“Potassium and sodium are like peas in a pod, except they’re in opposite pods

— Paul Whelton, epidemiologist and president and chief executive officer of the Loyola University Health System in Chicago

Foods that are high in potassium and potassium supplements may be helpful in the prevention and treatment of hypertension or high blood pressure.

Researchers recently measured average potassium and salt intake in a two-phase trial, known as the Trials of Hypertension Prevention (TOHP). The first trial lasted 18 months, and the second trial 36 months. The researchers followed 2,974 individuals, aged 30-to-54 for a period of 10 to 15 years to determine who develops cardiovascular disease.

Researchers found that study participants with high salt content in urine samples, collected intermittently throughout the trials, had a 20% greater risk for stroke, heart attack, and other forms of heart disease. Those with the highest sodium-to-potassium ratios in their urine had a 50% increased risk of heart disease compared to the lowest potassium to salt ratios in their urine.

Potassium has the opposite effect of sodium in lowering blood pressure, making potassium in the diet important for preventing cardiovascular disease by lowering blood pressure.

In 1997 researchers studied the effect of supplementation with oral potassium on blood pressure in humans. Thirty-three randomized controlled trials (2609 participants) in which potassium supplementation was the only difference between the intervention and control conditions. An extreme effect of potassium in lowering blood pressure was noted in Trial One. Ignoring the dramatic Trial One, potassium supplementation was still associated with a significant reduction in average systolic and diastolic blood pressure.

Systolic dropped an average 3.11 mm Hg (-1.91 to -4.31 mm Hg) and diastolic pressure dropped an average 1.97 mm Hg (-0.52 to -3.42 mm Hg). Effects of treatment appeared to be enhanced in studies in which participants were concurrently exposed to a high intake of sodium.

The scientists concluded that low potassium intake may play an important role in the occurrence of high blood pressure. Increased potassium intake should be considered as a recommendation for prevention and treatment of hypertension, especially in those who are unable to reduce their intake of sodium.

FOODS HIGH IN POTASSIUM (with links to NutritionData.com):
Bananas
Parsley
Spinach
Chives
Potato
Raisins
Orange Juice

Sources:
PRESS RELEASE Loyola University Health — loyolamedicine.org
Cutting Salt Isn’t the Only Way to Reduce Blood Pressure

Nancy R. Cook; Eva Obarzanek; Jeffrey A. Cutler; Julie E. Buring; Kathryn M. Rexrode; Shiriki K. Kumanyika; Lawrence J. Appel; Paul K. Whelton; for the Trials of Hypertension Prevention Collaborative Research Group. Joint Effects of Sodium and Potassium Intake on Subsequent Cardiovascular Disease: The Trials of Hypertension Prevention Follow-up Study. Arch Intern Med. 2009;169(1):32-40.

Whelton PK, He J, Cutler JA, Brancati FL, Appel LJ, Follmann D, Klag MJ. Effects of oral potassium on blood pressure. Meta-analysis of randomized controlled clinical trials. JAMA. 1997 May 28;277(20):1624-32

P. K. Whelton, J. He, J. A. Cutler, F. L. Brancati, L. J. Appel, D. Follmann and M. J. Klag
Welch Center for Prevention, Epidemiology and Clinical Research, The Johns Hopkins University School of Hygiene and Public Health, Baltimore, Md, USA.

It has been postulated that the loss of arterial compliance may precede cardiovascular diseases, and that arterial compliance is an important parameter to consider when evaluating arterial diseases such as essential hypertension (EH) and the effects of antihypertensive treatment. In all, 133 EH patients and 147 healthy subjects were enrolled in this study. Large arterial compliance (C1) and small arterial compliance (C2) were measured by the CVProfilor DO-2020 CardioVascular Profiling System. Thirty-five patients randomly received magnesium potassium supplementation (magnesium, 70.8 mg/d; potassium, 217.2 mg/d) for four weeks, and 32 patients received lacidipin (4 mg/d) as a control. Before and after the four weeks, blood pressure, C1, and C2 were measured. It was found that arterial compliance was significantly lower in EH patients compared with healthy subjects (C1: 12.53 +/- 0.33 vs. 15.63 +/- 0.30 ml/mmHg x 10, p < 0.01;C2: 3.79 +/- 0.17 vs. 5.69 +/- 0.25 ml/mmHg x 100, p < 0.01). On lacidipine, systolic and diastolic BP decreased 13.27 +/- 1.76 mm Hg and 6.33 +/- 1.55 mm Hg, and C1 and C2 compliance values increased 25.05% +/- 4.49% and 34.50% +/- 7.40%, respectively. On K+ and Mg2+ supplementation, systolic and diastolic BP decreased 7.83 +/- 1.87 mm Hg and 3.67 +/- 1.03 mm Hg, and C1 and C2 compliance values increased 12.44% +/- 4.43% and 45.25% +/- 6.67%, respectively. Decreases in systemic vascular resistance (mean arterial pressure divided by cardiac output) by 11.9% and 16.6 % (p < 0.01) were seen between the drug-induced changes, respectively. Both large arterial compliance and small arterial compliance were decreased in essential hypertension patients. In essential hypertension patients, magnesium and potassium supplementation could improve small arterial compliance, while lacidipine improved large arterial compliance significantly.

