j’s blog

MedlinePlus: Potassium, in Any Form, Lowers Blood Pressure

NEW YORK (Reuters Health) - Potassium citrate has similar blood pressure-lowering effects as the best-studied potassium compound, potassium chloride, according to a UK study

In comments to Reuters Health, Dr. Graham A. MacGregor said the important role of potassium in regulating blood pressure has been demonstrated in carefully controlled studies using potassium chloride and inactive “placebo” tablets. But it has not been clear, until now, how far other potassium salts lowered blood pressure.

“These results support other evidence for an increase in potassium intake and indicate that potassium does not need to be given in the form of chloride to lower blood pressure,” MacGregor and colleagues from St. George’s Hospital Medical School in London write in the American Heart Association’s journal Hypertension.

“Increasing the consumption of foods high in potassium is likely to have the same effect on blood pressure as potassium chloride,” the researches say.

They compared the effects on blood pressure of potassium chloride or potassium citrate in 14 adults with hypertension — that is, with blood pressure readings above 140/90. The participants took one compound for 1 week, waited a week, and then took the other for a week.

Average blood pressure at the start of the study was 151/93. It fell significantly to 140/88 with potassium chloride and to 138/88 mm Hg with potassium citrate.

“Our short-term study shows that potassium citrate is as effective as potassium chloride, and this supports the evidence that the main effect of increasing fruit and vegetable intake on blood pressure is due to the increase in potassium intake,” MacGregor said.

SOURCE: Hypertension, April 2005.

MedlinePlus: Poor Blood Pressure Control Ups Stroke Risk

NEW YORK (Reuters Health) - About half of all first-time strokes in patients being treated for high blood pressure result from the pressure not being adequately controlled, Swedish researchers report. Older age, diabetes, and smoking also raise the risk of stroke in these patients.

The study, published in the medical journal Stroke, included nearly 28,000 men and women aged 45 to 73 living in Malmo.

Sixty percent of patients had high blood pressure, but only 23 percent of them were being treated. Moreover, among those receiving treatment, nearly 90 percent had pressures above recommended limits, according to Dr. Cairu Li of Malmo University Hospital and colleagues.

Two-thirds of patients with inadequately controlled blood pressure were on single-drug regimens, the researchers note, with beta-blocker type drugs being the most commonly used overall.

During follow-up, which averaged six years, 137 strokes occurred among the patients with high blood pressure. The researchers found that 45 percent of the stroke risk could be attributed to inadequately controlled blood pressure.

While there were only minor initial differences in survival between patients with controlled or poorly controlled blood pressure, these differences increased over time.

“Adequate (blood pressure) control may prevent a substantial proportion of first-ever stroke among” patients treated for high blood pressure, the researchers conclude.

SOURCE: Stroke, April 1, 2005.

High Blood Pressure Common in the Overweight

Obese patients often have increased blood pressure, researchers report. Also, many do not experience a nighttime dip in blood pressure as occurs in normal-weight individuals, and this could lead to heart damage.

Dr. Vasilios Kotsis from the University of Mississippi Medical Center in Jackson and colleagues studied the relationship between body mass index

Only 35 patients were underweight, whereas 1,057 were normal weight, 1,299 were overweight, and 825 were obese. The subjects wore a monitor to record their blood pressure over a 24-hour period.

Blood pressure increased significantly with increasing BMI, the team reports in the American Heart Association‘s journal Hypertension.

“Obese individuals had increased 24-hour, daytime and nighttime blood pressure levels compared to non-obese individuals,” Kotsis commented to Reuters Health. Moreover, blood pressures during the night were more likely to be as high as during the day in overweight and obese individuals.

Obesity-induced hypertension is “one of the most significant” conditions related obesity, Kotsis noted.

“Primary care doctors must focus on obesity-induced hypertension in order to prevent future cardiovascular complications such as heart failure in their obese patients,” he said. “Body weight reduction, lifestyle modifications and antihypertensive treatment could reduce obese patients‘ cardiovascular risk.”

