Dietary patterns and the risk of non-Hodgkin lymphoma: the multiethnic cohort

Understanding the interplay between chronic lymphocytic leukemia and type 2 diabetes

INTRODUCTION

Comorbidities play an important role in the management of chronic lymphocytic leukemia (CLL) and may influence survival and treatment outcomes. Considering the aging general population and increasing incidence of type 2 diabetes (T2D), a comprehensive understanding of the interplay between CLL and T2D is essential for optimizing care and outcomes.

AREAS COVERED

We present current knowledge on co-existing CLL and T2D including prevalence, shared etiology and risk factors and how the conditions and treatment hereof may influence the outcome of one another. A literature search was performed using PubMed with the cutoff date on 1 February 2024.

EXPERT OPINION

The increased mortality observed in persons with CLL who have co-existing T2D is partially ascribed to infections, prompting physicians managing individuals with both conditions to consider closer monitoring during instances of infection and individualized prophylaxis. People with CLL and T2D should be managed for CLL in accordance with the international working group on CLL criteria, and we recommend that physicians exercise particular care not to delay treatment for these individuals. Multidisciplinary approaches with involvement of several specialties may be required for optimal supportive care of co-occurring T2D and CLL.

Dietary intake of animal-based products and likelihood of follicular lymphoma and survival: A population-based family case-control study

Background

The association between dietary intake of foods of animal origin and follicular lymphoma (FL) risk and survival is uncertain. In this study, we examined the relationship between dietary intake of dairy foods and fats, meat, fish and seafoods, and the likelihood of FL and survival.

Methods

We conducted a population-based family case-control study in Australia between 2011 and 2016 and included 710 cases, 303 siblings and 186 spouse/partner controls. We assessed dietary intake of animal products prior to diagnosis (the year before last) using a structured food frequency questionnaire and followed-up cases over a median of 6.9 years using record linkage to national death data. We examined associations with the likelihood of FL using logistic regression and used Cox regression to assess association with all-cause and FL-specific mortality among cases.

Results

We observed an increased likelihood of FL with increasing daily quantity of oily fish consumption in the year before last (highest category OR = 1.96, CI = 1.02-3.77; p-trend 0.06) among cases and sibling controls, but no associations with spouse/partner controls. We found no association between the likelihood of FL and the consumption of other types of fish or seafood, meats or dairy foods and fats. In FL cases, we found no association between meat or oily fish intake and all-cause or FL-specific mortality.

Conclusion

Our study showed suggestive evidence of a positive association between oily fish intake and the likelihood of FL, but findings varied by control type. Further investigation of the potential role of environmental contaminants in oily fish on FL etiology is warranted.

Etiology of non-Hodgkin lymphoma: A review from epidemiologic studies

Non-Hodgkin lymphoma (NHL) contributes to significant cancer burden and mortality globally. In recent years, much insight into the causes of NHL has been gained by evaluating global differences through international collaboration and data pooling. NHL comprises different subtypes that are known to behave differently, exhibit different prognoses, and start in distinct cell types (B-cell, T-cell, and NK-cell, predominantly), and there is increasing evidence that NHL subtypes have different etiologies. Classification of NHL can be complex, with varying subtype frequencies, and is a consideration when evaluating geographic differences. Because of this, international pooling of well-executed epidemiologic studies has conferred power to evaluate NHL by subtype and confidence with minimal misclassification. Given the decreasing burden in some regions while cases rise in Asia, and especially China, this report focuses on a review of the established etiology of NHL from the epidemiologic literature in recent decades, highlighting work from China. Topics covered include demographic patterns and genetic determinants including family history of NHL, as well as infection and immunosuppression, lifestyle, environment, and certain occupational exposures contributing to increased disease risk.

