Melatonin May Protect Brain After Stroke

NEW YORK – Melatonin, the hormone more commonly associated with jet lag and sleep cycles, may help protect the brain after a stroke, according to a new animal study.

Rats who received a dose of melatonin within two hours of a stroke experienced less tissue damage than rats who either received melatonin later or not at all.

Reducing tissue damage after a stroke can cut the overall amount of brain damage and help with recovery, study author Dr. Raymond Tak Fai Cheung said.

If these results apply to humans, melatonin could represent a new treatment for patients to protect the brain against stroke’s potentially life-threatening effects, said Cheung, who is based at Queen Mary Hospital in Hong Kong.

But Cheung cautioned that people should not believe that they are no longer in danger of stroke if they buy melatonin, which is commercially available.

Too many questions remained unanswered, he said, including how best to use the hormone against stroke in humans, and whether it even works in people. Many treatments that are successful in rats and mice never pan out for their human counterparts.

“Therefore, taking the usual oral dosage of melatonin may not affect (a person’s) chance of having a stroke, nor the severity of the stroke, Cheung said.

Melatonin is a hormone that is produced by the pineal gland in the brain when the body is exposed to light.

Previous research has shown the hormone can promote sleep and help regulate the body clock. Because melatonin is believed to help regulate sleep patterns, supplements have been touted as a treatment for sleep problems and jet lag.

Recently, investigators have uncovered evidence that the hormone may also protect the brain from stroke.

To investigate further, Cheung and his colleagues blocked blood flow in an artery feeding the brain — the most common cause of stroke — for three hours in a group of rats.

In one experiment, the researchers injected the rats with a single dose of melatonin either immediately, one hour, or three hours later.

In another experiment, the researchers injected rats with multiple doses of the same amount of melatonin, with the first dose occurring within three hours of stroke onset, and additional doses 24 and 48 hours later.

In the first experiment, Cheung and his colleagues found that one dose of melatonin decreased the amount of brain tissue damaged by stroke when administered immediately or one hour after stroke, but not three hours later.

In the second experiment, the authors found that multiple melatonin injections helped reduce the amount of brain tissue damage after stroke, relative to rats that received injections that did not contain the hormone, but only when the first injection was administered within two hours.

Much of the damage inflicted by stroke results from an overproduction of free radicals, particles that can inflict serious tissue damage, Cheung explained.

Melatonin is a potent scavenger of free radicals, a role that largely explains the hormone’s benefits in treating stroke, Cheung noted. “This is the main reason why melatonin protects the brain against stroke,” he said.

The next step, Cheung noted, is to investigate whether melatonin safely works in humans, and if so, how it should be administered.

“One needs to show that an oral or injectable preparation of melatonin can achieve an effective concentration in the blood of stroke patients, and the dose is safe in stroke patients before one can conduct clinical trials on its efficacy,” he said.

Funding for the current research was provided by the University of Hong Kong.

– Source: Reuters Health


Tea Is Proving Useful In Cutting The Risk Of Disease

Almost 300 tea studies were completed last year. Tea is also hot among consumers: U.S. sales rose from $1.84 billion in 1990 to about $5.03 billion in 2002, says a trade group. Americans have long preferred coffee over tea. Coffee may be good, but it’s increasingly hard to ignore the evidence that tea is good for you.

Long seen simply as a reason to relax or a folk remedy for colds and digestive problems, tea may cut the risk of some serious illnesses, including heart disease, cancer and osteoporosis, mounting research suggests.

A healthier heart
Studies show the polyphenols in tea interfere with free-radical molecules that cause low-density lipoprotein (or “bad’) cholesterol to form plaque inside the heart’s arteries. Studies show polyphenols have anti-clotting effects and can relax blood vessels, so they function better.

Such findings suggest tea could cut heart-disease risk or help tea drinkers fare better after a heart attack. In a study last year in the journal Circulation, Kenneth J. Mukamal followed more than 1,900 people who’d had a heart attack. Heavy tea drinkers (14 or more cups a week) had a 44 percent reduced risk of dying compared with nondrinkers. Moderate tea drinkers showed some protection, too.

If the findings can be duplicated, and tea does indeed reduce heart-attack deaths, “that is a major public-health benefit,” Mukamal said.

A Dutch study published last year also found that tea drinkers had half the risk of heart attack, and one-third the risk of a fatal one, compared with nondrinkers.

Tea consumption
Number of pounds of tea each person consumes on average each year, by country. Each pound equals about 200 servings.

United States 0.72
Japan 2.5
England 5.0
Kuwait 5.0
Ireland 5.9

Source: International Tea Committee (figures from 1999-2001)

An important component of both the Mukamal and Dutch studies was that the participants, men and women mostly in their 60s, were similar in other ways age, education, income and exercise, smoking and drinking habits. Some researchers suggest it may not be tea that helps tea drinkers but other lifestyle aspects, such as diet and exercise.

“Maybe it isn’t just an artifact of healthier people drinking tea,” Mukamal said.

