A small study of Australian teenagers showed that while those with and without attention deficit hyperactivity disorder had similar poor-quality diets, those who ate healthier foods had fewer problems with attention. The study, published in Nutritional Psychiatry, describes the link between certain dietary patterns and improved cognitive performance.
Attention-deficit/hyperactivity disorder is a developmental disorder characterized by challenges in concentration, organization, and impulse control. Treatment often includes medications to help manage these behaviors. Doctors and family members will also explore lifestyle changes that may help support daily activities.
Nutrition is a field that has received a lot of attention in recent years. Researchers want to know whether young people’s diet affects how their brains manage tasks. There is also evidence to suggest that deficiencies in certain nutrients may worsen behavioral symptoms.
Nutritionists often contrast the standard Western diet with the Mediterranean diet. Western patterns are generally characterized by large amounts of processed foods, added sugars, and saturated fats. The Mediterranean diet relies heavily on plant-based foods, olive oil, nuts, and fish.
This dietary pattern provides high levels of omega-3 fatty acids, vitamins, and antioxidants. Scientists think these ingredients may help reduce inflammation and support brain health. Most studies that have investigated these foods and attention have focused on young children in non-Western countries.
Naomi Lewis, a researcher at the University of the Sunshine Coast in Australia, led a team investigating this issue in older adolescents. Lewis and colleagues Jacob M. Levenstein and Anthony Villani wanted to track what teenagers in Western countries were actually eating. Adolescence is a time when young people gain more control over their food choices.
The teenage years are a period of rapid growth and require adequate nutrition. Researchers organized case-control studies to compare groups of people with certain diseases to those without. They recruited 39 adolescents between the ages of 13 and 18.
Eighteen of the participants had a formal diagnosis of attention-deficit/hyperactivity disorder, and 21 young people without the condition served as healthy controls. Scientists collected detailed health and demographic information from the teens and their parents. Participants also completed a 4-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 amount of vitamins, minerals, and fats that the teens ingested.
Researchers compared these intake levels to Australia’s national dietary guidelines. We also calculated a score for each participant based on how similar their eating habits were to the Mediterranean diet. To measure their cognitive abilities, the teens took a computerized vision test.
The 21-minute assessment required participants to respond quickly and accurately to specific images on the screen. The program measured their attention span, reaction time, and impulse control. Participants and their parents also completed standard questionnaires regarding behaviors related to concentration and hyperactivity.
Diagnosed teens had higher scores than controls on measures of inattention and impulsivity, consistent with their diagnosed condition. When the researchers looked at their overall eating habits, they found that both groups ate relatively little. Teens routinely exceeded recommended limits for saturated fat, sodium, and sugar.
Most young people did not get enough fiber, calcium, and long-chain omega-3 fatty acids. When comparing total nutrient intake between the two groups, the difference was not statistically significant. The young people who were diagnosed ate almost the same foods as other young people.
One of the only differences was that teens with this condition reported consuming candy and sweets more frequently. Researchers noticed some distinct age-related dietary trends. As participants in the control group got older, their diets tended to improve slightly.
In contrast, the diets of teenagers with the disease tended to worsen as they progressed through adolescence. The authors suggest that this age-related split may be related to increased dietary independence. As teenagers get older, they have more money and the freedom to choose their own meals and snacks.
Adolescents with attention problems may exhibit more impulsive and reward-seeking behavior. If parents no longer monitor each meal, this impulsivity can lead to choosing highly processed or sugary foods. Although the overall group had a similar diet, researchers found a strong pattern when they looked only at teens with the diagnosis.
Among this group, young people who ate a diet more similar to the Mediterranean diet reported fewer problems with concentration and hyperactivity. These same teens also performed better on computerized attention tests. We found that processing speeds were faster and reaction times were more stable.
Scientists have identified several specific nutrients that are associated with improved test scores. It was found that higher intakes of vitamin B12 resulted in significantly faster response times on computer tests. Vitamin B12 is essential for brain development and helps build a protective membrane around nerve cells.
Animal foods such as meat, dairy products, and eggs provide most of your vitamin B12. The balance of different types of fat in the diet was also consistent with cognitive performance. This 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 too much can promote inflammation. A lower ratio of omega-6 fats to omega-3 fats was found to improve alertness and impulse control during computer tests.
Researchers briefly analyzed individuals based on specific symptom profiles. Some people suffer primarily from inattention, while others have a combined form that includes high levels of hyperactivity. Data showed that teens with complex disorders met more of their daily nutritional needs than teens who only suffered from inattention.
The researchers noted that these groups were so small that it was difficult to firmly establish how different symptoms were related to dietary habits. The study also looked at whether prescription drugs influenced the diets of teenagers. Stimulants often reduce a person’s appetite.
The research team compared the dietary records of teens who were taking the drug and those who were not. They found no differences in total daily energy intake or body weight between the two groups. This suggests that medication status did not significantly alter the overall dietary patterns observed in the study.
Although this small study provides a snapshot of adolescent eating habits, it also has limitations. The sample size of 39 participants was too limited to be representative of all teenagers. The study was based on a cross-sectional design, meaning the scientists looked at a single point in time.
This methodology cannot prove that poor diet causes attention problems. Nor can it be proven that this disease leads to negative eating habits. This association simply indicates that the two elements exist together within this particular group.
Self-reported food diaries may also be unreliable. Teens may forget to track their snacks or misestimate their portions. The researchers did not take blood samples, which would have provided an accurate objective measure of how much vitamins and fats were in the participants’ bodies.
The authors suggest that future studies should involve larger groups of teenagers. Following participants over several years and using blood tests could help reveal exactly how food affects brain development.
The study, “The association of diet quality, nutrient adequacy, and symptoms in ADHD: a case-control study in Australian adolescents,” was authored by Naomi Lewis, Jacob M. Levenstein, and Anthony Villani.