Source:
Wu G, Tian H, Han K, Xi Y, Yao Y, Ma A.   Potassium magnesium supplementation for four weeks improves small distal artery compliance and reduces blood pressure in patients with essential hypertension. Clin Exp Hypertens. 2006 Jul;28(5):489-97.

From PubMed.gov …

Extracts enriched in different polyphenolic families normalize increased cardiac NADPH oxidase expression while having differential effects on insulin resistance, hypertension, and cardiac hypertrophy in high-fructose-fed rats.

Insulin resistance and oxidative stress act synergistically in the development of cardiovascular complications. The present study compared the efficacy of three polyphenolic extracts in their capacity to prevent hypertension, cardiac hypertrophy, increased production of reactive oxygen species (ROS) by the aorta or the heart, and increased expression of cardiac NAD(P)H oxidase in a model of insulin resistance. Rats were fed a 60%-enriched fructose food and were treated once a day (gavage) for 6 weeks with 10 mL/kg of water only (F group) or the same amount of solution containing a red grape skin polyphenolic extract enriched in anthocyanins (ANT), a grape seed extract enriched in procyanidins and rich in galloylated procyanidins (PRO), or the commercial preparation Vitaflavan (VIT), rich in catechin oligomers. All treatments were administered at the same dose of 21 mg/kg of polyphenols. Our data indicate that (a) the ANT treatment prevented hypertension, cardiac hypertrophy, and production of ROS, (b) the PRO treatment prevented insulin resistance, hypertriglyceridemia, and overproduction of ROS but had only minor effects on hypertension or hypertrophy, while (c) Vitaflavan prevented hypertension, cardiac hypertrophy, and overproduction of ROS. All polyphenolic treatments prevented the increased expression of the p91phox NADPH oxidase subunit. In summary, our study suggest that (a) the pathogeny of cardiac hypertrophy in the fructose-fed rat disease involves both hypertension and hyperproduction of ROS, (b) polyphenolic extracts enriched in different types of polyphenols possess differential effects on insulin resistance, hypertension, and cardiac hypertrophy, and (c) polyphenols modulate the expression of NAD(P)H oxidase.

Source:
Al-Awwadi NA, Araiz C, Bornet A, Delbosc S, Cristol JP, Linck N, Azay J, Teissedre PL, Cros G.   Extracts enriched in different polyphenolic families normalize increased cardiac NADPH oxidase expression while having differential effects on insulin resistance, hypertension, and cardiac hypertrophy in high-fructose-fed rats. J Agric Food Chem. 2005 Jan 12;53(1):151-7.

Holding your breath during exercise (the Valsalva Maneuver) is bad for your heart and blood vessels because it causes unnecessary elevation of blood pressure, which could put you at risk of heart strain and stroke. Commonly personal trainers advise people to exhale during the concentric action of a repetition. According to the study, inhalation or exhalation  to concentric or eccentric action made little or no difference with respect to blood pressure elevation during the lift.  Inhalation during concentric action did show a slight increase in heart rate compared to exhalation during concentric action. Another study has shown that blood pressure during heavy lifting is higher during concentric action in a repetition — compared to eccentric action during a repetition, reporting systolic and diastolic blood pressures rose rapidly to extremely high values during the concentric contraction phase for each lift and declined with the eccentric contraction. This could be due to less effort required as the internal frictional affect in muscle during lowering of the weight in an eccentric action.

Effect of breathing techniques on blood pressure response to resistance exercise.

Linsenbardt ST, Thomas TR, Madsen RW Hammons Heart Institute, Springfield, MO.

Twenty novice male weight lifters performed resistance exercises using three different breathing techniques to determine the effects on blood pressure. Systolic and diastolic blood pressures were measured by an automated non-invasive method while subjects performed the single arm curl and double knee extension using the different breathing techniques. Performing the Valsalva manoeuvre (breath-holding) during either the single arm curl or double knee extension produced the highest blood pressure responses. Inhaling during the concentric phase of the exercise was associated with blood pressure elevations that were similar to the elevations observed with exhaling during the concentric phase. The heart rate response was slightly higher with inhalation. These results suggest that performing the Valsalva manoeuvre exaggerates the blood pressure response to resistance exercise. In addition, coupling inhalation with the concentric phase of the lift offers no cardiovascular advantage over coupling exhalation with the concentric phase of the lift.

Linsenbardt ST, Thomas TR, Madsen RW. Effect of breathing techniques on blood pressure response to resistance exercise. Br J Sports Med. 1992 Jun;26(2):97-100.

PMID: 1623367 [PubMed - indexed for MEDLINE]

The following study gives credence to the healthy and effective practice of ‘not holding you breath during exercise.’ During weightlifting, don’t forget to remind your training partner to breathe. And don’t forget to remind yourself to breathe during weightlifting.

Influence of breathing technique on arterial blood pressure during heavy weight lifting.

