The conclusion was drawn from an analysis of responses from 441 Chiang Mai University undergraduate medical students who participated in an online cross-sectional survey conducted between May 2022 and April 2023.
Among these respondents, 29.9% exhibited an Adult ADHD Self-Report Scale (ASRS) risk score of 3 and above. The most prevalent ADHD symptoms were identified as difficulty wrapping up final details (48.8%), followed by challenges in remembering appointments (37%) and organising tasks (34%).
Researchers discovered that surpassing sex-specific daily sugar recommendations (36 grams for males and 25 grams for females per day) significantly (64 out of 132 participants reported ADHD symptoms consumed more than 25 gram of sugar beverage per day; p-value: 0.046) elevated the risk of developing ADHD symptoms.
Moreover, students who consumed higher amounts of sweetened drinks/water, green tea, and soy milk exhibited a statistically significant association (respective p-values: 0.043; 0.071, and 0.025), albeit borderline, with the presence of ADHD symptoms.
In addition to the sugar content in beverages, being overweight and having daily screen time exceeding seven hours are two other factors linked to the presence of ADHD symptoms among Thai medical students.
Sugar destroys the gut-brain axis pathway
ADHD is characterised by symptoms involving inappropriate levels of inattentiveness, hyperactivity, and impulsivity. There is emerging evidence suggesting a potential link between the consumption of sugar-sweetened beverages or caffeine and ADHD symptoms.
Numerous studies indicate that children with higher sugar-sweetened beverages or caffeine face an elevated risk of developing ADHD symptoms compared to those with lower consumption.
For medical students, sugar-sweetened beverages are popular non-prescription stimulants used to enhance academic performance or cope with academic stress.
Therefore, the primary objective of this study is to investigate the prevalence of ADHD symptoms among Thai medical students and discern a quantifiable association between the consumption of added sugar from common Thai beverages and the presence of ADHD symptoms.
Furthermore, the researchers are interested to explore other potential clinical characteristics relevant to ADHD that may suggest an increased risk of symptoms.
A potential mechanism through which sugary drinks may influence ADHD symptoms is by disrupting the gut-brain axis pathway.
Excessive consumption of sugary drinks can alter the gut microbiota, leading to increased intestinal permeability and the enhanced transport of lipopolysaccharide (LPS) and other food degradation by-products.
In the brain, LPS can bind to Toll-like receptors (TLRs) on microglial membranes, triggering the activation of the nuclear transcription factor kappa B (NF-kB) and promoting inflammation.
Microglial activation, in turn, influences the immune response, producing cytokines and other immune signalling molecules that interact with the nervous system. This cascade of events may contribute to central inflammation, potentially exacerbating ADHD symptoms.
Promoting the well-being of medical students
The survey used in this study consisted of three distinct sections covering demographic information, ADHD-relevant characteristics assessed through the Thai version of the Adult ADHD self-report scale (ASRS) screener version 1.1, and beverage consumption habits using the Thai Adolescence Sugar Sweetened Beverage Intake (THASSI) questionnaire version 3.
The THASSI questionnaire comprehensively explores common beverage products available in the Thai market. In this study, particular emphasis was placed on 10 beverages and participants were asked to provide retrospective information about their consumption during the preceding week.
The Thai version of the ASRS comprises 18 questions underscores both inattentive and hyperactive/impulsive symptoms. Participants were assigned one point for reporting “sometimes”, “often”, or “very often” as the frequency of occurrence for the first three questions.
For the remaining questions, one point was assigned if participants reported “often” or “very often” as the frequency. Participants scoring 3 or higher on the first six items were considered to have ADHD symptoms.
Researchers observed a consistent prevalence of ADHD symptoms and related findings in line with prior studies. However, they urged for further investigations to validate these findings. Mainly because the study adopts a cross-sectional design, so the causality between associated factors and ADHD symptoms could not be determined.
The design also constrains the study from exploring the longitudinal impact of added sugar consumption on ADHD symptoms. Moreover, there is a lack of standardised measurement for the proportion of sugar in Thai beverages. This introduces potential inaccuracies in assessing sugar consumption through the questionnaire. Recall bias among participants further complicates this issue.
Nevertheless, researchers anticipate the study findings will contribute valuable information to inform appropriate health policies related to beverage consumption, with an overarching goal to mitigate ADHD symptoms and enhance the learning and wellbeing of medical students.
“While evidence of an association in the general population can inform public health policy, it does not necessarily imply that all underlying subgroups are affected in the same way,” the researchers wrote.
“Analysing data from specific subgroups can spotlight particular segments of the population that may be at higher risk than average.”
Is the Consumption of Added Sugar from Common Beverages Associated with the Presence of Attention Deficit Hyperactivity Disorder Symptoms in Thai Medical Students?
Authors: Nalinee Yingchankul et al.