By: Margarethe Goetz
Demographic differences, socioeconomic status, and lifestyle factors are among a few of the potential causes of regional disparities in stroke, heart disease, and progression of chronic kidney disease. Demographic differences, socioeconomic status, and lifestyle factors are also associated with regional disparities in traditional cardiovascular risk factors like obesity, high blood pressure and diabetes. However, traditional risk factors do not fully explain the regional disparities in disease, leading public health researchers to examine whether other factors which influence health such as regional dietary differences, may further explain observed disparities.
Recently, a handful of studies using data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study, have investigated the association between different dietary patterns and the occurrence of cardiovascular diseases, such as heart attack, stroke and death in those with existing chronic kidney disease. The REGARDS study, which began in 2003, uses longitudinal data from over 30,000 non-Hispanic black and white participants in the continental United States. The main advantage of studying dietary patterns rather than specific dietary components like the amount of fat or sugar consumed is that study participant diets are instead considered in their entirety. Foods and nutrients are not eaten in isolation and dietary pattern analysis addresses this common limitation in dietary studies. For example, if those who eat large amounts of red meat are found to also have more heart disease, it is not clear whether all of that red meat is detrimental to heart health or if meat eaters consume too few fruits and vegetables which could be detrimental to heart health… or perhaps the combination of both too much meat and too few fruits and vegetables is detrimental. Dietary pattern analysis, as was conducted in these studies, takes into consideration both the meat intake and the fruit and vegetable intake as well as other dietary factors.
In three different studies, researchers considered five distinct dietary patterns from the dietary survey data reported by a subsample of about 17,000 REGARDS study participants. By identifying patterns within the diverse REGARDS study population, authors hoped to identify social or cultural dietary patterns in food selection. Each participant’s diet was scored based on how much it adhered to each diet pattern. Five different dietary patterns emerged from participant reporting:
- The “convenience” pattern was characterized by pasta dishes, Mexican food, Chinese food, mixed dishes and pizza.
- The “plant-based” pattern was characterized by greater consumption of fruits, vegetables, cereals, beans, yogurt, poultry and fish.
- The “sweets-based” pattern was characterized by a heavy intake of foods with added sugar, such as sweetened breakfast foods, candy and desserts.
- The “alcohol/salad” pattern was characterized by beer, liquor, and wine, as well as green leafy veggies, tomatoes and salad dressing.
- Finally, the “Southern” dietary pattern was characterized by fried foods, added fats, eggs and egg dishes, organ meats, processed meats and sugar-sweetened drinks.
While it is possible that eating a Southern style diet is simply a marker for other unhealthy lifestyle habits, the results of these studies suggest that added fats, fried foods, processed meats and sugar-sweetened beverages are linked to poorer health. Though these studies did not find any dietary pattern to be protective against cardiovascular disease and chronic kidney disease, other studies have found that higher consumption of plant-based foods is associated with lower risk of heart attack, stroke and progression of chronic kidney disease. Gradually shifting diet away from one heavy in fried foods, processed meats, and sugar sweetened beverages by replacing unhealthy choices with plant-based foods, grilled or baked meat and avoiding added sugars may benefit overall well-being, especially cardiovascular and kidney health.
Gutierrez OM, Muntner P, Rizk DV, McClellan WM, Warnock DG, Newby PK et al. Dietary patterns and risk of death and progression to ESRD in individuals with CKD: a cohort study. American journal of kidney diseases : the official journal of the National Kidney Foundation. Aug 2014;64(2):204-213.
Judd SE, Gutierrez OM, Newby PK, et al. Dietary Patterns Are Associated With Incident Stroke and Contribute to Excess Risk of Stroke in Black Americans. Stroke; a journal of cerebral circulation. Oct 24 2013.
Shikany JM, Safford MM, Newby PK, Durant RW, Brown TM, Judd SE. Southern Dietary Pattern is Associated with Hazard of Acute Coronary Heart Disease in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study. Circulation. Aug 10 2015.