Antioxidant and Antiproliferative Activities of Several Garlic Forms.

It is hypothesized that garlic, Allium sativum, might protect against oxidative stress that causes damage to cells and tissues leading to the development of various health conditions including cancer. However, it is not known whether garlic's potential anticancer benefits differ by form of garlic consumed. This study aimed to quantify and compare the in vitro antioxidant and antiproliferative activity of several garlic forms in water and alcohol extracts including fresh garlic, fresh garlic set aside, heated garlic, heated garlic set aside, garlic powder, black garlic, two commercially available garlic supplements. Antioxidant activity of different garlic forms were measured using three assays: DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay, superoxide assay, and hydroxyl assay. In vitro effects of garlic extracts were investigated against the most common lung cancer subtypes: H520, H1975, and A549 cell lines using the sulforhodamine B (SRB) assay. Among free radical scavenging assays, Garlicin®, a commercially available supplement, displayed high antioxidant activity in water and alcohol extracts (DPPH assay: 2.02 mg AAE (mg ascorbic acid equivalent)/g garlic and 3.53 mg AAE/g garlic, respectively; superoxide assay: 6.73 mg AAE/g garlic and 7.13 mg AAE/g garlic, respectively). In the hydroxyl assay, water extract of fresh garlic crushed and set aside for 10 min showed the highest antioxidant activity. Garlicin® alcohol extract and fresh garlic water extracts strongly inhibited the proliferation of H1975, A549 and H520 cells. Other forms of garlic including garlic powder and black garlic exhibited low antioxidant and antiproliferative activity. Our results demonstrate that the preparation and processing methods of garlic may lead to different antioxidant benefits.

Dietary omega-3 fatty acids and endometrial cancer risk in the Epidemiology of Endometrial Cancer Consortium: An individual-participant meta-analysis.

BACKGROUND: Limited data from prospective studies suggest that higher dietary intake of long-chain omega-3 polyunsaturated fatty acids (LCn3PUFA), which hold anti-inflammatory properties, may reduce endometrial cancer risk; particularly among certain subgroups characterized by body mass and tumor pathology. MATERIALS AND METHODS: Data from 12 prospective cohort studies participating in the Epidemiology of Endometrial Cancer Consortium were harmonized as nested case-control studies, including 7268 endometrial cancer cases and 26,133 controls. Habitual diet was assessed by food frequency questionnaire, from which fatty acid intakes were estimated. Two-stage individual-participant data mixed effects meta-analysis estimated adjusted odds ratios (OR) and 95% confidence intervals (CI) through logistic regression for associations between study-specific energy-adjusted quartiles of LCn3PUFA and endometrial cancer risk. RESULTS: Women with the highest versus lowest estimated dietary intakes of docosahexaenoic acid, the most abundant LCn3PUFA in diet, had a 9% increased endometrial cancer risk (Quartile 4 vs. Quartile 1: OR 1.09, 95% CI: 1.01-1.19; P trend = 0.04). Similar elevated risks were observed for the summary measure of total LCn3PUFA (OR 1.07, 95% CI: 0.99-1.16; P trend = 0.06). Stratified by body mass index, higher intakes of LCn3PUFA were associated with 12-19% increased endometrial cancer risk among overweight/obese women and no increased risk among normal-weight women. Higher associations appeared restricted to White women. The results did not differ by cancer grade. CONCLUSION: Higher dietary intakes of LCn3PUFA are unlikely to reduce endometrial cancer incidence; rather, they may be associated with small to moderate increases in risk in some subgroups of women, particularly overweight/obese women.

Dietary Fats and All-cause and Breast Cancer-specific Mortality among Women with Breast Cancer: The Western New York Exposures and Breast Cancer Study.

