ELEMENT Study Research
Early Life Exposures in Mexico to ENvironmental Toxicants
Detailed ELEMENT Study Findings
Comprehensive Research on Sleep Health in Mexican Youth
University of Michigan longitudinal cohort study from Mexico City
Study Background
The ELEMENT (Early Life Exposures in Mexico to ENvironmental Toxicants) study is a longitudinal cohort study conducted by the University of Michigan School of Public Health in collaboration with researchers in Mexico City.
Sleep Research Focus
The ELEMENT study has produced over 20 peer-reviewed publications specifically examining sleep health in Mexican children and adolescents, making it one of the most comprehensive studies of sleep in this population.
Key Research Areas:
- • Sleep duration and timing patterns
- • Environmental exposures and sleep
- • Diet and sleep relationships
- • Sleep and metabolic health
- • Epigenetic effects of sleep
Research Timeline
- Omega-3 Fats (in fish): Higher levels associated with 31 minutes longer weekend sleep and earlier sleep timing
- Milk Intake: Among boys, highest quartile of milk intake associated with 25-minute longer weekday sleep duration
- Water Consumption: Boys in highest quartile of water intake showed 26-minute longer weekday sleep duration
- Soda Intake: Higher soda consumption linked to 19-minute delay in sleep timing and 1.6% greater sleep fragmentation in girls
- Dietary Patterns: Fruit and vegetable diet patterns and regular breakfast consumption are beneficial for sleep duration and timing
- Insulin Resistance: Sleeping ≥1 hour below recommendations increased odds by 2.74×
- Later bedtimes and wake times: Associated with 2.63× higher insulin resistance odds
- Adiposity: Insufficient-stable sleep patterns linked to higher BMI and obesity prevalence
- Lead Exposure: Highest quartile associated with 23 minutes less sleep and increased fragmentation
- Prenatal Pesticides: Higher maternal exposure linked to 59 minutes longer but later sleep timing in girls
- Phthalates (Plasticizers): Higher exposure associated with increased fragmentation and later timing
- DNA Methylation: Multiple methylation loci significantly associated with sleep timing and duration
- Inflammation: Shorter, later, inconsistent sleep linked to higher inflammatory markers
- Sex Differences: Boys showed stronger links between sleep duration and inflammation
Double School Shift System
A 2024 ELEMENT study examined how Mexico's double school shift system affects adolescent sleep and lifestyle behaviors.
Key Findings:
- • Morning-shift students sleep 1.77 hours less on weekdays
- • Weekend sleep increases by 0.4 hours to compensate
- • More social jetlag and sedentary behavior in morning-shift students
- • 44% of students attended morning shift schools
Sleep Duration by School Schedule
Morning Shift (Weekdays)
Earlier school start times
~6.2 hrs
Below recommendations
Afternoon Shift (Weekdays)
Later school start times
~8.0 hrs
Closer to recommendations
Recent Publications (2020-2025)
Sleep and DNA Methylation (2025)
Jansen et al. - Epigenome-wide analysis
Double School Shift Impact (2024)
Peng et al. - Lifestyle behaviors study
Foundational Studies (2018-2022)
Sleep and Insulin Resistance (2023)
Jansen et al. - Prospective analysis
Prenatal Pesticide Exposure (2022)
Zamora et al. - Maternal exposure effects
Sleep Difficulties Assessment (2021)
Zamora et al. - Subjective vs objective sleep
ELEMENT Study
University of Michigan School of Public Health
For more information about the ELEMENT study, visit the University of Michigan website