|CRDAMC Homepage | CRDAMC Library Phone #: (254) 288-8366 | CRDAMC Library Fax #: (254) 288-8368|
Most people can't tell when their blood pressure is high, which is why hypertension is called the "silent killer." In this case, what you don't know can hurt you. Elevated blood pressure can lead to a greatly increased risk of heart attack, stroke, and many other serious illnesses. Along with high cholesterol and smoking, hypertension is one of the most important causes of atherosclerosis. In turn, atherosclerosis causes heart attacks, strokes, and other diseases of impaired circulation.
The mechanism by which high blood pressure produces atherosclerosis is somewhat similar to what happens in a hose fitted with a high-pressure nozzle. All such nozzles come with a warning label that states, "Make sure to discharge pressure in hose after using." Unfortunately, many people frequently fail to pay attention to the warning and leave the hose puffed up with full pressure overnight. This rather common practice does not produce any immediate consequences. The hose doesn't develop leaks at the seams or burst outright on the first occasion you leave it untended. However, a garden hose that is frequently left under pressure will begin to age more rapidly than it would otherwise. Its lining will begin to crack, its flexibility will diminish, and within a season or two the hose will be sprouting leaks in all directions.
Similarly, when blood vessels are exposed to constantly high pressure, a similar process is set in motion. Blood pressures as elevated as 220/170 (systolic pressure/diastolic pressure), quite common during activities, such as weight lifting, do no harm. Only when excessive pressure is sustained day and night do blood vessel linings begin to be injured and undergo those unhealthy changes known as atherosclerosis.
Although it is important to lower blood pressure with all deliberate speed, only rarely does it need to be lowered instantly. In most situations, you have plenty of time to work on bringing down your blood pressure. However, that doesn't mean that you should ignore it. Over time, high blood pressure can damage nearly every organ in the body.
The best way to determine your blood pressure is to take several readings at different times during the day and on different days of the week. Blood pressure readings will vary quite a bit from moment to moment; what matters most is the average blood pressure. Thus, if many low readings balance out a few high readings, the net result may be satisfactory. However, it is essential not to ignore a high value by saying, "I was just stressed then." Stress is part of life, and if it raises your blood pressure once, it will do so again. To come up with an accurate number, you must include every measurement in your calculations.
In most cases, the cause of hypertension is unknown. The kidneys play an important role in controlling blood pressure, and the level of squeezing tension in the blood vessels makes a large contribution as well.
Lifestyle changes, such as quitting cigarettes, losing weight, and increasing exercise, can dramatically reduce blood pressure. Regarding exercise, one study found that engaging in aerobic exercise 60 to 90 minutes weekly may be sufficient for producing maximum benefits.69 Another study found that taking four 10-minute "exercise snacks" of brisk walking per day significantly improves blood pressure.78
For many years doctors advised patients with hypertension to cut down on salt in the diet. Today, however, the value of this stressful dietary change has undergone significant questioning. Considering how rapidly our knowledge is evolving, we suggest consulting your physician to learn the latest recommendations.
If lifestyle changes fail to reduce blood pressure, or if you can't make these alterations, many effective drugs are available. Sometimes you need to experiment with a few to find one that agrees with you.
Principal Proposed Natural Treatments
There are no herbs or supplements for hypertension with solid scientific support. However, the supplement coenzyme Q 10 (CoQ 10) and extracts from the herb Stevia rebaudiana have shown some promise in preliminary trials.
Coenzyme Q 10
The supplement CoQ 10 has shown promise as a treatment for high blood pressure, but the evidence that it works is not yet strong.
An 8-week, double-blind, placebo-controlled study of 59 men already taking medication for high blood pressure found that 120 mg daily of CoQ 10 reduced blood pressure by about 9% as compared to placebo.7
In addition, a 12-week, double-blind, placebo-controlled study of 83 people with isolated systolic hypertension (a type of high blood pressure in which only the "top" number is high) found that use of CoQ 10 at a dose of 60 mg daily improved blood pressure measurements to a similar extent.53
Also, in a 12-week, double-blind, placebo-controlled trial of 74 people with diabetes, use of CoQ 10 at a dose of 100 mg twice daily significantly reduced blood pressure as compared to placebo.62
For more information, including dosage and safety issues, see the full CoQ10 article.
The herb stevia is best known as a sweetener. Its active ingredients are known as steviosides. In a 1-year, double-blind, placebo-controlled study of 106 people with moderate hypertension (approximately 165/103), steviosides at a dose of 250 mg three times daily reduced blood pressure by approximately 10%.12 Full benefits took months to develop. However, this study is notable for finding no benefits at all in the placebo group. This is unusual and tends to cast doubt on the results.
Benefits were also reported in a 2-year, double-blind, placebo-controlled study of 174 people with milder hypertension (average initial BP of approximately 150/95).70 This study used twice the dose of the previous study: 500 mg three times daily. A reduction in blood pressure of approximately 6%-7% was seen in the treatment group as compared to the placebo group, beginning within 1 week and enduring throughout the entire 2 years. At the end of the study, 34% of those in the placebo group showed heart damage from high blood pressure (left ventricular hypertrophy), while only 11.5% of the stevioside group did, a difference that was statistically significant. No significant adverse effects were seen.
However, once again, no benefits at all were seen in the placebo group. This is a red flag for problems in study design. Both of these studies were performed in China, a country that has a documented history of questionable medical study results.71
Furthermore, a study by an independent set of researchers failed to replicate these findings.129 And, another study involving people with diabetes, as well as healthy subjects, found that stevia, at a dose of 250 mg three times daily, had no significant effect on blood pressure after 3 months of treatment.130
Furthermore, a study by an independent set of researchers failed to replicate these findings.129 And, another study involving people with diabetes, as well as healthy subjects, found that stevia, at a dose of 250 mg three times daily, had no significant effect on blood pressure after 3 months of treatment.130
For more information, including dosage and safety issues, see the full Stevia article.