BACKGROUND: Study results of prediagnostic dietary fat intake and breast cancer mortality have been inconclusive. While dietary fat subtypes [saturated (SFA), polyunsaturated (PUFA), and monounsaturated (MUFA) fatty acids] may have different biological effects, there is little evidence regarding the association of dietary fat and fat subtype intake with mortality after breast cancer diagnosis. METHODS: Women with incident, pathologically confirmed invasive breast cancer and complete dietary data (n = 793) were followed in a population-based study, the Western New York Exposures and Breast Cancer study. Usual intake before diagnosis of total fat and subtypes were estimated from a food frequency questionnaire completed at baseline. HRs and 95% confidence intervals (CI) for all-cause and breast cancer-specific mortality were estimated with Cox proportional hazards models. Interactions by menopausal status, estrogen receptor (ER) status, and tumor stage were examined. RESULTS: Median follow-up time was 18.75 years; 327 (41.2%) participants had died. Compared with lower intake, greater intake of total fat (HR, 1.05; 95% CI, 0.65-1.70), SFA (1.31; 0.82-2.10), MUFA (0.99; 0.61-1.60), and PUFA (0.99; 0.56-1.75) was not associated with breast cancer-specific mortality. There was also no association with all-cause mortality. Results did not vary by menopausal status, ER status, or tumor stage. CONCLUSIONS: Prediagnostic intake of dietary fat and fat subtypes was not associated with either all-cause or breast cancer mortality in a population-based cohort of breast cancer survivors. IMPACT: Understanding factors affecting survival among women diagnosed with breast cancer is critically important. Dietary fat intake prior to diagnosis may not impact that survival.

Caffeine intake from coffee and tea and invasive breast cancer incidence among postmenopausal women in the Women's Health Initiative.

Research findings remain inconsistent whether caffeine consumption is associated with invasive breast cancer. We aimed to examine the association between caffeine intake from coffee and tea and incident invasive breast cancer among postmenopausal women. We included 79 871 participants in the Women's Health Initiative Observational Study in the current analysis. Incident invasive breast cancers were identified through September 30, 2015. Caffeine intake (mg/day) from caffeinated and decaffeinated coffee and tea was estimated based on self-reported frequency (cups/day) and average caffeine amount in each beverage. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Subgroup analyses were conducted to explore whether associations of caffeine intake from coffee and tea with invasive breast cancer were different by age, race and ethnicity, smoking status, body mass index, history of hormone therapy use, alcohol intake and subtypes of breast cancer. During a median follow-up of 16.0 years, 4719 incident invasive breast cancers were identified. No significant association was found between caffeine intake from coffee and tea and invasive breast cancer incidence after adjusting for demographic, lifestyle and reproductive factors: HRs (95% CIs) for increasing quartiles of caffeine intake compared to the lowest were 1.03 (0.94, 1.12), 1.04 (0.95, 1.13) and 1.03 (0.94, 1.13), respectively (P-for-trend = .54). No significant associations of coffee and tea intake (cups/day) with overall breast cancer risk were found. Our findings are consistent with others showing no clear association of caffeine consumption with invasive breast cancer among postmenopausal women.

Types of garlic and their anticancer and antioxidant activity: a review of the epidemiologic and experimental evidence.

Garlic, an Allium vegetable, contains rich flavonoids organosulfur compounds (OSCs) that have potent anticancer properties. The aim of the review is to provide an overview of the different types of garlic, their active compounds, and the potential anticancer benefits with a focus on antioxidant activity. Animal and cell line studies have provided convincing evidence that garlic and its organosulfur compounds inhibit carcinogenesis through a number of events including induction of apoptosis, inhibiting cellular proliferation, scavenging radical oxygen species (ROS), increasing the activities of enzymes such as glutathione S-transferase, and reducing tumor size. Epidemiological studies showed compelling evidence that garlic consumption is associated with decreased risk of colorectal cancer, but inconsistent evidence for stomach, breast, and prostate cancers. Studies also suggest that the presence and potency of garlic OSCs varies with respect to the preparation and form of garlic. Further epidemiological studies with information on garlic form consumed or preparation methods and molecular studies regarding its antioxidant mechanisms, such as increasing enzymatic and nonenzymatic antioxidants levels, are warranted.

Onion and Garlic Intake and Breast Cancer, a Case-Control Study in Puerto Rico.

