We uncovered the genetic basis of risk taking – and found it's linked to obesity and mental illness

May 7, 2018 by Emma Clifton, Felix Day And Ken Ong, The Conversation
Credit: Wolfgang Petrach/shutterstock

Those who take extreme risks often describe being drawn in by a feeling of compulsion. William Trubridge, a free-diving world record holder who regularly plunges his body hundreds of metres under water, simply explains "it beckons me beyond my means".

Most of us will be familiar with this feeling, even if we do not feel compelled to plummet headlong towards the ocean floor. But we do not all experience the urge to take risks in the same way – or to the same extent. So why is that? Researchers have long suspected that there may be genetic factors involved but that hasn't been confirmed until now. In our new study, published in Communications Biology, we have uncovered 26 genetic variants specifically linked to risk taking.

Our findings are important because, while the term "risk taker" might conjure images of an athletic individual who enjoys free diving and helmet-less mountain biking, the reality is less glamorous. Risk taking often manifests itself in day-to-day decisions which can result in poor health over time.

For example, risk prone individuals are more likely to be smokers and to have first tried smoking when they were young. They are also more likely to drink alcohol regularly and develop addictions. We wanted to examine the genetic determinants of risk taking to shed light on its biological mechanisms and their implications for health.

So, would you describe yourself as someone who takes risks? This was the question posed to 500,000 healthy adults from across the UK who enrolled in the UK Biobank study, which stores genetic data. Roughly one-quarter responded yes. On average, these individuals consumed more alcohol and were more likely to have tried smoking and report drug addictions than those who responded no – confirming that there might be important health implications involved with risk taking.

Surprising findings

Looking at their genomic data, our analysis revealed 26 variants in regions of the human genome () associated with a self-reported inclination toward risk taking. The genes located at these regions are richly expressed in the central nervous system and immune system.

That the brain plays a key role in risk-taking behaviour is hardly surprising. The four specific brain regions highlighted in our analysis – the pre-frontal cortex, hippocampus, and hypothalamus – have all been previously linked to personality traits relevant to risk taking. For example, the hippocampus regulates behavioural inhibition, the tendency to withdraw from the unfamiliar.

William Trubridge. Credit: Igor Liberti/wikipedia, CC BY-SA

The association with the immune system was initially more surprising. But there is increasing evidence that the immune system is involved in mood and behavioural problems, such as depression. There is also research suggesting that immune function and personality are linked.

Next, we investigated how the genetics of risk taking relates to the genetics of other health-related traits. We found that risk taking shares a genetic basis with aspects of body composition, such as childhood obesity and waist-to-hip ratio. There are also between risk taking and lifestyle decisions – such as having your first child early (for women) and having tried smoking. Additionally, we found that the genetic variants that make you risk-prone also make you more likely to develop psychiatric illnesses, such as bipolar disorder and schizophrenia.

Emotional eating and BMI

In addition, four of the 26 genetic loci implicated in risk taking are associated with body mass index (BMI), the measure commonly used to indicate if a person is overweight or obese. Our discovery of genetic links between risk taking and BMI is intriguing. Other (non-genetic) research suggests that overweight and obese individuals are more risk prone than their healthy weight counterparts. For example, extremely obese adolescents are more likely to have tried smoking than their peers.

Some studies go further and suggest that being risk-prone might actually contribute to causing obesity, hypothesising that impulsive food choices, poor meal planning or binge eating provide plausible mechanisms.

Our research provides partial support for the idea that behaviour surrounding food links risk taking to obesity. We found that the more risk increasing gene variants an individual carries, the more calories, fat and protein they tend to consume daily. These people are also more likely to skip breakfast and, if they are male, to eat in response to unpleasant emotions. Both of these food-related behaviours are linked to weight gain.

However, our results indicate that this is not the whole story. While skipping breakfast and emotional eating are both associated with weigh gain, the finding of an overall association between genetic variants involved in increased risk taking and these behaviours masks a wide variation in the effects of individual variants. In fact, some of which are actually associated with lower BMI. Our evidence suggests that, while risk taking and BMI are linked, it is unlikely that all broadly defined risk takers are directly vulnerable to obesity – there are several pathways involved.

