Carotenoids
Xanthophylls and Carotenes Classes
Carotenoids are organic pigments found in plants where they play a vital role in photosynthesis. Carotenoids are important antioxidants, several of which have been linked to the prevention of certain types of cancer as well as increased cancer survival. They have been shown to improve the immune system.
They are divided into two classes. Those in which the molecules contain oxygen atoms are classified as xanthophylls. Those which do not contain oxygen are known as carotenes. Below are several carotenoid antioxidants which have shown potential health benefits.
Xanthophylls Class
Lutein and Zeaxanthin
Lutein and Zeaxanthin are two carotenoid antioxidant compounds which have been shown to substantially reduce the risk of macular degeneration, an age related disease of the retina which is the leading cause of blindness in people over the age of 40.
Astaxanthin
Astaxanthin is an extremely potent antioxidant. It also exhibits significant anti-inflammatory properties. Astaxanthin has 100-500 times the antioxidant capacity of vitamin E and 10 times that of beta-carotene. Other studies also indicate that astaxanthin is a stronger antioxidant than even lycopene. Astaxanthin, unlike other carotenoids, does not convert to vitamin A. Too much vitamin A can be toxic to humans in high doses, but astaxanthin is not.
Due to its potent antioxidant activity and its ability to cross the blood-brain barrier, Astaxanthin has been studied as a means to reduce oxidative stress which contributes to ocular, and neurodegenerative diseases such as macular degeneration, glaucoma, Alzheimer’s, and Parkinson’s disease. Studies in mice showed that astaxanthin’s antioxidant activity had neuroprotective effects against retinal damage. Astaxanthin was also shown to inhibit reactive oxygen species-mediated cellular toxicity in dopaminergic cells (cells damaged in Parkinson’s disease). Studies have also suggested that astaxanthin could have protective effects against heart disease, and stroke. Evidence does suggest that astaxanthin can reduce ischemia related brain injury (as occurs during a stroke).
Carotenes Class
Beta-Carotene
Beta-Carotene is best known for its pro-vitamin A activity. Vitamin A is a pigment important for human vision. Like other carotenoids, beta-carotene may also play a protective role against prostate cancer. According to a new analysis of data collected in the Physicians’ Health Study, men who had lower baseline plasma levels of beta-carotene were at higher risk for prostate cancer that those with higher levels, but taking beta-carotene supplements reduced their risk substantially.
Another study published in the Archives of Internal Medicine showed that long term dietary supplementation with beta-carotene may protect against declines in memory, thinking and learning skills that often precede Alzheimer’s disease and other forms of dementia. Studies have shown that high doses of beta-carotene are associated with an increased rate of lung cancer in smokers. However, carotenoids have been shown in other studies to be associated with a lower incidence of lung cancer in non-smokers.Lycopene
Lycopene is a bright red phytochemical pigment found in tomatoes and other red fruit. Lycopene may be the most powerful carotenoid antioxidant as far as its ability to quench singlet oxygen molecules. In test tube studies, lycopene has been shown to be 100 times more efficient in quenching singlet oxygen molecules than vitamin E. Singlet oxygen production during exposure to UV rays of sunlight is known to be a primary cause of skin aging.
Lycopene is best known for its potential role in the prevention of certain cancers, especially prostate cancer. Much promising research has been done which suggests that dietary intake of lycopene is inversely related with the risk of many cancers. The most promising and well known research was in regard to prostate cancer. Studies have concluded that frequent consumption of lycopene was associated with a lower risk of prostate cancer. However, as of yet, the evidence has not made the US FDA standard for health claim approval. More studies and clinical trials are needed before definitive statements can be made. This area of research is ongoing.
Additional Resources for Antioxidants
Anti-aging Antioxidants - Nature's Anti-aging Secret
Anti-aging antioxidants: What are Antioxidants? How do antioxidants work? What are the benefits of antioxidants?
High-Quality, Reasonably Priced Antioxidant Supplements
Through his research, Dr. Gardner has found a high quality antioxidant supplement which is very reasonably price and still maintains all the high lab standards he looks for in any supplement.
The Antioxidant Network
The antioxidant network is our bodies' primary defense against free radicals. A review including Glutathione, Lipoic acid, Vitamin E, Vitamin C and CoQ10.
Polyphenols and Flavonoid Antioxidants
Learn about the anti-aging and health benefits of polyphenols and flavonoid antioxidants found in red wine, teas and chocolate.
Antioxidants in Tea
What are the antioxidants in tea? Do all teas have the same antioxidants? What are the health benefits of tea? The best ways to drinking green, white and oolong tea to get the maximum health benefits!
Free Radicals
What are they, where do they come from and how you can protect yourself from them!
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