Saxon Graham

Cohort Studies of Fat Intake and the Risk of Breast Cancer — A Pooled Analysis

BACKGROUND Experiments in animals, international correlation comparisons, and case-control studies support an association between dietary fat intake and the incidence of breast cancer. Most cohort studies do not corroborate the association, but they have been criticized for involving small numbers of cases, homogeneous fat intake, and measurement errors in estimates of fat intake. METHODS We identified seven prospective studies in four countries that met specific criteria and analyzed the primary data in a standardized manner. Pooled estimates of the relation of fat intake to the risk of breast cancer were calculated, and data from study-specific validation studies were used to adjust the results for measurement error. RESULTS Information about 4980 cases from studies including 337,819 women was available. When women in the highest quintile of energy-adjusted total fat intake were compared with women in the lowest quintile, the multivariate pooled relative risk of breast cancer was 1.05 (95 percent confidence interval, 0.94 to 1.16). Relative risks for saturated, monounsaturated, and polyunsaturated fat and for cholesterol, considered individually, were also close to unity. There was little overall association between the percentage of energy intake from fat and the risk of breast cancer, even among women whose energy intake from fat was less than 20 percent. Correcting for error in the measurement of nutrient intake did not materially alter these findings. CONCLUSIONS We found no evidence of a positive association between total dietary fat intake and the risk of breast cancer. There was no reduction in risk even among women whose energy intake from fat was less than 20 percent of total energy intake. In the context of the Western lifestyle, lowering the total intake of fat in midlife is unlikely to reduce the risk of breast cancer substantially.

Smoking, alcohol, dentition and diet in the epidemiology of oral cancer

This matched case-control study was conducted in Western New York. The smoking, alcohol consumption, dental hygiene and diet of 290 cases were compared with those of 290 sex-, age-, and neighbourhood-matched controls. The results confirm earlier findings that cigarette smoking and alcohol consumption impart substantial risk of oral cancer. The results also confirm that poor oral hygiene increases the risk of oral cancer, although this effect is much smaller than those of cigarette smoking and alcohol consumption. The results suggest that, of macronutrients, intake of fat is more likely than those of protein or carbohydrate to be related to risk. Of micronutrients, calcium, sodium, riboflavin and retinol are associated with risk, while thiamin, niacin, and dietary fibre are associated with decreased risk. Although patterns of dietary effects are discernable, these effects are in general much weaker than are those of smoking and alcohol consumption.

Dietary Carotenoids and Risk of Lung Cancer in a Pooled Analysis of Seven Cohort Studies

Intervention trials with supplemental β-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. β-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 α-carotene, lutein/zeaxanthin, and lycopene were also close to unity. β-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 β-cryptoxanthin, such as citrus fruit, may modestly lower the risk.

Diet and alcohol consumption and lung cancer risk in the New York State Cohort (United States)

The relationship between diet and alcohol and lung cancer was evaluated among participants of the New York State Cohort (United States),comprising 27,544 men (395 cases) and 20,456 women (130 cases) who completed a brief mailed questionnaire in 1980. Participants were followed up through1987 with the assistance of the New York State Department of Healths Vital Statistics Section and Cancer Registry. Among men, inverse relationships with vitamin C, folate, and carotenoids, and positive associations with total fat, monounsaturated and saturated fat were observed after adjusting for age, education, cigarettes/day, years smoking, and total energy intake. The relationships observed with folate and saturated fat were stronger for heavy smokers. Also, the effect of folate, total fat, and monounsaturated fat seemed to be limited to squamous cell carcinomas. We found no indication that cholesterol or polyunsaturated fat was associated with lung cancer. Diet did not appear to exert a major role on lung cancer risk among women. Although diet modification should never be considered a substitute for smoking cessation, its role as an additional strategy in lung cancer prevention deserves attention.