This conclusion is perhaps unsurprising given the wide range of behaviours that might be described as "risk-taking" – from extreme sports to risky investment decisions and unhealthy eating. Further investigation of risk taking and of the 26 genetic loci that we uncovered will deepen our understanding of specific facets of risk-taking propensity and behaviour that contribute to obesity risk. We expect that larger studies will uncover many more genes that contribute to risk taking in the future.

Risk taking has a mixed reputation. On one hand, it is celebrated for its links to human discovery and endeavour. Astronaut Neil Armstrong famously proposed that "there can be no great accomplishment without risk". On the other hand, we are wary of risk. Cultures that emphasise, and perhaps exaggerate, the control we have over our lives regard risk with a strong degree of caution. It is fitting, then, that our exploration of the genetic underpinnings of has added intrigue to our understanding of its links with health and well being.

Explore further: Five regular meals a day reduce obesity risk among adolescents

Related Stories

Five regular meals a day reduce obesity risk among adolescents

October 3, 2013
A regular eating pattern may protect adolescents from obesity, according to a Finnish population-based study with more than 4,000 participants. When eating five meals - breakfast, lunch, dinner and two snacks - a day, even ...

Genetic variants linked to higher BMI may be protective against Parkinson disease

June 13, 2017
Genetic variants linked to higher body mass index (BMI) are associated with lower risk of Parkinson disease, according to a study published by Nicholas Wood and colleagues from the University College London, UK, in PLOS Medicine.

Genome studies can help identify lifestyle risks for diseases

February 12, 2016
Genome wide association studies (GWAS) scan the entire genome in order to pinpoint genetic variants associated with a particular disease. The technique is employed to identify biological pathways - the series of actions and ...

Physical inactivity and restless sleep exacerbate genetic risk of obesity

October 20, 2017
Low levels of physical activity and inefficient sleep patterns intensify the effects of genetic risk factors for obesity, according to results of a large-scale study presented at the American Society of Human Genetics (ASHG) ...

Genetic effects are influenced by lifestyle

September 6, 2017
The risk for developing obesity is influenced by our lifestyle as well as our genes. In a new study from Uppsala University, researchers show that our genetic risk for obesity is not static, but is influenced by our lifestyle. ...

Risk of obesity from regular consumption of fried foods may depend on genetic makeup

March 18, 2014
People with a genetic predisposition to obesity are at a higher risk of obesity and related chronic diseases from eating fried foods than those with a lower genetic risk, according to a new study from researchers from Harvard ...

Recommended for you

Researchers identify new genetic disorder

September 21, 2018
Researchers from Michigan State University College of Human Medicine and physicians from Spectrum Health have identified for the first time in a human patient a genetic disorder only previously described in animal models.

Test could detect patients at risk from lethal fungal spores

September 20, 2018
Scientists at The University of Manchester have discovered a genetic mutation in humans linked to a 17-fold increase in the amount of dangerous fungal spores in the lungs.

Researchers identify a new cause of childhood mitochondrial disease

September 20, 2018
A rapid genetic test developed by Newcastle researchers has identified the first patients with inherited mutations in a new disease gene.

Why some human genes are more popular with researchers than others

September 18, 2018
Historical bias is a key reason why biomedical researchers continue to study the same 10 percent of all human genes while ignoring many genes known to play roles in disease, according to a study publishing September 18 in ...

Class of neurological disorders share 3-D genome folding pattern, study finds

September 18, 2018
In a class of roughly 30 neurological disorders that includes ALS, Huntington's Disease and Fragile X Syndrome, the relevant mutant gene features sections of repeating base pair sequences known as short tandem repeats, or ...

Researchers resolve decades-old mystery about the most commonly mutated gene in cancer

September 18, 2018
The most commonly mutated gene in cancer has tantalized scientists for decades about the message of its mutations. Although mutations can occur at more than 1,100 sites within the TP53 gene, they arise with greatest frequency ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.