Rates of obesity, high blood pressure and high cholesterol are lower among British adults in their 30s and 40s compared to their counterparts in the US, according to a new study led by UCL researchers.

However, people in Britain are more likely to be regular smokers and to judge their health as poor.

Published today in the International Journal of Epidemiology, the research also finds surprising evidence that American university graduates are more likely to have high blood pressure and high cholesterol than British adults without degrees. In addition, the study reveals that socioeconomic inequalities in health are wider in the US than in Britain, especially for diabetes and smoking.

Lead author, Dr Charis Bridger Staatz (UCL Centre for Longitudinal Studies) said: “Our new research shows that although British adults are more likely to believe that their health is poor, they tend to have better cardiovascular health than their US counterparts in midlife. While we were unable to directly investigate the causes of this, we can speculate that differences in levels of exercise, diets and poverty, and limited access to free healthcare may be driving worse physical health in the USA. Given political and social similarities between the US and Britain, the US acts as a warning of what the state of health could be like in Britain without the safety net of the NHS and a strong welfare system.”

Researchers from the UCL Centre for Longitudinal Studies, University of Oxford, Syracuse University and University of North Carolina analysed information from almost 10,000 British people born in 1970, who are taking part in the 1970 British Cohort Study (BCS70). They compared this data with information from 5,000 American adults, born between 1976-1983, who are being followed by the Add Health study. In both nationally representative studies, trained nurses measured blood pressure, cholesterol, BMI and whether blood sugar levels indicated diabetes. Study participants reported on how good they thought their health was and how regularly they smoked cigarettes.

US adults in midlife were more likely to have high blood pressure (22.5% v 19%) and high cholesterol (11% v 8%) compared to their middle-aged British counterparts. Additionally, they were more likely to be obese (40% v 34.5%). British adults, however, were more likely to smoke every day (28% v 21%) and report their health as poor (18% v 12%).

In a separate analysis, the study’s authors examined whether people’s health in each country differed by their socioeconomic background, measured by their income and education level. They discovered that in both Britain and the US, advantaged adults tended to have better physical health and healthier habits than their disadvantaged peers. However, for most health conditions, the US had significantly wider inequalities than Britain.

In the US, the poorest adults were around eight times more likely to have diabetes than the richest and were seven times more likely to smoke. In Britain, the poorest adults were twice as likely for both diabetes and smoking. Wider inequalities were also found in the US for obesity, high blood pressure and high cholesterol.

When looking at people’s health by their own education level and that of their parents, the researchers found that American graduates were more likely to have high blood pressure and high cholesterol than British adults without degrees. They also discovered that US adults with graduate parents were as likely to be obese as British individuals whose parents did not have degrees.

In some ways, these findings could be seen to paint a positive picture for the nation, as the health of adults in Britain is better than that in the USA. Nevertheless, this research should not distract us from the fact that more than a third of British adults are obese and a fifth have high blood pressure in midlife. The new government’s pledges to cut NHS waiting times will be severely tested if this and future generations continue to age in poor health.”

George Ploubidis, Senior Author, Professor, UCL Centre for Longitudinal Studies

Dr Bridger Staatz added: “Our findings reinforce previous research showing that health problems and inequalities in older age tend to have their origins earlier in life. In both Britain and the US, public health policies tend to focus on improving health awareness and behaviours in childhood or older age. However, intervening in midlife offers a great opportunity to promote healthier ageing.

“In the wake of Lord Darzi’s report into the state of the NHS, it is encouraging to hear the new prime minister prioritising a 10-year programme of reform for the health service. Long-term planning and investment in the NHS will likely help improve the health disparities we see in the UK and prevent the emergence of inequalities on the same scale as we see in the US. This will not only help to improve population health across life but create a happier and more prosperous society.”

Study limitations

The study is based on data from two observational studies. In BCS70, individuals have been followed from birth and across the whole of their lives, and in Add Health they have been tracked since early adolescence. This rich data has allowed the researchers to make use of detailed information on socioeconomic position to examine the association between socioeconomic background and midlife health.

However, despite the use of these rich data, the authors noted the challenges in establishing cause and effect, since it is impossible to rule out that there could be other, unobserved factors that have not been accounted for, that could also explain the association between socioeconomic background and midlife health.