A small study of Australian teens indicates that while adolescents with and without attention-deficit/hyperactivity disorder consume similarly poor diets, those who eat healthier foods experience fewer attention challenges. The research, published in Nutritional Psychiatry, describes links between specific eating patterns and better cognitive performance.
Attention-deficit/hyperactivity disorder is a developmental condition characterized by challenges with focus, organization, and impulse control. Treatment often involves medications that help manage these behaviors. Doctors and families also look for lifestyle changes that might help support daily functioning.
Nutrition has emerged as an area of high interest in recent years. Researchers want to know if what young people eat affects how their brains manage tasks. Some evidence suggests that a lack of specific nutrients might worsen behavioral symptoms.
Nutritionists often contrast the standard Western diet with the Mediterranean diet. The Western pattern generally features high amounts of processed foods, added sugars, and saturated fats. The Mediterranean diet relies heavily on plant-based foods, olive oil, nuts, and fish.
This eating pattern provides high levels of omega-3 fatty acids, vitamins, and antioxidants. Scientists suspect these components help reduce inflammation and support brain health. Most studies looking at these foods and attention have focused on younger children in non-Western countries.
Naomi Lewis, a researcher at the University of the Sunshine Coast in Australia, led a team to investigate this topic in older adolescents. Lewis and colleagues Jacob M. Levenstein and Anthony Villani wanted to track what teenagers in a Western country were actually eating. Adolescence is a time when young people gain more control over their food choices.
Teenage years represent a period of rapid growth that requires adequate nutrition. The researchers organized a case-control study, which compares a group of people with a specific condition to a group without it. They recruited 39 adolescents between the ages of 13 and 18.
Eighteen of the participants had a formal diagnosis of attention-deficit/hyperactivity disorder, while 21 youths without the condition served as the healthy control group. The scientists gathered detailed health and demographic information from the teens and their parents. The participants also filled out a four-day food diary.
They recorded everything they ate and drank over three weekdays and one weekend day using standard measuring cups and spoons. To evaluate the nutritional data, the team used specialized software. They calculated the exact amounts of vitamins, minerals, and fats the teens consumed.
The researchers compared these intake levels against Australian national dietary guidelines. They also calculated a score for each participant based on how closely their eating habits resembled a Mediterranean diet. To measure cognitive performance, the teens completed a computerized visual test.
The 21-minute assessment required participants to respond quickly and accurately to specific images on a screen. The program measured their attention span, reaction time, and impulse control. The participants and their parents also completed standard questionnaires about behaviors related to focus and hyperactivity.
The teens with the diagnosis scored higher on measures of inattention and impulsivity than the control group, matching their diagnosed status. When the researchers looked at the overall dietary habits, they found that both groups ate relatively poorly. The teens routinely exceeded recommended limits for saturated fat, sodium, and sugar.
Most of the youths failed to consume enough fiber, calcium, and long-chain omega-3 fatty acids. When comparing the total nutritional intake between the two groups, the differences were not statistically significant. The adolescents with the diagnosis ate mostly the same foods as their peers.
One isolated difference was that the teenagers with the condition reported consuming candy and sweets more frequently. The researchers did notice some distinct dietary trends related to age. As the control group participants got older, their diets tended to improve slightly.
In contrast, the diets of the teens with the condition tended to worsen as they moved through adolescence. The authors suggest this age-related split might relate to increasing dietary independence. Teenagers often have more money and freedom to choose their own meals and snacks as they get older.
Adolescents with attention challenges can exhibit more impulsive and reward-seeking behaviors. This impulsivity might translate into choosing highly processed or sweet foods when parents are no longer monitoring every meal. While the overall groups ate similar diets, the researchers found strong patterns when they looked just at the teens with the diagnosis.
Among this group, the youths who ate food more closely resembling a Mediterranean diet reported fewer struggles with focus and hyperactivity. These same teenagers also performed better on the computerized attention test. They showed faster processing speeds and more consistent reaction times.
The scientists identified several specific nutrients linked to better test scores. Higher consumption of vitamin B12 was associated with a much faster response time on the computer test. Vitamin B12 is essential for brain development and helps build the protective coating around nerve cells.
Animal products like meat, dairy, and eggs provide most dietary vitamin B12. The balance of different types of fats in the diet also corresponded with cognitive performance. The study looked closely at the ratio of omega-6 to omega-3 fatty acids.
Omega-3 fats, found in fish and certain seeds, help build brain cell membranes and reduce inflammation. Omega-6 fats, commonly found in vegetable oils and processed foods, are also necessary but can promote inflammation if consumed in excess. A lower ratio of omega-6 to omega-3 fats was linked to better attention and impulse control during the computer test.
The researchers briefly analyzed the individuals based on their specific symptom profiles. Some people primarily struggle with inattention, while others have a combined type that includes high hyperactivity. The data showed that the teens with the combined type met more of their daily nutritional requirements than those who only struggled with inattention.
The researchers noted that these groups were very small, making it difficult to firmly confirm how different symptoms might relate to eating habits. The study also checked if prescription medications influenced how the teens ate. Stimulant medications often reduce a person’s appetite.
The team compared the food records of the teens taking medication against those who were not. They found no differences in total daily energy intake or body weight between the two groups. This suggests the medication status did not heavily alter the overall dietary patterns observed in the study.
This small study provides a snapshot of adolescent eating habits, but it comes with limitations. The sample size of 39 participants is too limited to represent all teenagers. The research relies on a cross-sectional design, meaning the scientists looked at a single point in time.
This methodology cannot prove that a poor diet causes attention problems. It also cannot prove that having the condition leads to negative eating habits. The association only shows that the two factors exist together in this specific group.
Self-reported food diaries can also be unreliable. Teenagers might forget to record a snack or incorrectly estimate their portion sizes. The researchers did not take blood samples, which would have provided an objective measure of exactly how many vitamins and fats were in the participants’ bodies.
The authors suggest that future research should involve much larger groups of teenagers. Tracking participants over several years and using blood tests could help clarify exactly how food influences the developing brain.
The study, “Diet quality, nutrient adequacy, and symptom associations in ADHD: A case-control study of Australian adolescents,” was authored by Naomi Lewis, Jacob M. Levenstein, and Anthony Villani.