Americans are living longer than ever, according to the latest numbers from the Centers for Disease Control and Prevention (CDC). The CDC reports that in 2003, the overall U.S. life expectancy was 77.6 years. The life-expectancy gap between women and men continued to narrow with a 74.8-year life expectancy for men and an 80.1-year life expectancy for women. The preliminary age-adjusted death rate reached an all-time low of about 831 deaths per 100,000 people. Experts attribute these numbers to significant declines in mortality from the country’s leading killers, including heart disease, cancer, and stroke.

Athletes may want to stick to sipping water on the sidelines. Study results published in General Dentistry have found that sports drinks are more damaging to teeth than cola when consumed on a regular basis. Researchers found that noncola drinks caused up to 11 times more damage to teeth than cola-based drinks—with sports drinks, bottled lemonade, and energy drinks topping the list. Cola drinks commonly contain phosphoric and citric acids, but sports drinks contain other harmful additives and organic acids that can advance enamel erosion, according to researchers. A previous study by the same author found that tap water and root beer are the most tooth-friendly beverages.

Prenatal mercury exposure may affect a person’s pocketbook later in life. A study published in Environmental Health Perspectives has found that lower IQ levels caused by mercury exposure in utero cost Americans $9 billion per year in lost lifetime earnings. Researchers found that 4 percent of babies born each year in the United States (about 180,000 births) have mercury levels between 7.13 and 15 mcg per L, which can cause a 1.6-point decrease in IQ points. This amount of IQ loss could cost a person about $32,000 in lifetime earnings because of missed educational and employment opportunities, according to the report.

Can maternal obesity double the joy at delivery? Results of a study published in Gynecology & Obstetrics showed that women who are obese before becoming pregnant are more likely to give birth to fraternal twins. No link was found for identical twins or triplets. After adjusting for maternal race, age, parity, and height, researchers found that significantly more women with a pre-pregnancy body mass index (BMI) greater than 30 gave birth to fraternal twins than women whose BMI was in a normal range. The tallest women in the study were also more likely to have fraternal twins, but the link wasn’t as strong as it was with obese women.

Can smoking lead to suicide? It’s possible, according to a study recently published in Archives of General Psychiatry. After adjusting for suicidal predisposition and prior psychiatric conditions, researchers found that current daily smokers had an increased risk of suicidal thoughts or attempts compared with never daily smokers. However, past daily smokers didn’t have an increased suicide risk compared with current daily smokers. This association could be attributed to lower monamine oxidase activity in smokers, according to researchers who concluded that further neuroscience research is needed to prove whether smoking can independently increase suicide risk.

E-mails: house calls of the 21st century? The New York Times reports that health insurance groups around the country are paying physicians to answer patient e-mails as if they were conducting a regular office examination. According to the report, physicians say that the time they save using e-mail allows them more time to spend with patients who have a greater need to see the doctor face-to-face. At the same time, patients find e-mail more convenient, faster, and more comfortable than office visits. Industry experts say that fraud and privacy infringement have not been a problem so far, and government officials hope the initiatives will encourage physicians to switch to electronic health care information systems, which they say would cut down on mistakes and improve patient care.