What Is the Best Diet for PCOS?

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," said Lana Boter, MD, a 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, people with PCOS may find relief and healing from their PCOS symptoms by paying closer attention to what they eat. Here's why.

Diagnosis

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," said Alice Chang, MD, an endocrinologist at the Mayo Clinic. While difficult to diagnose, PCOS is common. The issue affects one in 10 women of childbearing age in the United States, according to the Office on Women's Health (OWH) in the Office at the U.S. Department of Health and Human Services.

People may be diagnosed with PCOS based on ultrasound findings of cysts on the ovaries. Hormone blood tests may also be used since people with PCOS have elevated levels of androgens, which are male hormones, per the OWH. Androgens can cause 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)," said Dr. Chang. "It can also cause higher blood pressure, abnormal cholesterol levels, and weight gain."

The Link Between Insulin and PCOS

According to MedlinePlus, in addition to high levels of male hormones, people with PCOS often also have high levels of the hormone insulin. Insulin allows this glucose to enter all the cells of your body and be used as energy. 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," said Dr. Boter. 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, people 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," said 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, said Dr. Chang. "Diets with fewer simple carbs will be less likely to stimulate the higher insulin levels that could be driving or increasing androgen production."

How Diet Affects 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, said Dr. Chang. "Most patients I refer to a dietitian are surprised by how much more protein and vegetables they should eat compared to carbs," said Dr. Chang. Dr. Chang recommended 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," said Dr. Boter. Dr. Boter suggested 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," said Dr. Boter.

Research published in Frontiers in Endocrinology in 2021 found that people with PCOS who followed low-carbohydrate diets were superior in optimizing reproductive outcomes in ameliorating symptoms.

Low-Carb Diets

The low-carb ketogenic diet limits carbohydrate intake, which will limit the stimulation of insulin secretion. So it may have some benefits when it comes to helping people with polycystic ovary syndrome: In a 12-week study published in February 2020 in the Journal of Translational Medicine, a keto diet has been shown to improve hormone ratios in overweight women with PCOS.

However, the choice of fats you're eating is important 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," said Dr. Chang. "Because insulin resistance is associated with abnormal cholesterol levels, in particular, higher than normal triglyceride levels, this might worsen already abnormal cholesterol levels."