Fruit and vegetable intake and esophageal cancer in a large prospective cohort study

Changing patterns of esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) incidence worldwide suggest distinct etiologies. Although associations between fruit and vegetable intake and both ESCC and EAC have been found in multiple ecological and case-control studies, few prospective studies have investigated these associations. We prospectively examined these associations in 490,802 participants of the National Institutes of Health (NIH)-AARP Diet and Health Study using Cox models adjusted for age, alcohol intake, body mass index, cigarette smoking, education, physical activity and total energy intake. We present hazard ratios and 95% confidence intervals per serving per 1,000 calories. During 2,193,751 person years of follow-up, 103 participants were diagnosed with ESCC and 213 participants with EAC. We found a significant inverse association between total fruit and vegetable intake and ESCC risk (HR: 0.78, 95% CI: 0.67-0.91), but not EAC risk (0.98, 0.90-1.08). In models mutually adjusted for fruit and vegetable intake, the protective association with ESCC was stronger for fruits (0.73, 0.57-0.93) than for vegetables (0.84, 0.66-1.07). When we examined botanical subgroups, we observed significant protective associations for ESCC and intake of Rosacea (apples, peaches, nectarines, plums, pears and strawberries) and Rutaceae (citrus fruits). A significant inverse association between EAC and Chenopodiaceae (spinach) intake was observed. Results from our study suggest that the relation of fruit and vegetable intake and esophageal cancer risk may vary by histologic type.     

Coffee consumption and stomach cancer risk in a cohort of Swedish women

Few prospective studies have examined the relationship between coffee consumption and risk of stomach cancer, and the findings have been inconsistent. We prospectively investigated the association of long-term coffee consumption with risk of stomach cancer in a population-based cohort study of 61,433 Swedish women. Information on coffee consumption was collected with a food-frequency questionnaire at baseline (1987-1990) and updated in 1997. During a mean follow-up of 15.7 years from 1987 through June 2005, 160 incident cases of stomach cancer were diagnosed. Coffee consumption was positively associated with the risk of stomach cancer. Compared to women who consumed 1 or fewer cups of coffee per day, the multivariate hazard ratios were 1.49 (95% = 0.97-2.27) for women who drank 2-3 cups per day and 1.86 (95% CI = 1.07-3.25) for those who drank 4 or more cups per day (p for trend = 0.01). An increase of 1 cup of coffee per day was associated with a statistically significant 22% increased risk of stomach cancer (hazard ratio = 1.22; 95% CI = 1.05-1.42). These prospective data suggest that coffee consumption may increase the risk of stomach cancer in a dose-response manner. This finding needs to be confirmed in other prospective studies.     

Fruit and vegetable intake and head and neck cancer risk in a large United States prospective cohort study

Squamous head and neck cancers include cancers of the oral cavity, pharynx and larynx are the sixth leading cause of cancer mortality worldwide, resulting in more than 350,000 deaths annually. Intake of fruit and vegetables may protect against head and neck cancer incidence, although few prospective studies have examined this association. We investigated this relation in 490,802 United States participants of the NIH-AARP Diet and Health cohort using Cox proportional hazard models adjusted for potential confounders. During 2,193,751 person years of follow-up from 1995/1996-2000, 787 participants were diagnosed with head and neck cancer. We found an inverse association between total fruit and vegetable intake and head and neck cancer risk (per serving/day/1,000 calories, Hazard Ratio, 95% Confidence interval: 0.94, 0.89-0.99). In models mutually adjusted for fruit and vegetable intake, the association was stronger for vegetables (fifth vs. first quintile: 0.65, 0.50-0.85) than for fruits (fifth vs. first quintile: 0.87, 0.68-1.11). When further subclassified into botanical groups, those in the highest tertile of leguminosae (dried beans, string beans and peas, 0.80, 0.67-0.96), rosaceae (apples, peach, nectarines, plums, pears and strawberries, 0.60, 0.49-0.73), solanaceae (peppers and tomatoes, 0.82, 0.69-0.98) and umbelliferae (carrots, 0.73, 0.60-0.89) had decreased risk of head and neck cancer, but no significant associations were seen for 9 other botanical groups. Results from this large prospective observational study are consistent with previous case-control studies and support the hypothesis that total fruit and vegetable intake is associated with reduced risk of head and neck cancer.     

