Blood Type B Linked To Higher Risk Of Type 2 Diabetes: New Study Insights

Blood type B linked to higher type 2 diabetes risk in large-scale study, researchers say

A new study from China’s Zhejiang University School of Medicine suggests people with blood type B may face a modestly elevated risk of developing type 2 diabetes compared to other blood types. The findings, published in a peer-reviewed epidemiological journal, add to a growing body of research examining how blood type—specifically the ABO and Rh antigens on red blood cells—might influence metabolic health.

According to the study, led by Dr. Fang Hua Liu, individuals with blood type B showed a 12% higher likelihood of type 2 diabetes diagnosis over a 10-year follow-up period than those with blood type O, the most common type globally. The association remained significant even after adjusting for known risk factors such as obesity, physical inactivity, and consumption of processed meats—a category linked to insulin resistance in prior research.

The research builds on earlier observational studies, including a 2020 meta-analysis in Nature Metabolism that found blood type A carriers had a slightly higher diabetes risk than type O, while type B’s role was less clear. This new study, however, is the first to quantify type B’s specific association using a cohort of over 200,000 participants from China’s national health registry.

Why does blood type matter in diabetes risk?

The biological mechanism remains speculative, but researchers point to two key pathways. First, the A and B antigens—sugars attached to red blood cells—may interact with gut bacteria in ways that alter glucose metabolism. A 2022 study in Cell Host & Microbe found that blood type A individuals had distinct gut microbiomes linked to higher inflammatory markers, a factor in insulin resistance.

Second, the Rh factor (positive or negative) may play a secondary role. While the Zhejiang study focused on ABO types, prior work suggests Rh-negative individuals, regardless of ABO type, tend to have slightly lower chronic disease risks—possibly due to differences in immune response.

“This isn’t about causality yet,” cautioned Dr. Liu in an interview with The Lancet Diabetes & Endocrinology. “But if replicated, blood type could become a low-cost screening tool to identify higher-risk groups for early intervention.”

How does this compare to other known risk factors?

The 12% increased risk for blood type B pales in comparison to established contributors:

• Obesity (BMI ≥30): 3.5x higher risk (Diabetes Care, 2023)
• First-degree relative with diabetes: 4x higher risk (JAMA, 2021)
• Physical inactivity (<150 mins/week exercise): 2.5x higher risk (BMJ, 2020)

Yet the finding takes on new weight given the global prevalence of blood type B (about 25% of the world’s population) and type 2 diabetes (now affecting 537 million adults worldwide, per the International Diabetes Federation). “For individuals already at risk—say, someone with a family history—this could be an additional data point,” said Dr. Emily Chen, an endocrinologist at Harvard Medical School, who was not involved in the study.

What’s next for blood type and diabetes research?

The Zhejiang study’s limitations include its observational design—meaning it cannot prove blood type causes diabetes, only correlates with it. Researchers are now testing two hypotheses:

1. Gut microbiome interventions: Could probiotics or fiber-rich diets (which vary by blood type) mitigate the risk for type B individuals?
2. Genetic overlap: Are the same genes regulating ABO antigens also influencing insulin secretion? A 2024 Genome Medicine study identified 14 genetic loci linked to both blood type and glucose metabolism.

The World Health Organization has not yet endorsed blood type screening for diabetes risk, but some clinicians in Asia are beginning to incorporate it into routine assessments. “We’re not advising people to panic,” said Dr. Liu. “But if you’re type B, it’s one more reason to prioritize a healthy diet, regular exercise, and regular check-ups.”

Key questions answered

What blood types are linked to lower diabetes risk?
Type O has consistently shown the lowest risk in multiple studies, including a 2021 Diabetologia analysis that found O carriers had a 10% reduced likelihood of type 2 diabetes compared to non-O types.

Could blood type influence treatment response?
Early data suggests type A individuals may respond better to metformin, while type O patients show slightly greater improvements with GLP-1 agonists like semaglutide (Journal of Clinical Endocrinology & Metabolism, 2023). However, these findings require larger trials.

Should people change their diet based on blood type?
While some wellness trends (e.g., “blood type diets”) lack scientific backing, emerging research on gut microbiome interactions may support tailored approaches—for example, type B individuals might benefit from diets higher in cruciferous vegetables, which have been linked to better glucose control in preliminary studies (Nutrients, 2022).

Sources and methodology

The Zhejiang University study analyzed data from China’s National Health and Nutrition Examination Survey (2015–2023), tracking 203,456 participants aged 18–75. Diabetes cases were confirmed via fasting glucose tests or HbA1c levels. Adjustments were made for age, sex, BMI, smoking status, alcohol use, processed meat intake, and physical activity levels.

Peer-reviewed sources cited:

• Liu, F.H. et al. (2024). “ABO Blood Group and Type 2 Diabetes Risk: A Prospective Cohort Study.” Journal of Clinical Endocrinology & Metabolism.
• Nature Metabolism (2020). Meta-analysis on blood type and metabolic disorders.
• Cell Host & Microbe (2022). Gut microbiome differences by blood type.
• International Diabetes Federation (2023). Global Diabetes Atlas.