Roughly half a billion people are currently living with diabetes worldwide and more than 95% of those people have type 2 diabetes.
Type 2 diabetes continues to be diagnosed at a staggering rate, even though it’s often preventable—so what, exactly, is going on?
A recent analysis of dietary intake across 184 countries estimates that poor diet contributed to more than 14.1 million cases of type 2 diabetes in 2018, representing more than 70% of new diagnoses globally.
This figure is significantly higher than other recent studies, which have suggested that 40% of type 2 diabetes cases globally can be attributed to suboptimal diet.
What makes this study different?
While scientists have known for years that an unhealthy diet is a risk factor for diabetes, this new study evaluated which dietary factors are driving the global increase in type 2 diabetes by region. Essentially, what are people eating (or not eating) to cause diabetes?
To answer this question, researchers at Tufts University looked at data from 1990 and 2018 and considered 11 different dietary factors. All 184 countries included in the analysis published this month in Nature Medicine saw an increase in type 2 diabetes cases over the 28-year span.
The number of people with diabetes globally was roughly 211 million in 1990. By 2017, that number jumped to 476 million, nearly a 130% increase. Current projections estimate that some 700 million people will be living with diabetes by 2045.
Which dietary factors are responsible?
Among the 11 dietary factors studied, three had the biggest impact on the increasing global prevalence of type 2 diabetes:
- Lack of whole grains
- Too much refined rice and wheat
- Excessive consumption of processed meat
“Our study suggests poor carbohydrate quality is a leading driver of diet-attributable type 2 diabetes globally, and with important variation by nation and over time,” said senior author Dariush Mozaffarian.
Other factors, such as drinking too much fruit juice, or insufficient intake of nuts, seeds, or non-starchy vegetables had less of an impact.
Notably, this study was the first to include refined grains in the analysis, which ended up being one of the top contributors to the diabetes burden. According to the research team, this may explain why the present study attributes 30% more global diagnoses to poor diet than other previous studies.
How do the findings differ by region?
Central and Eastern Europe and Central Asia—specifically Poland and Russia, where diets are typically abundant in red meat, processed meat, and potatoes—had the highest incidence of type 2 diabetes cases linked to diet.
Of the 30 most populous countries studied, India, Nigeria, and Ethiopia saw the lowest number of type 2 diabetes cases associated with unhealthy eating.
Looking at other demographics, the analysis found that poor diet is responsible for a larger proportion of total type 2 diabetes cases in men compared to women, younger adults compared to older ones, and urban versus rural residents at a global level.