancer risk.
Carotenemia
This is a condition in which the skin becomes yellowish because of a high amount of beta-carotene in the body.
Carotenemia is reversible, and while it is usually caused by intake through food, excessive intake via supplements can cause it, too.
Canthaxanthin Retinopathy
This condition is characterized by yellow-golden flecks in the eye, and sometimes vision field defects and problems with vision clarity. It is caused by taking high doses of a carotenoid called canthaxanthin. Fortunately, it is reversible: your eyes and vision will go back to normal once you stop consuming canthaxanthin.
Lycopenodermia
Taking high amounts of lycopene can cause your skin to temporarily become a deep orange color.
Allergic Reaction
As with many other substances, it is possible to have an allergic reaction to carotenoid supplements. You should see your physician immediately if you suspect you are having an allergic reaction. Itching, swelling, and rashes are typical signs of this.
Interactions with Medications
If you’re currently taking any medication, it’s best to consult with your physician before starting carotenoid supplements. Beta-carotene supplements, in particular, may have negative interactions with cholesterol-lowering drugs. *