Relaxation Therapies TOP
Although it seems intuitive that relaxation should lower blood pressure, the evidence for the benefits of relaxation therapies for treating hypertension is far from convincing. In a review of 25 studies investigating various relaxation therapies (totaling 1,198 participants), researchers found that those studies employing a control group had no significant effect on lowering blood pressure compared to sham (placebo) therapies.125
More specifically, biofeedback is widely advocated for treating hypertension. But, in an analysis of 22 studies, real biofeedback when used alone was found to be no more effective than sham (fake) biofeedback.63 A subsequent review of 36 trials with 1,660 participants found inconsistent evidence for the effectiveness of biofeedback for treatment of hypertension in comparison to drug therapy, sham biofeedback, no intervention or other relaxation techniques.141
However, not all studies have been unsupportive. A review of 9 randomized trials concluded that the regular use of transcendental meditation significantly reduced both systolic and diastolic blood pressure compared to a control.126 Similarly, an analysis of 17 randomized controlled trials of various relaxation therapies found that only transcendental meditation resulted in significant reductions in blood pressure. Biofeedback, progressive muscle relaxation, and stress management training produced no such benefit.127 In addition, a trial of 86 patients with hypertension suggested that daily, music-guided slow breathing reduced systolic blood pressure measured over a 24-hour period.143
Prehypertension is a condition where blood pressure is elevated above what is considered normal, but not the level of a hypertension diagnosis. A small randomized trial involving 43 patients with prehypertension showed that heart rate variability feedback reduced systolic blood pressure compared to slow abdominal breathing and control groups.148
Other Proposed Natural Treatments TOP
The Iranian herb Achillea wilhelmsii was tested in a double-blind trial of 60 men and women with mild hypertension.38 The results showed that treatment with an A. wilhelmsii extract significantly reduced blood pressure readings. In a double-blind study of 43 men and women with hypertension, use of a proprietary Ayurvedic herbal combination containing Terminali arjuna and about 40 other herbs proved approximately as effective for controlling blood pressure as the drug methyldopa.41
Although the research record is mixed,15-21,104,137 it appears that fish oil may reduce blood pressure at least slightly.56 Fish oil contains two major active ingredients, DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). Some evidence suggests that it is the DHA in fish oil, but not the EPA, that is responsible for this benefit.57
Three preliminary double-blind studies found that chocolate (high in polyphenols) might help mild hypertension.91,98,112 A review including several additional studies drew a similar conclusion.136 A larger analysis of 20 trials studied 856 patients with and without hypertension. The trials compared flavonol-rich cocoa products to low or non-flavonol foods for an average of 4 weeks. Cocoa was found to significantly decrease systolic blood pressure in 20 trials and diastolic blood pressure in 19 trials.147
Numerous studies have found weak evidence that garlic lowers blood pressure slightly, perhaps in the neighborhood of 5% to 10% more than placebo.132-135 It remains unclear whether garlic supplements can help patients with high blood pressure safely eliminate or avoid antihypertensive medications.
People who are deficient in calcium may be at great risk of developing high blood pressure.29,30,58 Among people who already have hypertension, increased intake of calcium intake might slightly decrease blood pressure, according to some but not all studies.31,59 In an extremely large randomized, placebo-controlled trial involving 36,282 postmenopausal women, 1,000 mg of calcium plus 400 IU of vitamin D given daily did not significantly reduce blood pressure over a 7 year period in women with or without hypertension.139 Weak evidence hints that use of calcium by pregnant mothers might reduce risk of hypertension in their children.107
In a 30-day, double-blind, placebo-controlled study of 39 people taking medications for hypertension, treatment with 500 mg of vitamin C daily reduced blood pressure by about 10%.33 Smaller benefits were seen in studies of people with normal blood pressure or borderline hypertension.34,35 One double-blind study compared 500 mg, 1,000 mg, and 2,000 mg of vitamin C, and found an equivalent level of benefit in all three groups.60 (Because of the lack of a placebo group, this study cannot be used as proof of effectiveness, only as a demonstration of the equivalence of the doses.) However, other studies have failed to find evidence of benefit with vitamin C.36,37,66 This mixed evidence suggests, on balance, that if vitamin C does have any blood pressure lowering effect, it is at most quite modest.
Unexpectedly, one study found that a combination of vitamin C (500 mg daily) and grape seed OPCs (1000 mg daily) slightly increased blood pressure.73 Whether this was a fluke of statistics or a real combined effect remains unclear.
Other studies suggest possible benefit with the Ayurvedic herb Eclipta alba (also known as Bhringraja or Keshraja),109beta-hydroxy-beta-methylbutyrate (HMB),61 theanine from black tea,122,145blue-green algae products,50chitosan,42 concord grape juice,88garlic,1-3gamma-aminobutyric acid (GABA),115-121 various forms of the herb hawthorn,32,55,89-90kelp,44lipoic acid combined with carnitine,106quercetin,123Salvia hispanica (a grain),114 and sweetie fruit (a hybrid between grapefruit and pummelo, high in citrus bioflavonoids).83 However, the supporting evidence cannot be considered reliable for any of these treatments.
There is mixed evidence on whether soy protein and their associated isoflavones are helpful for blood pressure.92, 102 A comprehensive review of studies investigating the influence of phytoestrogens (including soy) on blood pressure found no meaningful effect.131 However, another review found that soy protein alone could significantly reduce blood pressure.136 See also the section on Herbs and Supplements to Use Only With Caution.
The herbs astragalus, barberry, Coleus forskohliibacailin, hibiscus, maitake, maca, and the supplements beta-carotene, cordyceps, flaxseed oil, royal jelly, and taurine are sometimes recommended for high blood pressure, but as yet there is no meaningful evidence that they work.43,75,101,103,138,142
Researchers have also studied cinnamon’s role in reducing blood pressure. In a randomized study involving 58 people with type 2 diabetes, 2 g of cinnamon daily reduced high blood pressure levels, as well as HbA1c levels (a measurement of blood sugar levels over time).144
One study quoted as showing that a traditional Chinese herbal formula can reduce blood pressure actually failed to find any effect on blood pressure.93 In a review of 26 published studies examining the effectiveness of Tai Chi for high blood pressure, 85% demonstrated a reduction in blood pressure. However, only five of these 26 studies were of acceptable quality.128 A substantial study (192 participants) failed to find acupuncture helpful for high blood pressure.100 However, another study, this one enrolling 160 people, did report benefit,105,111 but it was small and also suffered from problems in its use of statistics. In a review of 11 randomized controlled trials on the subject, researchers determined that acupuncture’s ability to lower blood pressure remains inconclusive.140
The alternative therapies Hatha yoga, Qigong,113 and Tai Chi76 have shown a hint of potential 68 benefit for high blood pressure, the mechanism of action probably being similar for each. A recent review of multiple studies investigating the effectiveness self-practiced Qigong, for example, concluded that it was more effective at lowering blood pressure than no treatment controls. However, it was no more effective than standard treatments for hypertension: antihypertensive medications or conventional exercise.124. In a review of 11 randomized trials with adults who were either healthy or at high risk of heart disease qigong was evaluated for its effect on stroke or death rates. Three of the trials included adults currently taking antihypertension medications. Those assigned to Qigong had significant reductions in mortality and stroke during a 20-30 year follow-up period. However, the authors did not know if the patients actually performed Qigong exercises throughout the follow-up period.151
Another review analyzed the benefits of yoga added to conventional hypertension treatment in 120 studies with 6,693 people. In the 48 randomized trials, specific yoga techniques were associated with significant blood pressure decreases. The studies suggest a correlation between yoga and lower blood pressure, but the study populations were extremely variable, making it difficult to draw specific conclusions.149
For many years, the American Heart Association and other major foundations have recommended cutting down on saturated fat and increasing carbohydrates. However, growing evidence suggests that it is preferable to keep carbohydrate levels relatively low while replacing saturated fat with monounsaturated fats such as olive oil.110 See the article on Low-Carb Diet for more information.
For a discussion of homeopathic approaches to high blood pressure, see the Homeopathy database.
Finally, because atherosclerosis is the main harm caused by hypertension, treatments discussed in the Atherosclerosis article should be considered as well.
Herbs and Supplements to Use Only With Caution TOP
There is one highly credible case report of severe, dangerous hypertension caused by consumption of isoflavones made from soy during the course of a clinical trial on this supplement.94 This is most likely a rare, highly individual response, but if it could occur with one person, it could occur with another as well.
As noted above, in one study, a combination of vitamin C and grape seed OPCs mildly increased blood pressure. In another study, use of vitamin E raised blood pressure in people with type 2 diabetes.95
In addition, various herbs and supplements may interact adversely with drugs used to treat hypertension. For more information on this potential risk, see the individual drug article in the Drug Interactions section of this database.
References[ + ]
1. Silagy CA, Neil HA. A meta-analysis of the effect of garlic on blood pressure. J Hypertens. 1994;12:463-468.
2. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physicians' Guide to Herbal Medicine. 3rd ed. Berlin Germany: Springer-Verlag; 1998:119.
3. Auer W, Eiber A, Hertkorn E, et al. Hypertension and hyperlipidaemia: garlic helps in mild cases. Br J Clin Pract Suppl. 1990;69:3-6.
7. Singh RB, Niaz MA, Rastogi SS, et al. Effect of hydrosoluble coenzyme Q 10 on blood pressures and insulin resistance in hypertensive patients with coronary artery disease. J Hum Hypertens. 1999;13:203-208.
8. Digiesi V, Cantini F, Brodbeck B. Effect of coenzyme Q 10 on essential arterial hypertension. Curr Ther Res. 1990;47:841-845.
9. Langsjoen P, Langsjoen P, Willis R, et al. Treatment of essential hypertension with coenzyme Q 10. Mol Aspects Med. 1994;15(suppl):S265-S272.
10. Digiesi V, Cantini F, Oradei A, et al. Coenzyme Q 10 in essential hypertension. Mol Aspects Med. 1994;15(suppl):S257-S263.
12. Chan P, Tomlinson B, Chen YJ, et al. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol. 2000;50:215-220.
15. Lungershausen YK, Abbey M, Nestel PJ, et al. Reduction of blood pressure and plasma triglycerides by omega-3 fatty acids in treated hypertensives. J Hypertens. 1994;12:1041-1045.
16. Radack K, Deck C, Huster G. The effects of low doses of n-3 fatty acid supplementation on blood pressure in hypertensive subjects. A randomized controlled trial. Arch Intern Med. 1991;151:1173-1180.
17. Singer P, Jaeger W, Wirth M, et al. Lipid and blood-pressure-lowering effect of mackerel diet in man. Atherosclerosis. 1983;49:99-108.
18. Singer P, Melzer S, Goschel M, et al. Fish oil amplifies the effect of propranolol in mild essential hypertension. Hypertension. 1990;16:682-691.
19. Appel LJ, Miller ER III, Seidler AJ, et al. Does supplementation of diet with 'fish oil' reduce blood pressure? A meta-analysis of controlled clinical trials. Arch Intern Med. 1993;153:1429-1438.
20. Whelton PK, Kumanyika SK, Cook NR, et al. Efficacy of nonpharmacologic interventions in adults with high-normal blood pressure: results from phase 1 of the Trials of Hypertension Prevention. Trials of Hypertension Prevention Collaborative Research Group. Am J Clin Nutr. 1997;65(suppl 2):S652-S660.
21. Mori TA, Bao DQ, Burke V, et al. Docosahexaenoic acid but not eicosapentaenoic acid lowers ambulatory blood pressure and heart rate in humans. Hypertension. 1999; 34:253-260.
22. Sanjuliani AF, de Abreu Fagundes VG, Francischetti EA. Effects of magnesium on blood pressure and intracellular ion levels of Brazilian hypertensive patients. Int J Cardiol. 1996;56:177-183.
23. Witteman JC, Grobbee DE, Derkx FH, et al. Reduction of blood pressure with oral magnesium supplementation in women with mild to moderate hypertension. Am J Clin Nutr. 1994;60:129-135.
24. Dyckner T, Wester PO. Effect of magnesium on blood pressure. Br Med J (Clin Res Ed). 1983;286:1847-1849.
25. Henderson DG, Schierup J, Schodt T. Effect of magnesium supplementation on blood pressure and electrolyte concentrations in hypertensive patients receiving long term diuretic treatment. Br Med J (Clin Res Ed). 1986;293:664-665.
26. Whelton PK, He J, Cutler JA, et al. Effects of oral potassium on blood pressure. Meta-analysis of randomized controlled clinical trials. JAMA. 1997;277:1624-1632.
27. Whelton PK, Buring J, Borhani NO, et al. The effect of potassium supplementation in persons with a high-normal blood pressure. Results from phase I of the Trials of Hypertension Prevention (TOHP). Trials of Hypertension Prevention (TOPH) Collaborative Research Group. Ann Epidemiol. 1995;5:85-95.
28. Davis BR, Oberman A, Blaufox MD, et al. Lack of effectiveness of a low-sodium/high-potassium diet in reducing antihypertensive medication requirements in overweight persons with mild hypertension. TAIM Research Group. Trial of Antihypertensive Interventions and Management. Am J Hypertens. 1994;7:926-932.
29. Cappuccio FP, Elliott P, Allender PS, et al. Epidemiologic association between dietary calcium intake and blood pressure: a meta-analysis of published data. Am J Epidemiol. 1995;142:935-945.
30. Van Leer EM, Seidell JC, Kromhout D. Dietary calcium, potassium, magnesium and blood pressure in the Netherlands. Int J Epidemiol. 1995;24:1117-1123.
31. Bostick RM, Fosdick L, Grandits GA, et al. Effect of calcium supplementation on serum cholesterol and blood pressure. A randomized, double-blind, placebo-controlled, clinical trial. Arch Fam Med. 2000;9:31-38.
32. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physicians' Guide to Herbal Medicine 3rd ed. Berlin, Germany: Springer-Verlag; 1998:97.
33. Duffy SJ, Gokce N, Holbrook M, et al. Treatment of hypertension with ascorbic acid. Lancet. 1999;354:2048.
34. Osilesi O, Trout DL, Ogunwole JO, et al. Blood pressure and plasma lipids during ascorbic acid supplementation in borderline hypertensive and normotensive adults. Nutr Res. 1991;11:405-412.
35. Fotherby MD, Williams JC, Forster LA, et al. Effect of vitamin C on ambulatory blood pressure and plasma lipids in older persons. J Hypertens. 2000;18:411-415.
36. Ghosh SK, Ekpo EB, Shah IU, et al. A double-blind, placebo-controlled parallel trial of vitamin C treatment in elderly patients with hypertension. Gerontology. 1994;40:268-272.
37. Lovat LB, Lu Y, Palmer AJ, et al. Double-blind trial of vitamin C in elderly hypertensives. J Hum Hypertens. 1993;7:403-405.
38. Asgary S, Naderi GH, Sarrafzadegan N, et al. Antihypertensive and antihyperlipidemic effects of Achillea wilhelmsii.Drugs Exp Clin Res. 2000;26:89-93.
39. Arvill A, Bodin L. Effect of short-term ingestion of konjac glucomannan on serum cholesterol in healthy men. Am J Clin Nutr. 1995;61:585-589.
40. Reffo GC. Glucomannan in hypertensive outpatients: pilot clinical trial. Curr Ther Res. 1988;44:22-27.
41. Vuksan V, Jenkins DJ, Spadafora P, et al. Konjac-mannan (glucomannan) improves glycemia and other associated risk factors for coronary heart disease in type 2 diabetes. A randomized controlled metabolic trial. Diabetes Care. 1999;22:913-919.
42. Kato H, Taguchi T, Okuda H, et al. Antihypertensive effect of chitosan in rats and humans. J Tradit Med. 1994;11:198-205.
43. Haji Faraji M, Haji Tarkhani AH. The effect of sour tea ( Hibiscus sabdariffa) on essential hypertension. J Ethnopharmacol. 1999;65:231-236.
44. Chiu KW, Fung AY. The cardiovascular effects of green beans ( Phaseolus aureus), common rue ( Ruta graveolens), and kelp ( Laminaria japonica) in rats. Gen Pharmac. 1997;29:859-862.
45. Fuller KE, Casparian JM. Vitamin D: balancing cutaneous and systematic considerations. South Med J. 2001;94:58-64.
46. Rostand SG. Ultraviolet light may contribute to geographic and racial blood pressure differences. Hypertension. 1997;30(2 pt 1):150-156.
47. Krause R, Buhring M, Hopfenmuller W, et al. Ultraviolet B and blood pressure [letter]. Lancet. 1998;352:709-710.
48. Scragg R. Sunlight, vitamin D, and cardiovascular disease. In: Crass MF II, Avioli LV, eds. Calcium Regulating Hormones and Cardiovascular Function. Boca Raton, FL: CRC Press; 1995:213-237.
49. O'Connell TD, Simpson RU. 1,25-dihydroxyvitamin D3 and cardiac muscle structure and function. In: Crass MF II, Avioli LV, eds. Calcium-Regulating Hormones and Cardiovascular Function. Boca Raton, FL: CRC Press; 1995:191-211.
50. Merchant RE, Andre CA. A review of recent clinical trials of the nutritional supplement Chlorella pyrenoidosa in the treatment of fibromyalgia, hypertension, and ulcerative colitis. Altern Ther Health Med. 2001;7:79-80,82-91.
51. Gu D, He J, Wu X, et al. Effect of potassium supplementation on blood pressure in Chinese: a randomized, placebo-controlled trial. J Hypertens. 2001;19:1325-1331.
52. Hosseini S, et al. A randomized, double-blind, placebo-controlled, prospective, 16 week crossover study to determine the role of Pycnogenol in modifying blood pressure in mildly hypertensive patients. Nutrition Research. 2001; 21:1251-1260.
53. Burke BE, Neuenschwander R, Olson RD. Randomized, double-blind, placebo-controlled trial of coenzyme Q10 in isolated systolic hypertension. South Med J. 2001;94:1112-1117.
54. Walker AF, Marakis G, Morris AP, et al. Promising hypotensive effect of hawthorn extract: a randomized double-blind pilot study of mild, essential hypertension. Phytother Res. 2002;16:48-54.
55. Ammon HPT, Handel M. Crataegus, toxicology and pharmacology. Parts I, II and III [translated from German]. Planta Med. 1981;43:105-120,209-239,313-322.
56. Geleijnse JM, Giltay EJ, Grobbee DE, et al. Blood pressure response to fish oil supplementation: metaregression analysis of randomized trials. J Hypertens. 2002;20:1493-1499.
57. Mori TA, Bao DQ, Burke V, et al. Docosahexaenoic acid but not eicosapentaenoic acid lowers ambulatory blood pressure and heart rate in humans. Hypertension. 1999;34:253-260.
58. Porsti I, Makynen H. Dietary calcium intake: effects on central blood pressure control. Semin Nephrol. 1995;15:550-563.
59. Griffith LE, Guyatt GH, Cook RJ, Bucher HC, Cook DJ. The influence of dietary and nondietary calcium supplementation on blood pressure: an updated metaanalysis of randomized controlled trials. Am J Hypertens. 1999;12(1 Pt 1):84-92.
60. Hajjar IM, George V, Sasse EA, et al. A randomized, double-blind, controlled trial of vitamin C in the management of hypertension and lipids. Am J Ther. 2002;9:289-293.
61. Nissen S, Sharp RL, Panton L, et al. ß-hydroxy-ß-methylbutyrate (HMB) supplementation in humans is safe and may decrease cardiovascular risk factors. J Nutr. 2000;130:1937-1945.
62. Hodgson JM, Watts GF, Playford DA, et al. Coenzyme Q(10) improves blood pressure and glycaemic control: a controlled trial in subjects with type 2 diabetes. Eur J Clin Nutr. 2002;56:1137-1142.
63. Nakao M, Yano E, Nomura S, Kuboki T. Blood pressure-lowering effects of biofeedback treatment in hypertension: a meta-analysis of randomized controlled trials. Hypertens Res. 2003;26:37-46.
64. Seppo L, Jauhiainen T, Poussa T, et al. A fermented milk high in bioactive peptides has a blood pressure-lowering effect in hypertensive subjects. Am J Clin Nutr. 2003;77:326-330.
65. Inoue K, Shirai T, Ochiai H, et al. Blood-pressure-lowering effect of a novel fermented milk containing gamma-aminobutyric acid (GABA) in mild hypertensives. Eur J Clin Nutr. 2003;57:490-495.
66. Kim MK, Sasaki S, Sasazuki S, et al. Lack of long-term effect of vitamin C supplementation on blood pressure. Hypertension. 2002;40:797-803.
67. Mangoni AA, Sherwood RA, Swift CG, et al. Folic acid enhances endothelial function and reduces blood pressure in smokers: a randomized controlled trial. J Intern Med. 2002;252:497-503.
68. van Montfrans GA, Karemaker JM, Wieling W, et al. Relaxation therapy and continuous ambulatory blood pressure in mild hypertension: a controlled study. BMJ. 1990;300:1368-1372.
69. Ishikawa-Takata K, Ohta T, Tanaka H. How much exercise is required to reduce blood pressure in essential hypertensives: a dose-response study. Am J Hypertens. 2003;16:629-633.
70. Hsieh MH, Chan P, Sue YM, et al. Efficacy and tolerability of oral stevioside in patients with mild essential hypertension: a two-year, randomized, placebo-controlled study. Clin Ther. 2003;25:2797-808.
71. Vickers A, Goyal N, Harland R, et al. Do certain countries produce only positive results? A systematic review of controlled trials. Control Clin Trials. 1998;19:159-166.
72. Naismith DJ, Braschi A. The effect of low-dose potassium supplementation on blood pressure in apparently healthy volunteers. Br J Nutr. 2003;90:53-60.
73. Ward NC, Hodgson JM, Croft KD, et al. Effects of vitamin C and grape-seed polyphenols on blood pressure in treated hypertensive individuals: results of a randomised double blind, placebo-controlled trial. Asia Pac J Clin Nutr. 2003;12(suppl):S18.
74. Scheer FA, Van Montfrans GA, Van Someren EJ, et al. Daily nighttime melatonin reduces blood pressure in male patients with essential hypertension. Hypertension. 2004 Jan 19. [Epub ahead of print]
75. Herrera-Arellano A, Flores-Romero S, Chavez-Soto MA, et al. Effectiveness and tolerability of a standardized extract from Hibiscus sabdariffa in patients with mild to moderate hypertension: a controlled and randomized clinical trial. Phytomedicine. 2004;11:375-82.
76. Tsai JC, Wang WH, Chan P, et al. The beneficial effects of tai chi chuan on blood pressure and lipid profile and anxiety status in a randomized controlled trial. J Altern Complement Med. 2003;9:747-754.
77. Goertz CH, Grimm RH, Svendsen K, et al. Treatment of Hypertension with Alternative Therapies (THAT) study: a randomized clinical trial. J Hypertens. 2002;20:2063-2068.
78. Elley R, Bagrie E, Arroll B, et al. Do snacks of exercise lower blood pressure? A randomised crossover trial. N Z Med J. 2006;119:U1996.
79. Whelton SP, Hyre AD, Pedersen B, et al. Effect of dietary fiber intake on blood pressure: a meta-analysis of randomized, controlled clinical trials. J Hypertens. 2005;23:475-481.
80. Streppel MT, Arends LR, van 't Veer P, et al. Dietary Fiber and Blood Pressure: A Meta-analysis of Randomized Placebo-Controlled Trials. Arch Intern Med. 2005;165:150-6.
81. Jauhiainen T, Vapaatalo H, Poussa T, et al. Lactobacillus helveticus Fermented Milk Lowers Blood Pressure in Hypertensive Subjects in 24-h Ambulatory Blood Pressure Measurement. Am J Hypertens. 2005;18:1600-16005.
82. Rylander RC, Arnaud MJ. Mineral water intake reduces blood pressure among subjects with low urinary magnesium and calcium levels. BMC Public Health. 2004 Nov 30. [Epub ahead of print] .
83. Reshef N, Hayari Y, Goren C, et al. Antihypertensive effect of sweetie fruit in patients with stage I hypertension. Am J Hypertens. 2005;18:1360-1363.
84. Engelhard YN, Gazer B, Paran E, et al. Natural antioxidants from tomato extract reduce blood pressure in patients with grade-1 hypertension: a double-blind, placebo-controlled pilot study. Am Heart J. 2006;151:100.
85. Cagnacci A, Cannoletta M, Renzi A, et al. Prolonged melatonin administration decreases nocturnal blood pressure in women. Am J Hypertens. 2005;18:1614-1618.
86. Kozuma K, Tsuchiya S, Kohori J, et al. Antihypertensive effect of green coffee bean extract on mildly hypertensive subjects. Hypertens Res. 2006;28:711-718.
87. Engelhard YN, Gazer B, Paran E, et al. Natural antioxidants from tomato extract reduce blood pressure in patients with grade-1 hypertension: a double-blind, placebo-controlled pilot study. Am Heart J. 2005;151:100.
88. Park YK, Kim JS, Kang MH, et al. Concord grape juice supplementation reduces blood pressure in Korean hypertensive men: Double-blind, placebo controlled intervention trial. Biofactors. 2005;22:145-147.
89. Walker AF, Marakis G, Simpson E, et al. Hypotensive effects of hawthorn for patients with diabetes taking prescription drugs: a randomised controlled trial. Br J Gen Pract. 2006;56:437-443.
90. Asgary S, Naderi GH, Sadeghi M, et al. Antihypertensive effect of Iranian Crataegus curvisepala Lind.: a randomized, double-blind study. Drugs Exp Clin Res. 2005;30:221-225.
91. Grassi D, Necozione S, Lippi C, et al. Cocoa reduces blood pressure and insulin resistance and improves endothelium-dependent vasodilation in hypertensives. Hypertension. 2005 Jul 18. [Epub ahead of print]
92. He J, Gu D, Wu X, et al. Effect of soybean protein on blood pressure: a randomized, controlled trial. Ann Intern Med. 2005;143:1-9.
93. Arakawa K, Saruta T, Abe K, et al. Improvement of accessory symptoms of hypertension by TSUMURA Orengedokuto Extract, a four herbal drugs containing Kampo-Medicine granules for ethical use: A double-blind, placebo-controlled study. Phytomedicine. 2005;13:1-10.
94. Hutchins AM, McIver IE, Johnston CS, et al. Hypertensive crisis associated with high dose soy isoflavone supplementation in a post-menopausal woman: a case report [ISRCTN98074661]. BMC Womens Health. 2005 Jun 23. [Epub ahead of print]
95. Ward NC, Wu JH, Clarke MW, et al. The effect of vitamin E on blood pressure in individuals with type 2 diabetes: a randomized, double-blind, placebo-controlled trial. J Hypertens. 2007;25:227-234.
96. Bui LT, Nguyen DT, Ambrose PJ. Blood pressure and heart rate effects following a single dose of bitter orange. Ann Pharmacother. 2006;40:53-57.
97. Watanabe T, Arai Y, Mitsui Y, et al. The blood pressure-lowering effect and safety of chlorogenic Acid from green coffee bean extract in essential hypertension. Clin Exp Hypertens. 2006;28:439-49.
98. Grassi D, Necozione S, Lippi C, et al. Cocoa reduces blood pressure and insulin resistance and improves endothelium-dependent vasodilation in hypertensives. Hypertension. 2005 Jul 18. [Epub ahead of print]
99. Grossman E, Laudon M, Yalcin R, et al. Melatonin reduces night blood pressure in patients with nocturnal hypertension. Am J Med. 2006;119:898-902.
100. Macklin EA, Wayne PM, Kalish LA, et al. Stop hypertension with the acupuncture research program (SHARP). Results of a randomized, controlled clinical trial. Hypertension. 2006 Oct 2. [Epub ahead of print]
101. Paschos GK, Magkos F, Panagiotakos DB, et al. Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients. Eur J Clin Nutr. 2007 Jan 31. [Epub ahead of print]
102. Teede HJ, Giannopoulos D, Dalais FS, et al. Randomised, controlled, cross-over trial of soy protein with isoflavones on blood pressure and arterial function in hypertensive subjects. J Am Coll Nutr. 2006;25:533-540.
103. Herrera-Arellano A, Miranda-Sanchez J, Avila-Castro P, et al. Clinical effects produced by a standardized herbal medicinal product of Hibiscus sabdariffa on patients with hypertension: a randomized, double-blind, lisinopril-controlled clinical trial. Planta Med. 2007;73:6-12.
104. Theobald HE, Goodall AH, Sattar N, et al. Low-dose docosahexaenoic acid lowers diastolic blood pressure in middle-aged men and women. J Nutr. 2007;137:973-978.
105. Yin C, Seo B, Park HJ, et al. Acupuncture, a promising adjunctive therapy for essential hypertension: a double-blind, randomized, controlled trial. Neurol Res. 2007;29(suppl):98-103.
106. McMackin CJ, Widlansky ME, Hamburg NM, et al. Effect of combined treatment with alpha-lipoic acid and acetyl-L-carnitine on vascular function and blood pressure in patients with coronary artery disease. J Clin Hypertens. 2007;9:249-255.
107. Bergel E, Barros AJ. Effect of maternal calcium intake during pregnancy on children blood pressure: a systematic review of the literature. BMC Pediatr. 2007 Mar 26. [Epub ahead of print].
108. McMahon JA, Skeaff CM, Williams SM, et al. Lowering homocysteine with B vitamins has no effect on blood pressure in older adults. J Nutr. 2007;137:1183-7118.
109. Rangineni V, Sharada D, Saxena S. Diuretic, hypotensive, and hypocholesterolemic effects of Eclipta alba in mild hypertensive subjects: a pilot study. J Med Food. 2007;10:143-148.
110. Shah M, Adams-Huet B, Garg A. Effect of high-carbohydrate or high-cis-monounsaturated fat diets on blood pressure: a meta-analysis of intervention trials. Am J Clin Nutr. 2007;85:1251-1256.
111. Flachskampf FA, Gallasch J, Gefeller O, et al. Randomized trial of acupuncture to lower blood pressure. Circulation. 2007 Jun 4. [Epub ahead of print]
112. Taubert D, MD, Roesen R, Lehmann C, et al. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide. JAMA. 2007;298:49-60.
113. Lee MS, Pittler MH, Guo R, et al. Qigong for hypertension: a systematic review of randomized clinical trials. J Hypertens. 2007;25:1525-1532.
114. Vuksan V, Whitham D, Sievenpiper JL, et al. Supplementation of conventional therapy with the novel grain salba ( Salvia hispanica L.) improves major and emerging cardiovascular risk factors in type 2 diabetes: results of a randomized controlled trial. Diabetes Care. 2007 Aug 8. [Epub ahead of print]
115. Inoue K, Shirai T, Ochiai H, et al. Blood-pressure-lowering effect of a novel fermented milk containing gamma-aminobutyric acid (GABA) in mild hypertensives. Eur J Clin Nutr. 2003;57:490-495.
116. Hayakawa K, Kimura M, Yamori Y. Role of the renal nerves in gamma-aminobutyric acid-induced antihypertensive effect in spontaneously hypertensive rats. Eur J Pharmacol. 2005;524:120-125.
117. Hayakawa K, Kimura M, Kasaha K, et al. Effect of a gamma-aminobutyric acid-enriched dairy product on the blood pressure of spontaneously hypertensive and normotensive Wistar-Kyoto rats. Br J Nutr. 2004;92:411-417.
118. Hayakawa K, Kimura M, Kasaha K, et al. Effect of a gamma-aminobutyric acid-enriched dairy product on the blood pressure of spontaneously hypertensive and normotensive Wistar-Kyoto rats. Br J Nutr. 2004;92:411-417.
119. Hayakawa K, Kimura M, Kamata K. Mechanism underlying gamma-aminobutyric acid-induced antihypertensive effect in spontaneously hypertensive rats. Eur J Pharmacol. 2002;438:107-113.
120. Yamakoshi J, Fukuda S, Satoh T, et al. Antihypertensive and natriuretic effects of less-sodium soy sauce containing gamma-aminobutyric acid in spontaneously hypertensive rats. Biosci Biotechnol Biochem. 2007;71:165-173.
121. Hirata H, Kimura M, Nakagawa S, et al. Hypotensive effect of fermented milk containing gamma-aminobutyric acid (GABA) in subjects with high normal blood pressure. Journal of the Japanese Society for Food Science and Technology. 2004;51:79-86.
