beta carotene and lung cancer

[suzydu]

I am a former smoker, but stopped about 30 odd years ago.  I know there is a risk of taking beta carotene supplements for smokers.  How great is the risk for former smokers?  All the multi-vitamins contain beta carotene and not taking any negates all other beneficial vitamins and minerals carotene.   Do you think I should take a multi vitamin, and if  not what suggestions do you have for me to at least get the other vitamins and minerals I need ?.  Which would be important?  I am 64 years old.  I am also concerned because my Mother had lung cancer, but smoked for about 30 some years.  I smoked for 10.  I read a similar question someone had written, but they seemed to be a more current or recent smoker. Also, is there any way I may get more information on this subject.  I read about the Caret study and the atbc study, but they all seemed to be more geared toward current smokers, although there was some mention of former smokers, but it was not definitive to me.  Thank you so much.  I look forward to hearing from you.  Suzy

[National Jewish Health]

The risk is dose dependent and minimal to non-existent for former smokers.  The best way to address this concern would be to select a multi-vitamin preparation that contains low dose, less than 1 mg, of beta carotene.  See the study below published last month.

Authors
Full Name Tanvetyanon, Tawee. Bepler, Gerold.
Institution Thoracic Oncology Program, H. Lee Moffitt Cancer Center and
Research Institute, University of South Florida, 12902 Magnolia
Drive, Tampa FL 33612, USA. ***@****
Title Beta-carotene in multivitamins and the possible risk of lung cancer
among smokers versus former smokers: a meta-analysis and
evaluation of national brands.
Source Cancer. 113(1):150-7, 2008 Jul 1.
Abstract BACKGROUND: Some studies have suggested that beta-carotene
supplementation may increase the risk of lung cancer, particularly
among smokers or former smokers. Beta-carotene, a provitamin A,
is available in multivitamins. In the current study, the authors
investigated the risk of lung cancer associated with beta-carotene
in smokers or former smokers and surveyed the beta-carotene
content in national brand multivitamins.
METHODS: The authors systemically reviewed the published
literature using a search of the MEDLINE database and performed
a meta-analysis of large randomized trials that reported on the
effect of beta-carotene supplementation on the incidence of lung
cancer among smokers or former smokers. A sample of
multivitamins was evaluated for their beta-carotene content and the
suggested daily dosage.
RESULTS: Four studies contributing 109,394 subjects were
available for analysis. The average daily beta-carotene dosage in
these trials ranged from 20 to 30 mg daily. Among current smokers,
beta-carotene supplementation was found to be significantly
associated with an increased risk of lung cancer (odds ratio [OR],
1.24; 95% confidence interval [95% CI], 1.10-1.39). Among former
smokers, there was no significant increase noted (OR, 1.10; 95%
CI, 0.84-1.45). In a sample of 47 common multivitamins, beta-
carotene was present in 70% of the identified formulas. The median
dosage of beta-carotene was 0.3 mg (range, 0-17.2 mg) daily. The
beta-carotene content was found to be significantly higher among
multivitamins sold to improve visual health than among other
multivitamins, with a median daily dosage of 3 mg (range, 0-24
mg).
CONCLUSIONS: High-dose beta-carotene supplementation
appears to increase the risk of lung cancer among current smokers.
Although beta-carotene was prevalent in multivitamins, high-dose
beta-carotene was observed among multivitamin formulas sold to
promote visual health. (Copyright) 2008 American Cancer Society.