If you're in your childbearing years, chances are you've experienced the physical and emotional symptoms of premenstrual syndrome (PMS). Some women complain of fluid retention and weight gain, while others feel irritable, depressed or anxious. Many report tremendous food cravings that wreak havoc on healthy eating routines.
An estimated 70 per cent of menstruating women experience some form of PMS; as many as 40 per cent have symptoms that make life difficult. If PMS is a fact of life, your diet could be a contributing factor. Researchers are learning that certain foods can help ease or eliminate many PMS symptoms.
Several factors may play a role in triggering PMS. Some experts believe PMS is caused by an imbalance of estrogen and progesterone during the last two weeks of the menstrual cycle.
This hormone imbalance is thought to cause fluid retention and alter levels of serotonin and dopamine, two brain chemicals that affect mood, appetite and sleep.
While there is no PMS diet, per se, dietary modifications can help ease symptoms and possibly even prevent the condition.
Salt, caffeine, alcohol and fat
Eliminating table salt and high-sodium foods for the last few days before your period can help minimize fluid retention and bloating. Cutting out alcohol and caffeine can help improve mood and sleep patterns, and reduce breast tenderness.
A low-fat diet may curb PMS, too. Studies find when women with PMS follow a low-fat diet (15- to 20-per-cent fat calories), symptoms are fewer and less intense, including breast enlargement, water retention, bloating, weight gain, and cramps. A low-fat diet may affect PMS symptoms by influencing hormone levels, especially estrogen.
It's thought PMS-related mood swings and food cravings are caused by a deficiency of serotonin, a brain chemical associated with feelings of calmness and relaxation. Researchers have linked high serotonin levels with happier moods, and low serotonin levels with mild depression and irritability in women with PMS.
Carbohydrate-rich foods are one way to boost serotonin. A study from Harvard Medical School in Boston found that consuming a carb-rich beverage significantly decreased depression, anger and carb cravings in women with PMS. Not all carbs affect mood or cravings equally. Sugary foods like cookies and candy cause blood-sugar spikes, followed by sharp declines, a pattern that can worsen mood swings.
Choose "low glycemic" carbohydrates, which release their sugar more slowly into the bloodstream. These include grainy breads with seeds, large-flake oats, bran cereals, brown rice, sweet potatoes, pasta, apples, citrus fruit, grapes, pears, legumes, nuts, milk, yogurt and soymilk.
Eat every three hours to prevent fatigue, hunger and food cravings. To keep blood-sugar levels stable, plan for carb-rich snacks with a little protein, such as fruit and yogurt, a soy-milk smoothie, dried apricots and almonds, a small energy bar, or whole-grain crackers with low-fat cheese.
Calcium and vitamin D
Evidence suggests an adequate intake of calcium and vitamin D can reduce the severity of PMS symptoms and may even prevent its initial development. In one study, U.S. researchers gave 466 women with PMS 1,200 milligrams of calcium in a supplement or a placebo for three months. At the end of the study, the calcium-treated group reported a 48-per-cent reduction in overall PMS symptoms. Calcium supplementation led to a reduction in mood swings by 45 per cent, food cravings by 54 per cent, and bloating and water retention by 36 per cent.
Another study in the June issue of Archives of Internal Medicine followed 3,025 women for 10 years and found that, compared to women with a low calcium and vitamin D intake, those with the highest intakes were 30- to 40-per-cent less likely to have PMS.
Women aged 19 to 50 need 1,000 milligrams of calcium and 400 IU of vitamin D each day (teens need 1,300 milligrams of calcium). If you aren't getting the calcium you need from food, reach for a supplement with vitamin D added. Spread your calcium intake over the day; absorption from supplements is best in doses of 500 milligrams or less.
British researchers found that a daily 200-milligram magnesium supplement taken for two months significantly reduced PMS fluid retention. Magnesium is needed to maintain fluid balance by pumping sodium in, and potassium out, of cells. The recommended daily allowance (RDA) for women 19 to 30 is 350 milligrams; women 31 to 50 need 360 milligrams. The best sources are whole grains, nuts, seeds, legumes, soybeans, lentils, dried fruit, spinach, Swiss chard and green peas. If you supplement with magnesium, do not exceed 350 milligrams per day.
Because vitamin B6 is used to produce serotonin, a number of studies have investigated its effect on PMS. An analysis of nine trials involving 940 women concluded that B6 was significantly better than the placebo treatment in relieving PMS-related depression. Studies suggest that 50 to 100 milligrams of B6 per day are likely to benefit women who experience premenstrual depression. If you supplement with vitamin B6, do not exceed 100 milligrams per day.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic,
is on CTV's Canada AM every Wednesday.