Fruits, vegetables and lung cancer: A pooled analysis of cohort studies

Inverse associations between fruit and vegetable consumption and lung cancer risk have been consistently reported. However, identifying the specific fruits and vegetables associated with lung cancer is difficult because the food groups and foods evaluated have varied across studies. We analyzed fruit and vegetable groups using standardized exposure and covariate definitions in 8 prospective studies. We combined study‐specific relative risks (RRs) using a random effects model. In the pooled database, 3,206 incident lung cancer cases occurred among 430,281 women and men followed for up to 6–16 years across studies. Controlling for smoking habits and other lung cancer risk factors, a 16–23% reduction in lung cancer risk was observed for quintiles 2 through 5 vs. the lowest quintile of consumption for total fruits (RR = 0.77; 95% CI = 0.67–0.87 for quintile 5; p‐value, test for trend < 0.001) and for total fruits and vegetables (RR = 0.79; 95% CI = 0.69–0.90; p‐value, test for trend = 0.001). For the same comparison, the association was weaker for total vegetable consumption (RR = 0.88; 95% CI = 0.78–1.00; p‐value, test for trend = 0.12). Associations were similar between never, past, and current smokers. These results suggest that elevated fruit and vegetable consumption is associated with a modest reduction in lung cancer risk, which is mostly attributable to fruit, not vegetable, intake. However, we cannot rule out the possibility that our results are due to residual confounding by smoking. The primary focus for reducing lung cancer incidence should continue to be smoking prevention and cessation.

Relevance of major stress events as an indicator of disease activity prevalence in inflammatory bowel disease.

The impact of psychological stress in recurrence of inflammatory bowel disease (IBD) is unclear. Why some patients with ulcerative colitis (UC) or Crohns disease (CD) have unrelenting relapses whereas other IBD patients experience long periods of quiescent disease remains an enigma. The authors examined the risk of exposure to major stress events in clinical episodes of IBD. They followed up on 124 persons in a prospective study that monitored behavioral and biological characteristics for a period of 6 months. Stress-exposed subjects demonstrated increased risk of clinical episodes of disease when compared with unexposed subjects (RR = 2.6, 95% CI: 1.3-4.9). Elevated effect measures were highest for the domain of health-related stress (RR = 3.8, 95% CI: 1.5-9.9). In the multiple regression analysis, major stress events remained the most significant indicator of disease activity in the presence of the covariables considered. Only 7% of the variation in disease activity was uniquely attributed to stress. Baseline activity was the other notable indicator of subsequent disease activity in the study sample. All variables considered together explained 52% of the variance observed and implicated factors of potential clinical importance in monitoring recurrence of the disease.

Diet in the epidemiology of gastric cancer

We examined the nutritional epidemiology of gastric cancer in 293 cases and neighborhood-, age-, and sex-matched controls in communities throughout the counties of Niagara, Monroe, and Erie in western New York. The interview was highly detailed, requiring two and one-half hours to complete; it attempted to provide an estimate of total calories ingested as well as of macro- and micronutrients and behaviors that could affect alimentary exposures, such as the use of refrigeration. We found that risk was enhanced by sodium, fat, and retinol. Substantial reductions in risk were associated with ingestion of carotene, especially raw vegetables (including celery, cucumbers, carrots, green peppers, tomatoes, and onions), as well as with increased use of low-temperature food storage. Both refrigeration and carotene could inhibit oxidation products that could act as carcinogens in the stomach.

Diet and cancer of the esophagus

The reported dietary, alcohol consumption and smoking habits of 147 Roswell Park Memorial Institute white male patients diagnosed with cancer of the esophagus were compared with the reports of 264 white males of comparable ages with diagnoses other than cancer. Overall frequency of vegetable an fruit consumption was associated with lower risk; persons reporting fruit and/or vegetable consumption 31-40 times a month had significantly greater risk than those who reported consumption 81 times a month or more. Calculated indexes of vitamin A and vitamin C intake were similarly related to reduction in risk. Dose-response gradients were observed for frequency of vegetable and/or fruit consumption, as well as for vitamin A and C intake. The putative protective effect of vegetable and fruit intake remained evident after controlling for its possible association with smoking and drinking. Previously reported associations of smoking, alcohol use and social class, as measured by type of occupation, were replicated in these data. The findings of this investigation in instances of colon, lung, bladder, oral, and laryngeal cancers, and with evidence of tumor inhibition by vegetable properties in animals. Interpretation of the findings is limited by the difficulties of retrospective assessment of dietary intake and by possible confounding by other factors known to be related to esophageal cancer.