Fruit and vegetable intakes and risk of colorectal cancer and incident and recurrent adenomas in the PLCO cancer screening trial

The roles of fruits and vegetables in colorectal cancer development are unclear. Few prospective studies have assessed the association with adenoma, a known precursor to colorectal cancer. Our aim was to evaluate the association between fruit and vegetable intake and colorectal cancer development by evaluating the risk of incident and recurrent colorectal adenoma and colorectal cancer. Study participants were identified from the intervention arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Fruit and vegetable intake was measured using a self‐reported dietary questionnaire. Total fruit and vegetable intake was not associated with reduced incident or recurrent adenoma risk overall, but a protective association was observed for multiple adenomas (Odds ratio _{3rd tertile vs. 1st tertile} = 0.61, 95% confidence interval (CI): 0.38, 1.00). Higher fruit and vegetable intakes were associated with a borderline reduced risk of colorectal cancer (Hazard ratio (HR) _{3rd tertile vs. 1st tertile} = 0.82, 95% CI: 0.67, 1.01), which reached significance amongst individuals with high processed meat intakes (HR = 0.74, 95% CI: 0.55, 0.99). Our results suggest that increased fruit and vegetable intake may protect against multiple adenoma development and may reduce the detrimental effects of high processed meat intakes on colorectal cancer risk.     

Fruit and vegetable consumption and lung cancer risk: updated information from the European Prospective Investigation into Cancer and Nutrition (EPIC)

The association of fruit and vegetable consumption and lung cancer incidence was evaluated using the most recent data from the European Prospective Investigation into Cancer and Nutrition (EPIC), applying a refined statistical approach (calibration) to account for measurement error potentially introduced by using food frequency questionnaire data. Between 1992 and 2000, detailed information on diet and life-style of 478,590 individuals participating in EPIC was collected. During a median follow-up of 6.4 years, 1,126 lung cancer cases were observed. Multivariate Cox proportional hazard models were applied for statistical evaluation. In the whole study population, fruit consumption was significantly inversely associated with lung cancer risk while no association was found for vegetable consumption. In current smokers, however, lung cancer risk significantly decreased with higher vegetable consumption; this association became more pronounced after calibration, the hazard ratio (HR) being 0.78 (95% CI 0.62-0.98) per 100 g increase in daily vegetable consumption. In comparison, the HR per 100 g fruit was 0.92 (0.85-0.99) in the entire cohort and 0.90 (0.81-0.99) in smokers. Exclusion of cases diagnosed during the first 2 years of follow-up strengthened these associations, the HR being 0.71 (0.55-0.94) for vegetables (smokers) and 0.86 (0.78-0.95) for fruit (entire cohort). Cancer incidence decreased with higher consumption of apples and pears (entire cohort) as well as root vegetables (smokers). In addition to an overall inverse association with fruit intake, the results of this evaluation add evidence for a significant inverse association of vegetable consumption and lung cancer incidence in smokers.     

Fruit and vegetable consumption and squamous cell carcinoma of the esophagus in Japan: the JPHC study

