Natural Help for PMS: Carbohydrates

The condition known as PMS, or premenstrual syndrome, has been the victim for decades, indeed hundreds of years, of erroneous theories and ineffective treatments. As PMS is a cluster of physical, cognitive and emotional symptoms that range in intensity from barely noticeable to incapacitating, it has been hard to find one underlying cause and “cure.”

Women who experience PMS have suffered from scorn, isolation, ill-placed humor, and remedies as drastic as removing the uterus, or massive doses of diuretics to dry out the brain from the water that supposedly brought about the problem. Many years ago, while researching what was known about the causes and therapies for PMS, I came across a gynecologist’s review (his name has been lost to me). He said that many doctors don’t even want to discuss the problem with their patients because they know their suggestions — healthy foods, enough sleep, exercise, etcetera — do not bring about the relief their patients are seeking.

PMS usually occurs a few days before menstruation begins, but its duration varies. Some women may experience it for only a few hours, and others for a week or more. And there also may be a seasonal variability. There is some evidence that women are more likely to experience a worsening of their PMS during the late fall and winter due to the increased hours of darkness.

Typical symptoms include irritability, anger, depression, mood swings, confusion, and difficulty focusing, fatigue, disrupted sleep, cravings and increased food intake, especially sweet carbohydrates, bloating, breast tenderness, and constipation. Some women experience a more severe form called premenstrual dysphoric disorder or PMDD, which is similar to clinical depression but limited to the second half of the menstrual cycle.

Several years ago we wanted to see whether increased carbohydrate cravings during PMS were real, or simply anecdotal. Women stayed in an MIT research facility for a few days at the beginning of their menstrual cycle, and returned three weeks later when they had PMS. They had continual access to protein and carbohydrate foods at their meals and snacks. These women were of normal weight and at the beginning of their menstrual cycle, they consumed about 1800 calories a day, choosing both protein and carbohydrate foods. However, when they had PMS, their daily calorie intake increased by about 1100 calories each day, and the increase in calories came primarily from sweet and starchy carbohydrate.

Why were they eating so much carbohydrate? Was it making their symptoms better or worse? This question is important if one reads the endless suggestions that women cut out all sugar and carbohydrates, stick to a low or carbohydrate-free keto diet, or follow a diet of mostly vegetables, high-fiber grains, and lean protein if they want to lessen their symptoms. At the time we did the study, doctors were telling premenstrual women to stay away from chocolate even though their patients craved it, sometimes desperately. The reasoning was: “You have PMS. You eat chocolate, the chocolate causes the PMS.”

They were wrong. (The doctors, not the women). Our research showed that consuming carbohydrates significantly relieved PMS symptoms. Moods such as anger, carbohydrate craving, and attentiveness were improved when they consumed (unknown to them) a drink containing carbohydrate. A protein-containing drink produced no beneficial effect.

Why did these symptoms improve? The reason is likely related to the increase in serotonin produced after carbohydrates are consumed. Evidence that a decrease in serotonin activity may be responsible for some of the mood changes in PMS comes from studies showing that when serotonin activity is increased with drugs, women who suffer from severe forms of PMS feel better. Fortunately, the more typical milder symptoms of PMS seem to respond to a natural, non-drug intervention – carbohydrates.

Despite this research, proponents of the keto diet are recommending that women avoid carbohydrate in order to relieve their PMS symptoms. Indeed, carbohydrates are seen as contributing to their premenstrual distress. Fluctuations in blood sugar, some sort of vague inflammation related to sugar intake, elevated estrogen levels (they are actually quite low during PMS), changes in magnesium due to sugar intake and other speculative causes of PMS are put forth to support reasons to avoid carbohydrates. What the proponents of the keto diet do not consider is that carbs produce serotonin. Cutting out carbs could result in a worsening of symptoms, especially mood changes, sleep, and cravings. Moreover, those women who may experience the severe form of PMS, PMDD, because of a significant decrease in serotonin activity at the end of their menstrual cycle may found their symptoms worsen if they follow a keto diet.

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There is a way of refuting the claims of the keto diet proponents, or even those who tell women to cut out sugar (which means cutting out chocolate) or to try to decrease their carbohydrate intake. A study comparing PMS symptoms among women on a ketogenic diet to those on a Mediterranean-type diet with its emphasis on healthy carbohydrates should reveal the answer. Or simply ask women what makes them feel better: a regimen of protein and fat, or sweet and starchy carbohydrates when they are experiencing PMS mood changes. The answer may not be subtle.