Adherence to the mediterranean diet and lymphoma risk in the european prospective investigation into cancer and nutrition

There is a growing evidence of the protective role of the Mediterranean diet (MD) on cancer. However, no prospective study has yet investigated its influence on lymphoma. We evaluated the association between adherence to the MD and risk of lymphoma and its subtypes in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The analysis included 476,160 participants, recruited from 10 European countries between 1991 and 2001. Adherence to the MD was estimated through the adapted relative MD (arMED) score excluding alcohol. Cox proportional hazards regression models were used while adjusting for potential confounders. During an average follow-up of 13.9 years, 3,136 lymphomas (135 Hodgkin lymphoma [HL], 2,606 non-HL and 395 lymphoma not otherwise specified) were identified. Overall, a 1-unit increase in the arMED score was associated with a 2% lower risk of lymphoma (95% CI: 0.97; 1.00, p-trend = 0.03) while a statistically nonsignificant inverse association between a high versus low arMED score and risk of lymphoma was observed (hazard ratio [HR]: 0.91 [95% CI 0.80; 1.03], p-trend = 0.12). Analyses by lymphoma subtype did not reveal any statistically significant associations. Albeit with small numbers of cases (N = 135), a suggestive inverse association was found for HL (HR 1-unit increase = 0.93 [95% CI: 0.86; 1.01], p-trend = 0.07). However, the study may have lacked statistical power to detect small effect sizes for lymphoma subtype. Our findings suggest that an increasing arMED score was inversely related to the risk of overall lymphoma in EPIC but not by subtypes. Further large prospective studies are warranted to confirm these findings.

Meat, fish, dairy products and risk of hematological malignancies in adults - a systematic review and meta-analysis of prospective studies

This systematic review and meta-analysis of cohort studies examine the association of meat, fish, and dairy product consumption with the risk of hematological neoplasms in adults. Thirteen studies encompassing 1,480,986 participants and 10,442 incident cases were included. Red or processed meat consumption was not associated with the risk of leukemia, acute myeloid leukemia, non-Hodgkin lymphoma (NHL) and small lymphocytic lymphoma/chronic lymphocytic leukemia (CLL/SLL). Poultry consumption did not seem to affect the risk of leukemia, NHL, CLL/SLL, and multiple myeloma (MM). Fish consumption was not associated with leukemia, NHL, CLL/SLL, and MM risk. Interestingly though, fish consumption was positively associated with myeloid leukemia risk (pooled RR = 1.74, 95% CI: 1.22-2.47, random effects, highest vs. lowest category). Milk and dairy product consumption was not associated with NHL and leukemia risk. In conclusion, methodologically strict prospective studies are mandatory, in order to extract reliable conclusions concerning the role of these dietary factors in hematological malignancies.

Adherence to the Western, Prudent, and Mediterranean dietary patterns and chronic lymphocytic leukemia in the MCC-Spain study

Diet is a modifiable risk factor for several neoplasms but evidence for chronic lymphocytic leukemia (CLL) is sparse. Previous studies examining the association between single-food items and CLL risk have yielded mixed results, while few studies have been conducted on overall diet, reporting inconclusive findings. This study aimed to evaluate the association between adherence to three dietary patterns and CLL in the multicase-control study (MCC-Spain) study. Anthropometric, sociodemographic, medical and dietary information was collected for 369 CLL cases and 1605 controls. Three validated dietary patterns, Western, Prudent and Mediterranean, were reconstructed in the MCC-Spain data. The association between adherence to each dietary pattern and CLL was assessed, overall and by Rai stage, using mixed logistic regression models adjusted for potential confounders. High adherence to a Western dietary pattern (i.e. high intake of high-fat dairy products, processed meat, refined grains, sweets, caloric drinks, and convenience food) was associated with CLL [ORQ4 vs. Q1=1.63 (95%CI 1.11; 2.39); P-trend=0.02; OR 1-SD increase=1.19 (95%CI: 1.03; 1.37)], independently of Rai stages. No differences in the association were observed according to sex, Body Mass Index, energy intake, tobacco, physical activity, working on a farm, or family history of hematologic malignancies. No associations were observed for Mediterranean and Prudent dietary patterns and CLL. This study provides the first evidence for an association between a Western dietary pattern and CLL, suggesting that a proportion of CLL cases could be prevented by modifying dietary habits. Further research, especially with a prospective design, is warranted to confirm these findings.