SOURCE: Hypertension, April 2005

temporarily, in rats

Electroacupuncture can lower blood pressure

Dr. John C. Longhurst, director of the Susan Samueli Centre for Integrative Medicine at UC Irvine ,and researchers, have found that acupuncture using low levels of electrical stimulation can lower elevations in blood pressure by as much as 50 percent.

Acupuncture, an ancient form of Chinese medicine, involves inserting needles at specific points on the body to help cure disease or relieve pain.

The study, which appears in the March issue of the Journal of Applied Physiology, found that electroacupuncture treatments on rats provided temporary relief from the conditions that raise blood pressure during hypertensive states and they believe the treatment has the potential to become part of a therapeutic regimen for long-term care of hypertension and other cardiovascular ailments in people.

Longhurst says the study suggests that acupuncture can be an excellent complement to other medical treatments, especially for those treating the cardiac system and the Western World is waiting for a clear scientific basis for using acupuncture. He hopes the research will lead to the integration of ancient healing practices into modern medical treatment.

Longhurst and his UCI colleagues had already identified in previous studies, at the cellular and molecular level, how acupuncture excites brain cells to release neurotransmitters that either inhibit or heighten cardiovascular activity.

In this later study they found that when an acupuncture needle was inserted at specific sites on the wrist, inside of the forearm or leg, it triggered the release of opioid chemicals in the brain that reduce excitatory responses in the cardiovascular system. This decreases the heart’s activity and its need for oxygen, which in turn can lower blood pressure, and promotes healing for a number of cardiac ailments, such as myocardial ischemia ( insufficient blood flow to the heart ) and hypertension.

The team first applied acupuncture to specific points on the forelimb of test rats with artificially elevated blood pressure rates; these same sites on humans are on the inside of the forearm slightly above the wrist. The acupuncture alone had no effect on blood pressure.

But when they added electrical stimulation to the acupuncture treatment by running an electrical current through the needles, low frequencies lowered increased blood pressure by as much as 40 to 50 percent. Overall, the researchers found that a 30-minute treatment reduced blood pressure rates in the test rats by 25 mmHg - with the effect lasting almost two hours.

Longhurst, a cardiologist who is also the Lawrence K. Dodge Professor in Integrative Biology says this treatment is only effective on elevated blood pressure levels, such as those present in hypertension, and the treatment has no impact on standing blood pressure rates. Their goal is to help establish a standard of acupuncture treatment that can benefit everyone who has hypertension and other cardiac ailments.

Longhurst and his colleagues are currently testing this electroacupuncture treatment method in an ongoing human study.

Drs. Wei Zhou, Liang-Wu Fu, Stephanie C. Tjen-A-Looi and Peng Li of the UCI Department of Medicine participated in the study, which was funded by the National Heart, Lung and Blood Institute, and the Larry K. Dodge Endowed Chair.

http://www.uci.edu

Concord Grape Juice Lowered Blood Pressure in Preliminary Clinical Study; Also Lowered BP, Cholesterol and Inhibited Atherosclerosis in Lab Study

SAN DIEGO, Calif.–(BUSINESS WIRE)–April 4, 2005–

Concurrent Studies Point to Positive Effect on Blood Pressure, Other Cardiovascular Risk Factors

Three current studies point to a positive effect of Concord grape juice consumption on blood pressure, adding to the growing body of scientific evidence that drinking Concord grape juice assists with healthy cardiovascular function. In a preliminary study published in the current issue of Biofactors, drinking Concord grape juice lowered the blood pressure of mildly hypertensive men by almost seven points.

In addition, two laboratory studies presented today at the Experimental Biology meeting in San Diego complement the Biofactors study; one offers a possible mechanism of action for the blood pressure effect, the other shows similar effects in a laboratory model that closely mimics human cardiovascular behavior.

The Biofactors study tested 40 Korean men with mild hypertension (blood pressure averaging 146/94 mm Hg). In a double-blinded study, half drank Concord grape juice for eight weeks while the other half drank a calorie-matched placebo drink. At the end of the study, the grape juice group had a significant decline of 7.2 mm systolic and 6.2 diastolic compared to baseline. The placebo group saw a lesser decrease in both measurements.

