Experts weigh in on what to eat—and what not to eat—if you have PCOS.

By Emily Shiffer January 10, 2019

When you think of polycystic ovary syndrome (PCOS), you probably think of a gynecologic issue. (It has the word “ovary” right in the title, after all.) But PCOS is actually an endocrine disorder, which causes it to wreak havoc on the body's hormones.

"A lot of organs are victims to this syndrome—the ovaries are just one," says Lana Boter, MD, gynecologist at NYU Langone Health. "It affects the entire endocrine system, from the pancreas (which produces insulin) to the thyroid to the pituitary gland."

Because diet plays a role in maintaining the body’s endocrine system, women with PCOS may find relief and healing from their PCOS symptoms by paying closer attention to what they eat. Here’s why.

What is PCOS?

For starters, it helps to understand what exactly PCOS is. "Polycystic ovary syndrome is often misunderstood because there is no one test that gives the diagnosis," says Alice Chang, MD, endocrinologist at the Mayo Clinic. While difficult to diagnose, it’s common, affecting one in 10 women of childbearing age in the United States.

Women may be diagnosed based on ultrasound findings of cysts on the ovaries. Hormone blood tests may also be used, since women with PCOS have elevated androgens, or male hormones. And these can cause some noticeable physical symptoms.

"Some women have hair growth on the face or body or significant acne. Others may have primarily irregular menstrual periods that are typically fewer than nine per year, or some women have more frequent bleeding because they are not ovulating regularly (which can lead to infertility)," says Dr. Chang. "It can also cause higher blood pressure, abnormal cholesterol levels, and weight gain."

 

Insulin and PCOS

In addition to high levels of male hormones, women with PCOS often also have high levels of the hormone insulin. Their cells don't respond normally to the hormone, a problem called insulin resistance, so insulin builds up in their blood.

"We eat foods that require insulin output from the pancreas,” Dr. Boter explains. Then, “the body doesn't respond that well to insulin, so it has to produce much more to drop sugar levels and the pancreas works overtime.”

Therefore, women with PCOS have a higher risk of developing diabetes. "Because of the insulin resistance, women with PCOS are more likely to have pre-diabetes or impaired glucose tolerance," says Dr. Chang. "If your pancreas cannot make enough insulin to control blood glucose, you can develop diabetes and the medical consequences of high glucose to the body.”

But insulin levels can be lowered with diet and exercise, she adds. "Diets with fewer simple carbs will be less likely to stimulate the higher insulin levels that could be driving or increasing androgen production."

So how does your diet affect PCOS?

Following a lower-carb diet may help—and many women with PCOS may not have realized how many carbs they were eating to begin with, Dr. Chang says. "Most patients I refer to a dietitian are surprised by how much more protein and vegetables they should eat compared to carbs," she says. She recommends starting by making sure the majority of your plate is full of veggies and protein and staying away from simple carbs—like white flour and added sugar—that increase insulin secretion.

"By decreasing carbs, you're no longer feeding the beast of insulin," Dr. Boter adds. She suggests that patients with PCOS eat between 40 and 50 grams of carbohydrates each day. But that doesn't mean your diet should be all protein all the time.

"People think a low-carb diet is all steak and eggs, but making sure you get enough fiber and vitamins—especially from veggies like spinach, broccoli, mushrooms, and cauliflower—is extremely important," Dr. Boter says.

A 2013 review found that women with PCOS who followed a low-carb or low-glycemic-index diet experienced greater reductions in insulin resistance and cholesterol levels than those who followed a high-carb diet.

 

Not all low-carb diets are equal

The low-carb ketogenic diet is everywhere lately, and you may be wondering if it’s good or bad for PCOS. Since it limits carbohydrate intake, which will limit stimulation of insulin secretion, it may have some benefits when it comes to helping women with polycystic ovary syndrome: In small, preliminary studies of women with PCOS, a keto diet has been shown to improve hormone ratios and fertility.

However, you'll need to pay attention to the fats you're eating if you choose to follow a keto diet for PCOS. "Some ketogenic diets will not specifically limit 'bad fats' or specify healthier, plant-based unsaturated fats,” Dr. Chang says. “Because insulin resistance is associated with abnormal cholesterol levels, in particular higher than normal triglyceride levels, this might worsen already abnormal cholesterol levels.”