Mexican immigrants in Washington state who become highly adapted to mainstream American culture tend to change their eating habits for the worse, according to new Public Health Sciences Division research.
In a comparative study of Hispanic and non-Hispanic white adults in Yakima Valley, Dr. Marian Neuhouser and colleagues found that as immigrants became more acculturated-meaning they adopted the customs and beliefs of their new home-they ate fewer servings of fruits and vegetables each day. Highly acculturated Hispanics also had slightly greater fat intake than those who were less acculturated.
The findings add to a growing body of evidence that lifestyle factors such as diet may influence why people who move from one part of the world to another tend to adopt their new country's patterns of cancer, high blood pressure and other diseases.
The results of the PHS analysis will help researchers design new studies aimed at restoring healthful eating patterns lost upon acculturation, Neuhouser said.
"In contrast to other studies, ours was unique in that we examined not only fruit, vegetable and fat intake, but also specific dietary behaviors such as food purchasing and preparation habits," she said. "These behaviors could be targeted in intervention strategies designed to encourage healthier eating behaviors."
Few studies on dietary changes among Hispanics-the fastest growing ethnic group in this country-have been conducted. Those that have been published were based on populations of immigrants from multiple regions with different cultural and food habits, making interpretations of the results difficult. In contrast, nearly all of the participants in the PHS study had immigrated from Michoacan, Mexico.
The study also was notable for its inclusion of a large number of non-English speakers and those of low socioeconomic status, groups with infrequent participation in research studies. Survey response rates were high because of the use of bilingual interviewers who were residents of the communities.
The study appeared in the January issue of the Journal of the American Dietetic Association. Co-authors include PHS researchers Drs. Beti Thompson and Gloria Coronado and Cam Solomon, a former research associate in biostatistics at the University of Washington.
Thompson said that the National Cancer Institute recognizes the existing disparities in cancer-prevention behavior between whites and other ethnic groups and supports research to address these differences. The acculturation and diet study was part of "Celebrating Health!" an NCI-funded project led by Thompson to assess the effectiveness of a comprehensive cancer-prevention program, including a dietary intervention, in the Yakima Valley.
"This study, with its large population of people of Hispanic ethnicity, is providing information on factors that make a difference in how people protect themselves from cancer," she said.
Thompson said that these findings contribute to a growing body of evidence highlighting disparities in cancer-prevention and cancer-screening practices between Hispanic and non-Hispanic whites in Yakima Valley.
"In addition to differences in eating patterns, Hispanics in the Valley are less likely to be screened for breast, cervical and colorectal cancers than non-Hispanic whites," she said. "On the positive side, Hispanics have much lower smoking rates, both in terms of the percentage of people who smoke and the amount they smoke."
For the dietary analysis, in-person interviews were conducted with 1,689 adult Hispanic and non-Hispanic white residents of 20 communities in the Yakima Valley. To determine level of acculturation, participants were questioned about which language they most often spoke or used for thought, their ethnic identification of self, birthplace and other indicators of adaptation to their new country.
On average, Hispanics consumed one more daily serving of fruits and vegetables than non-Hispanic white residents. Hispanics who were highly acculturated ate close to half a serving fewer of fruits and vegetables compared with Hispanics who were considered of lower acculturation.
Food preparation habits appeared to have changed as Hispanics adapted to life in the United States. For example, those who were highly acculturated were more likely to fry chicken and potatoes and add fats, such as butter, to potatoes and bread at the table, compared to those who were less acculturated. Neuhouser said that although these changes in fat-related dietary habits are modest, they could influence health status.
"Changes of this magnitude can be enough to influence circulating levels of fat or levels of other nutrients that may negatively impact health," she said. "Interestingly, the dietary changes adopted by the highly acculturated Yakima Valley residents are the very habits we advise against in dietary intervention studies to promote low-fat eating patterns."