Department of Physical Medicine and Rehabilitation, Loma Linda University, CA 92354.

Arterial hypertension occurring during heavy resistance exercise may be a risk factor for stroke in healthy young adults. Any training method that ameliorates the pressor effect of exercise should reduce the risk of stroke. The objective of this study was to observe the influence of breathing technique on arterial blood pressure (BP) generated during heavy, dynamic weight lifting. BP was recorded in 10 male athletes by radial artery catheterization. Each subject then performed double-leg press sets at 85% and 100% of maximum. Each exercise was performed twice, once with closed glottis Valsalva, and then with slow exhalation during concentric contraction. The mean BP at 100% maximum with Valsalva was 311/284. The highest pressure recorded in an individual was 370/360. With slow exhalation, the mean BP was 198/175 when the same 100% maximum was lifted (p < .005). A reduced pressor response was also noted at 85% maximal lifting with slow exhalation. Arterial hypertension produced during heavy weight lifting with Valsalva is extreme and may be dramatically reduced when the exercise is performed with an open glottis (without Valsalva). It is concluded that heavy resistance exercise is safer when performed while the subject breathes with an open glottis.

Narloch JA, Brandstater ME. Influence of breathing technique on arterial blood pressure during heavy weight lifting. Arch Phys Med Rehabil. 1995 May;76(5):457-62.

PMID: 7741618 [PubMed - indexed for MEDLINE]

Exercise with resistance causes elevated blood pressure levels. The levels are temporary, but if they were noted in a resting individual, the doctor would send that individual to the emergency room for drug therapy to immediately lower the blood pressure. The following study of experienced body builders reports elevated blood pressure during weight lifting. The question that comes to mind is whether healthy, fit individuals have elastic vessels that tolerate temporary pressure increases that would put unhealthy individuals at risk of stroke or other vessel injury. A question also exists whether excessive pressures put healthy individuals at risk or bring injury to hidden anomalies in vessels. The authors of this study report that use of smaller muscles at near repetition max levels also bring large increases in blood pressure, which points out that even strenuous activities of daily living can cause elevated pressure. Other studies also address the concern of excessive pressure effect on the left ventricular wall of the heart.

Arterial blood pressure response to heavy resistance exercise.

MacDougall JD, Tuxen D, Sale DG, Moroz JR, Sutton JR.

The purpose of this study was to record the blood pressure response to heavy weight-lifting exercise in five experienced body builders. Blood pressure was directly recorded by means of a capacitance transducer connected to a catheter in the brachial artery. Intrathoracic pressure with the Valsalva maneuver was recorded as mouth pressure by having the subject maintain an open glottis while expiring against a column of Hg during the lifts. Exercises included single-arm curls, overhead presses, and both double- and single-leg presses performed to failure at 80, 90, 95, and 100% of maximum. Systolic and diastolic blood pressures rose rapidly to extremely high values during the concentric contraction phase for each lift and declined with the eccentric contraction. The greatest peak pressures occurred during the double-leg press where the mean value for the group was 320/250 mmHg, with pressures in one subject exceeding 480/350 mmHg. Peak pressures with the single-arm curl exercise reached a mean group value of 255/190 mmHg when repetitions were continued to failure. Mouth pressures of 30-50 Torr during a single maximum lift, or as subjects approached failure with a submaximal weight, indicate that a portion of the observed increase in blood pressure was caused by a Valsalva maneuver. It was concluded that when healthy young subjects perform weight-lifting exercises the mechanical compression of blood vessels combines with a potent pressor response and a Valsalva response to produce extreme elevations in blood pressure. Pressures are extreme even when exercise is performed with a relatively small muscle mass.

PMID: 3980383 [PubMed - indexed for MEDLINE]

Pauly DF, Pepine CJ. D-Ribose as a supplement for cardiac energy metabolism.
J Cardiovasc Pharmacol Ther. 2000 Oct;5(4):249-58.

The use of ribose use in patients with stable coronary artery disease improves time to exercise-induced angina and electrocardiographic changes.  Nucleotides (ATP, ADP, and AMP) are degraded and lost from the heart muscle, where the ability to resynthesize ATP is  limited by the availabilitgy of D-ribose — a necessary component of the adenine nucleotide structure.

During thallium imaging or dobutamine stress echocardiography, ribose is reported to help with detection of hybernating myocardium. Myocardial hybernation is a chronically developing area of subnormal contractility with metabolic switch to anaerobic glycolysis as an adaptation of the myocardium to chronic ischemia in an area of a stenotic artery.

Dunne L, Worley S, Macknin M. Ribose Versus Dextrose Supplementation, Association With Rowing Performance: A Double-Blind Study.
Clin J Sport Med. 2006 Jan;16(1):68-71.

Ribose is a monosaccharide.

Brody S. Blood pressure reactivity to stress is better for people who recently had penile-vaginal intercourse than for people who had other or no sexual activity. Biol Psychol. 2006 Feb;71(2):214-22.

Oxytocin, aka “pair bonding” hormone, may explain the calming effect.

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