Diet in the epidemiology of endometrial cancer in western New York (United States).

AbstractObjectives: We examined diet and risk of endometrial cancer among women in the Western New York Diet Study (1986–1991). Methods: Self-reported frequency of use of 172 foods and beverages during the 2 years before the interview and other relevant data were collected by detailed interviews from 232 endometrial cancer cases and 639 controls, frequency-matched for age and county of residence. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression, adjusting for age, education, body mass index (BMI), smoking history, hypertension, diabetes, age at menarche, parity, oral contraceptive use, menopausal status, menopausal estrogen use, and energy. Results: Risks were reduced for women in the highest quartiles of intake of protein (OR 0.4, 95% CI: 0.2–0.9), dietary fiber (OR 0.5, 95% CI: 0.3–1.0), phytosterols (OR 0.6, 95% CI: 0.3–1.0), vitamin C (OR 0.5, 95% CI: 0.3–0.8) folate (OR 0.4, 95% CI: 0.2–0.7), alpha-carotene (OR 0.6, 95% CI: 0.4–1.0), beta-carotene (OR 0.4, 95% CI: 0.2–0.6), lycopene (OR 0.6, 95% CI: 0.4–1.0), lutein + zeaxanthin (OR 0.3, 95% CI: 0.2–0.5) and vegetables (OR 0.5, 95% CI: 0.3–0.9), but unrelated to energy (OR 0.9, 95% CI: 0.6–1.5) or fat (OR 1.6, 95% CI: 0.7–3.4). Conclusions: Our results support previous findings of reduced endometrial cancer risks associated with a diet high in plant foods.

Intakes of Selected Nutrients, Foods, and Phytochemicals and Prostate Cancer Risk in Western New York

Abstract: A number of epidemiological studies have suggested that diet may affect the etiology of prostate cancer, but few have investigated the impact of phytochemical intakes on this cancer. We conducted a case-control study of diet and prostate cancer in western New York involving 433 men with primary, histologically confirmed prostate cancer and 538 population-based controls, frequency matched to cases on age and county of residence. Diet was assessed with a detailed food-frequency questionnaire. We calculated daily intakes of nutrients and the phytochemicals β-sitosterol, campesterol, stigmasterol, total phytosterols, total lignan precursors, quercetin, and kaempferol based on published food composition data. Odds ratios (ORs) and 95% confidence intervals (CIs) describing the association of prostate cancer risk with selected nutrients, phytochemicals, and food groups were estimated with unconditional logistic regression. Compared with men in the lowest quartile of intake, reduced risks were observed for men in the highest quartile of intake of vitamin C (OR = 0.49; 95% CI = 0.33-0.74), β-carotene (OR = 0.53; 95% CI = 0.36-0.79), α-carotene (OR = 0.67; 95% CI = 0.47-0.97), lutein (OR = 0.55; 95% CI = 0.37-0.81), lycopene (OR = 0.62; 95% CI = 0.42-0.92), total lignan precursors (OR = 0.66; 95% CI = 0.47-0.94), quercetin (OR = 0.64; 95% CI = 0.44-0.92), and total vegetables (OR = 0.53; 95% CI = 0.36-0.79), but weak increased risks were observed for snacks and sweets (OR = 1.46; 95% CI = 0.95-2.23). Estimates associated with nutrients and phytochemicals were attenuated after adjustment for total vegetable intake. Nevertheless, our results support the hypothesis that a phytochemical-rich, plant-based diet is of importance in reducing risks of hormone-related neoplasms.