Parents of children with attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are often seeking ways to manage symptoms and improve their child's overall well-being. Diet is often considered a potential factor, with many wondering if specific foods can alleviate or worsen symptoms like hyperactivity, inattention, and behavioral challenges. This article explores the current research and expert recommendations regarding dietary interventions for children with ADHD and autism.
The Link Between Nutrition and Brain Function
Research indicates that eating nutritious meals supports brain function. When we don't eat, we struggle to think clearly. Without nutrients, our brains have difficulty creating certain neurotransmitters, the "chemical messengers" that carry nerve signals to different parts of the body. Stephanie Ruggiero, PsyD, a psychologist in the ADHD and Behavior Disorders Center at the Child Mind Institute, notes that while nutritious meals benefit brain function, research hasn't definitively proven that specific foods, supplements, or diets directly affect ADHD symptoms.
General Dietary Guidelines
For overall good health, experts recommend following a more Mediterranean-style diet, consisting mainly of fruits and vegetables, lean proteins, healthy fats, and complex carbohydrates. This approach is recommended for a variety of reasons, including reducing rates of obesity, diabetes, and heart disease as well as improving brain health. “Staying away from simple carbs and sugary foods and eating what I would call a more well-rounded diet is what we would want people to generally adhere to for overall good health,” Dr. Ruggiero says.
Western Diet and ADHD
A 14-year-long study concluded that the Western diet - which tends to be high in fat, calories, and sugar - is associated with higher rates of ADHD in kids. However, the research only established a correlation and did not confirm that the Western diet causes ADHD. The study authors suggested that having ADHD may cause kids to crave fat-laden foods for comfort or that family distress, another lifestyle factor linked to ADHD, tends to influence dietary habits as well.
Ultra-Processed Foods
Children get most of their calories from ultra-processed foods, according to research published in JAMA in 2021.
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Sugar and Hyperactivity
Research on sugar and symptoms of hyperactivity remains mixed. Some studies have reported a modest increase in hyperactivity after eating sugar, while others have not found any change in symptoms. However, "There is definitive research that sugar does not cause ADHD,” Dr. Ruggiero says. “It may cause overactivity symptoms to intensify in someone who already has ADHD, because it gives them more energy - the same goes for caffeine - but it does not cause ADHD in someone who doesn’t have it.” Limiting sugary foods and eliminating soda and other sugary drinks is good for a variety of health-related reasons, including better weight management, reduced diabetes risk, and improved sleep. If it also helps your child’s ADHD symptoms, then all the better.
The Role of Food Additives and Elimination Diets
Many believe that eliminating preservatives, artificial coloring, MSG, nitrates, sugar, and other food additives is the key to reducing ADHD symptoms. Several studies have found that avoiding certain ingredients does lead to a reduction in symptoms, but the sample sizes of these studies, even when aggregated, are small, and the improvements in symptoms have been modest. Also, many of the studies are based on flawed methods, having relied on parent reporting to collect their data rather than objective means.
Dr. Ruggiero notes the potential for bias in parent-reported data: “It’s hard for parents to be objective in these types of studies, because they’re the ones changing what they serve their child and they’re also the reporter. So if you’re going through all that trouble to make the change to their diet, it might impact your perceived outcome on the results because you want it to work. I’m not saying always, but certainly it happens sometimes.”
If considering an elimination diet, consult with a pediatrician first. “I always recommend consulting with a pediatrician to make sure you’re not eliminating anything from your child’s diet they need to have,” Dr. Ruggiero says.
Supplements: Benefits and Risks
Research on supplements and ADHD has produced mixed results. Some studies suggest that giving a child zinc, iron, magnesium, or vitamin B and omega-3 supplements might reduce symptom severity. And that appears to be the case for children who are deficient in these vitamins and minerals. But there has not been any evidence that giving supplements to children who are not deficient is helpful. It could actually be harmful, Dr. Ruggiero says. “High doses of anything can be potentially toxic, particularly for children,” she says. “If you do feel like your child needs additional vitamins and minerals, it’s best they get them from the foods they eat. Zinc, iron, and magnesium in particular can be found in meat, poultry, seafood, nuts, and soy.” Vitamin B is abundant in leafy greens, broccoli, and chickpeas, while omega-3 fatty acids are found in salmon, walnuts, and edamame. If getting these nutrients from food is not possible, talk to your child’s pediatrician about supplements and make sure that you are administering the correct dose.
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Essential Trace Minerals
The 3 essential trace minerals that have been studied the most and are very important for brain development and functioning are zinc, iron and magnesium. Again, it’s important to note, that any treatment plan that consists of vitamin or mineral supplementation should first be consulted with a medical professional.
