Researchers show which blood group has the lowest cancer risk

In some populations, other findings vary. For instance, a study of Chinese men found that blood group B had a lower risk of gastrointestinal cancers than group A, highlighting how results can differ by region and genetics.

Overall, blood group O appears to offer the lowest relative cancer risk across many cancer types, although the differences are modest. One analysis estimated that people with blood group A had about a 19 percent higher risk of stomach cancer compared to group O.