What is Beta-Carotene and Where Does it Occur?
Beta-carotene belongs to the group of carotenoids, which are natural dyes that are mainly found in fruit and vegetables. Beta-carotene is an orange-red secondary plant dye. Beta-carotene is particularly rich in carrots and pumpkin as well as yellow to orange fruits such as apricots, persimmons, mangos, papayas, peaches, nectarines, sea buckthorn and pears or dark green vegetables such as broccoli, spinach, cress, endive, chicory and beet or dandelion leaves.
Beta-carotene is stored in the skin and increases the body’s own sun protection.
Why do We Need Beta-Carotene?
Beta-carotene acts as an important fat-soluble, bioactive precursor for vitamin A and contributes to a normal function of the immune system. It also helps to preserve mucous membranes, vision and skin. It is stored in the skin and increases the body’s own sun protection. UV radiation plays an essential role in the development of skin aging and damage. The skin is exposed to UV rays not only in summer or during holidays, but also during short stays outdoors, during which sunscreen is not regularly used.
15 – 30 mg/day over a period of 10 weeks reduce the development of inflammatory redness of the skin caused by UV radiation.
Carotenoids, especially beta-carotene, are used for long-term prevention of sun damage. The intake of 15 – 30 mg beta-carotene per day over a period of 10 weeks leads to a reduced development of inflammatory redness of the skin caused by UV radiation. Another study also shows that the increased intake of 30 mg/day of beta-carotene significantly protects against skin aging. However, in order to ensure complete protection against strong sunlight, it is essential to apply sun screen, which can, however, limit the production of vitamin D.
Due to their pronounced antioxidant properties, carotenoids are also of interest for preventive use in various cancers. Studies such as the Linxian study have shown a clear link between beta-carotene, selenium and vitamin E intake and a reduced risk of cancer. A reduced risk of prostate cancer was observed in men. Once the disease had broken out, however, it could not be prevented from progressing. This is consistent with in vivo studies which show that beta-carotene primarily inhibits the development of tumour cells, but not their progressive development.
The results of various intervention studies (e.g. CARET and ATBC studies) regarding the additional intake of beta-carotene and the risk of lung cancer often led to uncertainties regarding the use of carotenoid supplements in smokers. Although these studies found an increase in the risk of lung cancer in the participating smoking subjects, a more detailed analysis of the results led experts to the now recognized opinion that these studies do not meet the requirement of a primary preventive study design by the selection of the participants.
Both studies were a high-risk collective of relatively old, chronic smokers. The intake of beta-carotene in both studies was also in the upper dosage range of 20 mg/day.
In older, chronic smokers, however, no supplementation of beta-carotene to strengthen the body’s antioxidative systems should be considered. The aromatic compounds of green tea are recommended.
Who Needs Additional Beta-Carotene?
Vitamin A is a critical vitamin during pregnancy and lactation, as the vitamin requirement increases by 40% for pregnant women and by as much as 90% for nursing mothers. Vitamin A plays a particularly important role in the development of children’s lungs. However, long-term overdoses can damage the fetus. However, this does not apply to beta-carotene as a precursor of vitamin A. Nevertheless, national authorities have imposed a restriction on beta-carotene intake for pregnant women, and in some countries beta-carotene has even been completely banned in vitamin supplements for pregnant women.
This measure is heavily criticized by some leading nutritionists and physicians. Hans Konrad Biesalski, professor at the University of Hohenheim, Germany, urges that the warnings concerning beta-carotene on the labels be reconsidered and that pregnant and lactating women should instead be made aware of the dangers of an insufficient supply of vitamin A or beta-carotene for the development of the fetus.