Studies show an inverse association between onion and garlic intake and risk of cancers of the lung, prostate, and stomach. There is limited evidence on the association between onion and garlic intake and breast cancer. We assessed this association in a population-based, case-control study in Puerto Rico. Incident, primary breast cancer cases (n = 314) were identified among women aged 30-79 from hospital and clinic records. Controls (n = 346) were women with no history of cancer other than nonmelanoma skin cancer, residents of the same area. Dietary intake was estimated using a food frequency questionnaire. Total onion and garlic intake included sofrito (a popular garlic- and onion-based condiment) intake frequency. Unconditional logistic regression assessed the association between onion and garlic consumption and breast cancer adjusting for age, education, parity, family history, body mass index, age at menarche, total energy, and smoking. Inverse associations with breast cancer were observed for moderate (OR (odds ratio) = 0.59, 95% CI (confidence interval): 0.35, 1.01) and high consumption (OR = 0.51, 95% CI: 0.30, 0.87) compared to low consumption of onion and garlic (Ptrend = 0.02). Results were similar when stratified by menopausal status. Study results suggest that high onion and garlic consumption is protective against breast cancer in this population.

Calcium plus vitamin D supplementation and lung cancer incidence among postmenopausal women in the Women's Health Initiative.

BACKGROUND: Magnesium and calcium are antagonistic in many physiologic processes. However, few studies have investigated the associations of supplemental calcium with lung cancer risk taking this antagonism into account. We evaluated the effect of calcium and vitamin D supplementation on lung cancer incidence and explored whether the ratio of baseline calcium to magnesium (Ca:Mg) intake modifies the association in the Women's Health Initiative (WHI) calcium plus vitamin D supplementation (CaD) trial. METHODS: The intervention phase of the WHI CaD was a double-blinded, randomized, placebo-controlled trial in 36,382 postmenopausal women aged 50-79 years, recruited at 40U.S. centers. Post-intervention follow-up continued among 29,862 (86%) of the surviving participants. Risk of lung cancer in association with CaD supplementation was evaluated using proportional hazard regression models. RESULTS: After 11 years' cumulative follow-up, there were 207 lung cancers (incidence 0.11% per year) in the supplement arm and 241 (0.12%) in the placebo arm (hazard ratio (HR) for the intervention, 0.91; 95% confidence interval (CI), 0.71-1.17). Subgroup analyses suggested that the HR for lung cancer varied by baseline Ca:Mg intake ratio among women who were current smokers at enrollment (p=0.04 for interaction). CONCLUSIONS: Over the entire follow-up period, calcium and vitamin D supplementation did not reduce lung cancer incidence among postmenopausal women. In exploratory analyses, an interaction was found for the baseline Ca:Mg intake ratio on lung cancer among current smokers at the trial entry. This findings need to be further studied for the role of calcium with magnesium in lung carcinogenesis in current smokers.

Associations of intakes of magnesium and calcium and survival among women with breast cancer: results from Western New York Exposures and Breast Cancer (WEB) Study.

Magnesium (Mg) and calcium (Ca) antagonizes each other in (re) absorption, cell cycle regulation, inflammation, and many other physiologic activities. However, few studies have investigated the association between magnesium and calcium intakes and breast cancer survival, and the interaction between calcium and magnesium intake. In a cohort of 1,170 women with primary, incident, and histologically confirmed breast cancer from Western New York State, we examined the relationship between intakes of these two minerals and survival. Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). Mean follow-up time was 87.4 months after breast cancer diagnosis; there were 170 deaths identified. After adjustment for known prognostic factors, and intakes of energy, total vitamin D and total calcium, higher dietary intake of magnesium was inversely associated with risk of all-cause mortality (HR = 0.50, 95% CI, 0.28-0.90 for highest vs. lowest tertile; p trend = 0.02). Likewise, a marginal association was found for total Magnesium intake from foods and supplements combined (HR = 0.58, 95% CI, 0.31-1.08; p trend = 0.09). The inverse association of higher total magnesium intake with all-cause mortality was primarily presented among postmenopausal women and was stronger among women who had a high Ca:Mg intake ratio (>2.59). There were no clear associations for prognosis with intake of calcium. We found that magnesium intake alone may improve overall survival following breast cancer, and the association may be stronger among those with high Ca:Mg intake ratio.

Intake of vitamins A, C, and E and folate and the risk of ovarian cancer in a pooled analysis of 10 cohort studies.

