Who doesn’t love being in love? A true Valentine listens to you vent about work, lets you have that last slice of pizza, and (usually) remembers to take out the trash. He doesn’t expect you to watch the Super Bowl. And he always thinks you’re sexy, even in thermal underwear and bunny slippers.

Scientists have long been keen to prove that love gives us health benefits, too–beyond the obvious advantage of always having a date for New Year’s Eve. Researchers can’t say for sure that romance trumps an affectionate family or warm friendships when it comes to wellness. But they are homing in on how sex, kinship, and caring all seem to make us stronger, with health gains that range from faster healing and better control over chronic illnesses to living longer.

The benefits of love are explicit and measurable:

• A study last year from the University of Pittsburgh found that women in good marriages have a much lower risk of cardiovascular disease than those in high-stress relationships.

• The National Longitudinal Mortality Study, which has been tracking more than a million subjects since 1979, shows that married people live longer, have fewer heart attacks and lower cancer rates, and even get pneumonia less frequently than singles.

• And a new study from the University of Iowa found that ovarian cancer patients with a strong sense of connection to others and satisfying relationships had more vigorous “natural killer” cell activity at the site of the tumor than those who didn’t have those social ties. (These desirable white blood cells kill cancerous cells as part of the body’s immune system.)

Some experts think it won’t be long before doctors prescribe steamy sex, romantic getaways, and caring communication in addition to low-cholesterol diets and plenty of rest. If that sounds like a happy Rx, here are ways to make the emerging evidence translate into real-life advice.

The Benefits of Bear Hugs

Doctors at the University of North Carolina have found that hugging may dramatically lower blood pressure and boost blood levels of oxytocin, a relaxing hormone that plays a key role in labor, breastfeeding, and orgasms.

Researchers asked couples to sit close to one another and talk for 10 minutes, then share a long hug; afterward they found positive, albeit small, changes in both blood pressure and oxytocin.

But the power of frequent daily hugging was intense: The women with the highest oxytocin levels had systolic blood pressure that was 10 mm/Hg lower than women with low oxytocin levels–an improvement similar to the effect of many leading blood pressure medications, says Kathleen Light, PhD, a professor of psychiatry at UNC and one of the study’s authors.

“Getting more daily hugs from their husbands was related to higher oxytocin, and so the hugs were indirectly related to lower blood pressure,” she says. Men didn’t get the blood pressure benefit from hugging. But don’t feel bad for him: He probably gets the same health gains from steady sex that you do from daily snuggling.

A 2002 study from the University of Bristol in England found that men who had sex two or more times a week cut their risk of having a fatal heart attack in half. And a recent study from the National Cancer Institute found that men who ejaculate frequently may be protecting themselves against prostate cancer.

The hormone oxytocin has been linked to trust, and it helps women bond with everyone from newborns to stockbrokers. But its biggest benefit may turn out to be physical. Breastfeeding has been definitively linked to both lower breast cancer rates and the slower growth of some breast cancer cells; researchers speculate that oxytocin may be responsible.

“It is safe to say that oxytocin is linked to emotional as well as physical closeness in partners,” Light says. “And while the healing power of this connection is not yet proven, we think it will be soon.”

Oxytocin also surges through the bodies of men and women during orgasm. But whether sex itself directly improves women’s health is still not certain. One of the most concrete connections comes from a study by Carl J. Charnetski, PhD, a professor of psychology at Wilkes University and coauthor of Feeling Good Is Good for You.

In 2004, he measured the immune function of 112 college students, many of whom were in close, loving relationships. Those who had sex with their partner once or twice a week had significantly higher amounts of immunoglobulin A, an antibody that is the body’s first line of defense in fighting off disease and infections, than those who had sex less than once a week or not at all.

Although making sure you have weekly sex is great health advice, more isn’t necessarily better. Charnetski was surprised to discover that the immune systems of those who had sex three or more times a week were no better off than the no-sex-at-all group. Maybe, he theorizes, “couples who have sex just once a week are simply in healthier, more secure relationships, and have nothing to prove.”

Though researchers have yet to link orgasms from masturbation to any measurable physiological gains for women, it’s clear that women perceive instant health benefits.

Carol Rinkleib Ellison, PhD, a marriage counselor and sex researcher in Oakland, CA, and author ofWomen’s Sexualities, surveyed 2,632 women from their teens to their 90s and found that two-thirds had masturbated in the previous month. Although most cited the obvious (“because it feels good”), many also gave specific health-related reasons for double-clicking their own mouse–39% said it relaxed them, 32% said it helped them sleep, and 9% said it eased menstrual cramps.