Meat intake and non-Hodgkin lymphoma: a meta-analysis of observational studies

PURPOSE

High intake of meat has been inconsistently associated with increased risk of non-Hodgkin lymphoma (NHL). We carried out a meta-analysis to summarize the evidence of published observational studies reporting association between red meat and processed meat intake and NHL risk.

METHODS

Analytical studies reporting relative risks with 95 % confidence intervals (95 % CI) for the association between intake of red and/or processed meat and NHL or major histological subtypes were eligible. We conducted random-effects meta-analysis comparing lowest and highest intake categories and dose-response meta-analysis when risk estimates and intake levels were available for more than three exposure classes.

RESULTS

Fourteen studies (four cohort and ten case-control) were included in the meta-analysis, involving a total of 10,121 NHL cases. The overall relative risks of NHL for the highest versus the lowest category of consumption were 1.14 (95 % CI 1.03, 1.26) for red meat and 1.06 (95 % CI 0.98, 1.15) for processed meat. Significant associations were present when the analysis was restricted to case-control studies but not when restricted to cohort studies. No significant associations were found for major NHL etiological subtypes. Dose-response meta-analysis could be based only on eight studies that provided sufficient data, and compared to no meat consumption, the overall NHL relative risk increased nonlinearly with increased daily intake of red meat.

CONCLUSION

The observed positive association between red meat consumption and NHL is mainly supported by the effect estimates coming from case-control studies and is affected by multiple sources of heterogeneity. This meta-analysis provided mixed and inconclusive evidences on the supposed relationship between red and processed meat consumption and NHL.

Non-Hodgkin lymphoma in Southern Africa: review of 487 cases from The International Non-Hodgkin Lymphoma Classification Project

Comparative data on the distribution of non-Hodgkin lymphoma (NHL) subtypes in Southern Africa (SAF) is scarce. In this study, five expert haematopathologists classified 487 consecutive cases of NHL from SAF using the World Health Organization classification, and compared the results to North America (NA) and Western Europe (WEU). Southern Africa had a significantly lower proportion of low-grade (LG) B-NHL (34·3%) and a higher proportion of high-grade (HG) B-NHL (51·5%) compared to WEU (54·5% and 36·4%) and NA (56·1% and 34·3%). High-grade Burkitt-like lymphoma was significantly more common in SAF (8·2%) than in WEU (2·4%) and NA (2·5%), most likely due to human immunodeficiency virus infection. When SAF patients were divided by race, whites had a significantly higher frequency of LG B-NHL (60·4%) and a lower frequency of HG B-NHL (32·7%) compared to blacks (22·5% and 62·6%), whereas the other races were intermediate. Whites and other races had a significantly higher frequency of follicular lymphoma and a lower frequency of Burkitt-like lymphoma compared to blacks. The median ages of whites with LG B-NHL, HG B-NHL and T-NHL (64, 56 and 67 years) were significantly higher than those of blacks (55, 41 and 34 years). Epidemiological studies are needed to better understand these differences.

Epidemiology and etiology of non-hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) consists of many histologically and biologically distinct lymphoid malignancies with poorly understood, but possibly distinct, etiologies. The patterns of incidence and time trend vary not only by age, sex, and race/ethnicity in the USA, but also show significant geographic differences, suggesting the potential role of infectious agents, environmental factors, and lifestyle factors in addition to host genetic status in the development of NHL. Important pathogenetic mechanisms include immune modulation and chronic antigen stimulation. Epidemiologic studies in the past two decades have provided intriguing new insights on the possible causes of lymphoma and support the idea that there is some mechanistic commonality of lymphomagenesis, but significant etiologic heterogeneity clearly exists. This review presents a summary of the current understanding of the descriptive epidemiology and etiology of NHL and suggests areas of focus for future epidemiologic research.

Racial differences in mantle cell lymphoma in the United States

Background

MCL (mantle cell lymphoma) is a rare subtype of NHL (non-Hodgkin lymphoma) with mostly poor prognosis. Different races have different etiology, presentation, and progression patterns.