PURPOSE: Vitamins A, C, and E and folate have anticarcinogenic properties and thus might protect against cancer. Few known modifiable risk factors for ovarian cancer exist. We examined the associations between dietary and total (food and supplemental) vitamin intake and the risk of invasive epithelial ovarian cancer. METHODS: The primary data from 10 prospective cohort studies in North America and Europe were analyzed. Vitamin intakes were estimated from validated food frequency questionnaires in each study. Study-specific relative risks (RRs) were estimated using the Cox proportional hazards model and then combined using a random-effects model. RESULTS: Among 501,857 women, 1,973 cases of ovarian cancer occurred over a median follow-up period of 7-16 years across studies. Dietary and total intakes of each vitamin were not significantly associated with ovarian cancer risk. The pooled multivariate RRs [95% confidence intervals (CIs)] for incremental increases in total intake of each vitamin were 1.02 (0.97-1.07) for vitamin A (increment: 1,300 mcg/day), 1.01 (0.99-1.04) for vitamin C (400 mg/day), 1.02 (0.97-1.06) for vitamin E (130 mg/day), and 1.01 (0.96-1.07) for folate (250 mcg/day). Multivitamin use (vs. nonuse) was not associated with ovarian cancer risk (pooled multivariate RR = 1.00, 95% CI 0.89-1.12). Associations did not vary substantially by study, or by subgroups of the population. Greater vitamin intakes were associated with modestly higher risks of endometrioid tumors (n = 156 cases), but not with other histological types. CONCLUSION: These results suggest that consumption of vitamins A, C, and E and folate during adulthood does not play a major role in ovarian cancer risk.

Coffee, tea, and sugar-sweetened carbonated soft drink intake and pancreatic cancer risk: a pooled analysis of 14 cohort studies.

BACKGROUND: Coffee has been hypothesized to have pro- and anticarcinogenic properties, whereas tea may contain anticarcinogenic compounds. Studies assessing coffee intake and pancreatic cancer risk have yielded mixed results, whereas findings for tea intake have mostly been null. Sugar-sweetened carbonated soft drink (SSB) intake has been associated with higher circulating levels of insulin, which may promote carcinogenesis. Few prospective studies have examined SSB intake and pancreatic cancer risk; results have been heterogeneous. METHODS: In this pooled analysis from 14 prospective cohort studies, 2,185 incident pancreatic cancer cases were identified among 853,894 individuals during follow-up. Multivariate (MV) study-specific relative risks (RR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models and then pooled using a random-effects model. RESULTS: No statistically significant associations were observed between pancreatic cancer risk and intake of coffee (MVRR = 1.10; 95% CI, 0.81-1.48 comparing ≥900 to <0 g/d; 237g ≈ 8oz), tea (MVRR = 0.96; 95% CI, 0.78-1.16 comparing ≥400 to 0 g/d; 237g ≈ 8oz), or SSB (MVRR = 1.19; 95% CI, 0.98-1.46 comparing ≥250 to 0 g/d; 355g ≈ 12oz; P value, test for between-studies heterogeneity > 0.05). These associations were consistent across levels of sex, smoking status, and body mass index. When modeled as a continuous variable, a positive association was evident for SSB (MVRR = 1.06; 95% CI, 1.02-1.12). CONCLUSION AND IMPACT: Overall, no associations were observed for intakes of coffee or tea during adulthood and pancreatic cancer risk. Although we were only able to examine modest intake of SSB, there was a suggestive, modest positive association for risk of pancreatic cancer for intakes of SSB.

Folate intake and risk of pancreatic cancer: pooled analysis of prospective cohort studies.

BACKGROUND: Epidemiological studies evaluating the association between folate intake and risk of pancreatic cancer have produced inconsistent results. The statistical power to examine this association has been limited in previous studies partly because of small sample size and limited range of folate intake in some studies. METHODS: We analyzed primary data from 14 prospective cohort studies that included 319,716 men and 542,948 women to assess the association between folate intake and risk of pancreatic cancer. Folate intake was assessed through a validated food-frequency questionnaire at baseline in each study. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random effects model. All statistical tests were two-sided. RESULTS: During 7-20 years of follow-up across studies, 2195 pancreatic cancers were identified. No association was observed between folate intake and risk of pancreatic cancer in men and women (highest vs lowest quintile: dietary folate intake, pooled multivariable RR = 1.06, 95% CI = 0.90 to 1.25, P(trend) = .47; total folate intake [dietary folate and supplemental folic acid], pooled multivariable RR = 0.96, 95% CI = 0.80 to 1.16, P(trend) = .90). No between-study heterogeneity was observed (for dietary folate, P(heterogeneity) = .15; for total folate, P(heterogeneity) = .22). CONCLUSION: Folate intake was not associated with overall risk of pancreatic cancer in this large pooled analysis.