Zinc
Zinc levels have been found to be lower in ADHD and Autism. Zinc is a called a “cofactor” in neurotransmission, and it plays an important role in the healing of tissue and immune system functioning. In addition, zinc protects the gut barrier and the blood-brain barrier, and if one has a zinc deficiency, these barriers could breakdown. One study showed that zinc improved hyperactivity and impulsivity but not the symptoms of inattention. High copper to zinc ratios have been found in children with impulsivity, aggression, and Autism. Pediatricians can test for low zinc levels and guide supplementation if zinc levels are low.
Foods Rich in Zinc:
- Spinach
- Beef & lamb
- Shrimp
- Oysters
- Pumpkin seeds
- Kidney beans and garbanzo beans (chickpeas)
- Nuts such as cashews, pecans, almonds, walnuts, peanuts, and hazelnuts
- Pork & chicken
- Mushrooms
Iron
Iron is also a cofactor in the production and metabolism of neurotransmitters, and an iron deficiency can affect dopamine metabolism. Dopamine is a key neurotransmitter involved in ADHD. Iron deficiency in ADHD and Autism Spectrum Disorders can cause restless legs syndrome, sleeping problems, and sometimes fatigue and tachycardia (elevated heart rate).
Low ferritin (a protein that stores iron in the body and releases it) and abnormal iron indices are seen in ADHD children, particularly in children who are experiencing sleeping problems. ADHD children, who are taking stimulant medications, could also have an increased risk for iron deficiency as these medications tend to suppress the child’s appetite, which may result in the child not consuming enough nutrients.
Read also: Dietary Supports for Autism
For children who are suffering from ADHD and Autism Spectrum Disorders with sleeping difficulties, whose serum ferritin levels are below 50ng/ml, iron supplementation is recommended as it helps improve sleep in these children.
Foods Rich in Iron:
- Red meat, pork, poultry
- Seafood
- Beans & lentils
- Spinach
- Raisins & apricots
- Peas
- Chickpeas
- Sesame seeds
Magnesium
Magnesium is the third essential trace mineral and is involved in more than 300 enzymatic reactions in the body. To name just a few biochemical processes, magnesium is utilized in bone metabolism and growth, nerve function, neurotransmitter release, immune system functioning, and in the regulation of the hypothalamic-pituitary-adrenal axis in the brain-body connection involved in the stress process.
Blood tests measuring magnesium levels have shown low levels of the mineral in both ADHD and Autistic children. Kids with ADHD, who can be under increased stress, could be more vulnerable if they have magnesium deficiencies. Clinical symptoms of magnesium deficiency in children include irritability, anxiety, and agitation. Magnesium can reduce anxiety or irritability through its calming effect. There is no evidence, though, that magnesium supplementation in children on the Autism Spectrum is helpful unless there is a magnesium deficiency; in fact, too much magnesium supplementation can cause negative side-effects such as diarrhea.
Foods Rich in Magnesium:
- Spinach
- Squash & pumpkin seeds
- Fish
- Beans & lentils
- Brown rice
- Avocados
- Bananas
- Low-Fat dairy
- Dried fruits such as figs, prunes, apricots, dates, and raisins
Fatty Acid Supplementation
Fatty acid supplementation may be helpful too since every cell in our body (including our brain) is made up of fats. Excluding the water composition of the brain, the brain is composed of as much as 60% lipids. In improving brain functioning, research has shown that Omega-3 fatty acid supplementation is 40% as effective for ADHD as methylphenidate (Ritalin) but without the side-effects. That is an amazing statistic when you consider that Omega-3 fatty acids are not a drug but are dietary healthy fats.
Best sources of Omega-3 Fatty Acids:
- Coldwater fish (i.e., mackerel, tuna, salmon, and sardines)
- Cod liver oil
- Flaxseed and chia seeds
- Soybeans and tofu
- Walnuts
ADHD, Autism, and Eating Habits
Experts say having ADHD can make it more difficult to eat a healthy diet. For starters, ADHD medication can act as an appetite suppressant, and kids will commonly say they’re not hungry while they’re on it. Then, when the medication wears off, usually around the time they get home from school, they may become ravenous. That can make it difficult to wait for a healthy meal to be prepared. “This is when you’re going to see them eating a whole box of fruit snacks and whatever else they can find, because that’s when they feel hungriest,” Dr. Ruggiero says. “I talk to parents a lot about planning meals and trying to get a meal, and particularly some protein, into their kiddo before they take their meds in the morning to start them off on the day.” Then, it’s helpful to have healthy snacks on hand - think apple slices with nut butter, precut vegetables and hummus, low-fat yogurt and berries - to satisfy after-school hunger and tide them over until dinner.
Many individuals with autism have food aversions and sensitivities. Many also have behavioral issues that make mealtime particularly challenging. Researchers at Marcus Autism Center at Emory University School of Medicine reviewed and analyzed all published, peer-reviewed research relating to eating problems and autism spectrum disorder (ASD). They found that children with ASD are five times more likely to have mealtime challenges such as tantrums, extreme food selectivity and ritualistic eating behaviors.
