Carotenoids lung cancer

It is well known that excessive intake of P-carotene may lead to carotenodermia (yellow skin), and it is undoubtedly the case that some carotenoid is directly lost via the skin or through photo-oxidation in the skin. As far as is known the carotenoids are not cytotoxic or genotoxic even at concentrations up to 10 times the normal plasma concentration which may cause carotenodermia. However, they are associated with amenorrhoea in girls who may be consuming bizarre diets and, in long-term supplementation studies, with an increase in lung cancer (The Alpha-tocopherol, Beta-carotene Cancer Prevention Study Group, 1994). 

Holick, C.N. et al., Dietary carotenoids, serum beta-carotene, and retinol and risk of lung cancer in the alpha-tocopherol, beta-carotene cohort study, Am. J. Epidemiol., 156, 536, 2002. 

Ratnasinghe, D. et al., Serum carotenoids are associated with increased lung cancer risk among alcohol drinkers, but not among non-drinkers in a cohort of tin miners, Alcohol, 35, 355, 2000. 

Michaud DS, Feskanich DD, Rimm EB et al. (2000), Intake of specific carotenoids and risk of lung cancer in 2 prospective US cohorts, Am. J. Clin. Nutr. 92 990-997. 

Carotenoids are of physiological interest because some of them are precursors of vitamin A. They have been in the news recently because many exhibit radical or single oxygen trapping ability and as such have potential antioxidant activity in vivo. They may reduce the risk of cardiovascular disease, lung cancer, cervical... 

Garcia-Closas, R. et al., Intake of specific carotenoids and flavonoids and the risk of lung cancer in women in Barcelona, Spain, Nutr. Cancer — Int. J., 32, 154, 1998. 

Carotenoids, a class of yellow to deep-red pigments present in many commonly eaten fruits and vegetables, have been hypothesized to play a role in the prevention of chronic diseases such as cancer and heart disease. Most research to date has focused on the relationship between P-carotene and lung cancer. Lung cancer is one of the most common cancers in the U.S., and P-carotene was initially the most thoroughly studied carotenoid because of its role as a vitamin A precursor (Cooper et al., 1999). 

The relationship between dietary carotenoids and risk of lung cancer has been determined in a pooled analysis of seven cohort studies (studies with the asterisk in Table 7). The results (42) indicate that /3-carotene was not associated with lung cancer, that smoking was the strongest risk factor for lung cancer, and /3-cryptoxantin (contained in citrus fruit) may modestly reduce the risk. 

ATBC 3d e Carotenoids and vitamin A 6.1 27,084 M Lower risk of lung cancer in the highest quintile of carotenoids same for highest quintile of consumption of fruit and vegetables reduction of cerebral infarction 139,140... 

CNBSSe Case-cohort11 13 5681 F No association between dietary carotenoid intake and lung cancer risk 145... 

NCSDC Case-cohort11 6.3 2464 M Protective effect on lung cancer incidence was found for folate and vitamin C, particularly, for current smokers carotenoids do not show an evident protective activity 148... 

NCSDCc,f 6.3 yr 3405 3692 1074 M-F Dietary or supplemental intake of vitamin A, C, E, folates and carotenoids are not associated with bladder risk of cancer inverse association were found between the intake of vitamins, carotenoids, and dietary fibers and risk of gastric carcinoma inverse association with lung cancer is found both for vegetables and fruit intake. (148,212) (213)... 

Mannisto S, Smith-Warner SA, Spiegelman D, et al. Dietary carotenoids and risk of lung cancer in a pooled analysis of seven cohort studies. Cancer Epidemiol Biomarkers Prev 2004 13 40-48. 

The absorption and bioavailability of both lutein and zeaxanthin were studied and their epimeric isomers were found in human serum. Much evidence shows that a high intake of carotenoids in fruits and vegetables might be associated with a reduction in the risk of lung cancer, and in particular that a-carotene rather than -carotene may be associated with that reduced risk. 

It was observed that people with low carotenoid intake or low blood levels have an increased risk of degenerative diseases. In a number of these diseases free radical damage plays a role in the pathophysiology of the disease. Earlier studies were focused mainly on p-carotene and the lycopene protective effect against prostate and lung cancer, but there is as yet no definitive proof for a causal relationship or for a beneficial antioxidant effect of carotenoids. 

L.Le Marchand, J.H. Hankin, L.N. Kolonel, G.R. Beecher, L.R. Wilkens, L.P. Zhao. Intake of Specific Carotenoids and Lung Cancer Risk. Cancer Epidemiology, Biomarkers and Prevention, Vol. 2, pgs. 183-187,1993. 

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