Hispanics Coming to the US Adopt US Cultural Behaviors and Eat Less Healthy: Implications for Development of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated disease that affects approximately 1 million people in the USA and is on the rise globally [1, 2]. Studies examining the incidence of IBD indicate that immigrants arriving to countries where IBD has a high prevalence adopt a similar prevalence as that of the native population [3, 4]. This “immigrant effect” is observed primarily in immigrants moving to Westernized countries [3]. Similarly, the incidence of IBD is rising among Hispanics migrating to the USA compared to those remaining in Latin America [5]. In our previous study, we observed that, within one US-born generation, Hispanics resembled the IBD phenotype of White Americans [5]. These rapid shifts observed in IBD prevalence and presentation among immigrant groups coming to the USA support the strong role of the environment in IBD [5‐7]. Therefore, the study of lifestyle changes that occur with acculturation among Hispanic immigrants represents a natural experiment to identify novel contributors to the rising prevalence of IBD.

Epidemiologic studies suggest that diet plays a role in the development of IBD. Diets high in animal protein, particularly red meats, and low in fruits and vegetables are characteristic of a “Western” diet and are associated with IBD in large prospective datasets [8, 9]. We hypothesize that dietary acculturation to a Western diet pattern is likely a major contributor to the development of IBD among Hispanic immigrants. Acculturation to US cultural norms, including dietary acculturation, is a major determinant of certain chronic diseases among Hispanic immigrants. Several studies, including the Hispanic HANES, the NHANES III, and the Study of Latinos/Hispanic Community Health Study, indicate that hypertension, metabolic disease, obesity, and cardiovascular disease are associated with higher levels of acculturation to US culture among Hispanics [8, 9]. However, the acculturation instruments used in many epidemiological datasets are based on a unidimensional framework where Hispanic and US cultural endorsement are cast as opposing ends of a single dimension [10]. Validated measures of acculturation are more likely to assess Hispanic and US cultural influences separately, an approach that is more consistent with state-of-the-art acculturation models [11]. A study examining acculturation in Hispanics with IBD, using construct-valid measures of acculturation, could help us understand the social determinants and contributors to the rise of IBD in this large and growing demographic group.

In the present study, we sought to determine the extent to which (a) Hispanics change their diet after US immigration compared to Hispanics without IBD; (b) acculturation, including dietary acculturation, differs between Hispanics with versus without IBD; and (c) diet quality, a method of nutritional assessment that evaluates dietary adherence to the Dietary Guidelines for Americans, differs between Hispanics with versus without IBD [12]. Our study is the first to evaluate dietary adjustment occurring in Hispanics with IBD and the first to examine acculturation-related variables among Hispanic IBD patients and controls.

This is the first study to examine acculturation and diet among Hispanic immigrant patients living with IBD in the USA. It is essential to identify influential dietary and cultural practices that could explain the rising incidence of IBD in US immigrant and minority groups. We found no differences in US acculturation, including dietary acculturation, between Hispanics with and without IBD. In fact, both IBD and control participants were mostly bicultural, likely as a result of extended US residence (mean years in the USA was 28.6). In this study, we found that most Hispanics changed their diet following US immigration, with IBD patients most likely to report changes (72% vs. 57%). Additionally, we found similar poor eating behaviors, as measured using the Healthy Eating Index, in both IBD patients and controls. Given our findings, we conclude that dietary changes and adoption of US behaviors, on their own, do not explain the rise in IBD among Hispanic immigrants.

More than half of all participants, including both IBD patients and controls, reported changing their diet after immigration and not as a result of new diseases or financial constraints. A greater percentage of the IBD patients changed their diet and stated that they did so prior to developing any illness, although this difference did not reach statistical significance. This finding supports the notion that Western dietary acculturation on its own may not fully explain the rise of IBD among Hispanics. We have recently examined the genetic underpinnings of IBD in Hispanics and found that their genetic load is similar to non-Hispanic whites, suggesting that differences in incidence of IBD also do not rest in genetics alone [18]. Future studies need to investigate the interaction of diet with IBD genetic predisposition, as well as with microbiome interactions, that could better close in on the pathologic underpinnings of IBD in Hispanics.

