This narrative review sums up other studies of diet and ADHD. It reports no new data of its own. The authors did not leave out lower quality studies, such as case reports. Much of the evidence comes from children, not adults.
In children aged 6 to 14, a healthy diet went with lower odds of ADHD, and a Western diet or junk food with higher odds. In a Swedish twin study of almost 18,000 adults, an unhealthy diet was linked to inattention and hyperactivity. The authors call these links negligible to very small, and they rest on self-reported traits, not diagnoses. Sugary drinks were linked to higher odds of ADHD.
The Few-Foods Diet, and removing artificial dyes, looked most promising, but those data come from children. Mediterranean and DASH diets were linked to less ADHD in some studies, mostly in children. In a DASH trial of 80 boys with ADHD, most average ratings stayed above the ADHD threshold.
The authors conclude that evidence for diet approaches in adult ADHD is still limited. They say the data cannot show cause and effect, and for most nutrients there are too few trials to guide care. The authors suggest telling patients about this gap, having an experienced dietitian guide drastic changes such as elimination diets, and possibly starting by tracking symptoms against specific foods in a food diary or phone app.
Talk to a clinician about your own situation.
The numbers Stats and what the terms mean
The statistics behind the plain-language claims above.
- One included study (cited in Breda, 2022): a meta-analysis of 4,886 children aged 6 to 14, healthy diet and the odds of ADHD, OR = 0.63; 95%CI 0.41 to 0.96.
- One included study (cited in Breda, 2022): the same meta-analysis, Western diet and the odds of ADHD, OR = 1.92; 95%CI 1.13 to 3.26.
- One included study (cited in Breda, 2022): the same meta-analysis, junk food patterns and the odds of ADHD, OR = 1.51; 95%CI 1.06 to 2.16.
- One included study (cited in Breda, 2022): the Swedish twin study, unhealthy diet and inattention, correlation 0.11 (95%CI 0.09 to 0.13).
- One included study (cited in Breda, 2022): the Swedish twin study, unhealthy diet and hyperactivity, correlation 0.09 (95%CI 0.06 to 0.10).
- One included study (cited in Breda, 2022): a sugar meta-analysis, sugar-sweetened beverages and the odds of ADHD, effect size = 1.80; 95%CI 1.23 to 2.63.
- One included study (cited in Breda, 2022): a systematic review of meta-analyses of double-blind trials in children, the Few-Foods Diet, SMD 0.51 to 0.80.
- One included study (cited in Breda, 2022): the same systematic review, artificial food color elimination, SMD 0.08 to 0.44.
- One included study (cited in Breda, 2022): a case-control study of 60 ADHD cases and 60 controls, ADHD and lower Mediterranean diet adherence, OR = 7.07; 95%CI 2.65 to 18.84. What the terms mean:
- OR (odds ratio) compares the odds of ADHD between two groups, where above 1 means higher odds and below 1 means lower odds.
- 95%CI is the range the true value probably sits in, and a narrower range means a more precise estimate.
- Correlation shows how closely two things rise and fall together, from 0 for no link to 1 for a perfect link.
- Effect size here is a pooled measure of risk from a meta-analysis, where above 1 means higher risk.
- SMD is the difference between groups in standard units, where roughly 0.2 is small, 0.5 is moderate and 0.8 is large.
Source: Breda V, Cerqueira R, Ceolin G, et al.. Is there a place for dietetic interventions in adult ADHD?. Progress in Neuro-Psychopharmacology and Biological Psychiatry (2022). doi:10.1016/j.pnpbp.2022.110613