A study just published in the British Medical Journal provides a rare insight into how weight loss across the population of an entire country can affect death rates from heart disease and type 2 diabetes.
Dr Steven Hurel
, Consultant in Endocrinology and Diabetes at The Physicians’ Clinic, explains the main points of the study and provides his analysis of what it means for us in the UK.
How was the study carried out?
By studying the Cuban population in the years before, during and after the collapse of the former Soviet Union, the researchers demonstrated three distinct phases in recent Cuban history:
- From 1980 to 1991, the Soviet Union was still intact and this decade provides a fairly steady baseline against which to measure the impact of the following two decades.
- From 1991 to the late 1990s, Cuba experienced a severe decline in economic health, which led to a general lack of food, more people having to do manual labour and fuel shortages. In this period, the average Cuban lost 5.5 kilograms (just over 12 pounds) in body weight.
- From the late 1990s onwards, economic recovery started and people reverted to doing less physical activity and put back on the weight they had lost.
What were the results?
Dr Manuel Franco, who is based at the University of Alcala in Madrid, and his team from Spain, Cuba and the USA, then looked at the incidence of heart disease and type 2 diabetes, and at how many people died in Cuba each year from these two diseases.
- From 1980 to 1991, death rates from diabetes remained steady while the numbers of people dying from heart disease was falling, but only very slightly year by year.
- From 1991 to the late 1990s, as Cubans lost weight, the incidence of diabetes (the numbers of new cases diagnosed each year) started to fall dramatically. Deaths from heart disease (strokes and heart attacks) also plummeted. The most dramatic changes occurred in the mid-1990s with deaths from diabetes falling by 50%.
- From the late 1990s onwards, as the economy recovered people started to revert to a ‘less healthy’ lifestyle, eating more and doing less physical activity. The incidence of type 2 diabetes, heart disease and stroke started to rise.
- By 2002, the number of deaths per year from diabetes had risen to pre 1991 levels.
- Between 2002 and 2010, the death rate from diabetes had increased by a further 49%, going above pre-1991 levels.
What does it mean?
Rates of obesity are rising fast in developed nations of the World. This is a major concern as obesity is linked to diabetes and increased risk of heart disease and premature death
“The Cuban study, which is unique because of the social circumstances, provides strong evidence that lifestyle is important in preventing deaths from heart disease and type 2 diabetes. This serves to underline what we know already and makes perfect sense. By keeping your weight down and doing more exercise, you can reduce your risk of developing chronic disease. You also help lessen the chances that you will die prematurely as a result of a heart attack, stroke or diabetes complications
” comments Dr Hurel.
Read the BMJ press release
on this study
Read an editorial
by Professor Walter Willet at Harvard University in the USA.
Read the full text of the story on the BMJ website