“It is exciting to see complementary research presented at the same time on a topic as important as blood pressure,” explains John D. Folts, Ph.D., Professor of Medicine at the University of Wisconsin School of Medicine and an author of one of the laboratory studies. “Nonetheless, we need to be cautious when interpreting preliminary data such as from the Korean study. For example, the placebo group also saw a small drop in blood pressure, although not a significant one, and while the Concord grape juice group’s numbers were significant compared to baseline, they did not reach significance when compared group to group. A larger trial will be necessary to confirm the blood pressure lowering effect.

“On the other hand, our study also saw the lowering of blood pressure in a laboratory model, as well as the lowering of cholesterol and the inhibition of atherosclerosis–all significant versus a placebo group and all of which adds credence to the Korean study, suggesting that the Concord grape juice is functioning on a number of levels in the cardiovascular system.”

In the second laboratory study presented at Experimental Biology, researchers from the Louis Pasteur University in Strasbourg, France, led by Valerie Schini-Kerth, Ph.D., found that Concord grape juice produced arterial relaxation by increasing the activity of a nitric oxide synthase in cells lining the arterial wall.

“Dr. Schini-Kerth’s data certainly suggest a mechanism whereby Concord grape juice-based polyphenols may reduce blood pressure by encouraging the relaxation of the artery wall,” notes Dr. Folts. “Previous studies by my group have shown that Concord grape juice enables the brachial arteries to expand to accommodate increased blood flow. Likewise, other researchers have shown that nitric oxide production from platelets may well be the mechanism behind Concord grape juice’s ability to reduce the tendency for the blood to clot. So there are a lot of supporting data in this area.”

The U.S. National High Blood Pressure Education Program estimates that lowering systolic blood pressure by five points would results in a 14% drop in deaths from stroke, a 9% drop in heart disease deaths, and a 7% drop in overall mortality.

Experts also note that all foods should be consumed in moderation, and that a healthy diet should include a wide range of colorful fruits and vegetables, and complemented by regular physical exercise.

The Concord grape juice for these studies was provided by Welch Foods Inc. The laboratory studies were partially supported by grants from Welch Foods Inc.

IOS Press - Article
Concord grape juice supplementation reduces blood pressure in Korean hypertensive men: Double-blind, placebo controlled intervention trial

Yoo Kyoung Park A1, Jung-Shin Kim A2, Myung-Hee Kang A2

A1 Department of Medical Nutrition, Kyunghee University, 1 Hoekidong, Dongdaemoonku, Seoul 130-701, South Korea
A2 Department of Food and Nutrition, Hannam University, 133 Ojeong-dong, Daedeok-gu, Daejeon, Korea

Abstract:

Many of the flavonoids found in grapes and grape products such as juice or wine have been known to exert antioxidant, anti-inflammatory, platelet inhibitory and arterial relaxing effects either in vitro, in animal studies and in human trials. This study was designed to test the effect of Concord grape juice consumption on altering blood pressure in hypertensive patients. Forty subjects were given 5.5 ml/kg body weight/day of either Concord grape juice (CGJ) or a calorie-matched placebo drink every day for 8 weeks. Blood pressure (BP) was measured on weeks 0, 4 and 8. Compared to baseline, in the CGJ group systolic BP was reduced on average by 7.2 mm Hg (p = 0.005) and diastolic BP was reduced on average by 6.2 mm Hg (p = 0.001) at the end of 8 weeks. Comparable changes in the group getting the placebo product were -3.5 mm Hg (NS) and -3.2 mm Hg (p = 0.05) Consuming Concord grape juice, which is high in polyphenolic compounds, may favorably affect BP in hypertensive individuals.

Yahoo! News - Cranberries May Help Keep Arteries Clear

SUNDAY, April 3 (HealthDay News) — In a study in pigs, cranberry juice helped relax blood vessels clogged with high blood cholesterol and narrowed by atherosclerosis, according to a study by researchers at the University of Wisconsin School of Veterinary Medicine.