Possible cancer fighter
Various studies have suggested tea may reduce the risk of bladder, stomach, colorectal, esophageal and oral cancers.

Dr. Zuo Feng Zhang of the Jonsson Cancer Center at the University of California, Los Angeles, published a study in 2001 showing that drinking green tea can cut the risk of chronic gastritis by half. Chronic gastritis causes lesions which can progress to stomach cancer.

“This is a very promising area,” says Zhang. “Polyphenols can prevent cancer and also have vitamins C and E … very good for people’s health. We have very strong confidence that the effect we found with chronic gastritis is real.”

Zhang plans a randomized trial to see whether tea can prevent precancerous lesions in the stomach. And he and his UCLA colleagues have launched the largest clinical trial ever focusing on bladder cancer in smokers and former smokers. (Tobacco use is a major risk factor for bladder cancer.) Investigators will give the study participants a green-tea extract or an experimental drug called Iressa to gauge their effects at preventing cancer. Previous research at UCLA showed that green tea can cut growth of bladder cancer tumors in animals and humans.

Zhang’s work on stomach cancer is among several studies suggesting that tea has preventive properties. A 1994 study in the Journal of the National Cancer Institute found that drinking green tea reduced the risk of esophageal cancer by 60 percent, while a study presented at the Third International Symposium on Tea and Human Health last fall in Washington found that women who consumed high amounts of tea had a 60 percent reduced risk of rectal cancer. Researchers at Rutgers University have even identified a compound in black tea, called TF-2, that caused colorectal cancer cells to die in laboratory experiments leaving normal cells unaffected.

Stronger bones
Taiwanese researchers last year announced that longtime tea use appears to strengthen bones. The study, published in the Archives of Internal Medicine, found hip-bone density 6.2 percent higher in people who drank tea habitually for 10 years or more, compared with nondrinkers. People who drank tea for six to 10 years had 2.3 percent higher density.

A British study, published in 2000 in the American Journal of Clinical Nutrition, also found higher bone density in women who drank at least one cup of tea a day.

Tea may confer a protective effect on bones because it contains both fluoride and phytoestrogens, which act like estrogen, which is known to strengthen bone.

Other benefits
Early research suggests that tea can inhibit the growth of bacteria on teeth and that a white tea-extract cream can protect against changes in the skin caused by the sun.

The most common therapeutic use for tea in the U.S. to ease cold symptoms is also getting a closer look. A particular compound found in green tea, methylated epigallocatechin gallate, can block the production of two substances in the body that cause sneezing, watery eyes and coughing.

There may be yet another reason to drink tea, says Jeffrey Blumberg, a tea researcher at Tufts Nutrition Center in Boston. He calls it the “substitution effect.”

“How do you go about making healthy food choices? … If you drink tea, you may not be having some of this stuff that’s not good for you.”

– Source: Los Angeles Times


Red Clover Can Help Hot Flashes

Dietary supplement cuts frequency & severity, Peruvian study says…

FRIDAY, Sept. 13, 2002 – A dietary supplement made from red clover provides relief for women with hot flashes, claims a new study.

Promensil, a standardized red clover supplement, reduces the frequency and severity of hot flashes, say the research, which appears in the current issue of The Female Patient.

The study found that 40 milligrams a day of Promensil reduced hot flashes by 48.5 percent, while a placebo offered a 10.5 percent reduction.

The study included 30 healthy, non-vegetarian women who had been post-menopausal for more than a year. None of them had used hormone replacement therapy (HRT), soy or other estrogen-active plant products for at least 16 weeks.

Non-vegetarian women were used in the study to avoid potential biasing. Vegetarian women eat more soy and legumes, which contain isoflavones that help control hot flashes.

“This study demonstrates that dietary supplementation with red-clover derived isoflavones is an effective alternative for symptomatic relief of vasomotor symptoms in post-menopausal women, reducing both the average daily frequency and severity of hot flushes,” says study author Dr. Arturo Jeri, director of the climacteric unit at the Institute of Gynaecology and Reproduction in Peru.

– Source: Novogen Ltd.


Vitamins May Help Prevent Infections In Diabetics

March 3, 2003, NEW YORK – People with diabetes may be able to ward off colds and other minor infections by taking a daily multivitamin, according to a study released Monday.

Taking a vitamin and mineral supplement did not prevent infections in people without diabetes, but the study’s lead author did not rule out that some people without diabetes might see a drop in infections if they take a supplement.

“If the benefit seen in diabetics is due to the fact that their nutrition was more marginal, then any population at risk of having marginally inadequate nutrition, such as the elderly in general, might also benefit,” Dr. Thomas A. Barringer, of Carolinas Medical Center in Charlotte, North Carolina, told Reuters Health.

Noting that most of the people in the study were overweight or obese, Barringer said that “if obesity was a factor in why they benefited, then all obese people might benefit.”

Forty percent of US adults take some sort of vitamin or mineral supplement on a regular basis, but there is little scientific evidence showing that supplements actually boost health.

