Study Finds Variation in Land Use Correlates to Better DNA Health
Zhang recently studied the built environment — human-made features such as buildings and infrastructure — and its relationship to the length of telomeres in Mexican Americans living in Houston, Texas. Telomeres are the protective pieces found at the ends of DNA that shorten when cells divide. Their length is determined by genetics, behavior and environmental factors — and is often examined in relation to risk for cancer, cardiovascular disease and other chronic diseases. Studies also have found that telomere length is linked to hypertension, diabetes and obesity. Since it is well known that the landscape around us can impact our health, Zhang’s work aimed to learn more about how land use may be tied to telomere length.
The research team, which included researchers from Virginia Commonwealth University and the University of Texas, looked at the makeup of the land (residential, commercial, industrial, underdeveloped, farmland and more), how easily the land allowed for physical activity, and the number of healthy and less healthy food stores in the area. Telomere length was determined for 5,508 Mexican American participants enrolled who were over 20 years old and did not have cancer, diabetes or cardiovascular disease when they signed up to participate.
Results showed that higher variation in land use was associated with longer telomere length, with the association strongest for people under 38 years old, women, participants with obesity, those with low levels of physical activity and those who were born in Mexico. This means that those who were around more varied land had longer “protective caps” on their DNA.
“An area that is mixed in its use generally supports walking when compared to an area that is dominated by a particular land use,” explains Zhang. “Our study results support this idea — increased land use mixture may promote physical activity, enhance the immune system and decrease telomere length shortening.”
Trends in urban planning patterns have worked to keep residential, commercial, and recreational areas separate in an effort to protect community health; however, this low-mix land use is less supportive of physical activity, healthy eating and sustainable living — all factors that help to improve health.
“The biological evidence from our work shows that beneficial built environment features (access to physical activities facilities, parks and healthy food environment) is critical for healthy cities and healthy populations,” Zhang said. “We must work to create a favorable built environment that helps to slow down biological aging and ultimately improve overall health.”
The full report from the research team can be found in Scientific Reports.