Premenstrual cravings for carbohydrates have been known to women for years. While women with binge eating problems will really ratchet into high gear when they're premenstrual, even women whose eating patterns are usually normal will notice over the top cravings during the week or so before their periods.

When my daughter and I were researching PMS for our book, "You Mean I don't Have to Feel This Way?", we wanted to know whether there were medical reasons for the pronounced cravings women experience premenstrually. To find out, we went to the scientists who were early researchers on the subject. Dr. Richard J.Wurtman, a professor of neuroscience and brain chemistry and his wife, Dr. Judith Wurtman, a cell biologist and nutritionist, were the first to uncover fascinating data on both the "why" of premenstrual carbohydrate craving and a new way of taming the monster. Their research showed that depression, carbohydrate craving, and some other symptoms of PMS can be significantly reduced with antidepressant medication--OR by judiciously eating certain foods that are rich in complex carbohydrates. Their theory is that supplying the brain with a minimal amount of good (complex) carbohydrates prevents women from hungering for them and going wild. How did they come up with such a theory? To find out, my daughter Gabrielle and I interviewed Judith Wurtman in an office near her lab at MIT. Dr. Wurtman told us she'd begun thinking about a scientific basis for premenstrual cravings after hearing innumerable stories from her women patients about the changes in their eating habits around the time of menstruation. "Right before they get their periods many have an irresistible craving for sweet and starchy foods. You'll hear them say,'I could kill for chocolate!'"

The Wurtmans wanted to find out whether women actually do increase their food intake--in particular sweet and starchy food--"or whether they simply think they do because their craving is so pronounced." These researchers tested a group of women who were experiencing PMS symptoms and another group who weren't. All were given a choice of a variety of foods--some high in carbohydrates (potatoes, rice, cookies, candy, pretzels) and others high in protein (chicken, cheese, tuna salad). "What we found," Judith told us, "was that the women with PMS were eating large amounts of carbohydrate foods, but only for about three or four days before their periods. The control women--the women without PMS--didn't increase their food intake at all."

The two scientists had the same women consume a carbohydrate dinner at the beginning and at the end of their menstrual cycle. The meal consisted of a large bowl of corn flakes--"a neutral, high-carbohydrate food," said Judith Wurtman. Before eating the dinner the women's moods were tested--did they feel happy, sad, irritable?--and again an hour afterward. The reason for this? Eating a large carbohydrate meal increases the level of serotonin in the brain, Wurtman continued." And when brain serotonin is increased there's an improvement in certain types of emotional states. People feel less depressed, more calm, less irritable, more focused, less confused, less distractible, more tranquil. We knew that if the carbohydrates--in this case the cornflakes--were going to do anything, they would probably do it by increasing the serotonin."

After the meal, the women reported that they were indeed less depressed. "They were substantially calmer, substantially less tired and more alert," said Wurtman. "This was a wonderful finding because it means that when women choose to eat carbohydrates at the end of their menstrual cycle, they're doing so in order to make themselves feel better. And it also confirmed for us that this brain chemical, serotonin, may be involved in some of the mood changes of premenstrual syndrome."

So what about eating more carbohydrates premenstrually? Wurtman told us she thinks that in the week or so before they get their periods women should go into a "high-carbohydrate-mode of eating." This high-carb eating will not go on forever, as it has its own natural beginning, middle and end. And, of course, such a mode of eating doesn't involve fats. What Wurtman suggested was that premenstrual women eat complex carbohydrates like rice, potatoes, pasta, lentils, or beans, "along with, perhaps, some sweet carbohydrates if their craving is strong enough for those foods."

The Wurtmans were among those who pioneered the use of antidepressant medication in the treatment of PMS, in the 80s and early 90s. Today, the gold standard for medical treatment of PMS is a very low dose of antidepressant medication that ONLY has to be taken during the premenstrual week. Unlike antidepressant medication taken for depression, which can take weeks to build to adequate levels in the blood stream, the same medication used for the treatment of PMS shows positive effects on the day it's first taken.

Women suffering from both from depression and PMS will often find that they become depressed and/or irritable during the week before their periods, even when the medication protects them from mood swings the rest of the month. In such cases a psychopharmacologist will suggest adding very low doses of another medication--sometimes drops of Prozac--just during that premenstrual week.