February 08, 2017
Pediatrics
Abstract
OBJECTIVES
Although attention-deficit/hyperactivity disorder (ADHD) has been related to nutrient deficiencies and “unhealthy” diets, to date there are no studies that examined the relationship between the Mediterranean diet and ADHD. We hypothesized that a low adherence to a Mediterranean diet would be positively associated with an increase in ADHD diagnosis.
METHODS
A total of 120 children and adolescents (60 with newly diagnosed ADHD and 60 controls) were studied in a sex- and age-matched case-control study. ADHD diagnosis was made according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Energy, dietary intake, adherence to a Mediterranean diet, and familial background were measured. Logistic regression was used to determine associations between the adherence to a Mediterranean diet and ADHD.
RESULTS
Lower adherence to a Mediterranean diet was associated with ADHD diagnosis (odds ratio: 7.07; 95% confidence interval: 2.65-18.84; relative risk: 2.80; 95% confidence interval: 1.54-5.25). Both remained significant after adjusting for potential confounders. Lower frequency of consuming fruit, vegetables, pasta, and rice and higher frequency of skipping breakfast and eating at fast-food restaurants were associated with ADHD diagnosis (P < .05). High consumption of sugar, candy, cola beverages, and noncola soft drinks (P < .01) and low consumption of fatty fish (P < .05) were also associated with a higher prevalence of ADHD diagnosis.
CONCLUSIONS
Although these cross-sectional associations do not establish causality, they raise the question of whether low adherence to a Mediterranean diet might play a role in ADHD development. Our data support the notion that not only “specific nutrients” but also the “whole diet” should be considered in ADHD.
The rising prevalence of attention-deficit/hyperactivity disorder (ADHD) in populations has been puzzling to many—is this due to digital media? Antibiotic use? Food dyes? One theory relates to diet, in particular, the idea that high saturated fat and refined sugar intake and low fruit and vegetable intake may be associated with ADHD.
To test this, the authors of this paper took advantage of a novel set of social circumstances—they noted that the population in Spain is moving away from the traditional, well balanced Mediterranean diet to a diet more closely resembling the above. They decided to examine the dietary habits of children recently diagnosed with ADHD with healthy controls in an age- and gender-matched case–control study. Aside from diet, they also evaluated energy, overall dietary intake, and familial background.
So, what did they find? A lower adherence to the Mediterranean diet increased the likelihood of an ADHD diagnosis, even when adjusting for confounders. Specifically, decreased intake of fruits, vegetables, pasta, rice, and fatty fish as well as increased incidence of skipping breakfast, eating at fast-food restaurants, and intake of sugar, candy, and soft drinks seemed to be associated with an ADHD diagnosis. These findings would seem to support the general notion, although, of course, it does not necessarily point out the specific causal mechanism.
Although this is compelling at first glance, I do think that there was limited attention paid to parental education and other measures of socioeconomic status, which may be the common root for both ADHD-type symptoms as well as poorer diet. They did address it briefly, but not in detail.
Bottom line: diet is likely an important factor—and I recommend interested readers look at the excellent discussion section of this paper for more nuances—but we should be careful to consider influences and causes that go beyond diet as well when trying to understand the complex entity that is attention issues.