Did you know that tears contain toxins? Sounds like crying may remove byproducts of stress from the body. What does this mean for mind-body health?

Humans are the only animals who shed tears of emotion. Why do we cry? Are there any physical or health benefits from crying?

Years of tears

"Until the Industrial Revolution, crying in public was pretty normal, even for men," says Tom Lutz, Ph.D., an associate professor of English at the University of Iowa and author of Crying: The Natural and Cultural History of Tears. "Heroic epics from Greek times through the Middle Ages are soggy with weeping of all sorts," Dr. Lutz says. "Through most of history, tearlessness has not been the standard of manliness."

For instance, when Roland, the most famous warrior of medieval France died, 20,000 other knights wept so profusely they fainted and fell from their horses. Long before that, the Greek warrior Odysseus cries in almost every chapter of Homer's Iliad while St. Francis of Assisi was said to have been blinded by weeping. Later, in the 16th century, sobbing openly at a play, opera or symphony was considered appropriately sensitive for men and women alike.

Tearless generations

The industrial age needed diligent, not emotional, workers. Crying was then delegated to privacy, behind closed doors. Children learned that weeping itself was the problem and not the result of a problem. People everywhere became more uncomfortable with public tears.

In 1972, public crying was still so unacceptable that candidate Edmund Muskie was driven out of the U.S. presidential race when he shed tears during a speech.

The purpose of crying

Throughout history and in every culture, people cry. "Weeping often occurs at precisely those times when we are least able to fully verbalize complex, overwhelming emotions and least able to fully articulate our feelings," Lutz writes.

Crying can also be an escape; it allows us to turn away from the cause of our anguish, and inward toward our own bodily sensations. Scientists feel that weeping is probably necessary because no human behavior has ever continuously evolved unless it somehow contributed to survival.

"Science has proven that stress is terrible for the health of your brain, heart and other organs," says William Frey II, Ph.D., biochemist and tear expert of the Ramsey Medical Center in Minneapolis, Minnesota. "It isn't proven yet, but weeping has most likely served humans throughout our evolutionary history by reducing stress."

Studying the waterworks

In one oft-quoted study, Frey studied five different groups of people. The people kept records of all emotional and irritant crying episodes for a period of 30 days. Information such as date, time, duration, reason for crying, thoughts, emotions and physical components, such as "lump in throat," watery eyes vs. flowing tears, etc.

Frey found that 94 percent of the females had an emotional crying episode in the 30-day recording period, as compared with only 55 percent of the males. Eighty-five percent of women and 73 percent of men reported feeling better and more relieved after a good cry. Dr. Frey's lab also chemically examined tears produced by onions and compared them with emotional tears. While chemical tears (caused by onions) were 98 percent water, emotional tears contained more toxins.

Though there was no difference between men and women in average duration of crying episodes, men and women cry differently. Men cry quietly and their eyes brim neatly with tears. Women, on the other hand, make lots of crying noises as the tears stream down their cheeks. "Our testing revealed that men weep an average of 1.4 times a month while women cry about 5.3 times monthly," says Dr. Frey.

Why do people produce tears?

Some people believe that the rapid breathing associated with sobbing would quickly dry out the sensitive mucous membranes if tears did not keep them moist and that mucosal dehydration in the absence of tears could increase the risk of infection. While this may be one of the functions of emotional tearing, the clinical experiences of Dr. Frey and others indicate that sobbing is not a component of all crying and tearing episodes. And humans don't excrete tears while running or engaging in other forms of rigorous exercise where rapid breathing is also increased.

Tears are secreted through a duct, a process much like urination or exhalation. Frey believes that like these other processes, tearing may be involved in removing waste products or toxic substances from the body. Perhaps that is why so many people report feeling better after crying. Not only is the venting of emotions liberating, but the actual chemical composition which is known to be different from tears produced from cutting onions may be involved in this increased feeling of well-being.

"Crying is natural, healthy and curative," according to Barry M. Bernfeld, Ph.D., director of the Primal Institute in Los Angeles. "[But] crying which should be the most natural, accepted way of coping with pain, stress, and sorrow is hardly mentioned in psychiatric literature. Now we seem finally to recognize that crying is good for people."

Are times changing?

"In just a few short decades, we've gone from the view that crying is just a loss of control and a sign of weakness to a common perception that there might be some value in open emotional crying," says Dr. Frey.

For instance, a weeping, unashamed New York Yankee Darryl Strawberry fell into the arms of manager Joe Torre on national television. Gwyneth Paltrow was so tearful on national television that she could barely speak when awarded her Oscar for best actress. President Clinton routinely sniffles openly, and presidential candidate Bob Dole choked up while recalling how people in his home state helped him with his war injuries.

"Today, it might even be a plus for politicians to cry," says Dr. Frey. "People now like the idea that our leaders can be open about their feelings."

One of the main obstacles to good mental health is that by stifling crying, a person must also hide or shut down valid feelings and emotions. When legitimate emotions are not fully recognized and expressed, insensitive acts from rudeness to school shootings can result.