Leah M. Ferrucci

A Large Prospective Study of Meat Consumption and Colorectal Cancer Risk: An Investigation of Potential Mechanisms Underlying this Association

Although the relation between red and processed meat intake and colorectal cancer has been reported in several epidemiologic studies, very few investigated the potential mechanisms. This study examined multiple potential mechanisms in a large U.S. prospective cohort with a detailed questionnaire on meat type and meat cooking methods linked to databases for estimating intake of mutagens formed in meats cooked at high temperatures (heterocyclic amines, polycyclic aromatic hydrocarbons), heme iron, nitrate, and nitrite. During 7 years of follow-up, 2,719 colorectal cancer cases were ascertained from a cohort of 300,948 men and women. The hazard ratios (HR) and 95% confidence intervals (95% CI) comparing the fifth to the first quintile for both red (HR, 1.24; 95% CI, 1.09-1.42; P(trend) < 0.001) and processed meat (HR, 1.16; 95% CI, 1.01-1.32; P(trend) = 0.017) intakes indicated an elevated risk for colorectal cancer. The potential mechanisms for this relation include heme iron (HR, 1.13; 95% CI, 0.99-1.29; P(trend) = 0.022), nitrate from processed meats (HR, 1.16; 95% CI, 1.02-1.32; P(trend) = 0.001), and heterocyclic amine intake [HR, 1.19; 95% CI, 1.05-1.34; P(trend) < 0.001 for 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and HR, 1.17; 95% CI, 1.05-1.29; P(trend) <0.001 for 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx)]. In general, the elevated risks were higher for rectal cancer than for colon cancer, with the exception of MeIQx and DiMeIQx, which were only associated with colon cancer. In conclusion, we found a positive association for red and processed meat intake and colorectal cancer; heme iron, nitrate/nitrite, and heterocyclic amines from meat may explain these associations.

Factors that modify the association between knee pain and mobility limitation in older women: the Women's Health and Aging Study

OBJECTIVE To investigate the influence of pain severity, knee extensor muscle weakness, obesity, depression, and activity on the association between recent knee pain and limitation of usual and fast paced walking, and ability to rise from a chair. METHODS A cross sectional analysis of 769 older women (mean age 77.8, range 65–101) with physical disability, but no severe cognitive impairment. Severity of knee pain in the past month was classified as none, moderate, or severe. Mobility was measured using timed performance tests. RESULTS The prevalence of recent knee pain was 53% (408/769). One third of the women with pain reported it to be severe. In general, knee pain was only significantly associated with limited mobility if severe. Obesity, activity and, to a lesser extent, depression intensified the effects of pain. Knee extensor weakness did not. Obesity was a distinctive risk factor in that it substantially increased the risk of mobility limitation, but only in women with pain. In women who had severe pain, activity (walking more than three city blocks in the past week) increased the risk of walking disability more than inactivity. Depression had a minor, but statistically significant effect on walking ability, but not the ability to rise from a chair. CONCLUSION In older women with recent knee pain, a high pain severity score, obesity, and activity are important factors that increase the risk of mobility limitation.

Indoor tanning and risk of early-onset basal cell carcinoma

BACKGROUND Despite an increase in incidence of basal cell carcinoma (BCC) among young people and the ubiquity of indoor tanning in this population, few epidemiologic studies have investigated this exposure-disease relationship. OBJECTIVE We sought to evaluate the association between indoor tanning and early-onset BCC. METHODS Patients with BCC (n = 376) and control subjects with minor benign skin conditions (n = 390) who were younger than 40 years of age were identified through Yale Dermatopathology. Participants provided information on ever indoor tanning, age of initiation, frequency, duration, burns while tanning, and type of tanning device during an in-person interview. We calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariate logistic regression with never indoor tanners as the referent group. RESULTS Ever indoor tanning was associated with a 69% increased risk of early-onset BCC (95% CI 1.15-2.48). This association was stronger among females (OR 2.14, 95% CI 1.31-3.47), for multiple BCCs (OR 2.16, 95% CI 1.26-3.70), and for BCCs on the trunk and extremities (OR 2.81, 95% CI 1.57-5.02). Risk increased dose dependently with years using regular indoor tanning devices (P trend = .003), number of overall burns (P trend < .001), and burns to biopsy site (P trend < .001) from indoor tanning. Approximately one quarter (27%) of early-onset BCCs (or 43% among women) could be prevented if individuals never tanned indoors. LIMITATIONS Potential recall bias of indoor tanning by patients and generalizability of the control population suggest replication in other studies is warranted. CONCLUSIONS Indoor tanning was a strong risk factor for early-onset BCC, particularly among females. Indoor tanning should continue to be targeted by both policy-based and behavioral interventions, as the impact on BCC-associated morbidity may be substantial.