Methods

Data were analyzed on MCL patients in the United States reported to the SEER (Surveillance, Epidemiology, and End Results) database between 1992 and 2009. SEER contains the most comprehensive population-based cancer information in the U.S., covering approximately 28% of the population. Racial groups analyzed included non-Hispanic whites, Hispanic whites, blacks, and Asians/PIs (Pacific Islanders). Patient characteristics, age-adjusted incidence rate, and survival rate were compared across races. Stratification by age, gender, and stage at diagnosis was considered. Multivariate analysis was conducted on survival.

Results

In the analysis of patients’ characteristics, distributions of gender, marital status, age at diagnosis, stage, and extranodal involvement were significantly different across races. For all three age groups and both male and female, non-Hispanic whites have the highest incidence rates. In the analysis of survival, for cancers diagnosed in the period of 1992–2004, no significant racial difference is observed. For cancers diagnosed in the period of 1999–2004, significant racial differences exist for the 40–64 age group and stage III and IV cancers.

Conclusions

Racial differences exist among MCL patients in the U.S. in terms of patients’ characteristics, incidence, and survival. More extended data collection and analysis are needed to more comprehensively describe and understand the racial differences.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-764) contains supplementary material, which is available to authorized users.

Dietary patterns and the risk of non-Hodgkin lymphoma

OBJECTIVE

Previous studies examining the role of single foods or nutrients in the aetiology of non-Hodgkin lymphoma (NHL) have produced inconsistent findings. Few studies have examined associations for dietary patterns, which may more accurately reflect patterns of consumption and the complexity of dietary intake. The objective of the present study was to examine whether dietary patterns identified by factor analysis were associated with NHL risk.

DESIGN

Case-control.

SETTING

Population-based sample residing in Nebraska from 1999 to 2002.

SUBJECTS

A total of 336 cases and 460 controls.

RESULTS

Factor analysis identified two major dietary patterns: (i) a 'Meat, Fat and Sweets' dietary pattern characterized by high intakes of French fries, red meat, processed meat, pizza, salty snacks, sweets and desserts, and sweetened beverages; and (ii) a 'Fruit, Vegetables and Starch' dietary pattern characterized by high intakes of vegetables, fruit, fish, and cereals and starches. In multivariable logistic regression models, the 'Meat, Fat and Sweets' dietary pattern was associated with an increased risk of overall NHL (ORQ4 v. Q1 = 3·6, 95 % CI 1·9, 6·8; P trend = 0·0004), follicular lymphoma (ORQ4 v. Q1 = 3·1, 95 % CI 1·2, 8·0; P trend = 0·01), diffuse large B-cell lymphoma (ORQ4 v. Q1 = 3·2, 95 % CI 1·1, 9·0; P trend = 0·09) and marginal zone lymphoma (ORQ4 v. Q1 = 8·2, 95 % CI 1·3, 51·2; P trend = 0·05). No association with overall or subtype-specific risk was detected for the 'Fruit, Vegetables and Starch' dietary pattern. No evidence of heterogeneity was detected across strata of age, sex, BMI, smoking status or alcohol consumption.

CONCLUSIONS

Our results suggest that a dietary pattern high in meats, fats and sweets may be associated with an increased risk of NHL.

Incidence of haematological malignancies by ethnic group in England, 2001-7

The aetiology of most haematological malignancies is largely unknown. Studies of migrant populations can provide insights into the relative importance of genetic and environmental risk factors for these diseases. This study compares incidence rates in British Indians, Pakistanis, Bangladeshis, Black Africans, Black Caribbeans, Chinese and Whites in England from 2001 to 2007. We analysed 134,302 haematological cancer registrations with ethnicity obtained by linkage to the Hospital Episodes Statistics database. Mid-year population estimates from 2001 to 2007 were used. Incidence rate ratios adjusted for age, sex and income were calculated, comparing the six ethnic groups to Whites and to each other. Whites had the highest rates for most subtypes. However, Blacks experienced more than double the incidence of plasma cell and mature T-cell neoplasms compared to other ethnic groups. There were also significant differences in incidence between Indians, Pakistanis and Bangladeshis for Hodgkin lymphoma and mature B-cell neoplasms and between Black African and Black Caribbeans for mature B-cell and other lymphoid neoplasms (all P < 0.001). Our results show that the risk of haematological cancers varies greatly by ethnic group, including within those groups that have traditionally been grouped together (South Asians and Blacks) with many of these differences not explicable by known risk factors.

