ADHD and Diet

Sugar free, gluten free, additive-free, paleo, Mediterranean, low salycilate…. With all of the many and varied opinions on diet these days it is easy to feel overwhelmed when it comes to exploring diet and ADHD. Often the best approach is to start by looking at what scientific evidence is telling us…

Is there a link between diet and ADHD symptoms?

Yes, for some people there appears to be a link between diet and ADHD symptoms, that is not to say that diet causes ADHD, it simply means that diet can impact the symptoms of ADHD, in that children with ADHD show an improvement in their symptoms when certain changes are made to their diet or nutritional supplementation is added.

Photo by  Kelly Sikkema  on  Unsplash

Photo by Kelly Sikkema on Unsplash


What do we know?

According to a recent Australian study, diets loaded with saturated fat, refined sugars and sodium (salt) and also with deficiencies in Omega 3 fatty acids, fiber and folate have been shown to be associated with a higher diagnosis of ADHD in the population. A ‘healthy’ diet rich in fish, vegetables, fruit, legumes and whole-grain foods, however, shows the opposite effect, and is not associated with an ADHD diagnosis in the population (1).

Dietary Sensitivities

A recent literature review, summarising 35 years of research on dietary sensitivities and ADHD symptoms, found that in children with suspected food sensitivities, 65-89% react when challenged with 100mg of artificial food colours (1) and the exclusion of artificial food colours appear to have beneficial effects on ADHD symptoms (2, 5).  Along with additives, some children are also sensitive to foods. A trial of an antigen and additive free diet may be appropriate for children with sensitivities to foods or food colours. This diet requires the guidance of an experienced nutritional health care provider (1).



Hypoallergenic/Elimination Diet

Also known as an oligoantigenic diet, removes most known allergens from the diet to test for specific food intolerances. Studies have shown statistically significant decreases in ADHD symptoms using this diet (7). In some children, a short 3-week period of a restricted elimination diet under the guidance of an experienced nutritional health care provider is warranted (1, 7).


An example of a young child in Norman Doidge’s book, The Brain’s Way of Healing, highlights the benefits of taking the time to really observe a child’s negative reaction/response to very high sugar foods and the difference in them when these foods have been completely removed (6). Most studies demonstrate that sugar does not typically effect the behaviour or cognition of children, however the effect of sugar on small subgroups of children cannot be ruled out. More recently, reactive hypoglycaemia (that is reactive low blood sugar/glucose) has been suggested as an alternative explanation for sugar-induced inattention and decreased cognition amongst children. Children are more susceptible to the cognitive effects of low blood glucose than adults. It has been proposed that avoiding rapidly absorbed sugar containing foods (like lollies and heavily processed grains) in young children can prevent the exacerbation of ADHD symptoms (1).

Photo by  Patrick Fore  on  Unsplash

Photo by Patrick Fore on Unsplash


Omega 3 Fatty Acids

Omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) cannot be made in the body and thus need to be obtained from our diet. Omega-3 fatty acids are essential for adequate brain function and development (4) and have anti-inflammatory properties. Amongst many other positive health effects, it has been shown that Omega-3 can affect the transmission of serotonin and dopamine, particularly in the frontal cortex. A western diet is typically low in Omega-3 and high in Omega-6 and 9 (which have the opposite, inflammatory effect) (3). Recent studies have reported that children with ADHD often have low levels of Omega (3,3,4), which has prompted research into the effect of supplementation. Recent critical appraisals of the literature indicate that Omega-3 fatty acid supplementation has a modest effect on ADHD symptoms (7). Used by itself it appears to be more effective in mild cases of ADHD but also may be used in conjunction with stimulant medication to reduce the dosage of medication required. Supplementation appears to be well tolerate with minimal side-effects (3,4). It is important to note however, that the dosage of the EPA component within the supplement is directly proportional to the treatment effect. Omega-3 supplementation, in particular those with higher doses of EPA, appear to have the best effect on ADHD symptoms (3).

Photo by  Joanna Kosinska  on  Unsplash

Making Changes

Making changes to the diets of children can be challenging, try involving them in making fun foods that they can enjoy both making and eating, the benefits may astound you. Here is a recipe from The Healthy Mind Cookbook:


Brain-Berry Smoothie

1 cup plain organic full fat yoghurt

1 cup filtered water

1 teaspoon freshly squeezed lemon juice

1 teaspoon grated ginger

1 cup fresh or frozen blueberries

1 cup fresh or frozen blackberries

1 cup fresh or frozen cherries

3 tablespoons almond butter

1 tablespoon finely ground flaxseed

1 ½ teaspoons organic real maple syrup

Pinch of sea salt

Combine the yoghurt, water, lemon juice, and ginger in a blender and process until smooth. Add the blueberries, blackberries, cherries, almond butter, ground flaxseed, maple syrup, and salt and blend until smooth and creamy.

This smoothie, full of good fats, fibre and brain protective berries will be absorbed slowly by your body and not create a spike in blood sugar. Really berry good, enjoy!

To let us know what you thought of this article, Get in touch! We would love to see your take on the Brain Berry Smoothie.

About the author - Ms. Emily Goss (Occupational Therapist, Senior Clinician, The Perth Brain Centre).

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