Serum Carotenoids and Breast Cancer

Abstract

The consumption of vegetables and fruit may protect against many types of cancer, but research evidence is not compelling for breast cancer. Carotenoids are pigments that are present in most plants and have known antioxidant properties. Blood concentrations of carotenoids have been proposed as integrated biochemical markers of vegetable, fruit, and synthetic supplements consumed. In a case-control study (270 cases, 270 controls) nested within a cohort in New York during 1985-1994, the carotenoids lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, and beta-carotene were measured in archived serum samples using liquid chromatography. There was an evident increase in the risk of breast cancer for decreasing beta-carotene, lutein, alpha-carotene, and beta-cryptoxanthin. The risk of breast cancer approximately doubled among subjects with blood levels of beta-carotene at the lowest quartile, as compared with those at the highest quartile (odds ratio = 2.21; 95% confidence interval (CI): 1.29, 3.79). The risk associated with the other carotenoids was similar, varying between 2.08 (95% CI: 1.11, 3.90) for lutein and 1.68 (95% CI: 0.99, 2.86) for beta-cryptoxanthin. The odds ratio for the lower quartile of total carotenoids was 2.31 (95% CI: 1.35, 3.96). These observations offer evidence that a low intake of carotenoids, through poor diet and/or lack of vitamin supplementation, may be associated with increased risk of breast cancer and may have public health relevance for people with markedly low intakes.

Evaluation of antigenotoxic effects of carotenoids from green algae Chlorococcum humicola using human lymphocytes

“…There are several prospective studies investigating the possible effect of b-cryptoxanthin (and other carotenoids) on risk of various cancers. Toniolo found that levels of b-cryptoxanthin and lutein in serum were linked with reduced risk of breast cancer in a dose dependent fashion [32] . Beta carotene, lycopene, b-cryptoxanthin, zeaxanthin and lutein are reduced in colorectal adenomas, suggesting that mucosal carotenoids could serve as biomarkers for predisposition to colorectal cancer [33] .…”

Risk factors and risk reduction of breast and ovarian cancer

“…Although the assocation with the 'western' diet (characterized by meat, fat, dairy and sweets) remains unconfirmed [17,18], a number of other factors are now consistently associated with the risk of breast cancer; carotenoids decrease the risk [19] as well as folate [20]. The risk of low folate intake is more increased in combination with alcoholic beverages [21].…”

Nutrients and nipple aspirate fluid composition: the breast microenvironment regulates protein expression and cancer aetiology

“…Since increased blood levels of carotenoids were shown to be protective towards BC risk [53,[59][60][61], several studies evaluated the presence and the possible antioxidant activity of NAF carotenoids. While it was demonstrated that NAF carotenoid levels and their transport from the blood into the breast microenvironment may be enhanced by lactation [37], no association between BC risk and levels of provitamin A, carotenoid and vitamin E was found [9].…”

“…Several prospective or cohort studies have reported an inverse Vitamins [11,25] provitamin A [9] vitamin E [9] retinol [10,11,25] association between breast cancer risk and serum/plasma carotenoids, including a-and b-carotenes and lutein [59,60]. Despite being a relatively minor component among total carotenoids, it is intriguing that lutein showed a significant inverse association [25].…”

“…An important indication was that carotenoids in NAF increased with a high fruit and vegetable diet regardless of whether dietary fat intake was concomitantly decreased, but surprisingly little correlation between levels of micronutrients in NAF and plasma was found [10]. Dietary carotenoids were more strongly correlated with plasma levels than with adipose tissue levels [60], suggesting that plasma levels likely reflects absorption from the diet to a relatively greater degree, with the subsequent distribution of micronutrients within the body fluids. So, the source of micronutrients in NAF may derive from both the distribution of micronutrients in breast tissue and their accumulation into the extracellular fluids.…”