The foods Americans
eat have a lot to do with factors like race, age and where they live, and can
be categorized into five distinct dietary patterns, according to a new study.
Researchers analyzed food
questionnaires from a large group of black and white adults aged 45 and older
in the continental United States, with a focus on southeastern states.
The strongest
association they found was that black people were more likely than whites to
have "southern" diets, which are rich in fried foods, processed meats
and sweetened drinks.
"Nobody has
defined dietary patterns in a population like this," said
Suzanne Judd, assistant professor at the University of Alabama at Birmingham
and study co-author.
The findings are
slated for Tuesday presentation at the American Heart Association meeting in
San Diego.
The southern diet
probably emerged as a clear trend because the study included so many
participants from the Southeast, Judd added.
In addition to the
southern diet, the authors identified four other eating patterns.
The "traditional"
pattern was characterized by a mixed diet of mostly takeout and prepared foods.
A "healthy"
diet was mostly made up of fruits, veggies and grains.
"Sweets"
consisted largely of sweet snacks and desserts.
An "alcohol" pattern, which included salads, proteins (and
alcohol), was associated with younger ages and higher socioeconomic status.
The researchers
limited their study to black and white adults because the largest difference in
stroke risk exists between these two racial groups. Previous research has found
that black people are three times more likely to have a stroke than their white
counterparts at 45 years of age, although the gap in risk shrinks in older
adults.
People from the
Southeast region, known as the "stroke belt," are also more likely to
suffer a stroke.
The current study
involved nearly 22,000 adults, half of whom lived in the Southeast,
representing a range of income and education levels.
Participants filled out
a food frequency questionnaire about their diet over the past year. From these
responses, the researchers grouped similar foods into categories, then looked
at how food groups were consumed together to define dietary patterns.
Participants each received a score reflecting how closely their diet resembled
each pattern.
The researchers
identified a number of trends, notably that younger age groups (45-54 years)
were more likely than older adults to have a traditional diet, which features
convenient, ready-to-eat foods.
And while black
participants were associated with a southern diet, white people were more
likely to have a traditional or sweet diet. These diet differences could not be
explained by income and education differences alone, Judd said, adding that
culture and upbringing probably play a part in eating habits.
Previous research
suggests that one of the major culprits for increased stroke risk among black people is high blood pressure.
The southern diet, and in particular sodium intake, probably has an effect on
stroke risk by driving up blood pressure, although it may have other important
effects, such as on obesity, Judd said.
"Not maintaining
a healthy weight leads to so many problems in terms of how well blood vessels
function," she explained.
Although studies have
explored the intake of individual nutrients, such as sodium and calcium as well
as fats and fiber, among black and white people, there is a less clear
understanding of how overall diet differs between these groups.
Commenting on the
study, Connie Diekman, director of university nutrition at Washington
University in St. Louis, said, "We have to start looking at dietary
patterns because it is about the whole of what we do; it is not single
nutrients or single foods that are the cause or the blame for disease."
When it comes to
helping people change their eating habits, dietary patterns are also more
useful than labeling foods as "good" and "bad," Diekman
added.
The next step is to
look at the relationship between these dietary patterns and health, in
particular stroke risk. "I'll be surprised if we don't see an
association," Judd said.
If further research
shows an association, it would provide some foods to target, similar to how the
U.S. Centers for Disease Control and Prevention is working to reduce sodium in
the food supply, Judd said.
"Even from just
what is here [in this study], it certainly will add to the body of evidence
that's encouraging the change in sodium, portions, and the increased need for
education around nutrition and physical activity," Diekman said.