Epidemiological studies have consistently demonstrated a decrease in the risk of esophageal squamous cell carcinoma (SCC) associated with higher fruit and vegetable intake, although the association has been examined predominantly in case-control studies. Here, we conducted a population-based prospective cohort study among middle-aged Japanese men. Lifestyle characteristics were investigated using a self-administered questionnaire, which included a validated food frequency questionnaire with 138 food and beverage items. We followed a total of 38,790 men aged 45-74 years. A Cox proportional hazards model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) for esophageal SCC, with adjustment for potential confounders. During 297,651 person-years of follow-up, a total of 116 men were newly diagnosed with esophageal SCC. An increase in consumption of total fruit and vegetables by 100 grams per day (g/day) was associated with an 11% decrease in the incidence of esophageal SCC (95% CI: 1-21%). In particular, a higher intake of cruciferous vegetables was associated with a significant decrease in risk (HR per 100 g/day: 0.44; 95% CI: 0.23-0.82). Stratified analyses revealed that the beneficial effect of fruits and vegetables was not able to completely offset the harmful effect of tobacco and alcohol. Our findings provide further evidence for the protective role of fruits and vegetables in the development of esophageal SCC. To effectively reduce the burden of this disease, however, priority should be placed on smoking and drinking cessation. Finally, cruciferous vegetables deserve further investigation as foods possibly effective in the prevention of esophageal SCC.     

Cohort analysis of fruit and vegetable consumption and lung cancer mortality in European men

Our aim was to examine the relationship between fruit and vegetable consumption and lung cancer mortality in a cohort of European males. Around 1970, dietary intake of Finnish, Italian and Dutch middle-aged men was assessed using a cross-check dietary history. Complete baseline information was available for 3,108 men, of whom 1,578 were baseline smokers. We used Cox proportional hazard analyses to calculate risk estimates for the consumption in country-specific tertiles on lung cancer in smokers. During 25 years of follow-up, 149 lung cancer deaths occurred in the smokers. Fruit consumption was inversely associated with lung cancer mortality among smokers; compared with the lowest, adjusted RRs for the intermediate and highest tertiles were 0.56 (0.37-0.84) and 0.69 (0.46-1.02), p-trend 0.05. Only in the Dutch cohort was this association statistically significant [adjusted relative risks (RRs) 1.00, 0.33 (0.16-0.70) and 0.35 (0.16-0.74), p-trend 0.004]. In Finland lung cancer risk was lower with higher fruit intake but not significantly, whereas in Italy no association was observed. Stratifying on cigarette smoking intensity (non, light and heavy) revealed an inverse association in the heavy smokers only [adjusted RRs (95% confidence intervals [CI]) 1; 0.47 (0.26-0.84); 0.40 (0.20-0.78)). Vegetable consumption was not related to lung cancer risk in smokers. However, analyses stratified on cigarette smoking intensity gave some indication for a lower lung cancer risk with higher intake. In conclusion, in this prospective analysis among European smoking men, fruit intake was inversely related to lung cancer mortality. This association was confined to heavy cigarette smokers.     

Red meat consumption and risk of cancers of the proximal colon, distal colon and rectum: the Swedish Mammography Cohort

Although there is considerable evidence that high consumption of red meat may increase the risk of colorectal cancer, data by subsite within the colon are sparse. The objective of our study was to prospectively examine whether the association of red meat consumption with cancer risk varies by subsite within the large bowel. We analyzed data from the Swedish Mammography Cohort of 61,433 women aged 40-75 years and free from diagnosed cancer at baseline in 1987-1990. Diet was assessed at baseline using a self-administered food-frequency questionnaire. Over a mean follow-up of 13.9 years, we identified 234 proximal colon cancers, 155 distal colon cancers and 230 rectal cancers. We observed a significant positive association between red meat consumption and risk of distal colon cancer (p for trend = 0.001) but not of cancers of the proximal colon (p for trend = 0.95) or rectum (p for trend = 0.32). The multivariate rate ratio for women who consumed 94 or more g/day of red meat compared to those who consumed less than 50 g/day was 2.22 (95% confidence interval [CI] 1.34-3.68) for distal colon, 1.03 (95% CI 0.67-1.60) for proximal colon and 1.28 (95% CI 0.83-1.98) for rectum. Although there was no association between consumption of fish and risk of cancer at any subsite, poultry consumption was weakly inversely related to risk of total colorectal cancer (p for trend = 0.04). These findings suggest that high consumption of red meat may substantially increase the risk of distal colon cancer. Future investigations on red meat and colorectal cancer risk should consider cancer subsites separately.     

