Field Notes

Understanding Cultural Differences in Salt Usage May Help Lower Consumption

Almost all adults in the US consume more sodium (salt) than recommended, yet the sources and use of sodium vary among people of different races and ethnicities, indicating the need for culturally customized advice about sodium intake, according to new research published in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.

Consuming too much sodium can increase the risk of high blood pressure and CVD. The average US adult consumes about 3,400 mg of sodium each day, often in prepared foods, such as pizzas, tacos, burritos, cold cuts, canned soup, and breads. According to the USDA, one six-inch Italian sub sandwich (bread, ham, cheese, salami, pepperoni) has approximately 3,110 mg of sodium.

The American Heart Association recommends that an individual eat no more than 2,300 mg of sodium each day, which is about 1 tsp of salt. Ideally, if you have high blood pressure, you should aim for 1,500 mg of sodium per day.

"The World Health Organization calls sodium reduction one of the most cost-effective strategies for addressing chronic conditions such as heart disease. High sodium intake can even affect nonheart-related diseases like kidney disease," says lead study author Jessica Cheng, PhD, a postdoctoral research fellow in epidemiology at the Harvard T. H. Chan School of Public Health in Boston. "To lower sodium intake in diverse populations, researchers, health care professionals, and policymakers should help people understand the sodium content in packaged foods, restaurant meals, home cooking and table salt while suggesting methods to cut their salt intake."

In this study, researchers examined data from the National Health and Nutrition Examination Survey (NHANES) 2017–2020 (prepandemic) to assess racial and ethnic differences in sodium intake. A secondary analysis was conducted to challenge the database’s assumption that Asian Americans add salt to rice.

Among the study's findings:

Pizza, soup, and chicken were among the top sources of sodium among people in all racial and ethnic groups.
Among Asian American adults, four culturally unique food sources accounted for more than 14% of daily sodium intake: soy-based condiments (soy sauce), fish, fried rice and lo/chow mein, and stir-fry/soy-based sauce mixtures.
Mexican mixed dishes like enchiladas, tamales, taquitos, pupusas, gorditas, chimichangas, quesadillas, burrito bowls, fajitas, chiles rellenos, and chilaquiles were unique top sources of sodium for Mexican American adults.
For Black adults, foods such as chicken patties, nuggets, and tenders were among the top sources of sodium.
Black adults reported the highest rates of "attempting to" lower sodium compared with white adults, 67% vs 44%, respectively, and they had the highest rates of receiving physician advice to lower sodium intake at 35% vs 18% for Asian Americans.
Asian American adults were the most likely to use salt while cooking, yet they were the least likely to use salt at the table.
When comparing estimates derived under the assumption that rice is salted, assuming rice is unsalted reduces the daily sodium intake of Asian American adults by approximately 325 mg per day.

"We may have been overestimating sodium intake among Asian Americans for the last decade by assuming that salt was added to rice," Cheng says, who is also a postdoctoral research fellow in internal medicine at Massachusetts General Hospital. "Past research found that Asian American adults and children had the highest sodium intake of all racial and ethnic groups. However, those analyses assumed that rice was cooked with salt. Culturally, not all Asians salt plain rice. If they don't add salt to rice when cooking, then their sodium intake is among the lowest across all racial and ethnic groups."

Cheng says that reducing sodium may be good for many, and it doesn't have to be difficult. "Based on these findings, I suggest varying your diet and adding more potassium-rich foods such as vegetables, which can also help reduce blood pressure. You don't have to avoid pizza completely; eat it less often or try making it at home with low-sodium cheese, dough, and tomato sauce you make from scratch."

Cheng also suggested people consider a salt substitute to reduce sodium intake. "The World Health Organization recently recommended that nonpregnant adults without kidney issues opt for low-sodium salt substitutes that contain potassium. According to our analysis, which used the NHANES 2017–2020 prepandemic dataset, less than 4% of US adults use salt substitutes despite their wide availability in US supermarkets and relatively affordable cost. Talk to your health care professional before making this switch if you are concerned about your kidney function or medications that might affect kidney function," she explains.

— Source: American Heart Association

Dietary Shift After Migration Increases Cardiovascular Risk by Altering the Composition of an Individual's Gut Microbiome

An Amsterdam University Medical Center (Amsterdam UMC)-led study has found that migrants, in this case from West Africa to Europe, experience a “clear change” in their microbiome composition as compared with their nonmigrant peers in West Africa, which exposes them to an increased risk of CVD. These peer-reviewed findings were published in the journal Gut Microbes, demonstrating that participants who lost specific groups of microbes or acquired specific new groups of microbes had higher rates of cardiovascular risk factors such as hypertension, diabetes, obesity, and poor kidney function.

“The results clearly demonstrate the importance of our findings in the relation to migration-related health outcomes,” explains postdoctoral researcher at Amsterdam UMC and first author of the study, Barbara Verhaar, MMed, who carried out the research together with colleagues at the University of Ghana, and Kwame Nkrumah University of Science & Technology (KNUST).

"It was already thought that migration had an effect on an individual's microbiome, but previous studies have either lacked in the number of individuals included, didn't control for variations in diet, or only compared first- and second-generation migrants. Our study makes use of our own RODAM study cohort to definitively demonstrate this change,” Verhaar says.

The Amsterdam UMC-led study included more than 1,100 individuals from two separate continents and three locations: rural Ghana, urban Ghana, and Netherlands. Respondents completed identical dietary questionnaires and provided both fecal and blood samples to determine the composition of their gut microbiomes. Analyses revealed the presence of different microbes across the three groups, in line with the hypothesis that migration would affect microbiome composition. The findings show that some groups of microbes disappear, and new ones emerge along the migration axis.

Health Outcomes
Previous studies, as well as the World Health Organization, note that migrants frequently experience poorer health outcomes than native residents and research from Amsterdam UMC has found this also to be the case in the Netherlands.

"This research underscores the relevance of gut health and how we look at the adverse health outcomes that are often associated with migration. It is fascinating to learn that when we migrate, we lose some relevant microbes we acquired in our home countries and pick up new microbes in the new countries, and this can influence our health very importantly. We found that macronutrient groups such as protein, fat, and salt in food were most strongly associated with gut microbiota composition, and these were higher in migrants, which might have contributed to the shift in gut microbiota composition. Future longitudinal studies are needed to verify these findings,” adds Charles Agyemang, MPH, PhD, a professor of global migration, ethnicity, and health at Amsterdam UMC and senior author of the study.

Cardiometabolic risk is a growing concern for researchers across the globe, and Agyemang is currently leading a host of projects, both in the Netherlands and several African countries, that aim to develop better interventions to lower the risk of developing cardiometabolic diseases, such as diabetes and hypertension, and to improve management of cardiometabolic diseases.

As part of these efforts, as in this study, he works with several institutions across the globe, especially in the African region, to ensure that research in Amsterdam is strengthened with international data and, also, that research findings are translated into concrete policy.

"The findings of this study provide important insights into how migration can reshape our gut microbiota and subsequent health outcomes and emphasize the need for north-south collaborations,” adds Ellis Owusu-Dabo, MB, ChB, PhD, a professor of epidemiology and global health at KNUST.

— Source: Amsterdam University Medical Center