DC Online

Resistant Lice

Researchers from the University of California report that head lice appear to be gaining resistance to the over-the-counter, pesticide-laced shampoos used by millions of children each year. The shampoos contain a compound related to DDT, and the lice are beginning to show genetic changes that make them less susceptible to the poison. Researchers predict they will become totally immune in 5 to 10 years.

The University of California is researching better ways to control the pests, but since they have difficulty getting volunteers to host the bugs, researchers have had to develop artificial scalps. The researchers say that while chemicals are convenient, the best way to deal with head lice is still to comb out and pick off the lice and their eggs.^1,2

A study from a Pittsburgh prenatal clinic reports that women who drink early in their pregnancy may cause developmental changes in their child that last through puberty. Researchers found that as little as one alcoholic drink a day corresponded to a 16-pound drop in body weight, on average, at age 14. The research team also noted small differences in memory and learning performance.³

1. Alcoholism: Clinical and Experimental Research, October 2002.

A nonprofit group that reviews data from formal health-care studies reports that powered toothbrushes of the "rotational oscillation" type are superior to other classes for removing plaque and stimulating the gums. Compared to manual or other powered brushes, this type removed 11 percent more plaque and reduced gum bleeding by 17 percent. As the user brushes, a rotational oscillator rotates first in one direction, then the other. The study examined data from 29 clinical trials involving more than 2,500 participants.⁴

1. Reuters, Jan. 11, 2003.

A study of more than 7,000 men (average age: 66) suggests that they should be less concerned with standardized exercise programs than with simply whether or not they feel they're getting a good workout. Researchers calculated the amount of exercise in each man's typical workout and converted it to standardized federal exercise recommendations relating to multiples of the resting metabolic rate. They found this measure showed little correlation to the incidence of coronary artery disease.

However, among those men with similar calculated exercise indices, individuals who actually felt they were working out harder showed a marked decrease in cardiovascular disease.⁵ The research suggests that someone who struggles to get through a mild workout is probably getting more of a benefit than someone engaging in moderate workout that feels like a cakewalk. Physically demanding workouts were not examined in this study.

1. Circulation, February 2003.

Research from Johns Hopkins University suggests the length of the thigh may indicate one's likelihood of developing diabetes.⁶ This work found that average length of a person's thigh is about 15.8 inches if he or she has normal glucose metabolism. In those who show insulin resistance, the length is about 15.4; for those with outright diabetes, it's 15.1. The researchers think the correlation is probably due to some factor that influences both diabetic development and leg growth. In other words, it probably wouldn't help to have the length of your thighs extended artificially.

1. Associated Press, reporting on the work of Dr. Keiko Asao, as reported at a meeting of the American Heart Association, March 8, 2003.

European researchers report that women who have breast implants for cosmetic reasons appear to have a higher-than-average incidence of suicide. Among the more than 3,500 Swedish women studied who underwent the procedure, the suicide rate was three times the rate of similar women in the general population.⁷ The researchers think the link is probably due to underlying psychological problems among the patients that makes them more likely to undergo the procedures, not an effect of the surgery or implant itself. Approximately 250,000 women in the United States underwent breast augmentation surgery in 2002.⁸

1. British Medical Journal, March 8, 2003.
2. Reuters, March 3, 2003.

A study from the University of Toronto suggests a new diet can lower levels of LDL cholesterol by as much as 33 percent without affecting HDL levels. The "Portfolio Diet" is a vegetarian diet that emphasizes soy, plant sterols and soluble fiber. The diet includes oats; barley; legumes; eggplant; okra; soy; and almonds. Study participants found the foods very filling, and many stayed on the regimen after the study was complete.⁹

1. Associated Press, March 6, 2003, reporting on the work of Cyril Kendall.

A report from Children's Hospital in Boston concludes that people who eat breakfast every morning are less likely to be overweight or show signs of diabetes than those who skip breakfast. The researchers suspect that people who have a good breakfast are less likely to snack during the day, and may actually consume fewer calories overall.

The study examined 2,831 adult volunteers and broke the results down into male and female, white and black participants. White men and women were both only half as likely to be obese if they had breakfast every morning. Among blacks, breakfast-partaking men were 35 percent less likely to be obese, while breakfast did not appear to make a difference in black women.¹⁰

1. Associated Press, March 6, 2003, reporting on the work of Mark Pereira.

A study from the University of Rochester concludes that the early use of pacifiers contributes to breastfeeding problems. Among the 700 infants involved in the study, those given pacifiers a few days after birth were only half as likely to be breastfeeding exclusively one month later. Infants given supplemental feedings from a bottle also were likely to stop breastfeeding sooner. The study found that when supplemental feedings were required, using a cup instead of a bottle appeared to extend the length of time the baby would breastfeed.¹¹

1. Pediatrics, March 3, 2003.

A rather striking study from the University of North Carolina School of Medicine has found that daily multivitamin supplementation has a dramatic effect on the incidence of infections among diabetics. Researchers gave 130 patients daily doses of multivitamins or placebos for one year and tracked the number of respiratory, urinary tract, influenza and gastrointestinal infections during that time. Patients with adult-onset diabetes contracted one of the ailments at a rate of 17 percent if they received the vitamins, versus 93 percent with the placebo. None of the vitamin group missed any work, but 89 percent of the placebo group missed one or more days. The vitamins used were those typically found in most retail outlets.¹²

1. Annals of Internal Medicine, March 4, 2003.

A treadmill test is given to millions of Americans each year, but a 10-year study published in the New England Journal of Medicine¹³ suggests the standard method used to interpret the results should be modified.

Typically, the doctor only looks at the heart activity during the exercise test to make a judgment of the patient's condition. However, this study concludes that the recovery period after the workout is a better indicator of the risk of death over the next five years. The researchers predict that irregular heartbeats during recovery from exercise will soon become an accepted risk factor for heart disease.

1. NEJM, Feb. 27, 2003.

Research published in The Lancet¹⁴ reports that the level of arginine in a patient's blood is an accurate predictor of the severity of malaria attacks. The study, involving 75 African children, was conducted by researchers from the United States, Australia and Tanzania. Arginine is an amino acid present in most nuts and rice. It promotes higher levels of nitric oxide in the blood, which helps maintain flexibility of the vessels and can be poisonous to parasites.

1. The Lancet, Feb. 22, 2003.

Brian Sutton, DC
Colorado Springs, Colorado
brian.sutton@wcom.com