Diet and PCOS.

PCOS is a metabolic disease first and foremost. Studies have looked at the differences in dietary intake between patients with PCOS and those without. In general there are no differences in total caloric intake, macronutrient or micronutrient intake, or intake of hi-glycemic index carbohydrates. One study suggested patients with PCOS consumed more white bread and fried tomatoes, but the differences are really not that significant. Thus, PCOS is not a disease that patients bring on themselves like the diseases associated with tobacco use. It is a life-long condition that we can use various strategies to modify its course. Because weight gain and insulin resistance are important in the mechanism of the disease, it is not surprising that studies have examined the effects on diet modification and weight loss on PCOS.

Studies have shown that long-term use of hypocaloric diets will improve the metabolic derangements in patients with PCOS. Some have concerns about a low carbohydrate and high fat diet in PCOS due to the already abnormal lipid profiles seen in patients with PCOS. Many have tried low carbohydrate diets in an attempt to lower insulin levels. In a study published by Kiddy et al in 1992, twenty-four obese PCOS spent 6 months on a low calorie (1000 kcal), low fat diet. There was a marked improvement in their clinical parameters and lowered insulin levels. Another pilot study of a low calorie highly ketogenic diet (i.e. Adkins’s) found over a 24 week period a decrease in body weight of 12 %, decrease free testosterone of 22 %, and a decrease fasting insulin of 54 %. Of course, the long-term ability to stay on such a regimen is a concern. A report by Jakubowicz and Nestler showed a reduction in serum testosterone levels using a similar dietary regimen. A very well designed study from Italy examined the long-term effects of metformin and hypocaloric diet on PCOS. Metformin improved the hirsutism, menstrual function, visceral adipose tissue, and glucose stimulated insulin secretion. Metformin and other insulin sensitizers like pioglitizone appear to be very beneficial in correcting the metabolic disturbances of PCOS. Chromium picolinate (1000 mgm) has been shown to improve glucose disposal. Sibutramine (Meridia) and Orlistat (Xenical) have been shown to have positive effects in PCOS patients. Thus, it appears that diet and some pharmacologic may be helpful in patients with PCOS.

Many patients have attempted to diet all their life with limited success. Some have even attempted gastric bypass surgery to effectively starve themselves. Such drastic measures have corrected many of the metabolic disturbances and patients have conceived after the surgery. There is some evidence that "life style" modification may be an effective adjunct to our treatment of PCOS. A very interesting study from Sweden by Ek et al, showed that PCOS patients had a marked reduction in the lipolytic (i.e. fat breakdown) effects of noradrenalin due to a decreased number of noradrenalin receptors on fat cells.

Other experimental studies have suggested that the sympathetic nervous system, which innervates the ovary, may be activated in PCOS. Weight reduction has been shown to increase noradrenalin sensitivity in PCOS patients. Thus, there may be a link between the sympathetic nervous system and PCOS which exercise may help. The goal of life style modification should be greater than or equal to 7% loss in weight and maintenance with <25% of calories from fat and a total caloric intake of 1200 to 1800 calories per day. Also, we would like the patient to have more than 2 1 to 2 hours of moderate physical activity per week and be on a low glycemic index diet to improve insulin resistance.