Positive Health Online

Abstract

MULLEN and colleagues, Regional Centre for Endocrinology and Diabetes, Royal Victoria Hospital, Belfast, Northern Ireland, brian@mullen99.fsnet.co.uk, showed that ascorbic acid reduces blood pressure and arterial stiffness in type 2 diabetes.

Background

Experimental evidence suggests that acute parenteral administration of high-dose ascorbic acid (vitamin C) has beneficial vascular effects in type 2 diabetes. In this study, the haemodynamic effects of chronic oral supplementation were examined.

Methodology

30 diabetes type 2 patients aged 45 to 70 were randomly assigned in a double-blinded manner to receive either 500 mg ascorbic acid daily by mouth, or a placebo. Patients were studied at baseline and after 4 weeks of treatment. The central aortic augmentation index (AgIx) and the time to wave refraction (Tr) were derived from radial artery pulse wave analysis. AgIx and Tr were used as measures for systemic arterial stiffness and aortic stiffness, respectively.

Results

Ascorbic acid reduced brachial systolic blood pressure from 142.1 ± 12.6 to 132.3 ± 12.1 mm Hg (p = 0.01), brachial diastolic pressure from 83.9 ± 4.8 to 79.5 ± 6.9 mm Hg (p = 0.01), and AgIx from 26.8 ± 5.5% to 22.5 ± 6.8 % (p = 0.01). Tr increased from 137.1 ± 12.6 to 143.4 ± 9.2 ms (p = 0.01). Placebo had no haemodynamic effects.

Conclusion

The study shows that after one month, oral vitamin C supplementation lowered arterial blood pressure and improved arterial stiffness in patients with type 2 diabetes. Ascorbic acid supplementation may therefore be a useful and inexpensive adjunctive therapy for type 2 diabetes.

References

Mullen BA, Young IS, Fee H, McCance DR. Ascorbic acid reduces blood pressure and arterial stiffness in type 2 diabetes. Hypertension 40 (6): 804-809, Dec 2002.