PCOS and Veganism: Can Eating More Plants Help?

With the rising awareness of PCOS, many women are looking for the best ways to treat this frustrating health condition. Managing PCOS often involves making lifestyle changes, and diet plays a crucial role. 

One growing area of interest is whether a vegan diet—one that avoids all animal products—can help with PCOS symptoms.

As a vegan registered dietitian, I’ll discuss the potential benefits of a vegan diet for women with PCOS. You’ll learn about the current research on plant-based eating and how it might impact your symptoms, and I’ll also provide tips for modifying a vegan diet to ensure that it’s appropriate for PCOS.

Whether you’re considering going 100% vegan or just looking to add more plant-based foods to your meals, this article will help guide your choices and provide useful insights for managing PCOS with nutrition.

What is PCOS?

Polycystic Ovary Syndrome (PCOS)¹ is a fairly common metabolic endocrine disorder occurring in up to 20% of pre-menopausal women. 

To be diagnosed with PCOS, a person must have at least two of the following three criteria:

• Hyperandrogenism: Higher than normal levels of androgens, male sex hormones which are also present in women; causes insulin resistance and high blood sugar, leading to the production of damaging free radicals and inflammation
• Irregular or lack of ovulation: The body doesn’t release eggs according to a normal cycle, or doesn’t release them at all; common cause of infertility
• Polycystic ovaries: Presence of cysts (fluid-filled sacs) in the ovaries; may not be present in everyone with PCOS

Most PCOS symptoms start during early puberty, although many people don’t experience any symptoms. Symptoms can include:

• Irregular menstrual cycle
• Infertility
• Depression
• Anxiety
• Acne
• Unwanted or excessive facial and/or body hair growth

PCOS is related to a variety of other health concerns as well. People with PCOS are at increased risk for cardiovascular disease, type 2 diabetes, insulin resistance, metabolic syndrome, abdominal obesity, osteoporosis, psychological disorders, and some types of cancer.

Not all cases of PCOS are the same. Experts divide PCOS into 4 different types².

• Type A / Full-blown PCOS: You have all three PCOS-related issues: high androgen levels, ovarian cysts, and issues with ovulation
• Type B / Non-PCO PCOS: You have high androgen levels and and problems with ovulation/periods
• Type C / Ovulatory PCOS: You have high androgen levels and ovarian cysts
• Type D / Non-hyperandrogenic PCOS: Your androgen levels are normal, but you have problems with ovulation and ovarian cysts

You may also see PCOS divided into other types, such as inflammatory PCOS, insulin-resistant PCOS, hidden cause PCOS, or pill-induced PCOS, which likely have some physiological basis but aren’t formally recognized by health experts.

What is a vegan diet?

Vegans avoid eating anything that comes from an animal or is processed with ingredients that were obtained from an animal. This includes meat, poultry, seafood, dairy, eggs, butter, gelatin, and honey.

As vegans learn more about how foods are produced, most also avoid things like alcohol processed with egg albumen or fish bladder and cane sugar filtered through animal bone char to improve the color.

Vegans do eat a wide variety of plant-based foods, including:

• Fruits & vegetables
• Beans & legumes
• Seitan
• Grains
• Soy products (edamame, tofu, tempeh, soy curls, etc.)
• Nuts & seeds
• Vegetable oils
• Plant-based meat alternatives, non-dairy milk and yogurt, vegan butter, etc. 

The term “plant-based” is often used synonymously with “vegan”, but they aren’t necessarily the same thing.

Some people use “plant-based” or “plant-forward” to describe dietary patterns that are high in plant (vegan) foods, but may include small amounts of animal products. Vegan meals never include any foods obtained from an animal.

Research on PCOS and veganism

There’s a lot of interest in the potential of vegan diets for reducing PCOS symptom severity and reducing the risk of related diseases. Unfortunately, studies on 100% vegan diets for PCOS are still limited, although emerging evidence does suggest that plant-based diets can be beneficial.

Let’s take a look at the research that’s been done so far:

Vegan vs. low-calorie diet for weight loss in PCOS

A study³ published in 2014 explored whether a vegan diet or low-calorie omnivorous diet was more effective for weight loss in women with PCOS.

The researchers found that the vegan diet was significantly more effective for losing weight after 3 months, although both groups of women had lost the same amount of weight by 6 months. This suggests that vegan diets can help women with PCOS lose weight and may be more effective than a low-calorie diet in the short-term.

Dietary habits in women with PCOS-related infertility

Another small study⁴ from 2014 investigated the lifestyle habits of women with PCOS and infertility. Most fell in the obese range for BMI. They found that women with infertility tend to have diets high in saturated fat and low in whole grains, fiber, and iron. They also struggled to exercise regularly and had blunted hunger cues, making it difficult not to overeat.