Intake of meat, meat mutagens, and iron and the risk of breast cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

Background:Epidemiological evidence on meat intake and breast cancer is inconsistent, with little research on potentially carcinogenic meat-related exposures. We investigated meat subtypes, cooking practices, meat mutagens, iron, and subsequent breast cancer risk.Methods:Among 52 158 women (aged 55–74 years) in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, who completed a food frequency questionnaire, 1205 invasive breast cancer cases were identified. We estimated meat mutagen and haem iron intake with databases accounting for cooking practices. Using Cox proportional hazards regression, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) within quintiles of intake.Results:Comparing the fifth to the first quintile, red meat (HR=1.23; 95% CI=1.00–1.51, P trend=0.22), the heterocyclic amine (HCA), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), (HR=1.26; 95% CI=1.03–1.55; P trend=0.12), and dietary iron (HR=1.25; 95% CI=1.02–1.52; P trend=0.03) were positively associated with breast cancer. We observed elevated, though not statistically significant, risks with processed meat, the HCA 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx), mutagenic activity, iron from meat, and haem iron from meat.Conclusion:In this prospective study, red meat, MeIQx, and dietary iron elevated the risk of invasive breast cancer, but there was no linear trend in the association except for dietary iron.

Meat and components of meat and the risk of bladder cancer in the NIH‐AARP Diet and Health Study

Meat could be involved in bladder carcinogenesis via multiple potentially carcinogenic meat‐related compounds related to cooking and processing, including nitrate, nitrite, heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs). The authors comprehensively investigated the association between meat and meat components and bladder cancer.

Dietary meat intake in relation to colorectal adenoma in asymptomatic women.

OBJECTIVES:No previous study has concurrently assessed the associations between meat intake, meat-cooking methods and doneness levels, meat mutagens (heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons), heme iron, and nitrite from meat and colorectal adenoma in asymptomatic women undergoing colonoscopy.METHODS:Of the 807 eligible women in a cross-sectional multicenter colonoscopy screening study, 158 prevalent colorectal adenoma cases and 649 controls satisfactorily completed the validated food frequency and meat questionnaires. Using an established meat mutagen database and new heme iron and nitrite databases, we comprehensively investigated the components of meat that may be involved in carcinogenesis. Using logistic regression, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) within quartiles of meat-related variables.RESULTS:Red meat was associated positively with colorectal adenoma (OR fourth vs. first quartile=2.02; 95% CI=1.06–3.83; P trend=0.38). Intake of pan-fried meat (OR=1.72; 95% CI=0.96–3.07; P trend=0.01) and the HCA: 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (OR=1.90; 95% CI=1.05–3.42; P trend=0.07) were also associated with an increased risk of colorectal adenoma. The new databases yielded lower estimates of heme iron and nitrite than previous assessment methods, although the two methods were highly correlated for both exposures. Although not statistically significant, there were positive associations between iron and heme iron from meat and colorectal adenoma.CONCLUSIONS:In asymptomatic women undergoing colonoscopy, colorectal adenomas were associated with high intake of red meat, pan-fried meat, and the HCA MeIQx. Other meat-related exposures require further investigation.

Meat consumption and the risk of incident distal colon and rectal adenoma

Background:Most studies of meat and colorectal adenoma have investigated prevalent events from a single screening, thus limiting our understanding of the role of meat and meat-related exposures in early colorectal carcinogenesis.Methods:Among participants in the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial who underwent baseline and follow-up sigmoidoscopy (n=17 072), we identified 1008 individuals with incident distal colorectal adenoma. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) for associations between meat and meat-related components and incident distal colorectal adenoma using multivariate logistic regression.Results:We observed suggestive positive associations for red meat, processed meat, haeme iron, and nitrate/nitrite with distal colorectal adenoma. Grilled meat (OR=1.56, 95% CI=1.04–2.36), well or very well-done meat (OR=1.59, 95% CI=1.05–2.43), 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP) (OR=1.75, 95% CI=1.17–2.64), benzo[a]pyrene (OR=1.53, 95% CI=1.06–2.20), and total mutagenic activity (OR=1.57, 95% CI=1.03–2.40) were positively associated with rectal adenoma. Total iron (diet and supplements) (OR=0.69, 95% CI=0.56–0.86) and iron from supplements (OR=0.65, 95% CI=0.44–0.97) were inversely associated with any distal colorectal adenoma.Conclusion:Our findings indicate that several meat-related components may be most relevant to early neoplasia in the rectum. In contrast, total iron and iron from supplements were inversely associated with any distal colorectal adenoma.

