Summary: In a 12-week dose-response trial in Chinese middle-aged and older adults with high blood sugar, purified anthocyanin supplements at up to 640 mg/day showed no significant effect, and no dose-response, on arterial stiffness, blood pressure, or cardiovascular risk markers.
PICO Summary
| Element | Detail |
|---|---|
| Population | Chinese middle-aged and elderly adults with prediabetes or early diabetes (n=46 per group); secondary analysis of a 12-week double-blind, placebo-controlled trial, China. |
| Intervention | Purified anthocyanins at 160, 320, or 640 mg/day for 12 weeks. |
| Comparison | Placebo. |
| Outcome | No significant effect or dose-response relationship was seen for arterial stiffness (brachial-ankle pulse wave velocity), ankle-brachial index, four-limb blood pressures, or composite cardiovascular risk indices, at any dose. No notable adverse effects. |
Anthocyanins and arterial stiffness
RCT · dysglycemia · 12 weeks
Purified anthocyanin supplements up to 640 mg/day did not improve arterial stiffness, blood pressure, or cardiovascular risk over 12 weeks, with no dose-response. A clear negative result.
Expert Commentary
This is a well-constructed negative trial whose dose-response design makes the null result especially informative, since testing 160, 320, and 640 mg and finding no graded effect argues that the absence of benefit reflects true lack of efficacy on these vascular endpoints rather than simple underdosing. It is a useful corrective to the enthusiasm generated by observational data linking anthocyanin-rich diets to lower cardiovascular risk and by acute studies showing transient endothelial improvement after berry consumption, and it exemplifies a recurring lesson, that whole foods with their complex nutrient matrices often cannot be reproduced by isolated supplements. The honest caveats the post lists matter for interpretation: 12 weeks may be too short to reverse arterial stiffness that builds over decades, the population was Chinese with prediabetes or early diabetes and no established vascular disease, the formulation’s bioavailability was not confirmed in plasma, and background dietary intake was uncontrolled. Can I use this with my patients? Yes, as plain advice. I would not recommend purified anthocyanin supplements for vascular protection in this group, and would steer patients toward proven strategies, blood-pressure and glucose control, lipids, smoking cessation, and aerobic exercise, while continuing to encourage anthocyanin-rich foods as part of a healthy diet rather than as pills.
References
Liu Z, Li M, Chen Y, et al. Purified anthocyanins indicated no significant effect on arterial stiffness, four-limb blood pressures and cardiovascular risk—a 12-week dose-response trial in Chinese middle-aged and elderly adults with hyperglycemia. Nutrients. 2025;18(1):112. doi:10.3390/nu18010112