The pigs used in the study had a genetic defect — familial hypercholesterolemia (FH) — that causes them to develop high blood cholesterol, which in turn causes atherosclerosis and vascular dysfunction. However, some of these pigs were fed cranberry juice powder, made from whole cranberries, for six months and their blood vessels started to function like those in normal pigs.

FH pigs that weren’t fed the cranberry powder had much less vascular relaxation than either normal pigs or the FH pigs that ate the cranberry powder.

The study was to be presented Sunday at the Congress of the International Union of Physiological Sciences, in San Diego.

“Since the abnormal functioning of blood vessels is an important component of heart disease, finding ways to improve vascular function in patients with high cholesterol and atherosclerosis is critical to helping protect these patients from consequence such as heart attack or stroke,” study lead researcher Kris Kruse-Elliott said in a prepared statement.

“The value of fruits and vegetables in our diet has recently been an area of intense research, and studies like this help us to understand the specific mechanisms by which the nutrients we consume can protect against heart disease,” she said.

The research team now plans to determine which components of cranberries are most important in improving vascular relaxation.

More information

The American Heart Association has more about atherosclerosis.

Study: Acupuncture reduces hypertension - (United Press International)

Irvine, CA, Mar. 29 (UPI) — Acupuncture combined with a mild electrical current temporarily reduces high blood pressure in rats, University of California at Irvine researchers said.

The 3,000-year-old medical procedure invented by the Chinese involves inserting needles at specific points on one’s body to fight disease or relieve pain.

Researchers targeted specific areas of rats’ bodies and found electrically enhanced acupuncture temporarily reduces elevated blood pressure as much as 50 percent.

“This study suggests that acupuncture can be an excellent complement to other medical treatments, especially for those treating the cardiac system,” said study leader John Longhurst of the university’s Susan Samueli Center for Integrative Medicine.

“The Western world is waiting for a clear scientific basis for using acupuncture, and we hope that this research ultimately will lead to the integration of ancient healing practices into modern medical treatment,” Longhurst said.

The study appears in the March issue of the Journal of Applied Physiology.

Yahoo! News - When It Comes to Chocolate, Order Dark, Not White

Mon Mar 21

By Alison McCook

NEW YORK (Reuters Health) - Dark chocolate — but not white chocolate - may help reduce blood pressure and boost the body’s ability to metabolize sugar from food, according to the results of a small study.

Investigators from the University of L’Aquila in Italy found that after eating only 100 grams, or 3.5 ounces, of dark chocolate every day for 15 days, 15 healthy people had lower blood pressures and were more sensitive to insulin, an important factor in metabolizing sugar.

In contrast, eating roughly the same amount of white chocolate for the same period of time did not affect either blood pressure or insulin sensitivity.

This is not the first study to demonstrate potential health benefits of dark chocolate, which contains high levels of a kind of antioxidant called flavonoids. Research shows that flavonoids that can help maintain a healthy heart and good circulation and reduce blood clotting, which can lead to heart attacks and stroke.

Dr. Claudio Ferri and co-investigators explained that flavonoids help the body by neutralizing potentially cell-damaging substances known as oxygen-free radicals, which are a normal byproduct of metabolism.

However, despite dark chocolate’s apparent benefits, Ferri urges caution when interpreting the results. Dark chocolate contains antioxidants, but also a lot of fat and calories, Ferri said, and people who want to add some chocolate to their diet need to subtract an equivalent amount of calories by cutting back on other foods, to avoid weight gain.

He added that each 100 grams of dark chocolate contains roughly 500 calories.

Other research validates that when it comes to chocolate, type does matter. One study found that eating milk chocolate did little to raise antioxidant levels in the blood, perhaps because milk interferes with the absorption of antioxidants from chocolate.

Another study showed that elderly people with high blood pressure experienced a drop in pressure after eating dark chocolate bars, but not white chocolate, which contains no flavonoids.

Ferri and colleagues asked 7 men and 8 women, all healthy, to eat 100 grams of dark chocolate or 90 grams of white chocolate every day for 15 days. The subjects consumed no chocolate for the next 7 days and then switched to the other chocolate type for 15 days.