Lifetime history of indoor tanning in young people: a retrospective assessment of initiation, persistence, and correlates

BackgroundDespite educational and public health campaigns to convey the risks of indoor tanning, many individuals around the world continue to engage in this behavior. Few descriptive studies of indoor tanning have collected information pertaining to the lifetime history of indoor tanning, thereby limiting our ability to understand indoor tanning patterns and potentially target interventions for individuals who not only initiate, but continue to persistently engage in indoor tanning.MethodsIn-person interviews elicited detailed retrospective information on lifetime history of indoor tanning among white individuals (n = 401) under age 40 seen by a dermatologist for a minor benign skin condition. These individuals were controls in a case-control study of early-onset basal cell carcinoma. Outcomes of interest included ever indoor tanning in both males and females, as well as persistent indoor tanning in females - defined as females over age 31 who tanned indoors at least once in the last three or all four of four specified age periods (ages 11-15, 16-20, 21-30 and 31 or older). Multivariate logistic regression was used to identify sociodemographic and lifestyle correlates of ever and persistent indoor tanning in females.ResultsApproximately three-quarters (73.3%) of females and 38.3% of males ever tanned indoors, with a median age of initiation of 17.0 and 21.5, respectively. Among indoor tanners, 39.3% of females and 21.7% of males reported being burned while indoor tanning. Female ever indoor tanners were younger, had darker color eyes, and sunbathed more frequently than females who never tanned indoors. Using unique lifetime exposure data, 24.7% of female indoor tanners 31 and older persistently tanned indoors starting as teenagers. Female persistent indoor tanners drank significantly more alcohol, were less educated, had skin that tanned with prolonged sun exposure, and sunbathed outdoors more frequently than non-persistent tanners.ConclusionsIndoor tanning was strikingly common in this population, especially among females. Persistent indoor tanners had other high-risk behaviors (alcohol, sunbathing), suggesting that multi-faceted behavioral interventions aimed at health promotion/disease prevention may be needed in this population.

Epidemiological and Clinical Studies of Nutrition

In this review, we briefly summarize some of the key developments in nutritional epidemiology and cancer over the past two decades with a focus on the strengths and limitations of study designs and dietary assessment methods. We present the evidence on dietary fat, meat, fiber, antioxidant nutrients, and calcium in relation to carcinogenesis from large cohort studies and randomized clinical trials (RCTs) and refer to the conclusions of the 2007 World Cancer Research Fund/American Institute for Cancer Research summary report. One prominent theme that emerged is the lack of concordance of results from RCTs and observational studies. There are multiple potential reasons for these discrepancies, including differences in study population, dose and timing of the exposure, adherence to an intervention, length of follow-up, and the primary endpoint. Therefore, null findings of RCTs do not necessarily indicate a lack of effect for the tested dietary factors on cancer risk, as some of these nutrients may have chemopreventive effects if given at the right time and in the right dose. It is likely that potential benefits from diet are due to a combination of food constituents rather than single components acting in isolation. Future efforts need to recognize the integrative nature of dietary exposures and attempt to study nutrients in the larger context of the foods and diets in which they are consumed.

Complementary and alternative medicine use in chronic liver disease patients.

Goals To examine a wide range of sociodemographic and clinical characteristics as potential predictors of complementary and alternative medicine (CAM) use among chronic liver disease (CLD) patients, with a focus on CAM therapies with the greatest potential for hepatotoxicity and interactions with conventional treatments. Background There is some evidence that patients with CLD commonly use CAM to address general and CLD-specific health concerns. Study Patients enrolled in a population-based surveillance study of persons newly diagnosed with CLD between 1999 and 2001 were asked about current use of CAM specifically for CLD. Sociodemographic and clinical information was obtained from interviews and medical records. Predictors of CAM use were examined using univariate and multivariate logistic regression analysis. Results Of the 1040 participants, 284 (27.3%) reported current use of at least 1 of 3 CAM therapies of interest. Vitamins or other dietary supplements were the most commonly used therapy, reported by 188 (18.1%) patients. This was followed by herbal medicine (175 patients, 16.8%) and homeopathy (16 patients, 1.5%). Several characteristics were found to be independent correlates of CAM use: higher education and family income, certain CLD etiologies (alcohol, hepatitis C, hepatitis C and alcohol, and hepatitis B), and prior hospitalization for CLD. Conclusions Use of CAM therapies that have the potential to interact with conventional treatments for CLD was quite common among this population-based sample of patients with CLD. There is a need for patient and practitioner education and communication regarding CAM use in the context of CLD.