Once considered just a potent source of vitamin A, beta-carotene has gained prominence as a disease-fighting substance. Today, experts think that beta-carotene – along with the related nutrients called carotenoids –may protect against heart disease and cancer.
What it is?
Beta-carotene is part of a larger group of nutrients known as carotenoids, which are the yellow-orange pigments found in fruits and vegetables (see Carotenoids). Because the body can convert it to vitamin A, beta-carotene is sometimes called provitamin A. However, beta-carotene provides many benefits besides supplying the body with that vitamin.
What it does?
An immune system booster and a powerful anti-oxidant, beta-carotene neutralizes the free radicals that can damage cells and promote disease. By acting directly on cells, it combats – and may even reverse – some disorders. It appears to be most effective when combined with other carotenoids.
Prevention
Beta-carotene is a celebrated soldier in the war on heart disease. Results from a survey of more than 300 doctors enrolled in the Harvard University Physicians' Health Study revealed that taking 50 mg (85000 IU) of beta-carotene a day cut the risk of heart attack, stroke and all cardiovascular deaths in half. Other studies have shown that it can prevent LDL ('bad') cholesterol from damaging the heart and coronary vessels. High levels of beta-carotene may also offer protection against cancer of the lung, digestive tract, bladder, breast and prostate.
Major benefits
Acting as an antioxidant, beta-carotene has reversed some precancerous conditions, particularly those affecting the skin, mucous membranes, lungs, mouth, throat, stomach, colon, prostate, cervix and uterus. Further, it has been shown to inhibit the growth of abnormal cells, strengthen the immune system, fortify cell membranes and increase communication among cells.
One hint of concern did arise, however, about beta-carotene's cancer-fighting benefits. In the early 1990s, landmark studies in Finland and the US found that male smokers taking beta-carotene supplements had an increased risk of lung cancer. Though some found the studies flawed, many experts caution smokers to maintain adequate beta-carotene levels though natural food sources, not supplements.
Additional benefits
As an antioxidant, beta-carotene may be helpful for a wide range of additional ailments, including Alzheimer's disease, chronic fatigue syndrome, male infertility, fibromyalgia, psoriasis and a number of vision disorders.
Common Uses
- Acts as a preventive for cancer and heart disease.
- May reverse some precancerous conditions.
- Has cell-protecting properties that may aid in the treatment of a wide variety of ailments from Alzheimer's to male infertility.
Forms
- Capsule.
- Tablet.
- Soft gel.
- Liquid.
Caution!
- Consult your doctor before using beta-carotene if you have a sluggish thyroid (hypothyroidism), kidney or liver disease, or an eating disorder.
- Many experts recommend that smokers, particularly those who drink large amounts of alcohol, avoid synthetic beta-carotene supplements.
- Reminder: If you have a medical condition, talk to you doctor before taking supplements.
How much you need?
There is no RDI for beta-carotene though about 10000 IU (6 mg) may meet the RDI for vitamin A. Higher doses are needed, however, to provide the full antioxidant and immune boosting effects.
If you get too little
Signs of a beta-carotene deficiency are similar to those of inadequate vitamin A: poor night vision, dry skin, increased risk of infection, and the formation of precancerous cells. A deficiency may increase your risk of cancer and heart disease. However, vitamin A deficiencies are rare. Even if you don't eat fruits and vegetables or take supplements, you can still meet your vitamin A needs with eggs or other foods that supply it.
If you get too much
It's almost impossible to get too much beta-carotene, since the body discards what it doesn't process. If you ingest high levels – over 100000 IU a day – your palms and soles may turn a harmless orange tone, which will disappear when you lower the dose.
How to take it?
Dosage
Beta-carotene is probably most effective when combines with other carotenoids in a mixed carotenoid formula. Naturally sourced beta-carotene is preferable to the synthetic form. Most people benefit from 25000 IU (15 mg) of mixed carotenoids a day. Those at high risk of cancer can take up to 50000 IU (30 mg) twice a day.
Guidelines for use
Take supplements with meals. No adverse effects have been noted in pregnant or breast-feeding women taking up to 50000 IU a day.
Other sources
Carrots are a rich source of beta-carotene, as are other yellow, orange and red fruits and vegetables, from sweet potatoes to rock melon. Green vegetables, such as broccoli, are also beneficial – the darker the green, the more beta-carotene the product contains.
Shopping Hints
- Buy beta-carotene in combination with other carotenoids, such as lycopene, alpha-carotene, cryptoxanthin, zeaxanthin and lutein. These combination formulas are an effective and economical way to boost your antioxidant levels.
Latest Findings
- Beta-carotene may help to protect against many types of cancer – but in smokers it may actually increase the risk of lung cancer. Recent studies show that this surprising effect seems strongest in men who smoke at least 20 cigarettes daily, and increases even further when alcohol intake is 'above average'. (Interestingly, former smokers do not appear to be at heightened risk.) One theory is that smokers generally have low vitamin C levels, and that this imbalance causes beta-carotene to heighten, rather than decrease, free-radical formation.
Did you know?
You'd have to eat about half a kilo of fresh rock melon to get the beta-carotene supplied in just one 25000 IU capsule.
