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Smokers and beta-carotene lung cancer risk
A French study involving adult females published in the Journal of the National Cancer Institute (September 2005 issue) found that smokers with high beta-carotene levels had a higher risk of lung cancer and other smoking-related cancers than other smokers. They also found that non-smokers with high beta-carotene intake had a lower risk of lung cancer.
They found that the risk of lung cancer over a ten-year period was:
- 181.8 per 10,000 women for non-smokers with low beta-carotene intake
- 81.7 per 10,000 women for non-smokers with high beta-carotene intake
- 174 per 10,000 women for smokers with low beta-carotene intake
- 368.3 per 10,000 women for smokers with high beta-carotene intake.
Further research has suggested that the high intake among smokers is nearly always due to supplements, and not food intake.
Beta-carotene may slow down cognitive decline
Carrots are an excellent source of beta-carotene.
Men who have been taking beta-carotene supplements for 15 or more years are considerably less likely to experience cognitive decline than other males, researchers from Harvard Medical School reported in Archives of Internal Medicine (November 2007 issue).
Oxidative stress is thought to be a key factor in cognitive decline, the researchers explained. Studies have shown that antioxidant supplements may help prevent the deterioration of cognition.
Their study, involving 4,052 men, compared those on beta-carotene supplements for an average of 18 years to others who were given placebo. Over the short-term, they found no difference in cognitive decline risk between the two groups of men, but in the long-term it was clear that beta-carotene supplements made a significant difference.
The researchers emphasized that there may have been other factors which contributed to the slower decline in cognitive abilities among the men in the beta-carotene group.
Beta-carotene drug interactions
Drug interaction refers to a substance interfering in how a medication works, by either making it less effective, increasing its potency, or changing what it is supposed to do.
The following drugs may be affected by beta-carotene supplements:
- Statins - the effectiveness of simvastatin (Zocor) and niacin may be decreased if the patient is taking beta-carotene with selenium and vitamins E and C.
- Some cholesterol-lowering drugs - cholestyramine and colestipol can reduce blood levels of dietary beta-carotene by thirty to forty per cent.
- Orlistat (Xenical, Alli) - this is a weight control medication. It can undermine the absorption of beta-carotene by up to 30%, resulting in lower blood beta-carotene levels. Those choosing to take a multivitamin while on orlistat should take them at least two hours before having their medication.
- Mineral oil - used for the treatment of constipation can lower blood levels of beta-carotene.
Long-term alcohol consumption can interact with beta-carotene, raising the chances of developing liver problems.
Beta-carotene slows down lung power decline as people age
The British Medical Journal published a report in March 2006 which showed that high blood beta-carotene levels compensate for some of the damage to the lungs caused by oxygen free radicals.
They measured the FEV1 of 535 participants and measured their beta-carotene blood levels. FEV1 measures how much air you can breathe out in one go. They found that those with high beta-carotene levels had much slower decline in FEV1 measures.
Recent developments on supplements from MNT news
Over-the-counter dietary supplements and therapies sold to improve male sexual health may be ineffective and even unsafe, says a report published in the Journal of Sexual Medicine.
For patients with chronic heart failure, daily supplementation with vitamin D-3 may improve heart function. This is the conclusion of a new study recently presented at the American College of Cardiology 65th Annual Scientific Session & Expo in Chicago, IL.