Sugar-sweetened beverages pose a potential risk of ADHD

By Pooja Toshniwal PahariaReviewed by Lily Ramsey, LLMOct 19 2023

In a recent study published in Nutrients, researchers investigated whether the consumption of sugar-sweetened beverages (SSBs) was associated with Attention Deficit Hyperactivity Disorder (ADHD) symptoms among medical students in Thailand.

Study: Is the Consumption of Added Sugar from Common Beverages Associated with the Presence of Attention Deficit Hyperactivity Disorder Symptoms in Thai Medical Students? Image Credit: monticello/Shutterstock.com

Background

ADHD, a highly prevalent psychiatric disorder, can significantly impact their academic performance, work performance, and daily life. The condition may continue in adulthood or develop as a late-onset type among young adults despite not meeting ADHD diagnostic criteria in childhood.

Studies have reported that medical students, particularly those consuming SSBs in high amounts, are more prone to ADHD than those with low SSB intake.

However, there is limited research concerning ADHD among adult populations, including medical students, the dose-response association between SSBs and ADHD symptoms, and practical limits to ensure healthy consumption.

About the study

In the present cross-sectional study, researchers determined the association between added sugar intake from commonly consumed beverages and ADHD symptoms among medical students.

A web-based survey was conducted between May 2022 and April 2023 for medical students of Chiang Mai University recruited by snowball and convenience sampling. The target survey population included undergraduate students attending their first to sixth academic year in 2022. ADHD symptom presence was determined based on the Adult ADHD Self-Report Scale (ASRS) scores ≥3.0.

The team excluded individuals with active medical disorders, those with a prior history of mood disorders, including major depressive disorder (MDD), bipolar disorders, ADHD, and anxiety, and those who failed to complete the ASRS questionnaire.

Added sugar intake from frequently consumed beverages in Thailand was measured using the Thai Adolescence SSB Intake (THASSI) questionnaire, focusing on sweetened forms of water/drinks, carbonated beverages, coffee, energy drinks, green tea, yogurt drinks, fruit and vegetable juice, milk, soy milk, and herbal fluids.

Individuals documented the packaging type (can or bottle), beverage size, amount consumed on different occasions, and weekly consumption for all items. The total daily intake was categorized based on the American Heart Association-recommended limit of added sugar intake. 

Multivariate logistic regression modeling was performed to calculate the adjusted odds ratios (aORs), adjusting for age, gender, body mass index (BMI), family history of ADHD, monthly payment, household income, paternal educational attainment, screen time, and sleeping duration. 

Results

Of 1,472 medical students invited to participate in the survey, 534 (36%) responded, of which 441 eligible individuals were included. The mean participant age was 21 years, and 50% were male. Nearly 60% of the participants were from pre-clinical academic years. Among the participants, 30% (n=132) experienced ADHD symptoms.

The most common ADHD symptoms were difficulty finishing final details (49%), difficulty remembering appointments (37%), and difficulty getting things in order (34%). 

SSB intake exceeding 25 grams daily elevated ADHD risk (aOR, 1.8). Similar results were obtained using the gender-specific cut-offs (aOR, 1.7).

Students experiencing ADHD reported significantly higher intake of sweetened green tea (third tertile versus first tertile aOR 1.7) and water/drinks (third tertile versus first tertile aOR 1.8) than those without ADHD symptoms. Soy milk consumption yielded similar results (above median versus below median aOR 1.8).

Individuals who developed ADHD symptoms were significantly older, academically more senior, with higher BMI, and higher screen time than those with no ADHD symptoms.

Being overweight (aOR 1.9) and having more than seven hours of screen time each day (aOR 2.0) significantly elevated ADHD symptoms risk, adjusting for SSB intake.

A probable mechanism by which sweetened beverages could enhance ADHD symptom risk is by altering bi-directional communications between the gut and brain and disrupting the gut microbial balance.

Dysbiosis increases intestinal permeability, inflammation, and the transport of lipopolysaccharide (LPS) endotoxins across cells. LPS could bind with toll-like receptors (TLRs) on the membranes of microglial cells in the brain and increase inflammatory cytokine release through nuclear factor kappa B (NF-kB) stimulation. Central nervous system (CNS) inflammation could give rise to ADHD symptomatology.

Conclusions

Overall, the study findings showed that SSB intake of more than 25 grams per day may elevate ADHD symptom risk among medical students in Thailand. In particular, sweetened water/drinks, soy milk, and green tea could increase ADHD symptom risk.

The study findings support the implementation of health policies that promote healthy consumption behaviors among medical students to reduce ADHD symptoms and promote the learning and well-being of medical students.

However, further research must validate the findings, including prospective studies with larger sample sizes and diverse populations.