However, this type of study can’t tell us whether it’s the poor diet making infertility worse, or whether the mental health challenges that result from an infertility diagnosis are what lead to an unhealthy diet. In reality, each probably affects the other.

Effects of a pulse-based diet on cardio-metabolic risk factors in PCOS

A 2018 randomized controlled trial⁵ compared the benefits of a low-glycemic diet rich in beans and lentils to the Therapeutic Lifestyle Changes (TLC) diet, an omnivorous diet that emphasizes fruits, vegetables, low-fat dairy, fish, and poultry. 

Interestingly, participants in the pulse diet group maintained improvements in total and HDL cholesterol for up to a year longer than women on the TLC diet. Both diets were helpful, likely due to the emphasis on whole plant foods.

These results suggest that beans and legumes can be included in a PCOS-friendly, low-glycemic diet, despite being higher in carbohydrates than animal proteins.

Various dietary patterns and risk of PCOS

Interestingly, a 2019 study⁶ from researchers in Iran found that Western diets and plant-based diets were both associated with an increased risk of PCOS. Other studies looking at plant-forward diets for PCOS have found beneficial results, so it isn’t clear why this study didn’t. 

Effects of plant-based foods and exercise on metabolic health in PCOS

A recent study⁷ in 2023 looked into how plant-based foods impact the metabolic health of women with PCOS. The findings suggest that diets high in plant-based foods could improve various markers of metabolic health, including cholesterol and androgen levels and body fat percentage.

Benefits of vegan diets for PCOS

While research is limited, there are multiple ways that a nutrient-dense, balanced vegan diet could potentially help with PCOS management. I’ll discuss a few of these below.

Low in Advanced Glycation End Products (AGEs)

AGEs are proteins or fats that become glycated (attached to a glucose molecule) when they come in contact with sugars. They can form within the body when high levels of oxidative stress are present, or they can be formed in the foods we eat. 

High-fat animal foods like fatty meats, eggs, and cream cheese, especially those that have been cooked at high temperatures, typically contain the most AGEs. Fast food burgers and fries are an example of a meal high in AGEs. 

When exposed to too many AGEs, these compounds can cause damage to body tissues and contribute to inflammation. Consuming less AGEs may be an effective way to improve hormone levels and ovarian function in PCOS¹.

High in fiber

Fiber is incredibly helpful for regulating blood sugar levels and reducing chronic inflammation. All plant-based foods contain fiber, with the exception of highly processed foods like white bread or some breakfast cereals.

If choosing a vegan diet to manage PCOS, it’s important to include plenty of fruits, vegetables, beans, and whole grains. Just be sure to increase your intake of these fiber-rich foods slowly to give your gut enough time to adjust, and drink plenty of water throughout the day to assist with digestion. 

Can reduce oxidative stress & inflammation

By increasing the amount of plant foods in your diet, you’ll also get more antioxidants and polyphenols. Most animal products contain negligible amounts of antioxidants, and none contain polyphenols, plant-based compounds known for their powerful anti-inflammatory benefits.

Antioxidants are a key component of PCOS-friendly diets, as they prevent the oxidative damage that occurs alongside hyperandrogenism. Plant-based foods high in antioxidants and polyphenols include:

• Berries
• Dark leafy greens
• Coffee and tea
• Beans & legumes
• Apples, cherries, and plums
• Chili peppers, broccoli, onions, and garlic
• Cocoa powder 
• Vegan spices like turmeric, amla, and ginger

Additionally, when compared to meat-eaters and vegetarians, vegan diets are also associated with lower levels of Insulin-Like Growth Factor-1⁸ (IGF-1), a known indicator of inflammation. 

Contain phytoestrogens

Some plant-based foods also contain phytoestrogens, a type of polyphenol that is similar in structure to human estrogen but differs significantly in its effects on the body. 

Phytoestrogens are anti-inflammatory and bind to the same cellular receptors as human estrogen, blocking its activity in certain areas of the body. Experts suggest that phytoestrogens may be helpful in managing PCOS⁷.

The best sources of phytoestrogens are:

• Minimally processed soy foods like tofu, edamame, tempeh, and soy curls
• Flaxseeds and sesame seeds
• Whole grain wheat, barley, buckwheat, oats, and rye
• Chickpeas and green peas
• Berries
• Dried fruit
• Cruciferous vegetables (broccoli, kale, bok choy, cauliflower, cabbage, etc.)

Low in saturated fat

Animal products are higher saturated fat than most plant-based foods. It’s well-known that replacing saturated fat with unsaturated fats can help improve heart health, but it may also help with improving PCOS symptoms. 

In women with PCOS, saturated fat can promote hyperandrogenism, inflammation, and reduced insulin sensitivity. Since women with PCOS are also at higher risk for cardiovascular diseases, limiting saturated fats is an important strategy for improving metabolic health.