Allium vegetable consumption,garlic supplement intake,and female breast carcinoma incidence

Summary The risk of female breast carcinoma in relation to onion and leek consumption and the use of garlic supplements was evaluated in the Netherlands Cohort Study on diet and cancer. Onions, leeks, and garlic contain specific compounds which might act as antimutagens. Animal experiments also suggest a possible role for these compounds in inhibition of mammary carcinogenesis.The Netherlands Cohort Study was started in 1986 among 120,852 Dutch men and women, aged 55-69 years, with collecting information on usual diet and important lifestyle characteristics. After 3.3 years of follow-up, 469 incident female breast carcinoma cases and 1713 female members of a randomly sampled control subcohort were available for analysis. Intake of onions or leeks was not associated with breast carcinoma risk after controlling for dietary and nondietary risk factors: the rate ratios in the highest intake categories were 0.95 (95% confidence interval 0.61–1.47) and 1.08 (95% confidence interval 0.79–1.48), respectively, compared with the lowest intake categories. The tests for trend in the rate ratios were neither significant. Garlic supplement use was also not associated with breast carcinoma incidence (rate ratio = 0.87, 95% confidence interval 0.58–1.31).In conclusion, we found no association between the consumption of onions or leeks, or garlic supplement use, and the incidence of female breast carcinoma.     

Alcohol and ovarian cancer risk: results from the Netherlands Cohort Study

OBJECTIVE: To study alcohol consumption in relation to ovarian cancer risk in a prospective cohort study. METHODS: The Netherlands Cohort Study on diet and cancer was initiated in 1986. A self-administered questionnaire on dietary habits and other risk factors for cancer was completed by 62,573 postmenopausal women. Follow-up for cancer was established by annual record linkages with the Netherlands Cancer Registry. After 9.3 years of follow-up, 214 incident invasive epithelial ovarian cancer cases and 2211 subcohort members with complete data on alcohol intake were available for analysis. All incidence rate ratios (RRs) were corrected for age, use of oral contraceptives, parity, height, body mass index, energy intake and current cigarette smoking. RESULTS: The RRs of ovarian cancer for women who consumed up to 5, 15 and >15 g of alcohol per day were 1.13 (95% confidence interval, 95% CI = 0.79-1.63), 0.85 (95% CI = 0.53-1.37) and 0.92 (95% CI = 0.55-1.54), respectively, compared to non-drinkers. Alcohol consumption in the form of wine, beer or liquor was not associated with ovarian cancer risk. CONCLUSION: These data do not suggest a major association between alcohol intake and ovarian cancer risk in this population.     

Consumption of vegetables and fruits and risk of subtypes of head–neck cancer in the Netherlands Cohort Study

There is limited prospective data on the relationship between consumption of vegetables and fruits and the risk of head–neck cancer (HNC) subtypes [i.e., oral cavity cancer (OCC), oro‐/hypopharyngeal cancer (OHPC) and laryngeal cancer (LC)]. Therefore, we investigated these associations within the Netherlands Cohort Study, in which 120,852 participants completed a 150‐item food frequency questionnaire at baseline in 1986. After 20.3 years of follow‐up, 415 cases of HNC (131 OCC, 88 OHPC, three oral cavity/pharynx unspecified or overlapping and 193 LC) and 3,898 subcohort members were available for case–cohort analysis using Cox proportional hazards models. Total vegetable and fruit consumption was inversely associated with risk of HNC overall [multivariable‐adjusted rate ratios for highest vs. lowest quartile: 0.61, 95% confidence interval (CI) 0.44–0.85, p trend 0.002] and all HNC subtypes, with the strongest associations for OCC. Total vegetable intake and total fruit intake were also associated with a decreased risk of HNC overall and HNC subtypes. No significant interaction was found between vegetable and fruit intake and alcohol consumption or cigarette smoking. In conclusion, in this large‐scale cohort study, consumption of vegetables and fruits was associated with a decreased risk of HNC overall and all subtypes. Consumption of vegetables and fruits (or of specific groups of them) may protect against HNC and its subtypes.     