They also found inadequate nutrition to be more common among children with autism than in those unaffected by the disorder. In particular, they found an overall low intake of calcium and protein. Calcium is crucial for building strong bones. Adequate protein is important for growth, mental development and health.
Chronic eating problems also increase a child's risk for social difficulties and poor academic achievement, the researchers note. This may also increase risk for diet-related diseases such as obesity and cardiovascular disease in adolescence and adulthood.
Meal Planning and Preparation
Meal planning and cooking are great healthy eating strategies, but can be a challenge for people affected by ADHD. Preparation, time management, decision-making, and following multiple steps are all skills involved in creating any meal. Frustrated, many people with ADHD decide to eat out or order in rather than cook for themselves. When you cook at home, you know exactly what you’re putting into your dish. You can use fresh and healthy ingredients that are low in fat, sugar, and salt without artificial ingredients and additives that can make ADHD symptoms worse for some people.
Dietary Changes Should Complement Medical Treatment
Whether or not you find a particular diet or supplement to be effective at reducing your child’s ADHD symptoms, there’s one thing to remember: Dietary changes should not take the place of prescribed medical treatment. “While the research focusing on diet and ADHD is still questionable, we do have very good research on treating ADHD with a combination of medication and behavior therapy,” Dr. Ruggiero says. “That is why it’s the most recommended form of treatment in kids as young as 6.” There are several ADHD medications on the market today and each can affect people differently. If the medication your child has been prescribed doesn’t seem to be working or has problematic side effects, talk to your doctor about changing the dose or medication until you find one that works.
At the Drake Institute, they are advocates of evidence based, proven medical treatment programs utilizing the brain’s own resources, without drugs when possible, to improve disorders and symptoms with biofeedback and neurofeedback. Their ADHD and Autism treatment programs are non-drug and non-invasive.
Their ADHD and Autism treatment programs are centered on “retraining” the brain” for long term improvement, as opposed to simply medicating to control symptoms. Offering an improved diet for kids with ADHD & Autism is one of the best ways to help fully support our treatment process, and to increase the likelihood that your child will have the best possible long-term results from brain map guided neurofeedback.
Alternative Diets and Nutritional Deficiencies in Autism
The researchers expressed additional concern about alternative diets. Many parents report that their children’s autism symptoms and related medical issues improve when they remove casein (milk protein) and gluten (wheat protein) from their diets. However, casein/gluten-free diets can increase the challenge of ensuring adequate nutrition. "This highlights the importance of assessing diet as part of routine healthcare for all individuals with ASD,” comments Daniel Coury, M.D., medical director of Autism Speaks Autism Treatment Network. Dr. Coury is also a developmental-behavioral pediatrician with Nationwide Children’s Hospital, in Columbus, Ohio. “We know that the use of alternative diets is common among parents of children with ASD,” he says. “And so we encourage families to consult with their provider when considering these diets. While many of these diets are safe, they have potential for nutritional deficiencies."
Improving the Gut
Foods that are bad for the gut also include ones that contain high amounts of sugar, artificial food colorings, and toxic preservatives. In addition, there are non-food factors that can negatively impact gut flora such as childbirth by cesarean delivery as well as antibiotics (this is not to suggest avoiding antibiotics when necessary).
Children with ADHD and Autism have a greater prevalence of gastrointestinal symptoms. Our gut microbiota (gut flora) is composed of many microorganisms that are very important to our physical and mental health, immune system functioning (65% to 75% of all immune system functioning is taking place in the gut), brain development, and the synthesis of neurotransmitters. In fact, 90% of the neurotransmitter, serotonin, is actually produced in the gut and not in the brain.
Probiotics, such as Lactobacillus and Bifidobacterium, can improve gut flora. Parents should also consider including foods such as yogurt into their child’s diet, which can benefit the gut flora.
Practical Steps for Parents
- Consult Professionals: Always consult with pediatricians, registered dietitians, or other qualified healthcare professionals before making significant dietary changes or starting supplements.
- Focus on a Balanced Diet: Prioritize a diet rich in fruits, vegetables, lean proteins, healthy fats, and complex carbohydrates.
- Limit Processed Foods: Minimize the intake of ultra-processed foods, sugary drinks, and foods high in artificial additives.
- Plan Meals and Snacks: Prepare meals and snacks in advance to ensure healthy options are readily available, especially during times when ADHD medication wears off.
- Address Nutritional Deficiencies: Work with healthcare providers to identify and address any potential nutritional deficiencies through diet or appropriate supplementation.
- Consider Behavioral Therapy: Remember that dietary changes should complement, not replace, evidence-based treatments like medication and behavioral therapy.