Treating Hypertension…With Beet Root Juice?
Remember when your mother kept nagging you to eat your fruits and vegetables? After a while, you had heard it so many times that you were convinced your mom thought your appendages would begin to fall off without broccoli and spinach. And those naysayers began to disregard mom’s sage nutritional advice when initial studies addressing antioxidants commonly found in fruits and vegetables did not show measurable benefits.1
But recently, it was demonstrated that cherries do exert profound anti-inflammatory effects on gouty arthritis.2 So, maybe mother does know best. This month we reinforce mama’s age-old admonition regarding unhealthy food habits3 and tell our hypertensive patients: Drink your beet juice!
THE EVIDENCE
The evidence began to accumulate in 2010 to suggest that ingesting inorganic nitrate increased the nitrate count in vivo in humans.3 Nitrites—converted nitrates in the body (remember nitric oxide)—are potent vasodilators. Beets contain nitrates in palatable form; supplementing nitrates via as potassium nitrate capsules or by vegetables in the form of beetroot juice elevated plasma nitrite concentrations in healthy volunteers after a dose response curve was constructed. At higher doses, the study patients’ blood pressures declined as a result of nitrate supplementation. The authors observed that orally-ingested inorganic nitrate is converted to nitrite by bacteria in the oral cavity, absorbed in the stomach, and later converted into nitric oxide. That is the “money end” of nitrite-nitrate augmentation, especially on an endothelial, vascular level. The effect was demonstrated in “healthy” volunteers, but what about hypertensive individuals?
UPDATED RESULTS
Approximately 3 years later, the same group investigated nitrate augmentation in spontaneously hypertensive rats followed by studies in hypertensive patients (n=15; mean age 53 years; 8 women and 7 men).4 There was a profound benefit consequent to oral nitrate administration in hypertensive rats, when compared to Wistar-Kyoto control rats.
Fifteen drug naïve grade 1-hypertensive persons were then studied. Nitrite levels were raised approximately 1.5 fold after a cup of nitrate-chocked beetroot juice. The 1.5 fold rise in nitrites is significant as it represents an increase in nitrite levels previously reported2 to not affect the blood pressure of healthy volunteers.
In hypertensives, the same rise in plasma nitrites translated into a decline in systolic blood pressures of an average of 11-12 mm/hg, and a peak diastolic decline of approximately 10 mm/hg; lowering and pulse wave velocities decreased significantly as well.
After 24 hours, an average 8.5 mm/hg reduction in systolic pressure persisted. The changes in systolic pressure correlated with plasma nitrite levels. The impact on blood pressure may persist; the study was designed for longer-term followup. Despite the use of a vegetable product, the study individuals tolerated the with beetroot juice.
Yes, a longer study is necessary. And yes, hyperkalemia may occur in folks with renal disease. That said, beetroot juice may become a valuable adjunct in hypertensive individuals, and the same may be true for cherries in gouty attacks. Mom, if you are reading this, I promise to eat my fruits and vegeatables, and to spread the word to my patients! ■
REFERENCES:
1.Vivekananthan DP, Penn MS, Sapp SK, et al. Use of antioxidant vitamins for the prevention of cardiovascular disease: meta-analysis of randomized trials. Lancet. 2003;361:2017-2023.
2.Zhang Y, Neogi T, Chen C, et al. Cherry consumption and decreased risk of recurrent gout attacks. Arthritis Rheum. 2012;64:4004-4011.
3.Kapil V, Milsom AB, Okoroe M, et. al. Inorganic nitrate supplementation lowers blood pressure in humans: role for nitrite-derived NO. Hypertension. 2010;56:274281.
4.Ghosh SM, Kapil V, Fuentes-Calvo I, et al. Enhanced vasodilator activity of nitrite in hypertension: critical role for erythrocytic xanthine oxidoreductase and translational potential. Hypertension. 2013 Apr 15 [Epub ahead of print].
Gregory W. Rutecki, MD is with the Cleveland Clinic Foundation National Consultation Service in Cleveland, Ohio. He is also a member of the editorial board of Consultant. Dr Rutecki has no relevant financial relationships to disclose.