Epidemiology of non-Hodgkin lymphoma

Non-Hodgkin Lymphoma (NHL) occurs worldwide although there is notable geographical variation in incidence and subtype distribution. These differences are due to a combination of demographic, environmental and other unidentified factors. A dramatic increase in NHL incidence was seen starting around 1970, with subsequent stabilization 10 years ago. Despite this plateau, the number of new cases in many countries will increase significantly in coming years due primarily to aging populations. In the majority of cases, strong risk factors are not identifiable. There is significant epidemiological heterogeneity between NHL subtypes, yet cancer registries have tended to consider NHL as a single entity. This is one of several epidemiological obstacles discussed.

Exploring risk factors for follicular lymphoma

Follicular lymphoma (FL) is an indolent malignancy of germinal center B cells with varied incidence across racial groups and geographic regions. Improvements in the classification of non-Hodgkin lymphoma subtypes provide an opportunity to explore associations between environmental exposures and FL incidence. Our paper found that aspects of Western lifestyle including sedentary lifestyle, obesity, and diets high in meat and milk are associated with an increased risk of FL. Diets rich in fruits and vegetables, polyunsaturated fatty acids, vitamin D, and certain antioxidants are inversely associated with FL risk. A medical history of Sjogren's syndrome, influenza vaccination, and heart disease may be associated with FL incidence. Associations between FL and exposure to pesticides, industrial solvents, hair dyes, and alcohol/tobacco were inconsistent. Genetic risk factors include variants at the 6p21.32 region of the MHC II locus, polymorphisms of the DNA repair gene XRCC3, and UV exposure in individuals with certain polymorphisms of the vitamin D receptor. Increasing our understanding of risk factors for FL must involve integrating epidemiological studies of genetics and exposures to allow for the examination of risk factors and interactions between genes and environment.

Erythrocyte membrane fatty acid composition, serum lipids, and non-Hodgkin's lymphoma risk in a nested case-control study: the multiethnic cohort

PURPOSE

Composition of dietary fatty acid intake, which influences cytokine production, may contribute to the development of non-Hodgkin's lymphoma (NHL). Serum lipid levels may serve as biomarkers of inflammation associated with NHL risk.

METHODS

We conducted a case-control analysis (275 cases and 549 controls) nested within the Multiethnic Cohort Study (whites, Japanese Americans, Latinos, African Americans, and Native Hawaiians) to examine the association of prediagnostic, erythrocyte membrane phospholipid fatty acid composition, and serum cholesterol and triglyceride (TG) concentrations with the risk of NHL. Conditional logistic regression was used to calculate odds ratios (OR) and 95 % confidence intervals (CI) by tertiles of biomarker concentrations.

RESULTS

Higher total saturated fatty acids (SFA) were associated with an increase in NHL risk (OR(T3 vs. T1) = 1.57 [95 % CI: 1.03-2.39]; p(trend) = 0.01), whereas no associations were detected for total n-3 or n-6 polyunsaturated fatty acids. Inverse associations were observed for total cholesterol (TC; OR (T3 vs. T1) = 0.51 [95 % CI: 0.35-0.74]; p(trend) < 0.0001) and high-density lipoprotein cholesterol (HDL-C; OR (T3 vs. T1) = 0.47 [95 % CI: 0.31-0.71]; p(trend) = 0.0001) but not for low-density lipoprotein cholesterol or TG. Adjustment for the use of lipid-lowering medication did not modify the results substantially.

CONCLUSIONS

This prospective biomarker investigation offers supportive evidence for an adverse effect of higher erythrocyte membrane SFA levels on NHL risk, but preclinical effects cannot be excluded. Inverse relations between prediagnostic, circulating TC and HDL-C and NHL risk may be due to reverse causation or a result of protective actions of these lipids and lipoproteins.