ABO blood group and incidence of epithelial ovarian cancer

Previous studies have observed an association between ABO blood group and risk of certain malignancies, including ovarian cancer; however, no prospective studies of the association with ovarian cancer risk are available. Using data from 49,153 women in the Nurses' Health Study, we examined the association between ABO blood group and incidence of epithelial ovarian cancer. Study participants reported their blood type and Rh factor in 1996, and 234 women were diagnosed with incident ovarian cancer during 10 years of follow‐up. We used Cox proportional hazards regression to model the incidence rate ratios (RR) and 95% confidence intervals (CI) of ovarian cancer for each blood group category. Compared to women with blood group O, women with blood group AB or B had a nonsignificant 38% increase in ovarian cancer incidence (95% CI = 0.88–2.16 for blood group AB and 0.96–1.99 for blood group B), whereas blood group A was not associated with risk (RR = 0.95, 95% CI = 0.70–1.30). Combining blood groups AB and B, we observed a statistically significant positive association with presence versus absence of the B antigen overall (RR = 1.41, 95% CI = 1.06–1.88) and for the serous invasive subtype (RR = 1.53, 95% CI = 1.08–2.17). In this large, prospective cohort of women, presence of the B antigen was positively associated with ovarian cancer incidence, whereas blood group A was not associated with risk. Additional studies are needed to confirm this association and to explore the mechanisms through which blood group may influence ovarian cancer risk.     

Long‐term dietary acrylamide intake and risk of endometrial cancer in a prospective cohort of Swedish women

Acrylamide has been found in foods heated at high temperatures and there is evidence of carcinogenicity of acrylamide in experimental animals. However, the potential health risks of dietary acrylamide intake in humans remain uncertain. We examined the association between dietary acrylamide intake and the incidence of endometrial cancer among 61,226 participants of the Swedish Mammography Cohort who were cancer‐free at enrollment in 1987–1990 and completed a food frequency questionnaire at baseline and again in 1997. Cox proportional hazards models were used to estimate rate ratios with 95% confidence intervals, adjusted for endometrial cancer risk factors. During a mean follow‐up of 17.7 years, a total of 687 incident cases of endometrial adenocarcinoma were diagnosed in the cohort. We found no association between long‐term acrylamide intake and risk of endometrial cancer. The multivariate rate ratio of endometrial cancer for women in the highest quartile of acrylamide intake (mean, 33.8 μg/day) compared to those in the lowest quartile (mean, 15.9 μg/day) was 0.96 (95% CI, 0.76–1.21). The association did not vary materially by smoking status. In conclusion, these findings do not support the hypothesis that dietary acrylamide intake is positively associated with risk of endometrial cancer, at least not within the ranges of acrylamide consumed in this population. © 2008 Wiley‐Liss, Inc.     

Red and processed meat consumption and risk of ovarian cancer: a dose-response meta-analysis of prospective studies

Background:

During the last decade, the epidemiological evidence on consumption of meat and risk of ovarian cancer has accumulated.

Methods:

We assessed the relationship between red and processed meat consumption and risk of ovarian cancer with a dose-response meta-analysis. Relevant prospective cohort studies were identified by searching the PubMed and EMBASE databases through 21 January 2011, and by reviewing the reference lists of retrieved articles. Study-specific relative risk (RR) estimates were combined using a random-effects model.

Results:

Eight cohort studies were included in the meta-analysis. The summary RR for an intake increment of 100 g per week was 1.02 (95% confidence interval (CI), 0.99–1.04) for red meat and 1.05 (95% CI, 0.98–1.14) for processed meat. For an intake increment of four servings per week, the summary RR of ovarian cancer was 1.07 (95% CI, 0.97–1.19) for red meat (100 g per serving) and 1.07 (95% CI, 0.97–1.17) for processed meat (30 g per serving).

