MedicalResearch: What is the background for this study? What are the main findings?
Dr. Epstein: Hodgkin lymphoma is a relatively rare cancer, with about 9,000 new cases diagnosed in the US each year. Hodgkin lymphoma is most commonly diagnosed in earlier (aged 15-34 years) or later adulthood (aged ≥50 years). The causes of the disease are not well understood, and most identified risk factors are not modifiable (for example, age, sex, family history, and infection with Epstein-Barr virus [EBV]). Previous studies have suggested that chronic inflammation may play a role in the development of Hodgkin lymphoma. Therefore, it is possible that a factor that can influence inflammation, such as diet, may be associated with risk of Hodgkin lymphoma. Discovering modifiable risk factors for Hodgkin lymphoma could offer a means for preventing this disease. The few existing studies of diet and Hodgkin lymphoma risk have focused on individual nutrients or foods; this is the first study to examine dietary pattern and risk of Hodgkin lymphoma. By examining dietary patterns instead of individual foods, we sought to assess Hodgkin lymphoma risk from the food combinations that may more closely reflect typical dietary habits.
The current study includes 435 cases of Hodgkin lymphoma and 563 controls with no history of cancer from Massachusetts and Connecticut who were enrolled in the study between 1997 and 2000. Cases and controls provided information about their average intake of 61 food and beverage items over the year prior to the study. By evaluating foods commonly consumed by the study participants, we identified four major dietary patterns; high vegetable intake, high meat intake, high intake of fruit and low-fat dairy, and high intake of desserts and sweets. We looked for associations between each dietary pattern and risk of Hodgkin lymphoma overall, and also separately by age group (<50 years or ≥50 years old), tumor EBV status (positive or negative), and by tumor cell pattern (nodular sclerosis or mixed cellularity). The dietary pattern characterized by high intake of desserts and sweets was associated with a statistically significant increased risk of Hodgkin lymphoma among younger adults, and in particular, a 2-fold increased risk among younger adults with EBV-negative tumors. The dietary pattern featuring high meat intake was associated with a 3-fold increased risk of Hodgkin lymphoma among older adults, and again, we saw a stronger association among older adults with EBV-negative tumors, although the number of such cases in this group was small. We did not observe a clear association between the high vegetable dietary pattern, or the dietary pattern high in fruit and low-fat dairy intake, with Hodgkin lymphoma risk, and we also did not find any clear associations with EBV-positive tumors, which were relatively infrequent in the study population. The findings described above were obtained from statistical calculations that also took into account known Hodgkin lymphoma risk factors, other lifestyle factors, total caloric intake, and body mass index.
MedicalResearch: What should clinicians and patients take away from your report?
Dr. Epstein: Since this is the first study to examine dietary patterns and risk of Hodgkin lymphoma, additional research is needed to replicate these results in other study populations. However, our study suggests that in addition to other known benefits, following a healthy dietary pattern, and in particular one with limited consumption of meat and sweets, may also help to reduce risk of Hodgkin lymphoma.
MedicalResearch: What recommendations do you have for future research as a result of this study?
Dr. Epstein: Additional research is warranted to identify modifiable risk factors for Hodgkin lymphoma, to characterize the underlying biological mechanisms by which the disease develops, and to develop primary and secondary prevention strategies that can diminish both shorter- and longer-term consequences of a Hodgkin lymphoma diagnosis. Additional studies of dietary patterns would be informative in more ethnically diverse and larger populations, and would support a more detailed look at variability in the dietary associations with Hodgkin lymphoma risk among disease subtypes. Also, our results should be replicated in prospective studies, which are designed to assess dietary intake before cancer development and follow study participants over time to better examine the influence of long-term diet and its timing on risk of Hodgkin lymphoma. We also encourage future research in Hodgkin lymphoma to examine associations separately in younger and older adults.
Mara Meyer Epstein, ScD (2015). Dietary Patterns May Play A Role In Risk Of Hodgkin Lymphoma