Intakes of vitamins A, C, and E and use of multiple vitamin supplements and risk of colon cancer: a pooled analysis of prospective cohort studies.

OBJECTIVE: To evaluate the associations between intakes of vitamins A, C, and E and risk of colon cancer. METHODS: Using the primary data from 13 cohort studies, we estimated study- and sex-specific relative risks (RR) with Cox proportional hazards models and subsequently pooled RRs using a random effects model. RESULTS: Among 676,141 men and women, 5,454 colon cancer cases were identified (7-20 years of follow-up across studies). Vitamin A, C, and E intakes from food only were not associated with colon cancer risk. For intakes from food and supplements (total), the pooled multivariate RRs (95% CI) were 0.88 (0.76-1.02, >4,000 vs. ≤ 1,000 µg/day) for vitamin A, 0.81 (0.71-0.92, >600 vs. ≤ 100 mg/day) for vitamin C, and 0.78 (0.66-0.92, > 200 vs. ≤ 6 mg/day) for vitamin E. Adjustment for total folate intake attenuated these associations, but the inverse associations with vitamins C and E remained significant. Multivitamin use was significantly inversely associated with colon cancer risk (RR = 0.88, 95% CI: 0.81-0.96). CONCLUSIONS: Modest inverse associations with vitamin C and E intakes may be due to high correlations with folate intake, which had a similar inverse association with colon cancer. An inverse association with multivitamin use, a major source of folate and other vitamins, deserves further study.

Risk of colon cancer and coffee, tea, and sugar-sweetened soft drink intake: pooled analysis of prospective cohort studies.

BACKGROUND: The relationships between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk remain unresolved. METHODS: We investigated prospectively the association between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk in a pooled analysis of primary data from 13 cohort studies. Among 731 441 participants followed for up to 6-20 years, 5604 incident colon cancer case patients were identified. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random-effects model. All statistical tests were two-sided. RESULTS: Compared with nonconsumers, the pooled multivariable relative risks were 1.07 (95% CI = 0.89 to 1.30, P(trend) = .68) for coffee consumption greater than 1400 g/d (about six 8-oz cups) and 1.28 (95% CI = 1.02 to 1.61, P(trend) = .01) for tea consumption greater than 900 g/d (about four 8-oz cups). For sugar-sweetened carbonated soft drink consumption, the pooled multivariable relative risk comparing consumption greater than 550 g/d (about 18 oz) to nonconsumers was 0.94 (95% CI = 0.66 to 1.32, P(trend) = .91). No statistically significant between-studies heterogeneity was observed for the highest category of each beverage consumed (P > .20). The observed associations did not differ by sex, smoking status, alcohol consumption, body mass index, physical activity, or tumor site (P > .05). CONCLUSIONS: Drinking coffee or sugar-sweetened carbonated soft drinks was not associated with colon cancer risk. However, a modest positive association with higher tea consumption is possible and requires further study.

Intakes of coffee, tea, milk, soda and juice and renal cell cancer in a pooled analysis of 13 prospective studies.

Specific beverage intake may be associated with the risk of renal cell cancer through a diluting effect of carcinogens, alterations of hormone levels, or other changes in the renal tubular environment, but few prospective studies have examined these associations. We evaluated the associations between coffee, tea, milk, soda and fruit and vegetable juice intakes and renal cell cancer risk in a pooled analysis of 13 prospective studies (530,469 women and 244,483 men). Participants completed a validated food-frequency questionnaire at baseline. Using the primary data, the study-specific relative risks (RRs) were calculated and then pooled using a random effects model. A total of 1,478 incident renal cell cancer cases were identified during a follow-up of 7-20 years across studies. Coffee consumption was associated with a modestly lower risk of renal cell cancer (pooled multivariate RR for 3 or more 8 oz (237 ml) cups/day versus less than one 8 oz (237 ml) cup/day = 0.84; 95% CI = 0.67-1.05; p value, test for trend = 0.22). Tea consumption was also inversely associated with renal cell cancer risk (pooled multivariate RR for 1 or more 8 oz (237 ml) cups/day versus nondrinkers = 0.85; 95% CI = 0.71-1.02; pvalue, test for trend = 0.04). No clear associations were observed for milk, soda or juice. Our findings provide strong evidence that neither coffee nor tea consumption increases renal cell cancer risk. Instead, greater consumption of coffee and tea may be associated with a lower risk of renal cell cancer. (c) 2007 Wiley-Liss, Inc.