Steady sex may also make women healthier by making relationships happier: When couples are content with their sexual status quo, they’ve eliminated a big–and extremely stressful–area of conflict. While sex is hardly the only (or even the best) measure of how happy a couple is, it is a kind of romantic superglue.

Researchers from the University of Sheffield in England interviewed 28 participants who had been married at least 20 years and found that a consistent sex life continued to be important throughout marriage.

“The majority of our participants felt that sex granted their marriage a way to express love, commitment, and trust,” says Sharron Hinchliff, PhD, a psychologist researcher and author of the study. And when circumstances–a health problem or scheduling change, for instance–made it more difficult for these couples to have sex, they found a way to adapt their sex lives quickly so that they barely noticed the upheaval.

Why We Need to Feel Close

Experts are quick to point out that sex is only one aspect of connection, and not as powerful as the real magic in relationships: bonding. That sense of being united, even during bad times, is a trait that Brian Baker, a psychiatrist at the University of Toronto, calls cohesion. And his research has found that it’s more important to both health and happiness than a good sex life.

In one study, he tracked 229 adults who were under job strain. Though they had higher blood pressure at the start, spouses in pleasurable marriages actually lowered systolic blood pressure by 2.5 mm/Hg over a 12-month period.

What’s more, Baker says, happy couples seem to know almost instinctively that doing things together and spending more time with each other adds to their happiness. It’s not that sex didn’t matter to these couples. “It’s one component of satisfaction,” he says. “But couples who had less sex didn’t seem to have any less sense of cohesion, and it was their emotional collaboration–their partnership–that kept the marriage strong.”

Maybe, Ellison says, that bond is the brass ring of marriage, enabling us to build a safe cocoon in a world full of difficult bosses, too much traffic, and not enough time. “An ideal relationship gives you a place to come home and recharge your battery. Sitting down with your partner makes you feel calmer. You’re in a secure nest, and you’re less stressed,” she says. “How could that not be good for you?”

The Love Rx

Granted, sharing a bond of closeness with your sweetheart feels magical. But a relationship can seem more like a bed of thorns than roses when he’s criticizing you over the morning coffee. With the exception of Marge Simpson, most women outgrow the idea that they can change men.

But that doesn’t mean relationships can’t change; couples can learn to fight sweeter, replacing hostile comments with less judgmental ones. “Conflict itself is normal,” says Baker, “and it’s healthy–it engages couples in the relationship.”

But there is a difference between healthy fighting and fighting that wears down your immunity. Studies from the University of Washington show that happy couples manage to be far more positive than negative when they’re duking it out, interjecting playful jokes and affectionate pokes in the ribs.

In contrast, the I’m-ready-to-break-some-dishes-now anger that comes with fighting causes physiological changes that John Gottman, PhD, executive director of the Relationship Research Institute in Seattle, calls “flooding”; these leave heart rates too high for the couple to come to any effective solution.

Researchers believe that warm interactions between couples can bring about powerful health results, even when one of the partners is battling disease. At the Fox Chase Cancer Center in Philadelphia, Sharon Manne, PhD, studied couples struggling with the wife’s breast cancer diagnosis and treatment. Some couples were coached to be more supportive; others muddled through on their own.

The wives in the coached group fared better, as measured by their levels of distress and depression. And while Manne’s own research has focused solely on cancer, she thinks couples can use any stressful period to find a friendlier footing.

What worked best? “When partners learned to minimize negative comments and were responsive, and when they were willing to share their own concerns and worries, rather than pretending nothing was wrong…that can make a bad marriage good, or a good marriage even better,” says Manne.

In fact, the physiological findings from love research have inspired even the skeptics to change the way they look at relationships–in the lab and at home.

“My husband is an immunologist, and when we started our research, he’d be the first to admit that he thought the psychology part of this was a crock,” says Janice Kiecolt-Glaser, director of health psychology at Ohio State University’s College of Medicine. “Now, he’s seen what stress can do in bad relationships, and also how a good relationship can protect people from outside stresses–like work.”

And it’s made the two treasure the time they have to bond. “One of the things we like to do after dinner is to sit with a glass of wine, looking out over the Scioto River. It’s clear to us that close relationships are incredibly helpful to our health and well-being.”