Generality
Beta-carotene belongs to the category of carotenoids, plant pigments precursors of vitamin A (retinol) and responsible for the yellow-orange color of many vegetables.
Beta-carotene is found in many fruits, in cereals, in oils and in green leafy vegetables, in sweet potatoes, squash, spinach, apricots, peppers ... and of course in carrots.
Due to its antioxidant activity, Beta-carotene has gained considerable clinical importance over time, as we will see carefully in this article.
Figure: Chemical Structure of Beta-Carotene
Indications
Why is Beta-Carotene used? What is it for?
Beta-carotene has assumed a role of importance in the world of nutritional integration, due to its different biological properties.
Beta-carotene, in fact:
- It has antioxidant properties, counteracting the emergence of free radicals;
- It is the main source of vitamin A for vegetarians: if necessary, Beta-carotene is converted by the body into vitamin A, involved in very important biological functions (for example the synthesis of glycoproteins)
- It can be converted into retinol (essential for vision), which in turn is converted into retinoic acid, essential for cell growth and differentiation: in fact, if vitamin A is not formed, the organism is deficient, with the consequent abnormal growth of bones, dryness of the ocular cornea (xerophthalmia) and reproduction disorders;
- It also boasts important immunomodulatory properties, valuable in preserving the correct functionality of the immune system.
Its potential usefulness against the appearance of cancer and diseases affecting the cardiovascular system is being tested: to ascertain this possible effect, further studies will have to be awaited.
In light of these evidences the use of Beta-Carotene could be useful in the prevention of different morbid states united by the same oxidative genesis.
Property and Effectiveness
What benefit has Beta-carotene shown during the studies?
Despite the different clinical trials sometimes showing conflicting opinions, epidemiological data suggest the usefulness of Beta-carotene, taken through fruit and vegetables, in preventing different morbid conditions, both oxidative and oncological.
From a careful examination of the literature, with the due exceptions of the case, Beta-carotene could be useful in:
- Prevent clinical complications in women at high risk of breast cancer;
- Prevent sunburn in people with sensitive skin;
- Preventing bronchitis and breathing difficulties in smokers;
- Reducing the risk of ovarian cancer in women after menopause, even if there are still no certainties;
- Reduce the risk of death associated with pregnancy;
- Prevent night blindness, cataracts and macular degeneration;
- Improve oral leukoplakia;
- Improve physical performance in the elderly.
Specific discourse should instead be made for two very important clinical trials: "Alpha Tocopherol, Beta-Carotene Cancer Prevention Study" (ATBC or "Finnish study") and "Carotene and Retinol Efficacy Trial" (CARET), in which the use of Beta -carotene in smokers would have increased the incidence of lung tumors.
For the record, the leading experts in the field are still at work to adequately clarify the possible mechanisms that would see Beta-carotene assume in some cases an anti-tumorigenic activity and in others, instead, a co-carcinogenic effect.
Doses and method of use
How to use Beta-carotene
The most frequently used dosages of Beta-carotene in the non-smoking population are in the range of 3-15 mg daily.
In this regard, it could be useful to know that 2 mg of Beta-Carotene are contained in:
- 25 g of carrots
- 40 g of beets
- 45 g of formentino
- 50 g of spinach
- 55 g of red pepper
- 65 g of mango
- 110 g of melon
- 130 g of apricots
- 140 g of persimmon.
Cases of overdose are not known in the literature.
Intake of Beta-carotene supplements refers to the non-smoking population.
The indications for smokers are different, as adequately described in the precautions for use section.
Side effects
The use of Beta-carotene has generally proved to be safe and well tolerated.
However, at doses higher than 30 mg per day, taken for prolonged periods of time, Beta-carotene could determine the appearance of carotenodermia, a reversible condition characterized by a yellowish coloring of the skin.
Another possible side effect, resulting from an excessive consumption of Beta carotene, is to block the ability to recover fat-soluble vitamins from the liver, such as vitamin D, preventing the formation of a reserve of these vitamins: this side effect can become particularly important in countries far from the Equator, where the storage of vitamin D is essential to face the lack of winter light.
Contraindications
When should Beta-carotene not be used?
The use of Beta-carotene is contraindicated in case of hypersensitivity to the active principle or to structurally related molecules.
Pharmacological Interactions
Which drugs or foods can modify the effect of Beta-Carotene?
Concomitant use of cholestyramine, colestipol, mineral oils, orlistat, pectins and vitamin E could reduce the intestinal assortment of Beta-carotene.
Precautions for use
What do you need to know before taking Beta-carotene?
The intake of Beta-carotene during pregnancy and in the subsequent period of breastfeeding should be achieved mainly through a healthy and balanced diet, rather than through the use of supplements.
In any case, under these circumstances, the use of Beta-carotene from supplements should not exceed 6 mg daily.
The use of Beta-carotene, in the form of nutritional supplement, should also be avoided by smokers, given the absence of safe dosages.
In this regard, it should be noted that the use of 20 mg of Beta-carotene daily in smokers has been repeatedly associated with an increased incidence of lung cancer.
In other studies, it has been proven that excessive beta-carotene supplementation could increase the risk of prostate cancer, but not only: cardiovascular problems and intracerebral hemorrhage are possible consequences of an excess of Beta-carotene in smokers and in people accidentally exposed to asbestos.