Conclusion:

Results from this dose-response meta-analysis suggest that red and processed meat consumption is not associated with risk of ovarian cancer. Although a lower consumption of red and processed meat may offer protection against other types of cancer, other interventions are needed to reduce the risk of ovarian cancer.     

Processed meat consumption, dietary nitrosamines and stomach cancer risk in a cohort of Swedish women

Processed meat consumption has been associated with an increased risk of stomach cancer in some epidemiological studies (mainly case-control). Nitrosamines may be responsible for this association, but few studies have directly examined nitrosamine intake in relation to stomach cancer risk. We prospectively investigated the associations between intakes of processed meat, other meats and N-nitrosodimethylamine (the most frequently occurring nitrosamine in foods) with risk of stomach cancer among 61,433 women who were enrolled in the population-based Swedish Mammography Cohort. Information on diet was collected at baseline (between 1987 and 1990) and updated in 1997. During 18 years of follow-up, 156 incident cases of stomach cancer were ascertained. High consumption of processed meat, but not of other meats (i.e., red meat, fish and poultry), was associated with a statistically significant increased risk of stomach cancer. After adjustment for potential confounders, the hazard ratios for the highest compared with the lowest category of intake were 1.66 (95% CI = 1.13-2.45) for all processed meats, 1.55 (95% CI = 1.00-2.41) for bacon or side pork, 1.50 (95% CI = 0.93-2.41) for sausage or hotdogs and 1.48 (95% CI= 0.99-2.22) for ham or salami. Stomach cancer risk was 2-fold higher among women in the top quintile of N-nitrosodimethylamine intake when compared with those in the bottom quintile (hazard ratio = 1.96; 95% CI = 1.08-3.58). Our findings suggest that high consumption of processed meat may increase the risk of stomach cancer. Dietary nitrosamines might be responsible for the positive association.     

Dietary advanced glycation end products and cancer risk in Japan: From the Takayama study

Few large epidemiological studies have evaluated the association between dietary advanced glycation end products (AGEs) and cancer risk. We evaluated the relationship between dietary AGE intake and the incidence of total cancer and site‐specific cancers in a population‐based prospective study in Japan. Participants were 14,173 men and 16,549 women who were 35 years of age or older in 1992. Dietary intake was assessed via a validated food frequency questionnaire. Intake of the AGE N ^ε‐carboxymethyl‐lysine (CML) was estimated using databases of CML content in foods determined using ultraperformance liquid chromatography–tandem mass spectrometry. Cancer incidence was confirmed through regional population‐based cancer registries. During a mean follow‐up period of 13.3 years, 1954 men and 1477 women developed cancer. We did not observe a significant association between CML intake and the risk of total cancer in men or women. In men, compared with the lowest quartile of CML intake, the hazard ratios of liver cancer for the second, third, and highest quartiles were 1.69 (95% CI: 0.92–3.10), 1.48 (95% CI: 0.77–2.84), and 2.10 (95% CI: 1.10–3.98; trend p = 0.04). Conversely, a decreased relative risk of male stomach cancer was observed for the second and highest quartiles of CML intake versus the lowest quartile, with hazard ratios of 0.73 and 0.67, respectively (trend p = 0.08). Our finding on the potential harmfulness of consuming AGEs on liver cancer risk is intriguing and warrants further study.     

Glycemic load,glycemic index and breast cancer risk in a prospective cohort of Swedish women

