Dietary intakes of vitamins A, C, and E and risk of melanoma in two cohorts of women

Abstract

Within the two Nurses' Health Study cohorts of US women, we examined whether higher intakes of vitamin C, vitamin E, retinol, or individual tocopherols or carotenoids are associated with a lower risk of melanoma. We confirmed 414 cases of invasive melanoma among over 162 000 Caucasian women aged 25 -77 years during more than 1.6 million person-years of follow-up. Diet was measured every 4 years with a food frequency questionnaire and supplement use was reported every 2 years. Several measures of sun sensitivity were assessed and included in proportional hazards models. We found that vitamins A, C, E and their individual components were not associated with a lower risk of melanoma. Only retinol intake from foods plus supplements appeared protective within a subgroup of women who were otherwise at low risk based on nondietary factors (relative risk (RR) ¼ 0.39, 95% confidence interval (CI) 0.22 -0.71 for X1800 vs o400 mg day À1 , P for linear trend ¼ 0.01). Contrary to expectation, we observed higher risks of melanoma with greater intakes of vitamin C from food only (RR ¼ 1.43, 95% CI 1.01 -2.00 for X175 vs o90 mg day À1 , P for linear trend ¼ 0.05) and a significant positive dose -response with frequency of orange juice consumption (P ¼ 0.008). Further research is needed to determine whether another component in foods such as orange juice may contribute to an increase in risk.

Systematic review of studies investigating the association between dietary habits and cutaneous malignant melanoma

“…Seven studies [37,40,41,44,45,48,53] dealt with fish consumption, nine [37, 40, 41, 44-47, 53, 54] with vegetables and eight [37,40,41,[44][45][46][47][48] with fruit. Most studies did not identify any significant association between foods intake and CMM, except for two studies [37,45] out of seven (28.6%) demonstrating a significant reduction of about 35-37% associated to a higher fish consumption, three [37,45,47] out of nine (33.3%) showing a 40-57% risk reduction with a higher vegetables intake and two [37,47] out of eight (25%) highlighting a significant reduction ranging from 34% to 46% with respect to fruit.…”

“…The minimum score for case-control studies was five out of nine stairs, achieved by most studies, compared to a maximum of eight out of ten achieved only by Naldi et al [44]. Cohort studies were shown to be very good, reaching Feskanich et al [46] the highest score (nine out nine) and Veierød et al…”

“…The design of thirteen out of the fifteen studies was case-control [36, 37, 40-42, 44, 45, 47, 49, 51, 53, 54, 56, 61], while the remaining two [46,48] were cohort studies. Studies characteristics are shown in Table 1.…”

“…Sample size ranged from 108 (59 cases and 59 controls) [36] to 1,400 (474 cases and 926 controls) [54] in case-control studies and from 50,757 [48] to 162,078 [46] in cohort ones.…”

“…In particular, as far as the type of questionnaire is concerned, studies were performed as follows: a semi-quantitative food-frequency questionnaire was administered in five studies [36,40,42,48,51,53]; in two studies a food-frequency questionnaire was used [46,49]; in only one study the "Dobson short fat questionnaire" was used [56]; in four studies trained interviewers administered a structured questionnaire [37,44,54,61]; the study subjects were requested to complete a reduced version of the "Block-food-frequency questionnaire" in another study [45]; in only one study each participant completed a telephone survey and a questionnaire was administered during the phone interview [47]; last, in only one study in-persons interviews were conducted at subject's homes by trained interviewers [41]; -methods used in order to quantify servings were both qualitative (e.g. pictures or images) and quantitative (e.g.…”