Poor Diet Linked to Majority of Type 2 Diabetes Cases

Study links poor diet to 14 million cases of type 2 diabetes worldwide

Summary

The global burden of type 2 diabetes attributable to diet (T2D) is not well established. This risk assessment model estimated the incidence of T2D among adults attributable to the direct and body weight-mediated effects of 11 dietary factors in 184 countries in 1990 and 2018. In 2018, the suboptimal intake of these dietary factors was estimated to be attributable to 14.1 million (95% uncertainty interval (UI), 13.8–14.4 million) incident T2D cases, representing 70.3% (68.8–71.8%) of cases new worldwide. The highest T2D burdens were attributed to insufficient intake of whole grains (26.1% (25.0–27.1%)), excessive intake of refined rice and wheat (24.6% (22.3–27.1%) .2%)) and excessive intake of processed meat (20.3% (18.3–23.5%) %)).

Across all regions, the highest proportional burdens were in Central and Eastern Europe and Central Asia (85.6% (83.4–87.7%)) and Latin America and the Caribbean (81.8% (80. 1–83.4%)); and the lowest proportional burdens were in South Asia (55.4% (52.1–60.7%)). The proportions of T2D attributable to diet were generally higher in men than in women and were inversely correlated with age. Diet-attributable T2D was generally higher among urban than rural residents and among people with higher than lower educational attainment, except in high-income countries, central and eastern Europe, and central Asia, where burdens were higher in rural residents and in individuals with lower educational attainment.

Compared with 1990, global T2D attributable to diet increased by 2.6 absolute percentage points (8.6 million more cases) in 2018, with variations in these trends by world region and dietary factor. These findings inform nutritional priorities and clinical and public health planning to improve diet quality and reduce T2D globally.

The burden of T2D attributable to suboptimal diet by key sociodemographic factors globally in 2018 . Bars represent the estimated percentage burden (a) and absolute burden per 1 million population (b) of T2D incidence due to suboptimal intake of 11 dietary factors together: insufficient intake of whole grains, yogurt, fruits, nuts, and seeds, and non-starchy foods. vegetables and excessive consumption of refined rice and wheat, processed meats, unprocessed red meat, sugary drinks, potatoes and fruit juices. The burden due to a suboptimal diet was estimated using proportional multiplication, assuming that half of the benefit of whole grain intake is mediated by substitution of refined rice and wheat intake. See Supplementary Table 5 for more details on the entries for each dietary factor. Data are presented as the central estimate (median) and the corresponding 95% UI, derived from the 2.5th and 97.5th percentiles of 1000 multiway probabilistic Monte Carlo model simulations. 

Comments

A research model of dietary intake in 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.

A research model developed by researchers at the Friedman School of Nutrition Science and Policy at Tufts University 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. The analysis, which looked at data from 1990 and 2018, provides valuable insight into which dietary factors are driving the burden of type 2 diabetes by region of the world. The study was published in the journal Nature Medicine .

Of the 11 dietary factors considered, three had an outsized contribution to the rising global incidence of type 2 diabetes: Insufficient intake of whole grains, excesses of refined rice and wheat, and excessive consumption of processed meat . Factors such as drinking too much fruit juice and not eating enough vegetables, nuts or non-starchy seeds had a minor impact on new cases of the disease.

"Our study suggests that poor carbohydrate quality is one of the main drivers of diet-attributable type 2 diabetes worldwide, and with significant variations by country and over time," says lead author Dariush Mozaffarian. , Jean Mayer Professor of Nutrition and dean of policy at the Friedman School. . "These new findings reveal critical areas for the national and global approach to improving nutrition and reducing the devastating burdens of diabetes."

Type 2 diabetes is characterized by resistance of the body’s cells to insulin. Of the 184 countries included in the Nature Medicine study , all saw an increase in cases of type 2 diabetes between 1990 and 2018, placing an increasing burden on individuals, families, and healthcare systems.

The research team based their model on information from the Global Dietary Database, along with population demographic data from multiple sources, global type 2 diabetes incidence estimates, and data on how food choices affect people living with obesity and type 2 diabetes from multiple published articles.

The analysis revealed that poor diet is causing a greater proportion of the total incidence of type 2 diabetes in men versus women, in younger adults versus older adults, and in urban versus rural residents globally.

Regionally, Central and Eastern Europe and Central Asia, particularly Poland and Russia, where diets tend to be rich in red meat, processed meat and potatoes, had the highest number of diet-related cases of type 2 diabetes. The incidence was also high in Latin America and the Caribbean, especially in Colombia and Mexico, which was attributed to high consumption of sugary drinks, processed meat, and low consumption of whole grains.

Regions where diet had the least impact on type 2 diabetes cases included South Asia and sub-Saharan Africa, although the largest increases in type 2 diabetes due to poor diet between 1990 and 2018 were seen in sub-Saharan Africa. Of the 30 most populous countries studied, India, Nigeria and Ethiopia had the fewest cases of type 2 diabetes linked to unhealthy diet.

"If left unchecked and incidence is projected to only increase, type 2 diabetes will continue to impact population health, economic productivity, health care system capacity, and drive health inequalities around the world," it says. first author Meghan O’Hearn. She conducted this research while she was a PhD candidate at the Friedman School and currently works as Chief Impact Officer for Food Systems for the Future, a nonprofit institute and for-profit fund that enables innovative food and agriculture companies to improve measurably improve nutritional outcomes for underserved and low-income communities. "These findings can help inform the nutritional priorities of clinicians, policymakers, and private sector actors as they encourage healthier dietary choices that address this global epidemic."

Other recent studies have estimated that 40% of type 2 diabetes cases worldwide are attributable to a suboptimal diet, lower than the 70% reported in the Nature Medicine article . The research team attributes this to new information in their analysis, such as the first inclusion of refined grains, which was a major contributor to the diabetes burden; and updated data on dietary habits based on individual-level national dietary surveys, rather than agricultural estimates. The researchers also note that they presented the uncertainty of these new estimates, which may continue to be refined as new data emerge.