Meat intake and risk of non-Hodgkin lymphoma

We conducted a population-based, case-control study to test the hypothesis that consumption of meat and meat-related mutagens increases the risk of non-Hodgkin lymphoma (NHL), and whether the associations are modified by N-acetyltransferase (NAT) 1 and 2. Participants (336 cases and 460 controls) completed a 117-item food frequency questionnaire. The risk of NHL was associated with a higher intake of red meat (OR = 1.5; CI, 1.1-2.2), total fat (OR = 1.4; CI, 1.0-2.1), and oleic acid (OR = 1.5; CI, 1.0-2.2). NHL risk was also associated with a higher intake of very well-done pork (OR = 2.5; 95 % CI, 1.4-4.3) and the meat-related mutagen MeIQx (OR = 1.6; 95 % CI, 1.1-2.3). Analyses of the major NHL histologic subtypes showed a positive association between diffuse large B cell lymphoma (DLBCL) and higher intake of red meat (OR = 2.1; 95 % CI, 1.1-3.9) and the association was largely due to meat-related mutagens as a positive association was observed for higher intakes of both MeIQx (OR = 2.4; 95 % CI, 1.2-4.6) and DiMeIQx (OR = 1.9; 95 % CI, 1.0-3.5). Although the OR for follicular lymphoma (FL) was also increased with a higher red meat intake (OR = 1.9; 95 % CI, 1.1-3.3), the association appeared to be due to increased oleic acid (OR = 1.7; 95 % CI: 0.9-3.1). We found no evidence that polymorphisms in NAT1 or NAT2 modify the association between NHL and meat-related mutagens. Our results provide further evidence that red meat consumption is associated with an increase in NHL risk, and new evidence that the specific components of meat, namely fat and meat-related mutagens, may be impacting NHL subtype risk differently.

Diet and non-Hodgkin's lymphoma risk

BACKGROUND

The role of dietary factors in the epidemiology of Non-Hodgkin's lymphoma (NHL) remains largely undefined. Dietary habits may play a role in the etiology of NHL by influencing the immune system.

METHODS

Dietary patterns and the risk of NHL were analyzed in a case control study; including 170 NHL cases and 190 controls. All subjects completed a validated food-frequency questionnaire. The dietary pattern was investigated separately and in nine nutritional groups. Crosstab tables were used to estimate the odds ratios (OR), and P(trend).

RESULTS

Consumption of highest versus lowest quartile of proteins (OR, 8.088 P(trend)=0.000), fats (OR, 6.17 P(trend)=0.000) and sweets (OR, 8.806 P(trend)=0.000) were associated with a significantly increased NHL risk. The inverse association was found for fresh fruits (OR, 0.117 P(trend)=0.000) and vegetables (OR, 0.461 P(trend)=0.010).

CONCLUSION

An association between dietary intake and the risk of NHL is biologically plausible due to immunosuppressive effects of fat and animal proteins, and antioxidant properties of vegetables and fruits.

Meat intake is not associated with risk of non-Hodgkin lymphoma in a large prospective cohort of U.S. men and women

Meat intake has been inconsistently associated with risk of non-Hodgkin lymphoma (NHL), a heterogeneous group of malignancies of the lymphoid tissue etiologically linked to immunomodulatory factors. In a large U.S. cohort, we prospectively investigated several biologically plausible mechanisms related to meat intake, including meat-cooking and meat-processing compounds, in relation to NHL risk by histologic subtype. At baseline (1995-1996), participants of the NIH-AARP Diet and Health Study completed a diet and lifestyle questionnaire (n = 492,186), and a subcohort (n = 302,162) also completed a questionnaire on meat-cooking methods and doneness levels. Over a mean of 9 y of follow-up, we identified 3611 incident cases of NHL. In multivariable Cox proportional hazards regression models, we found no association between intake of red meat, processed meat, fish, poultry, heme iron, nitrite, nitrate, animal fat, or protein and NHL risk. MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline) and DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline), heterocyclic amines formed in meats cooked to well done at high temperatures, were inversely associated with chronic lymphocytic leukemia/small lymphocytic lymphoma [n = 979; HR (95% CI) for the highest vs. lowest quintile of intake: 0.73 (0.55, 0.96) and 0.77 (0.61, 0.98), respectively]. In this large U.S. cohort, meat intake was not associated with NHL or any histologic subtypes of NHL. Contrary to findings in animal models and other cancer sites, meat-cooking and -processing compounds did not increase NHL risk.

