WEDNESDAY, Aug. 26 (HealthDay News) -- Feeling stressed early in the menstrual cycle may worsen women's premenstrual symptoms, but teaching women how to reduce their stress levels may help, a new study suggests.

The study included 259 healthy women, aged 18 to 44, who were provided with an at-home fertility monitor to follow the phases of their monthly cycle. The participants also completed questionnaires about their stress levels for each of the four weeks of their cycle. None of the women were taking oral contraceptives or any other hormone medications.

Women who said they felt stressed two weeks before the beginning of menstruation were two to four times more likely to report moderate to severe premenstrual symptoms than those who didn't feel stressed, according to the report published recently online in the Journal of Women's Health.

Symptoms reported by the participants included mood swings, depression, fatigue, decreased concentration, breast swelling/tenderness, general aches, abdominal bloating, and feelings of anger and anxiety.

"It might be possible to lessen or prevent the severity of these symptoms with techniques that help women cope more effectively with stress, such as biofeedback, exercise, or relaxation techniques," researcher Audra Gollenberg, a postdoctoral fellow in the Division of Epidemiology, Statistics and Prevention Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), said in a news release from the U.S. National Institutes of Health.

There are a number of medications available to treat the symptoms of premenstrual syndrome, noted study author Mary Hediger, also of the NICHD.

"Each woman is an individual, and some women may experience severe symptoms that require medications," she said in the news release. "However, future studies may show that stress reduction techniques can prevent or reduce the severity of premenstrual syndrome, which might provide a cost effective alternative to medications for some women."

More information

The U.S. National Women's Health Information Center has more about premenstrual syndrome.

THURSDAY, Aug. 19 (HealthDay News) -- HIV-1 in semen is different than HIV-1 in blood, possibly due to changes it undergoes in the genital tract, scientists have found.

In their study, the researchers sought to better understand the process by which HIV -- the virus that causes AIDS -- is transmitted. They compared the gene encoding the major surface protein of HIV-1 in semen and blood.

The team, from the University of North Carolina at Chapel Hill, the Edward Jenner Institute for Vaccine Research in the United Kingdom and the Baylor Pediatric Center of Excellence (Malawi), published their findings in the Aug. 19 online edition of the journal PLoS Pathogens.

"In some men, the virus population in semen was similar to that in the blood, suggesting that virus was being imported from the blood into the genital tract and not being generated locally in the genital tract," study author Ronald Swanstrom said in news release from the journal's publisher.

"However, we found two mechanisms that significantly altered the virus population in the semen, showing that virus can grow in the seminal tract in two different ways," he added.

One way involves the rapid growth of one or more viruses in the seminal tract over a short period of time, resulting in a relatively similar population of HIV, compared to the complex population in blood. In the other way, HIV replicates in T-cells in the seminal tract over a long period, leading to a separate population of HIV in semen that is both complex and distinct from HIV in the blood, the study authors explained in the news release.

It's not known if these differences change the biology of HIV or if these changes play an important role in HIV transmission. What is clear is that HIV in the blood doesn't always represent the HIV at the site of transmission, the scientists reported.

More information

The U.S. National Institute of Allergy and Infectious Diseases has more about HIV/AIDS.

SUNDAY, Aug. 15 (HealthDay News) -- Having sex while in a romantic relationship doesn't generally affect teens' grades in school, but casual sex might, a new study shows.

"Compared to abstinence, sexual intercourse in committed romantic relationships is often academically harmless, whereas in other types of relationships it is more detrimental," noted Bill McCarthy and Eric Grodsky, sociologists at the University of California, Davis and the University of Minnesota, respectively. "Females and males who have sex only with romantic partners are generally similar to abstainers on most of the education measures we examined."

In their analysis of U.S. national data, the researchers focused on specific measures of education: school attachment; high school GPA; college aspiration; college expectations; problems in school; truancy; and school suspensions/expulsions or dropping out.

Compared to abstainers, teens who only have casual sex are at greater risk for lower grades and problems in school, and are more likely to be expelled or suspended, less likely to be attached to school, and less likely to go to college.

But the school performance of teens who have sex only with romantic partners is not much different from that of abstainers.

The study was to be presented Sunday at the American Sociological Association's annual meeting in Atlanta.

"Collectively, our results find that the detrimental outcomes commonly attributed to adolescent sexual intercourse occur mostly in non-romantic contexts," the researchers said in a news release from the American Sociological Association. "These findings raise doubts about the veracity of sexual education programs that link adolescent sex to a plethora of negative outcomes."

More information

The American College of Obstetricians and Gynecologists has more about teen sexuality  .

TUESDAY, July 27 (HealthDay News) -- Family and friends may do more than provide companionship: They also may boost your longevity, making as much of a difference as not smoking, a new analysis of studies suggests.

Researchers combined the results of 148 studies and estimated that adults with strong personal relationships may live an average of almost 4 years longer than those with weaker social ties.

The analysis doesn't prove that relationships directly help people live longer, but it seems clear that "our relationships come with more than just emotional benefits," said study author Julianne Holt-Lunstad, an associate professor of psychology at Brigham Young University.

"They can influence our longevity and our health," she added.

The study is published in the July issue of PLoS medicine.

Holt-Lunstad and colleagues examined studies involving almost 309,000 people on the effects of relationships -- such as those with friends, family, roommates and spouses -- on life span. The studies, conducted in North America, Europe, Asia and Australia, followed people for an average of 7.5 years.

"Among adults over age 18, those with strong social relationships are likely to live an average of 3.7 years longer than those with weaker social relationships," said study co-author Timothy Smith, a psychology professor at Brigham Young University.

The effect held up even when researchers adjusted their figures for factors such as age and health status.

It appears that strong relationships had an effect comparable to that of quitting smoking and a greater effect than known risk factors such as obesity and alcohol abuse, Holt-Lunstad said.

The challenge now is to put this information to good use, said the authors, who noted that in this era of technology, the quantity and quality of relationships seems to be decreasing.

Sonja Lyubomirsky, a psychology professor who studies happiness at the University of California at Riverside, said friends and family can affect your health in a variety of ways. "They help support good health habits: They remind us to put that seat belt on and ask us about that pain we've had, have we had that checked out? That may be the biggest factor."

Relationships may also reduce stress and boost the immune system, she said.

Or, it could be that people with more relationships live longer because "they're healthier to begin with: They could be more active and have more energy to engage in social activities," she said.

But other factors may also play a role, and it may be impossible to ever definitively say that more social relationships translate to longer lifespans, she said.

When scientists want to know if one thing causes another, they often turn to the gold standard of research: They randomly assign people to groups -- maybe one gets a medication and one doesn't -- and see what happens.

But, "you can never do a experiment where you isolate 100 people and then take 100 people and give them lots of friends," she said.

More information

The U.S. National Library of Medicine has details on stress.