"Chewing tobacco is not a uniform public health problem, and our findings show that a relatively small number of countries bear an overwhelming share of its health burden," said Gabriela Gil, lead author and research scientist at IHME. "Understanding how patterns of use differ within these populations is critical to designing more effective prevention and tobacco control strategies."

What does the age and sex breakdown look like?

Chewing tobacco was more common among males than females globally, with use beginning to rise in early adulthood and continuing to increase with age before peaking among people ages 60 to 64.

In South Asia, nearly one in five males and one in 10 females used chewing tobacco in 2023. Male use peaked at ages 60 to 64, while female use peaked among adults ages 80 and older.

Bangladesh reversed the pattern. Chewing tobacco use was higher among females than males across all age groups older than 30, although use remained common in both sexes.

What health conditions drive the burden?

Researchers used the Burden of Proof framework to estimate health risks, quantifying attributable burden across six outcomes: stroke, lip and oral cavity cancer, esophageal cancer, other pharyngeal cancer, laryngeal cancer, and nasopharyngeal cancer.

Stroke carried the largest share of health loss:

• 55.9 disability-adjusted life-years (DALYs) per 100,000 people
• Lip and oral cavity cancer: 17.4 DALYs per 100,000

A DALY combines years lost to premature death with years lived with disability, measuring total health loss from a condition.

Chewing tobacco caused 17.3% of lip and oral cavity cancer DALYs worldwide, rising to 30.5% in South Asia.

Is the burden growing or shrinking?

The total number of DALYs attributed to chewing tobacco climbed 116% between 1990 and 2023, reaching 6.48 million globally. Most of this burden came from premature death, accounting for 6.17 million years of life lost in 2023.

"These findings show why chewing tobacco control cannot take a one-size-fits-all approach," said Dr. Emmanuela Gakidou, senior author and professor in the Department of Health Metrics Sciences at IHME. "Prevention and cessation strategies need to reflect how patterns of use differ by country, age and sex, as well as the cultural and social factors that shape tobacco use in each setting."

Why has chewing tobacco been overlooked?

Despite decades of progress in tobacco control, the global prevalence of chewing tobacco use has remained relatively unchanged. Researchers point to longstanding cultural and social practices, misconceptions about harm, limited surveillance, and higher use among some rural and lower-income populations as factors sustaining use.

Chewing tobacco has historically received less attention than smoked tobacco in global tobacco control efforts. The authors call for stronger integration of smokeless tobacco prevention and cessation into national tobacco control and noncommunicable disease strategies, with targeted approaches reflecting differences by age, sex, local use patterns, and socioeconomic context.

What are the study's limitations?

Like all Global Burden of Disease analyses, the estimates rely on country-level data that vary in quality and completeness. Chewing tobacco is particularly difficult to track in many low-income settings where most use occurs, meaning figures may underestimate the true burden in some regions. The authors also note that prevalence rates do not always reflect absolute burden, since populous countries can dominate totals even at moderate rates.