Over the past few years, you’ve probably heard the message about how eating plant-based is the gold standard for health and the planet. And whilst switching from an ultraprocessed diet to a wholefoods diet which includes fresh produce will definitely do wonders for your health; I am seeing more and more clients in my practice who have been eating a plant-based vegan diet who are seriously struggling with their hormones and fertility. Some recent examples would include: a young woman who has such heavy periods that for two weeks of the month she has to change their pad every hour (even during the night), a teenager whose period has disappeared, a woman who is so fatigued she can’t even lift up a glass of water, and many women who have spent years struggling to get – and stay – pregnant.
Now, before I go on, I want to say that if you are eating a plant based diet and feel great – then that’s amazing! Everyone is different, and this is not meant to be an attack on anyone’s preferred way of eating. You do you, girl!
However, if you’ve been eating a vegan diet and are feeling tired, anxious, bloated, or struggling with irregular cycles, fertility issues or menopausal symptoms, you may want to keep reading. The truth is, a vegan diet might not be giving your hormones everything they need to thrive.
Here’s a breakdown of what could be at play (and what you can do about it):
You’re probably not eating enough
Plant foods (fruits, vegetables, beans, legumes, grains) are full of fiber and water—great for feeling full, right? Yes… but also no. When you’re eating mostly plants, it’s surprisingly easy to under-eat without even realizing it. Think salads, smoothies, steamed veggies—they fill you up fast, but don’t offer many calories. And your body needs those calories to make hormones. When you consistently under-eat, your body senses stress. It turns down reproductive function, lowers thyroid activity, and shifts into survival mode. This can throw off your estrogen to progesterone balance, leading to PMS, irregular periods, fertility issues and fatigue.
Bottom line: undereating = stress, and chronic stress wrecks hormones. You can read more about the dangers of chronic undereating in my other blog post here. You may want to track your food intake for a few weeks to see if you are eating enough.
You’re missing real Vitamin A (Retinol)
Vitamin A is a big deal for hormones. It supports thyroid health, ovarian function, and helps your body make pregnenolone, the hormone that kicks off progesterone production (the true female hormone, in my opinion). It’s also an amazing nutrient for immune system health and skin health. All those fancy anti-ageing creams and serums you’re slathering on? Yup, they contain retinol (or retinoids).
But did you know that plant foods do not contain any true Vitamin A? They contain beta-carotene, which your body has to convert into retinol. But (plot twist) up to 45% of women carry a gene variant that makes this conversion super inefficient. So even if you’re eating all the carrots and sweet potatoes, you might still be deficient in vitamin A.
Some of the best sources of retinol (the active form) include:
- Egg yolks (from pasture-raised chickens)
- Grass-fed dairy
- Liver (even a small amount goes a long way)
- Cod liver oil
Without enough retinol, your body struggles to make key hormones—especially progesterone. And if you’re not making enough progesterone, you will most likely experience unopposed estrogen symptoms such as heavy periods, PMS, mood swings, insomnia, hot flashes, fertility issues, miscarriages, thyroid dysfunction, cysts/ polyps/ fibroids, migraines, weight gain etc. Sound like you? You can read more about estrogen: progesterone imbalances here.
You’re eating lots of PUFAs
Another issue I see a lot with clients eating a plant based diet is that they are predominantly eating a ton of polyunsaturated fatty acids (PUFAs), which are found in a lot of vegan staples like nuts and seeds, beans and legumes, plant milks, vegan cheeses, dairy substitutes, and seed oils (like sunflower, rapeseed, and soybean oil).
While foods like nuts and seeds are often touted as healthy, high PUFA intake can actually suppress thyroid function, increase inflammation, and create estrogen dominance. One study in The Journal of Nutrition showed that diets high in PUFAs decreased levels of T3—the active form of thyroid hormone. PUFAs are also high in omega-6 fatty acids, and if you’re not balancing those with enough omega-3s (which is hard to do on a vegan diet, as they are mostly found in oily fish), you’re increasing inflammation. And chronic inflammation = hormonal chaos.
Did you know? We make all of our sex hormones from cholesterol. So aside from high PUFA consumption, lack of dietary cholesterol can impact pregnenolone production.
So what can you do? The first step is to switch your fats to more saturated versions such as coconut oil or ghee (if you’re open to it). Coconut oil is especially supportive of thyroid health and is easy to digest. Switch your plant milks to coconut milk if you’re struggling with dairy (BTW, a lot of dairy intolerance stems from low thyroid function. But eliminating it is not the answer, optimising thyroid health is! A topic for another time, perhaps). Working on gut health is also crucial if dairy is an issue. I have seen it re-introduced successfully once these issues were addressed.
High Soy Consumption is Messing With Your Estrogen
If you’re vegan and looking to consume enough protein, then soy is most likely your best friend. Soy is everywhere in vegan diets—soy milk, tofu, tempeh, mock meats… the list goes on. While soy does offer a great source of vegetable protein, it’s also a potent phytoestrogen, meaning it mimics estrogen in the body. So much so, in fact, that women with estrogen positive cancers are told to stay away from soy. Now, if your hormones are already out of balance (which in my experience very often due to low progesterone in relation to estrogen), this can make things worse by tipping you further into estrogen dominance—a common issue in women that leads to symptoms like PMS, tender breasts, mood swings, and painful periods, as well as menopausal symptoms (yep! It’s not low estrogen, ladies), fertility issues, and even symptoms like hayfever. On top of that, soy also contains goitrogens, which can interfere with iodine uptake in the thyroid. And as you know by now, a sluggish thyroid equals sluggish hormone production across the board.