Most Hispanics in our study, including IBD and controls, were classified as bicultural. The two groups reported similar levels of liking and knowing how to prepare American foods. We also observed similar levels in Hispanic dietary preferences and in other US and Hispanic cultural behaviors across groups, including language and social components. Therefore, these findings indicate that Hispanic immigrants with IBD and their non IBD counterparts share similar cultural dietary preferences that suggest a blend of Hispanic and American practices. Although we did not find that US and Hispanic dietary preferences differed between IBD and controls in Hispanics, we did find that, in general, Hispanic immigrants adopt American practices, which have been associated with development of various diseases in prior studies [18‐20]. For instance, in the Third National Health and Nutrition Examination Survey (NHANES III), Mexicans were more likely to adhere to dietary guidelines if they were born in Mexico than in the USA [19]. Recent reviews also indicate that Hispanic immigrants arrive in the USA practicing healthier behaviors than White Americans—but as they adopt American behaviors, they experience a high burden of poor health outcomes such as type 2 diabetes [19, 20]. Evidence is also mounting that second-generation Hispanics’ diets are less healthy compared to those of foreign-born Hispanics—such that second-generation Hispanics live approximately 2.9 years less than Hispanic immigrants [21].

In our study, we found that both IBD and controls scored within the “needs improvement” range in their overall HEI diet assessment and are not in adherence to recommended dietary guidelines. Interestingly, both groups scored below recommended standards but for differing reasons. IBD patients had lower than recommended intake across several food groups, including vegetable and fruit intake, perhaps as a result of GI symptoms brought on with food items high in fiber. In turn, IBD patients replaced high-fiber foods with foods high in salt and refined grains. Control participants ate less than optimally because of lower adherence to recommended intake of vegetables, sea, and plant protein, as well as greater consumption of “empty calories,” which included greater intake of alcohol and of foods with added sugars and solid fats. The dietary patterns among controls may be explained by greater adherence to an “American diet” characterized by higher intake of fats and added sugars, coupled with low intake of fruits and vegetables. The patterns among control participants are likely a result of symptom-based elimination diets. In a prior survey study, 71% of IBD patients believe their diet affects their symptoms [22], and as high as 90% of Crohn’s disease patients utilize elimination diets to minimize their symptoms [23]. Unfortunately, dietary modification based solely on symptom control can lead to avoiding nutritionally important foods and increased risk for nutritional deficiencies [24]. Our results highlight the importance of emphasizing healthy dietary practices among IBD patients, which can in turn also influence the course of ongoing disease progression [25].

The present findings should be interpreted in light of some important limitations. Although we conducted a cross-sectional study evaluating current dietary intake, our sample size was small. However, our study is a first-pass examination, and our findings suggest some clinically significant differences in diet quality. Our IBD patients and controls were similar in terms of proportions of countries represented, age at immigration, and gender—all factors that can influence diet and acculturation. Therefore, differences observed between IBD patients and controls were not likely a result of differences in these variables. Additionally, nutritional intake may be influenced by disease activity in our IBD patients. IBD patients may choose to avoid “trigger” foods that can worsen their symptoms and so this may alter their daily consumption [24]. To minimize the chances that diet intake was influenced by current disease activity, we chose IBD patients without a prior surgical history, and who reported minimal active GI symptoms or a change in diet in the last week.

Our results underscore the importance of cultural behaviors and highlights how behaviors and cultural beliefs can change as a result of immigration and duration in the US. Findings also indicate that most Hispanics change their diet upon arrival to the USA and that their diet is poor regardless of disease status. Further studies are needed to validate these findings and to identify the role that diet plays when in the presence of other risk factors, including IBD genetic predisposition. We hope that the present work inspires additional research examining links between acculturation and diet among individuals with various health conditions.