Dietary lignan intakes and risk of breast cancer by tumor estrogen receptor status.

We examined the association of dietary lignan intake with estrogen receptor negative (ER-) and ER positive (ER+) breast cancer risk in a breast cancer case-control study. Among premenopausal women only, there was a reduced risk of ER- breast cancer for those in the highest compared to the lowest quartile of lignan intake suggesting that the observed negative association of lignans with breast cancer may be limited to ER- tumors.

Intakes of vitamins A, C and E and folate and multivitamins and lung cancer: a pooled analysis of 8 prospective studies.

Intakes of vitamins A, C and E and folate have been hypothesized to reduce lung cancer risk. We examined these associations in a pooled analysis of the primary data from 8 prospective studies from North America and Europe. Baseline vitamin intake was assessed using a validated food-frequency questionnaire, in each study. We calculated study-specific associations and pooled them using a random-effects model. During follow-up of 430,281 persons over a maximum of 6-16 years in the studies, 3,206 incident lung cancer cases were documented. Vitamin intakes were inversely associated with lung cancer risk in age-adjusted analyses; the associations were greatly attenuated after adjusting for smoking and other risk factors for lung cancer. The pooled multivariate relative risks, comparing the highest vs. lowest quintile of intake from food-only, were 0.96 (95% confidence interval (CI) 0.83-1.11) for vitamin A, 0.80 (95% CI 0.71-0.91) for vitamin C, 0.86 (95% CI 0.76-0.99) for vitamin E and 0.88 (95% CI 0.74-1.04) for folate. The association with vitamin C was not independent of our previously reported inverse association with beta-cryptoxanthin. Further, vitamin intakes from foods plus supplements were not associated with a reduced risk of lung cancer in multivariate analyses, and use of multivitamins and specific vitamin supplements was not significantly associated with lung cancer risk. The results generally did not differ across studies or by sex, smoking habits and lung cancer cell type. In conclusion, these data do not support the hypothesis that intakes of vitamins A, C and E and folate reduce lung cancer risk.

Dairy foods, calcium, and colorectal cancer: a pooled analysis of 10 cohort studies.

BACKGROUND: Studies in animals have suggested that calcium may reduce the risk of colorectal cancer. However, results from epidemiologic studies of intake of calcium or dairy foods and colorectal cancer risk have been inconclusive. METHODS: We pooled the primary data from 10 cohort studies in five countries that assessed usual dietary intake by using a validated food frequency questionnaire at baseline. For most studies, follow-up was extended beyond that in the original publication. The studies included 534 536 individuals, among whom 4992 incident cases of colorectal cancer were diagnosed between 6 and 16 years of follow-up. Pooled multivariable relative risks for categories of milk intake and quintiles of calcium intake and 95% confidence intervals (CIs) were calculated. All statistical tests were two-sided. RESULTS: Milk intake was related to a reduced risk of colorectal cancer. Compared with the lowest category of intake (<70 g/day), relative risks of colorectal cancer for increasing categories (70-174, 175-249, and > or =250 g/day) of milk intake were 0.94 (95% CI = 0.86 to 1.02), 0.88 (95% CI = 0.81 to 0.96), and 0.85 (95% CI = 0.78 to 0.94), respectively (P(trend)<.001). Calcium intake was also inversely related to the risk of colorectal cancer. The relative risk for the highest versus the lowest quintile of intake was 0.86 (95% CI = 0.78 to 0.95; P(trend) =.02) for dietary calcium and 0.78 (95% CI = 0.69 to 0.88; P(trend)<.001) for total calcium (combining dietary and supplemental sources). These results were consistent across studies and sex. The inverse association for milk was limited to cancers of the distal colon (P(trend)<.001) and rectum (P(trend) =.02). CONCLUSION: Higher consumption of milk and calcium is associated with a lower risk of colorectal cancer.

Dietary carotenoids and risk of lung cancer in a pooled analysis of seven cohort studies.

