Third-Party Funded Projects on ADHD

Eat2beNICE - Effects of Nutrition and Lifestyle on Impulsive, Compulsive, and Externalizing Behaviours

Project duration: 2017-2022

Does an unhealthy lifestyle worsen aggression, impulsivity and compulsivity? Can specific diets reduce ADHD symptoms? Is physical exercise beneficial in improving impulsive behavior?

It is widely accepted that a healthy lifestyle, including a balanced (and varied) diet and regular physical exercise, is beneficial to our general health and prevents costly public health burdens such as cardiovascular disease, obesity, Diabetes and other somatic diseases. Less well known is that our mental health also benefits from a healthy diet and regular exercise. We focus on  maladaptive impulsive, compulsive and aggressive behaviors that may benefit from lifestyle interventions. While beneficial in certain situations, extreme or uncontrolled forms of these behaviors are central to several psychiatric conditions and can lead to emotional and social maladjustment, such as obesity, addiction, crime and death.  

The factors influencing impulsivity, compulsivity and aggression are not yet fully identified, but nutrition, lifestyle (in particular physical activity), socioeconomic status (SES), sex, genetic determinants and their interactions play pivotal roles in the variability among persons with such extreme behaviors. Although pharmacological therapies to reduce or improve these behaviors exist, not every user (patient) responds well to medication and some people prefer non-pharmacological alternatives. Lifestyle-based interventions are promising non-pharmacological treatment options (either replacing medication or complementing treatment as usual), but have not yet been clinically tested in well-powered trials. In addition, understanding the etiological pathways that mediate the association between lifestyle and behavior will aid in further developing such non-pharmacological treatments. To understand these etiological pathways, we need to study the interaction between genes and environment, including epigenetics and the communication between gut microbiota and the brain (figure 1).


Figure 1: How diet and physical exercise are associated with impulsive, compulsive and aggressive behaviors through epigenetic mechanisms and the communication between gut microbiota and the brain.



We aim to answer the question how diet and physical exercise are associated with impulsive, compulsive and aggressive behaviors (Figure 1). We review evidence from a wide range of fields: randomized controlled clinical intervention studies with populations at high risk of developing mental health disorders; large population-based epidemiological studies that identify risk factors for maladaptive behaviors; genetic (candidate gene and genome-wide) studies on common risk variants associated with these behaviors; neuroimaging studies on brain structure and function involved in the variation of impulsivity, compulsivity and aggression; microbiological studies on the influence of diet on the gut-brain axis; and animal studies that investigate epigenetic mechanisms. The horizon2020 research consortium Effects of Nutrition and Lifestyle on Impulsive, Compulsive, and Externalizing Behaviours ("Eat2beNICE") brings together experts from these various fields to identify nutritional drivers and lifestyle variations that prevent detrimental effects of impulsivity, compulsivity and aggression, characterize the etiological paths leading to these behaviors, and promote societal changes to counteract these maladaptive behaviors.  

Eat2beNICE investigates the question of how diet and physical exercise are associated with impulsive, compulsive and aggressive behavior. The project starts with a description of the clinical implications of impulsive, compulsive and aggressive behaviors, and why it is relevant to focus on extreme forms of these behaviors in particular. We then discuss epidemiological findings on the association between diet and lifestyle and these behaviors (and associated psychiatric disorders). We will highlight the mechanisms through which diet and lifestyle can influence behavior. This first of ALL depends on an individual's genetic background, which accounts for 30-65% of phenotypic variance in impulsive, compulsive and aggressive behavior. Second, the gut-brain axis (GBA) is a key player in the interaction between lifestyle and behavior. Gut microbiota modulate this axis and are in turn affected by diet, stress and other lifestyle factors. Already early in life these influences can predispose an individual towards mental health problems later on. Third, nutrition is a key environmental factor regulating the epigenome, serving as another mechanism through which diet can influence behavior. Genes, epigenetic factors and gut microbiota ALL influence brain processes that regulate behavior. We highlight the brain networks and Neurotransmitter systems involved in impulsive, compulsive and aggressive behavior, and that are most likely affected by the listed mechanisms. Furthermore  the evidence supporting the effect diet and lifestyle based interventions may have in improving behavior (i.e. reduction in symptomatology) in individuals that are at high risk of mental illness will be explored. We discuss different diets (the Mediterranean diet, WHO-guidelines diet and restriction elimination diet) as well as nutritional supplements (probiotics, vitamins and minerals). The effect of physical exercise on mental health is also discussed, as energy consumption (i.e. through exercise) is closely tied to energy intake (i.e. through diet). Notably, the mentioned lifestyle interventions rely on accurate, real-time and ecologically valid measurements of dietary intake, physical activity, mood and behavior. We therefore also discuss the benefits of ambulatory assessment in the context of investigating lifestyle effects on behavior.

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