But some research does suggest that a multivitamin enhances immune function, Barringer noted. The elderly and people with diabetes often do not consume adequate amounts of nutrients and they also have a slightly higher risk of infection, so Barringer’s team studied whether a vitamin and mineral supplement would prevent minor infections.

A multivitamin did seem to ward off infections, at least in people with diabetes, the researchers report in the March 4th issue of the journal Annals of Internal Medicine. All the diabetic patients had type 2 diabetes, the most common form of the disease.

Only 17% of diabetics taking a multivitamin reported having an infection, such as an upper respiratory infection, the flu or a gastrointestinal infection, compared with 93% of diabetics who were taking a dummy pill. In addition, 89% of people with diabetes who took a placebo pill reported missing at least one day of work during the one-year study compared with none of the diabetics taking a multivitamin.

The reduction in infections was found almost exclusively in people with diabetes, according to the report. Participants with diabetes were more likely to be deficient in at least one vitamin or mineral at the start of the study, which could explain the beneficial effect of a multivitamin, Barringer’s team points out. The researchers are uncertain, however, whether these small differences fully explain the effect.

The study included 130 adults ages 45 and older. Roughly two out of three participants were overweight or obese and about 30% had type 2 diabetes. Although the researchers originally wanted to measure the effect of multivitamins in the elderly, too few older people enrolled in the study for them to make a conclusion. Only 33 patients were over 65.

Since most participants in the study were overweight, Barringer said it is uncertain whether people who are overweight but who do not have diabetes, or who only have diabetes but are not overweight would also benefit.

Even though Barringer cautioned that the study is not the final word on the effect of multivitamins on the immune system, he pointed out that supplements are safe and relatively inexpensive, so taking a daily multivitamin is “a reasonable option” for people who are overweight, who have any type of diabetes, who may not receive adequate nutrition or whose immune system is weak.

The study represents a step toward understanding the effects of supplements, but it has several limitations, including its small size, according to Drs. Wafaie Fawzi and Meir J. Stampfer at Harvard School of Public Health in Boston, Massachusetts.

They note that two out of three similar studies found no beneficial effect of a multivitamin when it came to preventing infections. However, those two studies were conducted in people who already had an adequate intake of nutrients before taking the supplement.

“The potential impact of supplements merits further rigorous study, especially among diabetic persons and other vulnerable populations,” they conclude in an editorial that accompanies the study.

The study was funded by an independent, charitable organization known as the Charlotte-Mecklenburg Health Services Foundation.

– Source: Reuters Health


Folic Acid Helps Open Clogged Arteries

A new study says folic acid lowers levels of homocysteine, an amino acid that’s been linked to coronary artery disease. The new research, reported in the September 2000 Journal of the American College of Cardiology, was led by Dr. Lawrence Title, an interventional cardiologist at the Queen Elizabeth II Health Sciences Centre in Halifax, Nova Scotia.

Other studies have looked at the effects of folic acid, a form of vitamin B, but in groups of patients with different medical histories, such as people with high cholesterol levels, or those with no evidence of heart disease or still others with normal levels of homocysteine. While homocysteine can increase the risk of artery disease, Title says it’s “just one of the many players, along with cholesterol, smoking, diabetes and high blood pressure.”

Title’s study looked at folic acid’s effects on 75 patients with coronary artery disease and slightly elevated levels of homocysteine. The patients were randomly divided into three groups: one took folic acid, another took folic acid plus the antioxidant vitamins C and E, and the third took placebos. At the start of the experiment and after four months of treatment, the researchers measured homocysteine levels and used ultrasound to determine how well their impaired brachial arteries — located in the arms — had expanded to handle a temporary increase in blood flow.

The patients who took folic acid alone showed an 11 percent decrease in homocysteine levels compared to the placebo group, and their brachial arteries had expanded by 2 percent, says Title. The antioxidant vitamins had no effect. Title says the researchers had expected more than an 11 percent decrease but were heartened by the improvements to the brachial arteries.

“The most impressive finding was that we had a very significant increase in the function of the lining of the artery,” he says. “What is striking is that that degree of improvement is similar to what’s been shown with other drugs, such as cholesterol-lowering drugs called statins and also heart medications called ACE inhibitors.”

How it works: Folic acid is a B vitamin that’s essential for proper nerve function in the brain; a Harvard Medical School study showed that 38 percent of depressed women are deficient in it. “In many cases, the only sign of a folic acid deficiency is a feeling of sadness,” says R. Murali Krishna, M.D., clinical professor of psychiatry and behavioral sciences at the University of Oklahoma.

What you can do: In addition to taking a vitamin supplement, eat folic acid-rich foods so you’ll get a good balance of B vitamins, suggests Mary F. Morrison, M.D., assistant professor of psychiatry and internal medicine at the University of Pennsylvania Medical Center in Philadelphia.

One cup of beans or peas, plus four to five servings of fruits and green leafy vegetables daily, is often enough to correct the deficiency.