Intervention trials with supplemental beta-carotene have observed either no effect or a harmful effect on lung cancer risk. Because food composition databases for specific carotenoids have only become available recently, epidemiological evidence relating usual dietary levels of these carotenoids with lung cancer risk is limited. We analyzed the association between lung cancer risk and intakes of specific carotenoids using the primary data from seven cohort studies in North America and Europe. Carotenoid intakes were estimated from dietary questionnaires administered at baseline in each study. We calculated study-specific multivariate relative risks (RRs) and combined these using a random-effects model. The multivariate models included smoking history and other potential risk factors. During follow-up of up to 7-16 years across studies, 3,155 incident lung cancer cases were diagnosed among 399,765 participants. beta-Carotene intake was not associated with lung cancer risk (pooled multivariate RR = 0.98; 95% confidence interval, 0.87-1.11; highest versus lowest quintile). The RRs for alpha-carotene, lutein/zeaxanthin, and lycopene were also close to unity. beta-Cryptoxanthin intake was inversely associated with lung cancer risk (RR = 0.76; 95% confidence interval, 0.67-0.86; highest versus lowest quintile). These results did not change after adjustment for intakes of vitamin C (with or without supplements), folate (with or without supplements), and other carotenoids and multivitamin use. The associations generally were similar among never, past, or current smokers and by histological type. Although smoking is the strongest risk factor for lung cancer, greater intake of foods high in beta-cryptoxanthin, such as citrus fruit, may modestly lower the risk.

A plant food-based diet modifies the serum beta-sitosterol concentration in hyperandrogenic postmenopausal women.

Plant sterols or phytosterols are common components of plant foods, especially plant oils, seeds and nuts, cereals and legumes. The most common phytosterols are campesterol, beta-sitosterol and stigmasterol. Phytosterols have anticarcinogenic properties. Previous studies have suggested that populations with low breast cancer incidence often consume diets high in phytosterols. The present study evaluated whether consumption of a plant food-based diet, low in animal fat, may increase serum phytosterol levels in postmenopausal women. One hundred and four women volunteers were randomized to dietary intervention or control groups. The dietary intervention included intensive dietary counseling to replace animal products with plant-based foods. Subjects in the dietary intervention group participated twice a week for 18 wk in workshops about the preparation and consumption of a plant food-based diet. The absolute change in serum total phytosterol concentration was greater in the dietary intervention group than in the control group. The percent change tended to differ between groups (P = 0.06). However, only for beta-sitosterol did the absolute and percent changes within a group differ significantly between groups (P = 0.0017). The decrease in serum total cholesterol in the dietary intervention group (-14%) was greater than that in the control group (-4%; P = 0.0005). The results of this study show that circulating levels of phytosterols can be affected by dietary modification. These findings indicate that phytosterols, in particular beta-sitosterol, can be used as biomarkers of exposure in observational studies or as compliance indicators in dietary intervention studies of cancer prevention.

Risk of human ovarian cancer is related to dietary intake of selected nutrients, phytochemicals and food groups.

Intakes of specific nutrients and food groups have been shown previously to be related to ovarian cancer risk, but no studies, to our knowledge, have emphasized the effect of phytochemical intakes on this cancer. We conducted a case-control study of diet and ovarian cancer in western New York involving 124 primary, histologically confirmed ovarian cancer cases and 696 population-based controls, frequency matched to cases on age and county of residence. Diet was assessed with a detailed food-frequency questionnaire. Nutrient and phytochemical intakes were calculated from published food composition data. The odds ratios (OR) and 95% CI for risk of ovarian cancer with each nutrient, phytochemical and food group were estimated with unconditional logistic regression adjusting for age, education, total months menstruating, difficulty becoming pregnant, oral contraceptive use, menopausal status and energy intake. Compared with women in the lowest quintile of intake, reduced risks were observed for women in the highest quintile of intake of dietary fiber (OR 0.43, 95% CI, 0.20-0.94), total carotenoids (OR 0.33, 95% CI, 0.16-0.68), stigmasterol (OR 0.42, 95% CI, 0.20-0.87), total lignans (OR 0.43, 95% CI, 0.21-0.85), vegetables (OR 0.47, 95% CI, 0.23-0.97) and poultry (OR 0.45, 95% CI, 0.22-0.92). These results support a protective effect on ovarian cancer of phytoestrogen intakes, and our results support the hypothesis that a plant-based diet may be important in reducing risks of hormone-related neoplasms.