Fortunately, vegan diets are lower in saturated fat and higher in heart-healthy monounsaturated and polyunsaturated fats. Just be sure to watch your consumption of the few plant-based foods that are high in saturated fat:

• Coconut, coconut oil and coconut milk
• Dark chocolate
• Palm oil (often used in convenience foods)

You don’t need to avoid these foods, but limiting your consumption to a few times a week or so may be helpful.

Effective for weight loss

Weight loss is a cornerstone lifestyle management strategy for women with PCOS⁹ who live in larger bodies. 

While it may not cure PCOS, weight loss often reduces chronic disease risk, improves cardiovascular and metabolic biomarkers, promotes fertility, and relieves chronic inflammation. It can also help improve quality of life¹⁰ and symptoms of depression and anxiety.

Because whole, minimally processed plant-based foods tend to be lower in calories and higher in fiber than animal products, they can be effective for weight loss. Basing meals on vegan proteins, whole grains, fruits, and vegetables while limiting added sugars and too many high-fat foods is of key importance for maintaining a calorie deficit for weight loss.

Criticisms

Of course, there are some people who feel that vegan diets aren’t appropriate for women with PCOS. Let’s take a look at some of these criticisms.

Low in vitamin D, calcium, iron, and omega-3 fats

Vitamin D and calcium are critical for bone health, iron is essential for preventing anemia, and omega-3 fats are important for heart health and keeping chronic inflammation at bay. These are nutrients that many people worry you can’t get enough of on a vegan diet. 

However, the Academy of Nutrition and Dietetics feels differently. In their position paper on vegetarian diets¹¹, they state that well-planned vegan diets can provide all the nutrients your body needs. This is true for both men and women and people of all ages, including children and older adults.

So yes, you’ll need to be intentional about getting enough of these nutrients on a vegan diet, but it can be done. The best sources of these nutrients include:

• Vitamin D: Fortified plant milks, irradiated mushrooms, and supplements
• Calcium: Calcium-set tofu, fortified plant milks, chia seeds, white beans, almonds
• Iron: Blackstrap molasses, beans, plant-based protein powders, lentils, tempeh, tofu, edamame (Check out the 12 best iron-rich vegan foods)
• Omega-3 fats: Flax seeds, flax oil, walnuts, chia seeds, hemp seeds, canola oil, algal DHA/EPA supplements

High in carbohydrates

Another reason why some people may feel that vegan diets aren’t appropriate for PCOS is the belief that they’re too high in carbohydrates, which will make it difficult to keep your blood sugar levels under control.

It’s true that vegan diets tend to be higher in carbohydrates since fruits, starchy vegetables, and beans all contain carbs. However, they’re also high in dietary fiber, which keeps us full over time and prevents blood sugar from spiking as quickly as high-carb, low-fiber foods like white bread or sweets. 

This is why vegan diets based on whole or minimally processed plant foods tend to have a low glycemic load. 

Of course, you’ll want to make sure to watch your intake of less nutritious vegan foods like sweets, chips, and sugary beverages to manage PCOS most effectively.

Low in protein

A related concern is that because vegans don’t eat meat, fish, dairy, or eggs, vegan diets are too low in protein to support blood sugar management. Fortunately, plant-based diets offer a great variety of protein-rich foods. 

I recommend that vegans include a good source of protein at every meal. Some of the best sources of protein for vegans include:

• Seitan
• Soy foods (tempeh, tofu, edamame, soy curls)
• Vegan protein powder
• Beans & lentils
• Pasta made from beans or lentils
• High-protein plant-based milks
• Nuts
• Pumpkin seeds
• Soy yogurt

Summary

While direct research on vegan diets for PCOS is still limited, existing studies suggest that incorporating more plant-based foods can be beneficial for managing the condition thanks to their anti-inflammatory dietary fiber, antioxidants, polyphenols, and low saturated fat content.

That said, there’s no one best diet for PCOS. Experts haven’t yet determined whether a vegan diet is better than other diets for this condition.

If you’re interested in trying a vegan diet to manage PCOS, try the following tips:

• Include plant protein, fruits, and vegetables at every meal
• Eat fiber-rich foods to support healthy blood sugar levels
• Choose calcium-fortified non-dairy milks to support bone health
• Include foods rich in omega-3s, or consider an algae-based DHA & EPA supplement to help support heart health and lower inflammation
• Watch your intake of vegan sweets and convenience foods that are low in fiber and high in added sugars, fat, and sodium 

And don’t forget to check out my Practical Guide to Planning Balanced Vegan Meals for more detailed information!

The scientific information in this article was accurate at the time of publishing but may change over time as new research becomes available.

References

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