The Health Benefits of Carotenoids

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 thing 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 all 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.

Much of carotenoids benefits come from their antioxidant abilities.

Carotenoid supplements can help reduce the risk of developing age-related macular degeneration. The National Institutes of Health acknowledge that taking carotenoid supplements containing carotenoids with antioxidant properties like beta-carotene, lutein, and zeaxanthin, might be helpful to treat and prevent age-related macular degeneration. 

Some studies have shown that carotenoids can help reduce your risk of developing atherosclerosis (the buildup of plaque in your artery walls that serve to narrow 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.

Also, carotenoids may also help improve early atherosclerosis that hasn't yet progressed into full-on cardiovascular disease. However, it seems that these cardiovascular benefits can only be reaped when there has been consumption of the carotenoids for a long period of time (nine to 20 years as suggested by one study).

Most of skin aging is caused by UV-radiation. 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 the lycopene or beta-carotene supplement is combined with vitamin E.

Many studies have shown that carotenoids help protect against the development of skin cancer and pre-skin cancers. One way it does this is by promoting cell differentiation and inhibiting cell cycle. Another way it protects against skin cancer is by modulating apoptosis (cell death). Carotenoids are able to induce cell death in melanoma cells.

In addition to the known health benefits of carotenoids, there are additional potential benefits that some studies suggest.

• Bone Health: A study suggests that carotenoids, particularly lycopene, have a positive effect on bone health. Another study also suggests that taking beta-carotene and beta-cryptoxanthin can help lower the risk of developing osteopenia (a condition where your bones are weaker than normal).
• Slowing Rate of Mental Decline: A medical article published in the Journal of American Medical Association showed that taking beta-carotene supplementation long-term may provide cognitive benefits.
• Boost Immunity: It is widely thought that carotenoids boost immunity, especially the provitamin A carotenoids because of vitamin A in itself necessary for good immune system function.
• Lung Cancer: Some studies have shown that high intake of carotenoids is associated with a lower risk of developing lung cancer in non-smokers. However, clinical trials that have been conducted have not shown that carotene supplements can help prevent lung cancer.
• 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.

Many studies have shown that high intake of carotenoids (beta-carotene), either through foods or as a supplement, significantly increases the risk of current and former smokers developing lung cancer. One study, in particular, gave current smokers 20 milligrams per day of beta-carotene supplements for five to eight years.

The results showed that there was a higher incidence in lung cancer, 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 intakes of carotenoids.

This is a condition in which the skin becomes yellowish because of a high amount of beta-carotene in the body.

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 and your eyes and vision will go back to normal once you stop taking the canthaxanthin.

Taking high amounts of lycopene can cause your skin to be temporarily discolored deep orange color.

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 one. Itching, swelling, and rashes are typical signs of this.

If you’re currently taking any medication, it’s best you consult with your physician before starting any carotenoid supplements. Beta-carotene supplements, in particular, may have negative interactions with cholesterol-lowering drugs.

Except it’s to treat a vitamin A deficiency, the Food and Nutrition Board advises against taking beta-carotene supplements. However, a safe dosage guideline which you may follow is:

• 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).

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

While there are many potential health benefits from carotenoids, taking them in high doses may be harmful. The best way to get your carotenoids is from a healthy diet that includes plenty of the carotenoid-containing fruits and vegetables. It is generally not a good idea to take carotenoid supplements, and if you think you want to do so, you should discuss it with your doctor first.