School-based Gardening Program Improved Glucose Control, Reduced LDL-C in At-risk Children

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In a secondary analysis of a cluster randomized controlled trial of minority youth aged 7 to 12 years at elevated metabolic risk, a school-based gardening intervention called Texas Sprouts resulted in reductions of 0.02% for hemoglobin A_1c (HbA_1c) and 6.40 mg/dL for low-density lipoprotein cholesterol levels.

Researchers with UTHealth Houston School of Public Health and The University of Texas at Austin published their findings in JAMA Network Open.

Over the past several decades, childhood obesity in the US has increased, particularly among Hispanic children. According to the US Centers for Disease Control and Prevention, between 2017 and 2020, obesity prevalence was 26.2% among Hispanic children compared with 24.8% among non-Hispanic Black children, 16.6% among non-Hispanic White children, and 9.0% among non-Hispanic Asian children.

“Hispanic children are also more likely than non-Hispanic White children to develop obesity-related metabolic diseases, such as metabolic syndrome and type 2 diabetes,” wrote senior author Adriana Pérez, PhD, professor of biostatistics and data science, Michael & Susan Dell Center for Healthy Living, UTHealth Houston School of Public Health, and colleagues.

Consuming more fruit and vegetables (FV) could reduce the risk of obesity-related metabolic diseases, however, most US children do not meet the recommended daily FV intake, and intake is lowest among low-income children and those with obesity.

“Therefore, evidence-based interventions are needed to improve FV intake and reduce obesity-related cardiometabolic diseases in low-income children from minoritized racial and ethnic groups,” wrote the team. In the last decade, studies have consistently shown that school-based gardening interventions can improve FV intake and dietary-related psychosocial variables in children.

According to Pérez and colleagues, most school-based interventions that have looked at the effects of controlled trials on metabolic outcomes have evaluated a program with multiple components, ie, nutrition, physical activity, and behavior change. No cluster randomized controlled trial has evaluated the effects of a school-based gardening intervention alone on metabolic outcomes. Therefore, the team evaluated the effects of the Texas Sprouts school-based gardening, nutrition, and cooking intervention compared with a control program on changes in metabolic outcomes in 695 children aged 7-12 years.

From 2016 to 2019, investigators analyzed 16 low-income elementary schools in the greater Austin, Texas area with majority Hispanic student populations. The schools were randomly assigned to either Texas Sprouts intervention or delayed intervention (ie, control).

Texas Sprouts spanned 1 school year, which was 9 months, and consisted of the formation of a Garden Leadership Committee; a 0.25-acre outdoor teaching garden; 18 student gardening, nutrition, and cooking lessons taught by trained educators throughout the school year; and 9 monthly parent lessons. The delayed intervention was implemented the following academic year and was identical to the original, according to researchers.

At baseline and postintervention, participants’ demographics were obtained via survey and investigators measured students’ height, weight, and body mass index, as well as, glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR) and obtained a lipid panel via an optional fasting blood draw.

Key findings

Among the final total study cohort of 695 children, the mean age was 9.28 years and approximately 44% were boys, 69% Hispanic, and 65% were eligible for free or reduced-price lunch.

Researchers observed that compared with children from control schools, those from Texas Sprouts schools had a 0.02% reduction in mean HbA_1c (95% CI, 0.03%-0.14%; P=.005) and a 6.40 mg/dL reduction in mean low-density lipoprotein cholesterol (95% CI, 3.82-8.97 mg/dL; P=.048).

There were no intervention effects on glucose, insulin, HOMA-IR, or other lipid parameters.

“Given that there is a critical need to reduce obesity-related metabolic disease in children, especially in low-income and Hispanic populations, this intervention has the potential to be implemented and scaled across the US,” concluded Pérez and colleagues. “School-based gardening programs improve dietary intake, academic performance, and reduce metabolic diseases in even the most high-risk minority pediatric populations. These findings provide direct evidence to help encourage policy makers, administrators, and school district personnel to adopt and/or support garden-based learning into elementary schools.”

Reference: Pérez A, Davis JN, Landry MJ, et al. Effects of a school-based nutrition, gardening, and cooking intervention on metabolic parameters in high-risk youth: A secondary analysis of a cluster randomized clinical trial.JAMA Netw Open. 2023;6:e2250375.