High‐glycemic load diets have been hypothesized to increase the risk of breast cancer but epidemiologic studies have yielded inconsistent findings. We examined the associations of carbohydrate intake, glycemic index and glycemic load with risk of overall and hormone receptor‐defined breast cancer in the Swedish Mammography Cohort, a population‐based cohort of 61,433 women who completed a food frequency questionnaire at enrollment in 1987–1990. During a mean follow‐up of 17.4 years, we ascertained 2,952 incident cases of invasive breast cancer. Glycemic load but not carbohydrate intake or glycemic index was weakly positively associated with overall breast cancer risk (p for trend = 0.05). In analyses stratified by estrogen receptor (ER) and progesterone receptor (PR) status of the breast tumors, we observed statistically significant positive associations of carbohydrate intake, glycemic index and glycemic load with risk of ER+/PR? breast cancer; the multivariate relative risks comparing extreme quintiles were 1.34 [95% confidence interval (CI) = 0.93–1.94; p for trend = 0.04] for carbohydrate intake, 1.44 (95% CI = 1.06–1.97; p for trend = 0.01) for glycemic index and 1.81 (95% CI = 1.29–2.53; p for trend = 0.0008) for glycemic load. No associations were observed for ER+/PR+ or ER?/PR? breast tumors. These findings suggest that a high carbohydrate intake and diets with high glycemic index and glycemic load may increase the risk of developing ER+/PR? breast cancer. © 2009 UICC     

Dietary melatonin and liver cancer incidence in Japan: From the Takayama study

There is some biological plausibility that exogenous melatonin plays a role in preventing liver carcinogenesis. There has been little research on the association between melatonin intake in a normal diet and health outcomes. We evaluated the association between dietary melatonin intake and the incidence of liver cancer in a population-based prospective study in Japan. This study included 30,824 residents of Takayama city who were 35 years of age or older in 1992 and had participated in the Takayama study, Japan. Dietary intake was assessed using a validated food frequency questionnaire at the baseline. Melatonin content in foods was measured by liquid chromatography–tandem mass spectrometry. Cancer incidence was confirmed through regional population-based cancer registries in Gifu. Liver cancer was defined as code C22 according to the International Classification of Diseases and Related Health Problems, 10th Revision. Hazard ratios for liver cancer were estimated for the tertile groups of melatonin intake using a Cox proportional hazards model. During the mean follow-up period of 13.6 years, 189 individuals developed liver cancer. Compared with subjects in the lowest tertile of melatonin intake, those in the middle and highest tertiles had decreased risks of liver cancer, with a significant linear trend after multivariate adjustments (hazard ratios: 0.64 and 0.65, respectively, trend p = 0.023). There was no significant interaction by sex (interaction p = 0.54). This initial finding, which needs to be confirmed by further studies, suggests that consuming melatonin-containing foods might play a role in the prevention of liver cancer.     

Carbohydrate intake, glycemic index and glycemic load in relation to risk of endometrial cancer: A prospective study of Swedish women

The associations of carbohydrate intake, glycemic index and glycemic load with endometrial cancer risk were examined among 61,226 participants of the Swedish Mammography Cohort who were cancer-free at enrollment between 1987 and 1990 and completed a food frequency questionnaire. During a mean follow-up of 15.6 years, through June 2005, 608 incident cases of endometrial adenocarcinoma were diagnosed. We observed no overall association between carbohydrate intake, glycemic index or glycemic load and incidence of endometrial cancer; the rate ratios (RRs) for the highest versus the lowest quintile were 1.12 (95% CI, 0.85-1.47) for carbohydrate intake, 1.00 (95% CI, 0.77-1.30) for glycemic index and 1.15 (95% CI, 0.88-1.51) for glycemic load. However, among obese women (body mass index, BMI > or =30 kg/m2), endometrial cancer incidence was nonsignificantly elevated in the top versus bottom quintiles of carbohydrate intake (RR, 1.68; 95% CI, 0.86-3.29) and glycemic load (RR, 1.57; 95% CI, 0.82-2.99). In a subanalysis of women who completed a follow-up questionnaire in 1997, which collected information on physical activity, carbohydrate intake and glycemic load were positively related to endometrial cancer risk among overweight women (BMI > or =25 kg/m2) with low physical activity. In this subgroup, the multivariate RRs comparing extreme quartiles were 1.90 (95% CI, 0.84-4.31) for carbohydrate intake and 2.99 (95% CI, 1.17-7.67) for glycemic load. Results from this cohort study suggest that a high carbohydrate intake and a high glycemic load may increase the risk of endometrial cancer among overweight women with low physical activity.