Prediagnostic circulating carotenoid levels and the risk of non-Hodgkin lymphoma: the Multiethnic Cohort

This analysis examined the association of non-Hodgkin lymphoma (NHL) with prediagnostic carotenoid levels, a marker for a diet rich in fruits and vegetables. We conducted a nested case-control study within the Multiethnic Cohort with 271 NHL cases and 538 controls matched on sex, ethnicity, location (Hawaii or Los Angeles), birth year, date and time of blood draw, and hours fasting before blood draw. Serum carotenoid levels were obtained by high-pressure liquid chromatography with photodiode array detection. Conditional logistic regression was used to calculate odds ratios (ORs) according to tertiles of serum carotenoids and trend tests using continuous variables. Higher total serum carotenoids (OR(T3 vs T1) = 0.66 [0.46-0.96]; P(trend) = .02), lycopene (OR = 0.54 [0.38-0.78]; P(trend) = .003), and α-cryptoxanthin (OR = 0.53 [0.36-0.78]; P(trend) = .003) were associated with a lower risk of NHL. For retinol (OR = 0.90 [0.61-1.33]; P(trend) = .04), a statistically significant inverse linear trend was detected. Risk estimates remained unchanged with adjustment for NHL risk factors and were similar in analyses stratified by sex and ethnicity; heterogeneity with NHL subtype was detected only for β-carotene. Other carotenoids, including α-carotene, β-carotene, lutein, β-cryptoxanthin, and zeaxanthin, showed no association with risk. These data provide support for a protective role of carotenoid-rich fruits and vegetables in the etiology of NHL.

Food-frequency questionnaire-based estimates of total antioxidant capacity and risk of non-Hodgkin lymphoma

Antioxidants, primarily from fruits and vegetables, have been hypothesized to protect against non-Hodgkin lymphoma (NHL). The oxygen radical absorbance capacity (ORAC) assay, which measures total antioxidant capacity of individual foods and accounts for synergism, can be estimated using a food-frequency questionnaire (FFQ). We tested the hypothesis that higher intake of antioxidant nutrients from foods, supplements and FFQ-based ORAC values are associated with a lower risk of NHL in a clinic-based study of 603 incident cases and 1,007 frequency-matched controls. Diet was assessed with a 128-item FFQ. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals adjusted for age, sex, residence and total energy. Dietary intake of α-tocopherol (OR=0.50; p-trend=0.0002), β-carotene (OR=0.58; p-trend=0.0005), lutein/zeaxanthin (OR=0.62; p-trend=0.005), zinc (OR=0.54; p-trend=0.003) and chromium (OR=0.68; p-trend=0.032) was inversely associated with NHL risk. Inclusion of supplement use had little impact on these associations. Total vegetables (OR=0.52; p-trend<0.0001), particularly green leafy (OR=0.52; p-trend<0.0001) and cruciferous (OR=0.68; p-trend=0.045) vegetables, were inversely associated with NHL risk. NHL risk was inversely associated with both hydrophilic ORAC (OR=0.61, p-trend=0.003) and lipophilic ORAC (OR=0.48, p-trend=0.0002), although after simultaneous adjustment for other antioxidants or total vegetables, only the association for lipophilic ORAC remained significant. There was no striking heterogeneity in results across the common NHL subtypes. Higher antioxidant intake as estimated by the FFQ-ORAC, particularly the lipophilic component, was associated with a lower NHL risk after accounting for other antioxidant nutrients and vegetable intake, supporting this as potentially useful summary measure of total antioxidant intake.