How African Caribbean background can affect your heart health
Professor Nishi Chaturvedi tells Senior Cardiac Nurse Christopher Allen how your ethnic origin can affect your heart and circulatory health
People of African Caribbean heritage make up 1–2 per cent of the UK population, concentrated in major cities, especially London and Birmingham. If you’re of African Caribbean heritage, you may have a higher risk of some heart and circulatory diseases.
Explanations for this are unclear. A strong contender is that African Caribbean communities tend to be in more deprived areas and deprivation can make it harder for a person to have a healthy lifestyle. Genetic differences may also be having an effect, and evidence for this is still being researched.
It’s never too early or too late to make lifestyle changes, such as losing weight and being more physically active.
Even changes made in older age can reduce your risk.
How is your heart health risk different if you have an African Caribbean background?
African Caribbean people have a much higher risk of high blood pressure, type 2 diabetes, and stroke, but a lower risk of coronary heart disease (CHD). This is very unusual – normally, high blood pressure and diabetes increase your risk of CHD. This disassociation isn’t yet understood, but we know that on average, cholesterol levels are much better for those of African Caribbean heritage than they are for white Europeans, and this seems to offer some protection against CHD.
If we can understand this mechanism, we could then apply it to other populations. There is evidence that African Caribbean children have some insulin resistance (an early diabetes warning sign) and healthier cholesterol levels, but no difference in blood pressure from the white European population. Higher blood pressure tends to emerge in their teenage years.
There are gender differences, too. African Caribbean men have about a 50 per cent lower risk of CHD than white European men, but for women, the risk is only about 25 per cent lower. This is partly because obesity rates are higher in African Caribbean women than men.
Do some medications affect African Caribbean people differently?
There’s strong evidence that African Caribbean people respond differently to blood pressure medications. This is reflected in the official guidelines from NICE (National Institute for Health and Care Excellence). Usually, one of the first drugs considered for high blood pressure would be an ACE inhibitor, but African Caribbean people have been shown to respond less well to this. NICE guidance suggests calcium channel blockers, as these have been shown to be more effective in lowering blood pressure in those of African Caribbean heritage.
Early data from the SABRE study [see box below] suggests that blood pressure control is worse in ethnic minorities, but it’s not clear why that is. It may be that the right medication, or a sufficient dose, isn’t being prescribed, or that medications are not always taken, but we need more research to find this out. When someone doesn’t have symptoms and doesn’t feel unwell, it is difficult for them to accept that they have to take medications, possibly for the rest of their life. It’s a very hard message to get across, especially when medications can cause side effects.
What about attitudes to body shape and exercise?
In African Caribbean communities larger female body shapes are more likely to be seen as something to aspire to. There is therefore less pressure for women to lose weight. Statistics also suggest that women and older people are less likely to exercise. Due to a large number of people in African Caribbean communities being overweight, the issue is normalised.
This is also the case with type 2 diabetes. Because many people are living with the condition and seem fine, it’s seen as inevitable and not taken seriously.
Access to physical activity options is also an issue for those living in deprived areas, where there may be few facilities to exercise safely in a comfortable environment.
Are there other differences in lifestyle risk factors?
There is evidence to suggest African Caribbean people may be more sensitive to the effects of salt on blood pressure. The biology of high blood pressure appears to be different; it’s not that African Caribbean people consume more salt – across the UK, we all eat too much. On the positive side, people of African Caribbean origin tend to smoke less than the overall UK population and drink less alcohol.
CV Nishi Chaturvedi
- Professor of Clinical Epidemiology at University College London
- Worked on some of the largest studies of heart and circulatory disease and diabetes in the UK ethnic minority community
- Member of the BHF Board of Trustees
Much of what we know about ethnic origin and disease risk comes from the Southall and Brent Revisited (SABRE) study. This covered white European, South Asian and African-Caribbean people aged 40–69 in 1988–91. They’ve been followed for 25 years, funded by the BHF, Wellcome Trust, Medical Research Council and Diabetes UK. The focus of investigation, led by Professor Nishi Chaturvedi, is now health in older age.