You’re consuming vegan processed foods which are wrecking your gut
The popularity of plant-based eating has not escaped the attention of food manufacturers. And in a quest to cash in, you’ve probably seen a plethora of plant based foods line the shelves and supermarket fridges. Even the most whole-food-loving vegans usually reach for some store-bought alternatives—things like vegan cheese, oat milk, or meat substitutes. The problem? These foods are often filled with refined seed oils, carrageenan, guar gum and other additives to create texture, isolated and hydrolyzed plant proteins. These ingredients can irritate your gut lining, disrupt your microbiome, and impair your ability to detox excess estrogen properly. A healthy gut is essential for hormone balance, so if your digestion is off, chances are your hormones are, too.
Caveat: this obviously does not only apply to vegan processed foods – all ultra processed foods contain these ingredients! So please check the labels!
Your calcium to phosphate ratio is off
This is something you may not have heard about before, so stick with me. If you are eating a plant based diet, your calcium to phosphorous ratio will most likely be off, with high phosphate levels. This can also apply to people eating animal products but avoiding dairy. Phosphate is found in many foods such as meat, fish, dairy, vegetables, cereals and legumes. Phosphate is also a common food additive.
When there is an higher phosphate to calcium ratio, there is an increased production of parathyroid hormone and prolactin; two hormones which negatively impact thyroid function, but can also impact hormonal health. High prolactin can disrupt the menstrual cycle and cause missing periods. Having high levels of parathyroid hormone and prolactin can also lead to osteoporosis, by robbing your bones of calcium.
On top of that, high phosphate can impact our cells ability to make energy. Ray Peat, PhD, observed that “whilst increased phosphate slows mitochondrial energy production, decreasing its intracellular concentration increases the respiratory rate and the efficiency of ATP formation.” (Source) What does that mean? Phosphate is a molecule that’s involved in how your cells make energy. Your cells use mitochondria to turn food into energy — this energy is stored as ATP. However, if phosphate builds up inside your cells, it can slow down energy production. And if we are not producing energy at a cellular level, this will have a knock on effect on our tissues, organs, and body systems.
Research suggests that excess phosphate can contribute to various health problems, including inflammation, tissue damage, blood vessel calcification, cancer, dementia, and accelerated aging. This is supported by studies indicating that high phosphate levels can exacerbate inflammation, promote the development of cancer, and accelerate age-related diseases.
But hang on, it’s not just plant foods that contain phosphorus, so why am I banging on about this?? What matters here is the ratio between calcium and phosphate, so we want to choose foods that have a higher ratio of calcium to phosphate. Ray Peat, PhD, who introduced me to this concept in his brilliant work, says:
“The foods naturally highest in phosphate, relative to calcium, are cereals, legumes, meats, and fish. Many prepared foods contain added phosphate. Foods with a higher, safer ratio of calcium to phosphate are leaves, such as kale, turnip greens, and beet greens, and many fruits, milk, and cheese. Coffee, besides being a good source of magnesium, is probably helpful for lowering phosphate, by its antagonism to adenosine (Coulson, et al., 1991).” Ray Peat, PhD,t (Source)
He was also quoted as saying “The ratio of calcium to phosphate is very important; that’s why milk and cheese are so valuable for weight loss, or for preventing weight gain. For people who aren’t very active, low fat milk and cheese are better, because the extra fat calories aren’t needed.” (Source)
So if your diet consists of beans, legumes and cereals and no dairy, this could be an issue.
So… What’s the Solution?
You don’t have to swing to the other extreme and go all out carnivore and eat nothing but meat. After all, it is really important to consume enough whole food carbohydrates into the diet for optimal health and energy. But adding back a few high-quality animal foods can do wonders for your hormones. My favourite hormone supporting animal products are:
- Organic pasture-raised eggs – rich in choline, B vitamins, and cholesterol (the building block of all hormones)
- Grass-fed dairy – full of retinol, calcium, and saturated fat to support hormone production.
- Wild-caught fish and shellfish – excellent sources of protein as well as iodine, zinc, and selenium for thyroid and ovarian health.
- Organ meats (like liver) – the highest source of retinol, but also packed with b vitamins, iron, and copper
- Bone broth and gelatin – rich in glycine, which supports liver detoxification, soothes the gut lining and and aids progesterone production
If you haven’t consumed these foods in a while – especially dairy – you may need to start small. Even incorporating just a few servings a week of these foods can make a big difference in how you feel—more energy, better mood, more regular cycles, and fewer PMS symptoms.
To conclude, if you’re thriving on a vegan diet, this article is not really for you, but thank you for reading until the end! If you’ve been eating a vegan diet and something just feels off, trust that feeling. Your hormones are incredibly sensitive to nutrient intake, and while a plant-based lifestyle might work for some people, or you may have felt great at first, it may not fully support the complex hormonal needs of a woman’s body—especially long-term.
If you are struggling with any of the symptoms above and would like to delve deeper into hormonal balance with a bespoke nutrition and lifestyle plan, I would love to chat to you! Click here to book a discovery call and let’s chat about how some bespoke diet and lifestyle changes can help your hormones flourish.
Further Reading:
Ray Peat Phosphate, activation, and aging
Ray Peat PhD Natural Estrogens
Studies:
