Treatment of Hypertension (High Blood Pressure)
by Hans R. Larsen, MSc ChE
Treating hypertension helps prevent atrial fibrillation
GENEVA, SWITZERLAND. There is increasing evidence that essential hypertension (high blood pressure) is an important risk factor in the development of atrial fibrillation. What is less clear is whether treating the hypertension lessens the risk of afib. Swiss researchers now report that appropriate treatment does indeed reduce the risk and that the risk reduction is independent of the type of blood pressure reducing agent used. The study involved a group of 597 patients who, after having been diagnosed with hypertension (systolic blood pressure equal to or greater than 140 mm Hg and/or diastolic pressure equal to or greater than 90 mm Hg), were placed on antihypertensive therapy using ACE inhibitors (46%), angiotensin II receptor blockers (23%), calcium channel blockers (52%), and beta-blockers (21%) either alone or in combination.
After a 7-year follow-up the researchers found that the risk of developing atrial fibrillation decreased by 24% with a 12 mm Hg drop in systolic pressure after adjusting for age, gender, body mass, and pulse pressure (systolic blood pressure minus diastolic pressure). All blood pressure measurements were averages of 24-hour ambulatory measurements. Those of the patients who did develop atrial fibrillation were slightly older than those who did not, were more likely to be men, and to be overweight or obese. A decrease in pulse pressure also correlated with a decrease in AF risk, but this trend was not statistically significant. There was no indication that one class of blood pressure medications was superior in preventing the development of AF. The researchers conclude that an increased systolic pressure and pulse pressure may promote the onset of atrial fibrillation by modification of left ventricular diastolic function.
Ciaroni, S, et al. Prognostic value of 24-hour ambulatory blood pressure measurement for the onset of atrial fibrillation in treated patients with essential hypertension. American Journal of Cardiology, Vol. 94, December 15, 2004, pp. 1566-69
Olive oil lowers blood pressure
NAPLES, ITALY. Several studies have shown that replacing saturated fat with unsaturated fat in the diet can help lower blood pressure in hypertensive individuals. Research has shown that some unsaturated fats (oils) are more effective in lowering blood pressure than others. Fish oils containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), for example, have been found quite effective in lowering both blood pressure and triglyceride levels. Now researchers at the University of Naples report that olive oil is also highly effective in lowering blood pressure.
Their one-year study involved 23 men and women with mild hypertension (systolic pressure less than 165 mm Hg and diastolic pressure less than 104 mm Hg at the start of the study). The participants were randomized into two groups. One group was told to add olive oil to their food after cooking while the other group was told to add sunflower oil (a rich source of linoleic acid). Men added 40 grams/day (approx. four spoonfuls) and women added 30 grams/day (approx. three spoonfuls) to arrive at a diet containing 8368 kJ and 6276 kJ respectively. The overall composition of the diet was 17 per cent protein, 57 per cent carbohydrates, and 26 per cent fat.
The participants' blood pressures were measured every two months. After six months the average systolic blood pressure in the olive oil group had dropped to 127 mm Hg from the 134 mm Hg recorded at the start and the diastolic pressure had dropped from 90 mm Hg to 84 mm Hg. There were no significant changes in the sunflower oil group.
The level of antihypertensive medication was adjusted during the experiment by a separate group of doctors who did not know which diet their patients were following. The ones in the olive oil group were able to reduce their medication use by an average 48 per cent and eight of them were able to discontinue their medications completely. None of the ones in the sunflower oil group were able to discontinue their medications and the average reduction in medication usage was only 4 per cent.
The researchers conclude that a reduction in saturated fat intake combined with the increased use of extra-virgin olive oil lowers the need for antihypertensive medication. They speculate that the high content of polyphenols in olive oil may be a major factor in its beneficial effects.
Ferrara, L. Aldo, et al. Olive oil and reduced need for antihypertensive medications. Archives of Internal Medicine, Vol. 160, March 27, 2000, pp. 837-42
Fish oil supplementation reduces blood pressure
CINCINNATI, OHIO. Conventional blood pressure lowering medications often have detrimental effects on quality of life and may lead to unfavourable changes in cholesterol levels. Several studies have found that supplementation with large amounts of fish oil (5-15 grams/day) lowers blood pressure significantly in hypertensive individuals. Whether smaller amounts are equally effective has been open to question.
Researchers at the University of Cincinnati (Ohio) College of Medicine now report that daily supplementation with low doses of fish oil is indeed effective in lowering blood pressure in mildly hypertensive patients. Their study involved 33 patients (men and women) with a diastolic pressure between 90 and 104 mm Hg. After a four-week washout period during which the participants discontinued all medications the patients were randomly allocated to one of two groups. Group 1 supplemented with 2.04 grams/day of fish oil containing 410 mg of eicosapentaenoic acid and 285 mg of docosahexaenoic acid. Group 2 was given a placebo capsule daily containing safflower oil (80% linoleic acid). After 12 weeks and a four-week washout period the groups switched supplementation so that group 1 now received the placebo. Blood pressure, heart rate, and body weight were recorded at two-week intervals during the study and blood samples were collected and analyzed at the beginning and end of each treatment period.
The researchers found that fish oil supplementation reduced diastolic pressure (sitting) by an average of approximately 4.4 mm Hg and systolic pressure by an average of 6.5 mm Hg when compared to values obtained prior to the start of treatment. There were no adverse effects on cholesterol levels. They conclude that fish oil supplementation is a safe and effective way of lowering blood pressure in mildly hypertensive subjects, but noted that the beneficial effects wear off relatively quickly once supplementation is discontinued. NOTE: This study was funded by a grant from RP Scherer Ltd. a manufacturer of fish oil products.
Radack, Kenneth, et al. The effects of low doses of n-3 fatty acid supplementation on blood pressure in hypertensive subjects. Archives of Internal Medicine, Vol. 151, June 1991, pp. 1173-80
Salt restriction and fish oil supplementation lower blood pressure
ADELAIDE, AUSTRALIA. Salt (sodium) restriction can help lower blood pressure in people with hypertension, but is less effective in people with normal pressure. Blood pressure tends to rise with age and there is some evidence that sodium restriction may help reduce this age-related increase. Fish oil supplementation is also effective in lowering blood pressure in hypertensive individuals, but its effect on people with normal pressure is unclear.
Australian researchers report that a combination of fish oil supplementation and salt restriction is highly effective in lowering both systolic and diastolic blood pressure in elderly people with normal pressures. Their study involved 50 healthy volunteers aged 60 to 80 years whose mean initial systolic and diastolic blood pressures were 133 and 77 mm Hg respectively. The participants were randomly assigned to one of four groups. Group 1 supplemented with 8 fish oil capsules per day (providing 4.2 g of omega-3 fatty acids) while maintaining a normal sodium intake. Group 2 supplemented with fish oil while consuming a low-sodium diet. Group 3 supplemented with sunflower oil combined with normal sodium intake while group 4 took sunflower oil while consuming a low-sodium diet. After 4 weeks the mean systolic blood pressure in group 1 had decreased by 8.9 mm Hg and the diastolic pressure by 6.0 mm Hg. There were no significant changes in blood pressure in the group supplementing with fish oil while maintaining a normal sodium intake. The researchers conclude that sodium restriction combined with fish oil supplementation effectively lowers blood pressure. They suggest that this finding may be of particular relevance in the treatment of hypertension in the elderly.
Cobiac, Lynne, et al. Effects of dietary sodium restriction and fish oil supplements on blood pressure in the elderly. Clinical and Experimental Pharmacology and Physiology, Vol. 18, 1991, pp. 265-68
Controlled trials confirm blood pressure reduction with fish oils
BOSTON, MASSACHUSETTS. Numerous studies have concluded that fish oil consumption lowers blood pressure, but a few have found no effect and others have been inconclusive. Researchers at the Harvard Medical School have just completed a major evaluation of the results of 31 placebo-controlled trials involving 1356 subjects. They found that fish oil supplementation (mean dose of 5.6 grams/day) lowers systolic blood pressure (first [highest] reading of blood pressure measurement) by an average of 3.4 mm Hg and diastolic pressure (second [lowest] reading) by an average of 2.0 mm Hg. The effect is highly dose-dependent with 1 gram/day of fish oil lowering systolic pressure by an average of 0.66 mm Hg and diastolic pressure by an average of 0.35 mm Hg. Fish oil supplementation does not affect blood pressure in people with normal blood pressure, but relatively dramatic effects are seen in patients with high cholesterol levels and in patients with atherosclerosis. Both eicosapentaenoic and docosahexaenoic acids (the main components of fish oils) are effective in blood pressure reduction with docosahexaenoic acid being slightly superior. The Harvard researchers conclude that supplementation with 7.7 to 9 grams/day of fish oils will reduce systolic blood pressure by 4 mm Hg and diastolic pressure by 3 mm Hg in hypertensive individuals. Blood pressure reductions may be substantially larger among patients with atherosclerosis or high cholesterol levels.
Morris, Martha Clare, et al. Does fish oil lower blood pressure? A meta-analysis of controlled trials. Circulation, Vol. 88, No. 2, August 1993, pp. 523-33
Vitamin C combats hypertension
BOSTON, MASSACHUSETTS. There is increasing evidence that free radicals (reactive oxygen species) play a significant role in essential hypertension (high blood pressure). Now researchers at the Boston University School of Medicine report that daily supplementation with vitamin C (ascorbic acid) can significantly reduce blood pressure in people suffering from hypertension. Their randomized, placebo-controlled study involved 39 patients (average age of 49 years) 29 of whom were taking antihypertensive medication.
The study participants had diastolic blood pressure between 90 and 110 mm Hg and did not suffer from diabetes, coronary artery disease or heart failure. They also did not take estrogens or antioxidants within one month of the start of the study. After fasting overnight the patients had their blood pressures (systolic, mean, and diastolic) measured and had urine and blood samples collected. The measurements were repeated two hours after receiving a 2-gram oral dose of ascorbic acid or placebo and again after 30 days of oral supplementation with 500 mg/day of ascorbic acid or placebo.
The researchers found that blood pressures were similar at baseline and after the acute treatment (2-gram dose). At the end of the 30-day period, however, the average systolic pressure in the vitamin C group had decreased from 155 mm Hg to 142 mm Hg and the mean pressure had decreased from 110 to 100 mm Hg. No changes were observed in the placebo group. The average diastolic pressure in the vitamin C group also decreased, but the difference from the placebo group was not statistically significant. Blood plasma levels of ascorbic acid increased significantly in the vitamin C group during the study; from 50 micromol/L to 149 micromol/L two hours after ingesting the 2-gram dose and levelling out at 99 micromol/L at the end of the 30-day test period. The researchers conclude that oral supplementation with 500 mg/day of ascorbic acid is useful for blood pressure control in patients with high blood pressure.
Duffy, Stephen J., et al. Treatment of hypertension with ascorbic acid. The Lancet, Vol. 354, December 11, 1999, pp. 2048-49 (research letter)
Beta-blockers may be a poor choice as an antihypertensive medication for patients who engage in vigorous exercise
ALBUQUERQUE, NEW MEXICO. This review of the effect of blood-pressure-lowering drugs on exercise performance found that the converting enzyme inhibitors, calcium channel blockers, and alpha-blockers have the least potential for adverse effects. Beta-blockers and the CCB, verapamil, were found to impair left ventricular function during exercise. The CCB's nifedipine and diltiazem preserved myocardial contractility better while other antihypertensive agents had negligible effects. Beta-blockers and CCB's (verapamil and diltiazem) have mild antiarrhythmic properties and may provide some protection against ventricular tachycardia. Beta-blockers however, reduce time to exhaustion - nonselective beta-blockers to a greater extent than selective beta-blockers.
Chick, Thomas W., et al. The effect of antihypertensive medications on exercise performance: a review. Medicine and Science in Sports and Exercise, Vol. 20, No. 5, October 1988, pp.447-52
Cigarette smoking may interfere with treatment of hypertension
MIAMI, FLORIDA. A comparative study of the efficacy of propranolol and hydrochlorothiazide in treatment of hypertension was analyzed to determine if patients who were non-smokers reacted differently than did smokers. The study involved 105 smokers, 81 former smokers, and 147 who never smoked. It was found that smokers responded less to propranolol than did non-smokers; however, further stratification of the data showed that most of the effect was attributable to black patients. A similar trial involving nadolol and bendroflumethiazide showed no difference between smokers and non-smokers in their response to nadolol. This study involved 96 smokers and 187 non-smokers.
Materson, Barry J., et al. Cigarette smoking interferes with treatment of hypertension. Archives of Internal Medicine, Vol. 148, No. 10, October 1988, pp. 2116-19
Potassium proves effective in lowering blood pressure
NAPLES, ITALY. Researchers at the University of Naples have concluded a one-year trial to determine if an increased potassium intake decreases the need for anti-hypertensive medication. A group of 54 patients who were all controlling their high blood pressure with medication participated in the study. Half of the group maintained their regular diet while the diet of the other half was modified to increase the amount of potassium-rich food. The extent of the dietary modification was such that the sodium to potassium ratio was 1:1 rather than the customary 3.5:1. At the end of the trial period the group on the high potassium diet consumed less medication than the other group and 38% of them had discontinued medication altogether. The group on the potassium-rich diet also reported a significant (55%) reduction in symptoms related to their hypertension. NOTE: Increasing potassium intake may be dangerous when taking certain diuretics such as spironolactone.
Supplemental dietary potassium reduced the need for antihypertensive drug therapy. Nutrition Reviews, Vol. 50, No. 5, May 1992, pp. 144-5
Fish oils reduce blood pressure
BALTIMORE, MARYLAND. The daily consumption of fish oils (omega-3 polyunsaturated fatty acids) can significantly lower blood pressure in people suffering from hypertension. The benefit of the fish oils is comparable to that obtainable by sodium reduction and weight loss. A group of medical researchers at the Johns Hopkins Medical School evaluated the results of 17 clinical trials involving supplementation with fish oils for periods of three months or less. They found that the consumption of 3 grams per day of fish oil (6-10 capsules) or more led to impressive reductions in the blood pressure of hypertensive individuals. Systolic pressure was lowered by an average of 5.5 mm Hg and diastolic pressure was lowered by 3.5 mm Hg. The effect was found to be more pronounced at higher blood pressures and no significant effects were noted in people with normal blood pressure. Twenty-eight percent of the participants in the trials reported side effects such as a fishy taste or belching. The doctors suggest that fish oil supplementation may be a valuable therapy in patients with borderline hypertension who would otherwise be candidates for conventional drug therapy. They point out that the effects of long term (> 3 months) supplementation are unknown and that lower dosages than 3 g/day may be desirable and perhaps as effective. NOTE: Systolic pressure is the first (highest) reading given for a blood pressure measurement, diastolic is the second (lowest) reading, i.e. 120/80.
Appel, Lawrence J., et al. Does supplementation of diet with "fish oil" reduce blood pressure? Archives of Internal Medicine, Vol. 153, June 28, 1993, pp. 1429-38
Vitamin C lowers blood pressure
AUGUSTA, GEORGIA. Researchers at the Medical College of Georgia have confirmed that people with a high vitamin C concentration in their blood have lower blood pressures than do people with little vitamin C. They tested 168 healthy people, 56 of which were taking supplements containing ascorbic acid. Among their findings: plasma ascorbic acid levels were 11% higher in supplement users than in non-users; both diastolic and systolic blood pressure were about 5 mm lower in people having a high plasma level of vitamin C than in people having a low level. Blood levels of selenium, vitamin A and vitamin E were not found to affect blood pressure, but both obesity and smoking had a significant adverse effect.
Moran, John P., et al. Plasma ascorbic acid concentrations relate inversely to blood pressure in human subjects. American Journal of Clinical Nutrition, Vol. 57, March 1993, pp. 213-17
Magnesium supplement lowers blood pressure
ROTTERDAM, THE NETHERLANDS. A double-blind controlled trial was recently carried out by Dutch and Belgian researchers in order to determine if oral supplementation with magnesium is an effective way of lowering blood pressure in women suffering from mild to moderate hypertension. Their experiment involved 91 women between 35 and 77 years of age who did not take anti-hypertensive medication. All the women had a systolic blood pressure between 140 and 185 mm Hg and a diastolic pressure between 90 and 105 mm Hg. After a two-week period where all subjects received a placebo, the participants were randomly assigned to two groups. One group continued to receive the placebo while the other group received 485 mg per day of magnesium aspartate-HCl. Both the placebo and the magnesium supplement were supplied in the form of four packets of water-soluble powder per day to be taken with meals. At the end of the six-month trial period the systolic blood pressure in the magnesium supplementation group had decreased by 2.7 mm Hg and the diastolic pressure by 3.4 mm Hg when compared to the placebo group. The researchers conclude that oral supplementation with magnesium aspartate-HCl may be effective in lowering blood pressure in people suffering from mild to moderate hypertension who are not taking anti-hypertensive drugs.
Witteman, Jacqueline C.M., et al. Reduction of blood pressure with oral magnesium supplementation in women with mild to moderate hypertension. American Journal of Clinical Nutrition, Vol. 60, July 1994, pp. 129-35
Natural mineral salt lowers blood pressure
ROTTERDAM, THE NETHERLANDS. Medical researchers at the Erasmus University Medical School have discovered a natural mineral salt that significantly lowers blood pressure in people suffering from mild to moderate hypertension. The salt, "Saga Salt" (Akzo Nobel, Netherlands) occurs naturally in Iceland and contains 41 per cent sodium chloride, 41 per cent potassium chloride, 17 per cent magnesium salts and 1 per cent trace minerals. The researchers tested the salt in a randomized double blind placebo controlled trial involving 100 men and women aged 55 to 75 years. The participants had systolic blood pressures between 140 and 200 mm Hg or diastolic pressures between 85 and 100 mm Hg. Half the group used the mineral salt in food preparation and at the table while the other half used common table salt (sodium chloride). Blood pressures were measured at the start of the experiment and after 8, 16 and 24 weeks. After eight weeks the average blood pressure in the mineral salt group had fallen significantly. The systolic blood pressure (mean of measurement at weeks 8, 16 and 24) fell by 7.6 mm Hg and the diastolic pressure by 3.3 mm Hg in the mineral salt group as compared with the control group. After 24 weeks all participants went back to using common table salt and at week 25 there was no longer any difference in blood pressures between the two groups. The researchers conclude that replacing common table salt with a low sodium, high potassium, high magnesium mineral salt is an effective way of lowering blood pressure in older people suffering from mild to moderate hypertension. NOTE: Systolic pressure is the first (highest) reading given in a blood pressure measurement, diastolic is the second (lowest) reading, i.e. 120/80
Geleijnse, J.M., et al. Reduction in blood pressure with a low sodium, high potassium, high magnesium salt in older subjects with mild to moderate hypertension. British Medical Journal, Vol. 309, August 13, 1994, pp. 436-40
Calcium combats high blood pressure
PORTLAND, OREGON. Researchers at the Oregon Health Sciences University have just published a major overview on the current knowledge concerning the effect of dietary minerals on high blood pressure. They conclude that the effect of sodium intake on blood pressure is still not clear. It may be that only a subset of people with a genetic defect is sensitive to salt intake. The chloride ion in itself does not seem to increase blood pressure, but when combined with sodium it does cause hypertension in salt-sensitive individuals. A four-year study of 60,000 nurses concluded that women who have a calcium intake of 800 mg/day or more have a 23 per cent lower risk of developing high blood pressure than women with an intake of 400 mg/day or less. The benefits of calcium are even greater among pregnant women. Controlled trials have found that women who consume between 1500 - 2000 mg/day of calcium reduce their risk of developing pregnancy-induced hypertension by as much as 50 per cent.
It has also been shown that maternal calcium intake directly affects the infant's blood pressure. Women with a high calcium intake gave birth to babies with higher birth weights and lower blood pressures. This lower pressure persisted throughout at least the first five years of life. The effect of potassium on blood pressure is still being actively investigated. One trial found that a 50 per cent increase in potassium from natural foods lowered blood pressure and dramatically reduced the need for blood pressure-lowering drugs. Another trial found that supplementation with potassium lowered blood pressure by 10 - 14 mm Hg. Several studies suggest that a low magnesium intake is associated with hypertension, stroke, and ischemic heart disease. It has been proposed that supplementation with about 900 mg/day of magnesium, about 2.5 times the RDA, is required in order to effectively lower blood pressure. (71 references)
Reusser, Molly E. and McCarron, David A. Micronutrient effects on blood pressure regulation. Nutrition Reviews, Vol. 52, No. 11, November 1994, pp. 367-75
Fish oils recommended for diabetes and hypertension
TROMSO, NORWAY. Fish and fish oils help protect against the development of atherosclerosis and heart disease. It is believed that fish oils exert their protective effect by lowering blood pressure and the levels of triglycerides and very-low-density lipoprotein (VLDL). Fish oils are also believed to reduce platelet aggregation and to suppress the growth of smooth-muscle cells in the arterial walls. Many people with hypertension also suffer from diabetes and there has been concern that fish oil supplementation may aggravate problems with glucose intolerance. Researchers at the University of Tromso now report that fish oil supplementation lowers blood pressure significantly in people with hypertension and has no effect on glucose control even in people with mild diabetes. The study involved 78 obese volunteers with essential hypertension. The participants were randomly assigned to one of two equal-sized groups. The fish oil group received four fish oil capsules a day (containing a total of 3.4 grams of a mixture of eicosapentaenoic acid and docosahexaenoic acid) for a period of 16 weeks. The control group received four corn oil capsules a day.
At the end of the test period the average (mean) systolic blood pressure had dropped by 4.4 mm Hg and the diastolic pressure by 3.2 mm Hg in the fish oil group. The average blood pressure in the control group did not change. The researchers also found that plasma triglyceride and VLDL levels in the fish oil group decreased significantly (by about 9 per cent) while they increased significantly (by about 12 per cent) in the control group. There were no changes in total or low-density-lipoprotein levels in either group. Extensive tests (oral glucose tolerance, hyperglycemic and hyperinsulemic clamps) were done to evaluate the effect of fish oil supplementation on glucose control. No adverse effects were found. An editorial accompanying the research report concludes that fish or fish oil is useful in the prevention of vascular disease in diabetics. Patients with diabetes should eat fish two to three times a week or, as an alternative, supplement with two to three one gram capsules of fish oil per day.
Toft, Ingrid, et al. Effects of n-3 polyunsaturated fatty acids on glucose homeostasis and blood pressure in essential hypertension. Annals of Internal Medicine, Vol. 123, No. 12, December 15, 1995, pp. 911-18
Connor, William E. Diabetes, fish oil, and vascular disease. Annals of Internal Medicine, Vol. 123, No. 12, December 15, 1995, pp. 950-52
Qigong effective in treatment of many illnesses
SAN FRANCISCO, CALIFORNIA. Qigong is an integral part of Traditional Chinese Medicine and has been used for over 3,000 years to improve health and achieve longer life. The types of qigong used for healing and health maintenance involve meditation, breathing exercises, and physical movements. It is estimated that 60 million Chinese practice qigong daily. Reports of long-term scientific studies of the medical benefits of qigong are beginning to appear. Researchers at the Shanghai Institute of Hypertension recently released the results of a 30-year study of the benefits of qigong in combating hypertension. Their investigation involved 242 patients with high blood pressure who were randomly assigned to one of two groups. One group of 122 patients, the qigong group, performed Yan Jing Yi Shen Gong for 30 minutes twice a day; the other group of 120 patients was used as a control group. Both groups received standard drug therapy to control blood pressure. At the end of the 30-year period 32.5 per cent of the members of the control group had died from a stroke compared to only 15.6 per cent in the qigong group. The researchers also found that the blood pressure of the qigong group stabilized over the study period whereas that of the control group kept increasing. Required dosages of anti-hypertensive drugs decreased for the qigong group and were completely eliminated for 30 per cent of the patients. Required drug dosages for members of the control group generally increased throughout the study period.
The regular practice of qigong has also been found to increase bone density in men, to reverse the unfavourable shift in the production of sex hormones caused in aging, to improve heart function, and to effectively combat many of the side effects of cancer. Studies have also shown that drug therapy combined with qigong exercises is more effective than drug therapy on its own.
Sancier, Kenneth M. Medical applications of qigong. Alternative Therapies, Vol. 2, No. 1, January 1996, pp. 40-46
Relaxation therapy controls high blood pressure
TAIPEI, TAIWAN. Hypertension (diastolic blood pressure of 90 mm Hg or higher or systolic pressure of 140 mm Hg or higher) is widespread in northern Taiwan. A recent survey found that 27.2 per cent of males and 13.6 per cent of females suffer from this condition. A team of researchers from the National Taiwan University and the University of Hawaii now reports that relaxation techniques, frequent blood pressure measurements, and educational techniques are all effective in controlling hypertension. Their experiment involved 590 patients. The patients were randomly assigned to practise relaxation techniques at home, to have frequent, routine blood pressure measurements by health professionals, to read information packages about hypertension control or to receive no treatment (control group). The relaxation techniques involved one-on-one instruction sessions, taped messages of progressive relaxation procedures, and encouragement to perform Buddhist meditation. At the end of the two-month test period the average drop in systolic pressure in the relaxation group was 11 mm Hg and the drop in diastolic pressure was 4.7 mm Hg greater than in the control group. The patients who participated in the frequent blood pressure measurement program also lowered their pressure significantly as did the self-learning group. Almost 50 per cent of the members of the relaxation and self-learning groups achieved a drop in systolic pressure of 10 mm Hg or more and a drop in diastolic pressure of 5 mm Hg or more as a result of the program.
Yen, Lee-Lan, et al. Comparison of relaxation techniques, routine blood pressure measurements, and self-learning packages in hypertension control. Preventive Medicine, Vol. 25, No. 3, May/June 1996, pp. 339-45
Blood pressure drugs increase risk of heart attack
MALMOE, SWEDEN. It is generally accepted practice to treat people with high blood pressure with antihypertensive drugs in order to prevent heart attacks (myocardial infarctions). This despite the fact that clinical trials and recent population studies have both raised serious questions about the effectiveness of antihypertensive drugs in reducing the incidence of heart attacks. Nevertheless, the prescription of antihypertensive drugs for the prevention of heart attacks continues and there is an increasing trend to prescribe them for people having only a marginal elevation above normal. Now Swedish researchers report that treating elderly men who have a diastolic blood pressure less than 90 mm Hg with antihypertensive drugs increases their risk of having a heart attack by a factor of four. The study involved 484 Swedish men born in 1914. The men were first examined in 1969-70 and again in 1982-83. They were followed-up until December 31, 1992. In 1969-70 only about 3 per cent of the men were taking antihypertensive drugs, in 1982-83 over 23 per cent were doing so. Thirty-six men (13 per cent) with a diastolic pressure below 90 mm Hg were taking antihypertensive drugs while 231 men were not.
During the follow-up period the incidence of heart attacks in the men taking antihypertensive drugs was 3.9 times greater than among the men not taking blood pressure medication. This significantly increased risk remained even when the data was adjusted for the presence of heart disease, diabetes, smoking, high cholesterol, etc. The risk of having a heart attack among men with a diastolic blood pressure greater than 90 mm Hg was twice as high among men taking antihypertensive drugs; however, this increased risk largely disappeared when other cardiovascular risk factors were taken into account. The researchers conclude that treating men with a diastolic blood pressure of 90 mm Hg or less with antihypertensive drugs significantly increases their risk of having a heart attack.
Merlo, Juan, et al. Incidence of myocardial infarction in elderly men being treated with antihypertensive drugs: population based cohort study. British Medical Journal, Vol. 313, August 24, 1996, pp. 457-61
Popular hypertension drug is dangerous
NEW ORLEANS, LOUISIANA. An international team of medical researchers strongly recommend that the use of short-acting nifedipine be abandoned as a treatment for emergencies involving hypertension. Nifedipine capsules have, over the past two decades, become a very popular treatment option in emergency situations brought on by high blood pressure. It is widely used in hospitals and doctors' offices to swiftly lower an excessively high blood pressure brought on by such conditions as renal failure and pregnancy-induced hypertension. The popularity of short-acting nifedipine has continued despite the fact that its use has been linked to serious adverse effects such as stroke, heart attacks, arrhythmias, foetal distress, uncontrollable fall in blood pressure, and even death. The drug has never been approved by the Food and Drug Administration (FDA) for use in hypertensive emergencies. It is often given in the form of sublingual capsules that the research team found to be next to useless unless swallowed. Apparently the drug is only absorbed in the intestine not in the mouth. The use of short-acting nifedipine for hypertensive emergencies was condemned as early as 1985 by the Cardiorenal Advisory Committee of the FDA. The committee concluded that the use of the drug should be abandoned because it is neither safe nor efficacious. The researchers believe that the reason short-acting nifedipine is still being used to treat hypertensive emergencies is that the manufacturers of the drug have not informed physicians that it is highly dangerous. The research team points out that while the approval of a drug is usually rapidly brought to the attention of physicians, the denial of approval because of lack of efficacy or safety concerns is not. NOTE: The concerns about short-acting nifedipine do not apply to time-release versions of the drug (Procardia XL, Adalat CC).
Grossman, Ehud, et al. Should a moratorium be placed on sublingual nifedipine capsules given for hypertensive emergencies and pseudoemergencies? Journal of the American Medical Association, Vol. 276, No. 16, October 23/30, 1996, pp. 1328-31
Sour milk reduces blood pressure
TOKYO, JAPAN. Calpis sour milk has been used traditionally in Japan for many years. It is prepared by fermenting skim milk with a starter culture containing Lactobacillus helveticus and Saccharomyces cerevisiae. The fermented milk contains about 0.7 billion L. helveticus and 2.5 million S. cerevisiae cells per millilitre. Researchers at the Kyorin University School of Medicine have discovered that Calpis sour milk is effective in lowering blood pressure in patients with hypertension. Their experiment involved 30 hypertensive patients, 26 of which were receiving antihypertensive medication such as calcium antagonists, beta-blockers, diuretics, and ACE inhibitors. Seventeen of the patients were fed 95 ml of Calpis sour milk daily for an eight-week period. The remaining 13 patients were given a placebo sour milk prepared by adding lactic acid to skim milk. At the end of the trial period the systolic blood pressure in the Calpis milk group had decreased by an average of 14.1 mm Hg and diastolic pressure by 6.9 mm Hg. No significant blood pressure changes were observed in the placebo group. The blood pressure decreases in the Calpis milk group remained four weeks after the end of treatment. The researchers conclude that daily supplementation with sour milk is a useful and practical way of reducing blood pressure in patients with hypertension. NOTE: This work was done in cooperation with Calpis Food Industry Co., the manufacturer of Calpis sour milk.
Hata, Yoshiya, et al. A placebo-controlled study of the effect of sour milk on blood pressure in hypertensive subjects. American Journal of Clinical Nutrition, Vol. 64, November 1996, pp. 767-71
Potassium supplementation lowers blood pressure
BALTIMORE, MARYLAND. Researchers at the Johns Hopkins University School of Medicine have come out in favour of using supplementation with potassium in the treatment and prevention of hypertension (high blood pressure). A group of seven medical researchers reviewed 33 randomized, controlled supplementation trials involving over 2600 participants. They conclude that potassium supplementation is effective in lowering both systolic and diastolic blood pressure. The average observed decrease in hypertensive patients was 4.4 mm Hg and 2.5 mm Hg for systolic and diastolic pressure respectively. In people with normal blood pressure the observed decreases were 1.8 mm and 1.0 mm. The amount of elemental potassium used in the studies varied from 60 mmol (2.5 grams) to 120 mmol (5.0 grams) daily. Sixty mmol of potassium is equivalent to 4.5 grams of potassium chloride, 6 grams of potassium bicarbonate or 20 grams of potassium citrate. Oral potassium supplementation appeared to be well tolerated in all the studies examined. The researchers conclude that potassium supplementation "should be considered as part of recommendations for prevention and treatment of hypertension." Potassium supplementation is particularly important in people who are unable to reduce their intake of sodium.
Whelton, Paul K., et al. Effects of oral potassium on blood pressure. Journal of the American Medical Association, Vol. 277, May 28, 1997, pp. 1624-32
Combination diet lowers blood pressure
BALTIMORE, MARYLAND. High blood pressure (hypertension) is a major problem in the United States. It is estimated that 24 per cent of all American adults (about 43 million people) have high blood pressure, i.e. systolic pressure greater than 120 mm Hg and diastolic pressure greater than 80 mm Hg. Among older adults the proportion of people with hypertension is substantially higher. It is clear that diet affects blood pressure. Vegetarians, for example, tend to have lower blood pressures than non-vegetarians. Now researchers at the Johns Hopkins Medical School report that a diet rich in fruits, vegetables and low-fat dairy products is highly effective in lowering blood pressure. Their study involved 459 adults with systolic blood pressures below 160 mm Hg and diastolic pressures between 80 and 95 mm Hg. For the first three weeks of the experiment the participants were fed a control diet typical of the average diet in the United States (high in fat, low in fruits, vegetables, and dairy products). They were then randomly assigned to three groups. One group continued on the control diet, another group consumed a diet similar to the control diet except it provided more fruits and vegetables and less sweets and snacks, and the third group received a combination diet with reduced amounts of fats and cholesterol and increased amounts of fruits, vegetables and low-fat dairy foods. The calorie content of all diets was identical as was the sodium content at about three grams per day.
After eight weeks on the three diets the participants' blood pressures were again measured. The combination diet resulted in an average (mean) drop in systolic and diastolic blood pressure of 5.5 mm Hg and 4.0 mm Hg respectively when compared to the control diet. The fruits and vegetables diet (modified control diet) produced a drop in systolic and diastolic blood pressure of 2.8 mm Hg and 1.1 mm Hg respectively. The reduction in blood pressure began to take effect within two weeks and was maintained for the next six weeks. The combination diet provided a daily intake of saturated fat of seven per cent of energy, a potassium intake of 4.4 g/day, magnesium 480 mg/day, and calcium 1265 mg/day. In contrast, the control diet provided a saturated fat intake equalling 14 per cent of energy, potassium 1.89 g/day, magnesium 176 mg/day, and calcium 443 mg/day. The researchers conclude that the combination diet may help reduce blood pressure and could serve as an effective alternative to drug therapy in people with mild (stage 1) hypertension.
Appel, Lawrence J., et al. A clinical trial of the effects of dietary patterns on blood pressure. New England Journal of Medicine, Vol. 336, April 17, 1997, pp. 1117-24
L-arginine and heart disease
STANFORD, CALIFORNIA. The inside of blood vessels is lined with a layer of single cells called the endothelium. Among other functions, the endothelium produces nitric oxide that serves to relax (vasodilate) the blood vessels so as to facilitate the flow of blood. It is now generally accepted that many heart problems involve a dysfunction of the endothelial vasodilator mechanism. Antioxidants, estrogen, exercise, folic acid, and fish oils can in a number of cases, reverse this dysfunction. Now researchers at the Stanford University School of Medicine report that supplementation with the amino acid L-arginine is highly effective in reversing endothelial dysfunction. It has been established that L-arginine is the precursor for endothelium-derived nitric oxide (EDNO). EDNO, in turn, is a potent vasodilator and inhibits platelet aggregation and the adherence of circulating blood cells to blood vessel walls. L-arginine administration, either orally or intravenously, has been found useful in preventing and reversing atherosclerosis, in increasing coronary blood flow in heart disease patients, in alleviating intermittent claudication, and in improving functional status of heart failure patients. L-arginine infusions have been found to lower blood pressure and to inhibit restenosis (reclosing of arteries) after balloon angioplasty. The most common used dosage of L-arginine is between six and thirty grams per day (113 references).
Maxwell, Andrew J. and Cooke, John P. Cardiovascular effects of L-arginine. Current Opinion in Nephrology & Hypertension, Vol. 7, January 1998, pp. 63-70