Unmedicated children with attention-deficit/hyperactivity disorder (ADHD) who eat more fruits and vegetables are less likely to show severe symptoms of inattention, according to data published in Nutritional Neuroscience.1 The findings add to previous research showing that diet plays a role in symptoms of ADHD and emotional regulation in children, the study authors noted.
“What clinicians usually do when kids with ADHD start having more severe symptoms is increase the dose of their treatment medication, if they are on one, or put them on medication,” said study coauthor Irene Hatsu, PhD, MS, associate professor of human nutrition at The Ohio State University.2 “Our studies suggest that it is worthwhile to check the children’s access to food as well as the quality of their diet to see if it may be contributing to their symptom severity.”
The Role of Diet in ADHD Symptoms
The findings stem from the larger randomized Micronutrients for ADHD in Youth (MADDY) Study, in which researchers examined the efficacy of a 36-ingredient supplement containing vitamins, minerals, amino acids, and antioxidants to treat symptoms of ADHD and poor emotional control in the 134 kids aged 6 to 12 years. Previously published findings from the study show that children who took the supplement were three times as likely to experience significant improvements in ADHD and emotional dysregulation symptoms as those who took placebo. Other published research from this larger trial found that children with ADHD whose families had higher levels of food insecurity were more likely to show more severe symptoms of emotional dysregulation (chronic irritability, angry moods, and anger outbursts).
In the present analysis, the researchers examined foods eaten by the 134 children with ADHD during a 90-day period. The children were recruited from 3 sites — Columbus, Ohio; Portland, Oregon; and Lethbridge, Alberta, Canada — between 2018 and 2020. Participants were either not taking medication or stopped using it 2 weeks before the study began.
The studies on fruit and vegetable intake and the role of food insecurity were based on data collected when the children were first enrolled in the study before they began taking the micronutrient supplement or placebo. Dietary intake was collected using a food frequency questionnaire, diet quality was based on the Healthy Eating Index-2015 (HEI-2015) and ADHD symptoms were assessed using the Child and Adolescent Symptom Inventory-5 and Strengths and Difficulties Questionnaire.
Key Study Findings
The mean HEI Total Score of 63.4 (SD, 8.8), which was considered to be relatively high, was not significantly associated with any outcome symptoms. However, in an analysis that adjusted for covariates, HEI component scores for total fruit intake (β = −0.158, P =.037) and total vegetable intake (β = −0.118, P = .004) were negatively associated with inattention.
The findings are limited by the exploratory study design, relatively small sample, and use of the food frequency questionnaire completed by parents/caregivers, which may have led to reporting or systematic errors. Causality could not be established. The findings may not be generalizable given the relatively high HEI scores found in this patient population, the study authors noted.
Vitamins, Minerals May Help the Body Produce Neurotransmitters
ADHD is believed to be related to low levels of neurotransmitter catecholamines (epinephrine, norepinephrine, and dopamine), and vitamins and minerals play key roles in neurotransmitter synthesis and overall brain function, the study authors wrote. Previous studies have linked improved cognition and ADHD symptoms with omega-3 fatty acids, zinc, iron, and magnesium supplementation, the researchers explained.
“Everyone tends to get irritated when they’re hungry and kids with ADHD are no exception. If they’re not getting enough food, it could make their symptoms worse,” she said. Parental stress in low-income homes may create tension that translates into increased symptoms of ADHD in children, the authors suggested.
Given that the American diet tends to fall short on fruit and vegetable intake, “some symptoms might be more manageable by helping families become more food secure and able to provide a healthier diet,” Dr Hatsu said. “We believe clinicians should assess the food security status of children with ADHD before creating or changing a treatment program.”
Emphasize Nutrition Quality Over Quantity
Experts now advise focusing on assessing nutrition security rather than access to food alone during patient counseling. Clinicians need to recognize that “… a healthy diet is not equitable for all people in the US,” said Anne Thorndike, MD, MPH, Associate professor of medicine at Harvard Medical School and a physician at Massachusetts General Hospital in Boston. “If we are counseling our patients about diet and don’t have background information about their ability to purchase or acquire food, we can’t offer effective counseling.”
Dr Thorndike suggested using the 2-question Hunger Vital Sign tool and asking patients what they ate in the past 24 hours as a way to ease into the conversation (Table).3 Dr Thorndike is chair of an American Heart Association (AHA) policy statement writing group that recently released a report on strengthening US policies and programs to promote equity in nutrition security.
Table. Hunger Vital Sign
|1. Within the past 12 months, we worried whether our food would run out before we got money to buy more||2. Within the past 12 months, the food we bought just didn’t last and we didn’t have money to get more|
Dr Hatsu and colleagues concluded that larger studies on this topic are needed and that future research could focus on adherence to specific diets such as the Mediterranean diet, which may more accurately capture nutrients associated with ADHD and emotional symptoms in US and Canadian populations.
1. Robinette LM, Hatsu IE, Johnstone JM, et al. Fruit and vegetable intake is inversely associated with severity of inattention in a pediatric population with ADHD symptoms: the MADDY Study. Nutr Neurosci. 2022:1-10. doi:10.1080/1028415X.2022.2071805
2. Ohio State University. Diet plays key role in ADHD symptoms in children. News release. May 19, 2022. Accessed May 22, 2022. https://news.osu.edu/diet-plays-key-role-in-adhd-symptoms-in-children/
3. Hager ER, Quigg AM, Black MM, et al. Development and validity of a 2-item screen to identify families at risk for food insecurity. Pediatrics. 2010;126(1):e26-32. doi:10.1542/peds.2009-3146