122. Rogers PJ, Smith JE, Heatherley SV, et al. Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. Psychopharmacology (Berl). 2007 Sep 23. [Epub ahead of print]
123. Edwards RL, Lyon T, Litwin SE, et al. Quercetin reduces blood pressure in hypertensive subjects. J Nutr. 2007;137:2405-2411.
124. Guo X, Zhou B, Nishimura T, et al. Clinical effect of Qigong practice on essential hypertension: a meta-analysis of randomized controlled trials. J Altern Complement Med. 2008 Jan 16.
125. Heather OD, Fiona C, Fiona RB, et al. Relaxation therapies for the management of primary hypertension in adults. Cochrane Database Syst Rev. 2008;CD004935
126. Anderson JW, Liu C, Kryscio RJ. Blood pressure response to transcendental meditation: a meta-analysis. Am J Hypertens. 2008;21:310-316.
127. Rainforth MV, Schneider RH, Nidich SI, et al. Stress reduction programs in patients with elevated blood pressure: a systematic review and meta-analysis. Curr Hypertens Rep. 2007;9:520-528.
128. Yeh GY, Wang C, Wayne PM, et al. The effect of tai chi exercise on blood pressure: a systematic review. Prev Cardiol. 2008;11:82-89.
129. Vickers A, Goyal N, Harland R, et al. Do certain countries produce only positive results? A systematic review of controlled trials. Control Clin Trials. 1998;19:159-166.
130. Barriocanal LA, Palacios M, Benitez G, et al. Apparent lack of pharmacological effect of steviol glycosides used as sweeteners in humans. A pilot study of repeated exposures in some normotensive and hypotensive individuals and in Type 1 and Type 2 diabetics. Regul Toxicol Pharmacol. 2008 Mar 5.
131. Rosero Arenas MA, Rosero Arenas E, Portaceli Arminana MA, et al. Usefulness of phyto-oestrogens in reduction of blood pressure. Systematic review and meta-analysis. Aten Primaria. 2008;40:177-186.
132. Silagy CA, Neil HA. A meta-analysis of the effect of garlic on blood pressure. J Hypertens. 1994;12:463-468.
133. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physicians' Guide to Herbal Medicine. 3rd ed. Berlin, Germany: Springer-Verlag; 1998: 119.
134. Auer W, Eiber A, Hertkorn E, et al. Hypertension and hyperlipidaemia: garlic helps in mild cases. Br J Clin Pract Suppl. 1990;69:3-6.
135. Ried K, Frank OR, Stocks NP, et al. Effect of garlic on blood pressure: A systematic review and meta-analysis. BMC Cardiovasc Disord. 2008 Jun 16.
136. Hooper L, Kroon PA, Rimm EB, et al. Flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2008;88:38-50.
137. Erkkila AT, Schwab US, de Mello VD, et al. Effects of fatty and lean fish intake on blood pressure in subjects with coronary heart disease using multiple medications. Eur J Nutr. 2008 Jul 29.
138. Mozaffari-Khosravi H, Jalali-Khanabadi BA, Afkhami-Ardekani M, et al. The effects of sour tea ( Hibiscus sabdariffa) on hypertension in patients with type II diabetes. J Hum Hypertens. 2008 Aug 7
139. Margolis KL, Ray RM, Van Horn L, et al. Effect of calcium and vitamin D supplementation on blood pressure: the Women's Health Initiative Randomized Trial. Hypertension. 2008;52:847-855.
140. Lee H, Kim SY, Park J, et al. Acupuncture for lowering blood pressure: systematic review and meta-analysis. Am J Hypertens. 2009;22:122-128.
141. Greenhalgh J, Dickson R, Dundar Y. Biofeedback for hypertension: a systematic review. J Hypertens. 2010 Jan 19 early online.
142. Wahabi HA, Alansary LA, Al-Sabban AH, et al. The effectiveness of Hibiscus sabdariffa in the treatment of hypertension: a systematic review. Phytomedicine. 2010;17(2):83.
143. Modesti PA, Ferrari A, Bazzini C, et al. Psychological predictors of the antihypertensive effects of music-guided slow breathing. J Hypertens. 2010;28(5):1097.
144. Akilen R, Tsiami A, Devendra D, Robinson N. Glycated haemoglobin and blood pressure-lowering effect of cinnamon in multi-ethnic Type 2 diabetic patients in the UK: a randomized, placebo-controlled, double-blind clinical trial. Diabet Med. 2010;27(10):1159-1167.
145. Hodgson JM, Puddey IB, Woodman RJ, et al. Effects of black tea on blood pressure: a randomized controlled trial. Arch Intern Med. 2012;172(2):186-188.
146. Susalit E, Agus N, Effendi I, et al. Olive (Olea europaea) leaf extract effective in patients with stage-1 hypertension: comparison with Captopril. Phytomedicine. 2011;18(4):251-258.
147. Ried K, Sullivan TR, Fakler P, et al. Effect of cocoa on blood pressure. Cochrane Database Syst Rev. 2012;8:CD008893.
148. Lin G, Xiang Q, Fu X. Heart rate variability biofeedback decreases blood pressure in prehypertensive subjects by improving autonomic function and baroreflex. J Altern Complement Med. 2012;18(2):143-152.
149. Tyagi A, Cohen M. Yoga and hypertension: A systematic review. Altern Ther Health Med. 2014;20(2):32-59.
151. Hartley L, Lee MS, Kwong JS, et al. Qigong for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2015;6:CD010390.
Last reviewed September 2014 by EBSCO CAM Review Board
Last Updated: 7/17/2015