Summary:
In Chinese middle-aged and elderly adults with prediabetes or early diabetes, purified anthocyanins supplementation (160, 320, 640 mg/day) did not significantly improve arterial stiffness or cardiovascular risk factors compared to placebo, and was not associated with notable side effects.
| PICO | Description |
|---|---|
| Population | Chinese middle-aged and elderly adults with prediabetes or early-stage diabetes (dysglycemia). |
| Intervention | Daily supplementation with purified anthocyanins at doses of 160 mg, 320 mg, and 640 mg over a 12-week period. |
| Comparison | Placebo control group receiving no active anthocyanins. |
| Outcome | No statistically significant improvements in arterial stiffness (measured by baPWV), ankle-brachial index, four-limb blood pressures, or composite cardiovascular risk factors across any dosage compared to placebo. No notable adverse effects reported. |
Clinical Context
Arterial stiffness represents a fundamental aspect of vascular aging that is accelerated in individuals with dysglycemia. Measured by pulse wave velocity, arterial stiffness independently predicts cardiovascular events, stroke, and mortality beyond traditional risk factors. Older adults with prediabetes and early diabetes face compounded vascular risk due to the combined effects of aging and metabolic dysfunction on the arterial wall. Anthocyanins, the pigments giving berries and other plant foods their deep colors, have attracted attention as potential vascular protective agents based on mechanistic studies demonstrating antioxidant properties, endothelial function enhancement, and nitric oxide pathway modulation. Epidemiological observations have associated higher anthocyanin intake with reduced cardiovascular disease incidence. However, the translation of these findings into therapeutic applications requires rigorous clinical trial evidence. This dose-response study evaluated whether purified anthocyanin supplementation could improve vascular health markers in a high-risk dysglycemic population.
Clinical Pearls
- Purified anthocyanin supplementation at doses ranging from 160 to 640 mg daily for 12 weeks produced no measurable improvement in brachial-ankle pulse wave velocity, the primary measure of arterial stiffness.
- Ankle-brachial index, which reflects peripheral arterial disease presence, showed no significant change with anthocyanin treatment at any dose level.
- Four-limb blood pressure measurements remained unchanged, indicating no antihypertensive effect from anthocyanin supplementation in this population.
- The absence of a dose-response relationship suggests that the null findings are not due to inadequate dosing but represent true lack of efficacy on vascular parameters.
Practical Application
Healthcare providers should counsel patients with prediabetes or early diabetes that anthocyanin supplements cannot be recommended for improving vascular health or reducing arterial stiffness based on current evidence. Patients seeking to improve their vascular health should be directed toward interventions with established efficacy including blood pressure control, glycemic management, lipid optimization, smoking cessation, and regular aerobic exercise. While consuming anthocyanin-rich foods such as berries, cherries, and purple vegetables remains part of a healthy dietary pattern, taking purified anthocyanin supplements specifically for cardiovascular protection is not supported by this trial. The supplement’s acceptable safety profile means patients already using anthocyanins need not discontinue immediately, but expectations regarding vascular benefits should be appropriately moderated.
Broader Evidence Context
These findings contrast with observational studies suggesting cardiovascular benefits from higher anthocyanin intake and with acute studies showing improvements in endothelial function following anthocyanin-rich food consumption. The discrepancy highlights important differences between habitual dietary patterns, acute physiological responses, and sustained clinical endpoints. Whole foods provide complex matrices of nutrients and phytochemicals that may act synergistically in ways isolated supplements cannot replicate. The negative results align with a broader pattern in cardiovascular nutrition research where supplement interventions often fail to reproduce benefits observed with whole food consumption patterns.
Study Limitations
- The 12-week study duration may be insufficient to reverse established arterial stiffness, which develops over decades and may require longer intervention periods.
- The study was conducted exclusively in Chinese adults, and results may not generalize to other populations with different genetic backgrounds affecting anthocyanin metabolism.
- Participants had prediabetes or early diabetes without documented cardiovascular disease, and effects might differ in those with established vascular pathology.
- Bioavailability of the specific anthocyanin formulation was not verified through plasma measurements.
- Background dietary anthocyanin intake was not controlled and could confound supplementation effects.
Bottom Line
Purified anthocyanin supplementation at doses up to 640 mg daily for 12 weeks does not improve arterial stiffness, blood pressure, or cardiovascular risk markers in middle-aged and elderly adults with prediabetes or early diabetes. Evidence-based cardiovascular risk reduction strategies should take priority over anthocyanin supplementation in this population.
Source: Zhaomin Liu, 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.” Read article here.