Ferri’s team found that after eating dark chocolate, participants’ blood pressure decreased, and they showed improvements in insulin sensitivity, meaning they were better able to metabolize glucose (sugar), according to the report in the American Journal of Clinical Nutrition (news - web sites).

“The identification of healthy foods and the understanding of how food components influence normal physiology will help to improve the health of the population,” Dr. Cesar G. Fraga of the University of California, Davis, notes in an accompanying editorial.

SOURCE: American Journal of Clinical Nutrition, March 2005.

The Telegraph Online

Taking folic acid supplements - along with eating more foods high in folate, such as oranges, leafy greens and fortified grains - might help some women reduce their risk of hypertension.

The possible link between folate consumption and lower blood pressure was found by researchers culling results from questionnaires returned by nurses participating in an ongoing study of women’s health habits. The results were from an eight-year period in the 1990s. The report was published in the Jan. 19 issue of the Journal of the American Medical Association.

Among younger women, those who took more than 1,000 micrograms of folate daily had 6.7 cases of hypertension per 1,000 women, compared with 14.8 cases per 1,000 women in those who took fewer than 200 micrograms - suggesting that eight women per 1,000 might have avoided high blood pressure if they had consumed more folate. Among older women, taking more than 1,000 micrograms per day of folate appeared to prevent about six cases of hypertension per 1,000 women.

But the researchers at Brigham and Women’s Hospital in Boston cautioned that they weren’t ready to recommend that women start increasing their folate intake.

ABC News: Dietary Fiber Fights High Blood Pressure

Health Library:

FRIDAY, March 4 (HealthDay News) — A high-fiber diet may help reduce high blood pressure and may even improve healthy blood pressure levels, a new study finds.

Researchers at Tulane University analyzed data on almost 1,500 adults in more than two dozen studies and found that eating between about 7 to 19 grams of fiber a day led to a reduction in both systolic and diastolic blood pressure.

“We performed a comprehensive analysis of data from 25 clinical trials and all the data pointed to one strong conclusion — adding fiber to a person’s diet has a health effect on their blood pressure,” lead author and medical student Seamus Whelton said in a prepared statement.

This type of study, called a meta-analysis, combines data from a number of studies to spot trends that otherwise might not be observed. “Analyzing a large number of studies lends strength to the conclusions of clinical trials that involved too few participants [individually] to show an effect of dietary fiber on blood pressure,” Whelton explained.

He and his colleagues recommend that people eat fruits and vegetables in order to increase their intake of dietary fiber. Other changes in diet and exercise can also help reduce blood pressure and people should discuss these with their doctor, Whelton added.

More information

The U.S. National Heart, Lung, and Blood Institute has more about how to lower your blood pressure.

So you say you want to learn how cannibals shrink heads, but don’t want to have to buy a large pot and slave over a hot fire? Well here’s something you might want to consider. There’s an easier way, but, there’s a catch. Everyone should get checked for High Blood Pressure and treat it if they have it or take steps to prevent it if the don’t. Even young children sometimes have Hypertension, so everyone should get checked regularly.

Scoop: Hypertension Accelerates Brain Shrinkage

Hypertension Accelerates Brain Shrinkage
Monday, 28 February 2005
By Marietta Gross

Scoop Report: The normal aging process of the brain is being accelerated by high blood pressure, according to a long term survey by the Max-Planck-Institute in Berlin, Germany. Seventy two healthy adults aged between 20 and 77 underwent a magnetic resonance tomography every five years. “Hypertension is obviously even more dangerous than previously assumed. Perhaps it increases the risk for Alzheimer’s Disease”, explains study author Ulman Lindenberger.

According to the study, the human brain starts to shrink around middle age. Women are at the same risk as men and the brain volume made no difference. But the process was individually variable.

Scientists have found brain shrinkage does have gender differences associated with hypertension, and results suggest this is independent from treatment. Patients with high blood pressure showed an extreme shrinkage of memory relevant regions such as the hippocampus. The longer the patients had been suffering from high blood pressure, the more intensive the effect of shrinkage was.

Currently, Lindenberger and his colleagues are examining the connection between changes in the brain and coinstantaneous changes in psychological performance tests.