Hair Dye, Cancer May Be Linked After All
Vanity about our hair has a new price tag, and that price is an increased risk of cancer, according to USC researchers.
Carcinogenic chemicals in permanent hair dyes, they say, can significantly increase the risk of bladder cancer for those using the dyes for long periods, and the risk is even more severe for hairdressers and others who use the dyes in their work.
The hair dyes contain a class of chemicals called arylamines that have been shown to cause cancer in laboratory animals. Previous studies have tenuously linked the dyes to an increased risk of lymphoma and leukemia, as well as to bladder cancer, but the overall risk appeared to be low. The new findings present a more somber picture.
Dr. Manuela Gago-Dominguez and her colleagues at USC studied 1,514 bladder cancer patients and 1,514 similar healthy people who lived in the same neighborhoods. When cigarette smoking and other known risk factors were accounted for, the team reported in the February International Journal of Cancer Research, people who used the dyes for at least a year had double the normal risk of bladder cancer. Those who used them for at least 15 years had three times the normal risk. Hairdressers and barbers who had used the dyes for at least 10 years had five times the normal risk.
Small amounts of the chemicals are absorbed through the skin during use and pass through the bladder before being expelled through the urine.
Bladder cancer currently accounts for about 6% of all new cancer cases in men and 2% in women. The American Cancer Society estimates that 53,200 Americans were diagnosed with bladder cancer in 2000 and that 12,200 died from it.
In Europe, Japan and North America alone, more than one in three women over age 18 and one in 10 men over age 40 use some type of hair coloring, the researchers report. Worldwide, permanent dyes account for about three-quarters of the dyes used.
Researchers said that only the permanent dyes were linked to an increased risk of cancer, not semi-permanent or temporary hair color, which rinses out and fades after a series of shampoos.
Statins Garner More Favorable Notices
Three new studies reinforce the value of statins, a new family of drugs that reduce cholesterol levels and have been shown to reduce the risk of heart attacks. These studies show that the drugs, which are sold under such names as Pravachol, Zocor and Lipitor, reduce the risk of stroke and diabetes and lower the likelihood of a second heart attack if given shortly after the first.
The first study combined results from three large clinical trials of pravastatin that began in 1992 and that included 19,768 patients, half of whom received the drug while the rest received a placebo. A team led by epidemiologist Robert P. Byington of Wake Forest University School of Medicine reported in the Jan. 23 Circulation: Journal of the American Heart Assn. that those receiving the statin had 22% fewer strokes than those receiving a placebo.
The second new report involved 5,974 men in a Scottish trial of pravastatin. Again, about half received the drug and half a placebo. Dr. Allan Gaw of the Glasgow Royal Infirmary and his colleagues reported in the same issue of Circulation that those receiving pravastatin were 30% less likely to develop diabetes than those receiving a placebo. Researchers are not yet sure how the drug reduced diabetes risk.
And finally, a Swedish study of 19,599 heart attack victims looked at patients given a statin during their hospitalization. Doctors have hesitated to give the drugs to such patients immediately because it prevents accurate measurement of cholesterol levels during hospitalization. But a team headed by Dr. Ulf Stenestrand of University Hospital in Linkoping reported in the Jan. 24 Journal of the American Medical Assn. that those receiving the drug immediately had a 25% lower death rate than those who did not receive the drug until three months after their heart attack.
Glucosamine Seems to Ease Osteoarthritis
Glucosamine sulphate, an over-the-counter supplement, may provide relief from the symptoms of osteoarthritis over the long term, according to Belgian researchers. Earlier studies have hinted at its effectiveness, and the U.S. National Institutes of Health has just begun a study of glucosamine in conjunction with chondroitin, another supplement. But the Belgian study appears to be the best to date.
Dr. Jean Reginster and colleagues at CHU Centre Ville in Liege studied 212 osteoarthritis patients who were randomly assigned to receive either glucosamine sulphate or a placebo for three years. X-rays of the knees were taken at enrollment and at one and three years, and other symptoms were measured.
The team reported in the Jan. 27 Lancet that patients receiving a placebo showed deterioration in the knees, while those receiving glucosamine did not. And those who received the supplement had a 20% to 25% improvement in symptoms, while those receiving placebo had a worsening.
Radiation May Bolster Unclogging of Arteries
Briefly irradiating clogged arteries after they are reopened by angioplasty can prolong the time until the arteries clog up again, according to two new studies in the Jan. 25 New England Journal of Medicine.
An estimated 750,000 Americans undergo angioplasty each year to reopen clogged arteries. In about 60% of those cases, surgeons insert a steel coil called a stent in an effort to prop the vessel open. Nonetheless, about 25% of those arteries stented and about 35% of those not stented get reclogged within a few months.
In the two new studies, researchers briefly inserted radioactive pellets or wires into the artery during angioplasty in an effort to delay clogging. One study was of patients undergoing their first angioplasty. The second involved people who had already had an artery become reclogged.
In the study of 181 patients undergoing their first angioplasty, researchers found that 29% of arteries had reclogged after six months in those receiving the lowest dose of radiation, compared with only 15% in those getting a dose twice as high.
In the study of patients who had already suffered a failed angioplasty, researchers compared 131 patients who received radiation with 121 who received a dummy treatment. After six months, 28% of those receiving radiation had become reclogged, compared to 44% of those who did not.
Bicarbonate Could Harm Diabetic Children
A common treatment for children with a diabetes crisis can cause a rare, but often fatal, complication known as cerebral edema, according to researchers at UC Davis Medical Center.
Cerebral edema is a swelling of the brain caused by accumulation of water, and is fatal in as many as 90% of children who develop it. It is the leading cause of diabetes-related deaths in children.
About 13,000 children are diagnosed with diabetes each year, and in nearly half of them, the first sign is ketoacidosis, in which toxic levels of acids called ketones build up in the blood. Ketoacidosis can also occur when the diabetic misses insulin shots. Physicians in emergency rooms often use bicarbonate to reduce acid levels in children with ketoacidosis.
Dr. Nathan Kuppermann and his colleagues at Davis studied the records of 6,977 children hospitalized for diabetic ketoacidosis over a 15-year period, comparing those who received bicarbonate with those who did not. They reported in the Jan. 25 New England Journal of Medicine that children treated with bicarbonate were four times as likely to develop cerebral edema as those not treated. And those who did not receive bicarbonate recovered just as well as those who did.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
