This month NHS England approved plans to pay for an additional 1,000 social prescribing workers in primary care networks. Social prescribing connects patients to community services that improve health and well-being by supporting changes in lifestyle. Belonging, and being supported as part of a group, are often key to that change. This is exciting news, as such nationwide interventions, if successful, are likely to moderate the obesity epidemic, and in turn reduce the risk of diseases associated with it, including dementia, specific cancers, and cardiovascular disease.
Although genes play a considerable role in obesity, a recent study I carried out with colleagues suggests that lifestyle choices could offset some of that genetic influence. However, my research also shows that education, income, and emotional stability reduce genetic susceptibility to obesity, and to date there is little in the way that any prescription can bring to bear on these social and psychological factors.
As an analyst I work with anonymised data from health studies, interrogating genetic, environmental and lifestyle variables, which play an important part in complex diseases like dementia. For reliability and validity, I need large enough datasets to test hypotheses and reveal trends, particularly when dealing with genetic data. As more and more researchers examine these data, important trends can emerge. For example, physical exercise can reduce the risk of poor brain health, although there is currently no evidence that it can improve it. It does this by reducing the risk of obesity, type II diabetes, high blood pressure and heart disease, which are all linked to poor brain health and dementia.
In my paper, I investigate the relationship between genes linked to obesity, and social, psychological, and lifestyle factors. My approach was to quantify the cumulative effect of a number of genes on obesity, using polygenic scores. This technique predicts each person's risk of having a trait or complex disease – in this case high body mass index and a high waist-to-hip ratio. This works well with large datasets that carry genome data on individuals. Using the UK Biobank study – a DPUK partner and the largest single cohort in the UK – I tested which lifestyle, psychological and social factors moderated the association between the polygenic risk scores and actual measurements of obesity in mid to late life.
The findings of my research add to a growing body of evidence that your genes do not necessarily have to define your health destiny. The results show that more physical activity and moderate versus low alcohol consumption, is related to a lower risk of becoming obese for those with a higher genetic susceptibility. For women the positive impact of these lifestyle factors were stronger than for men. And if you’re wondering why low alcohol isn’t associated with a positive impact: low alcohol consumption can often be a response to poor health and this was difficult to separate out in the context of this study. This is one more step towards understanding the extent to which lifestyle may offset our genetic risk of disease.
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