I’ve written many posts about PCOS, and today I want to explore the relationship between PCOS and dietary fibre.
To recap, polycystic ovary syndrome (PCOS) is the most common hormonal disorder in reproductive-aged women. Whenever I mention PCOS to my clients, many of them say that they don’t have cysts on their ovaries. Here’s the thing, you can be diagnosed with PCOS without having cysts.
To be diagnosed, you need at least 2 of the 3 following criteria:
Delayed ovulation or irregular menstrual cycles (oligomenorrhea)
High androgenic hormones like testosterone
Polycystic ovaries on ultrasound
Whenever I’m suspecting PCOS, I like to run blood work to determine androgen levels. In addition, because insulin resistance is common with PCOS, it’s important to also assess those parameters.
Some of the tests I like to run:
Sex Hormone Binding Globulin (SHBG)
A 2019 study looked at the relationship between fibre, insulin resistance and PCOS. It demonstrated that a low fibre intake in people with PCOS is a significant factor in insulin resistance, and people with PCOS consumed less fibre than those without PCOS.
Fibre is a complex carbohydrate that isn’t digestible. There are 2 types – soluble and insoluble. Soluble helps to lower things like blood glucose and cholesterol. While insoluble helps to bulk up stool, improve motility, and it can also increase insulin sensitivity.
However, many of us don’t eat nearly as much fibre as we should. A low-fibre diet is associated with many health problems including type 2 diabetes and metabolic syndrome (which is essentially a cluster of syndromes including increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels).
Fibre can help regulate blood glucose by slowing it’s absorption in the blood, which then improves glucose tolerance. The 2019 study also showed that in people with PCOS who did not eat much fibre, they tended to have increased testosterone and DHEAS levels. Moreover, insulin resistance may actually worsen high androgens.
This means that including more fibre-rich foods in your diet may lower insulin resistance and manage high androgen levels and improve those PCOS parameters.
Foods that are rich in fibre include fruits, vegetables, beans and legumes, as well as grains. Some fibre-rich foods include:
Raspberries – 4g of fibre for 1/2 cup
Pear – 5.2g of fibre for 1 medium pear
Apple – 3.3g of fibre for 1 medium apple
Brussel sprouts (cooked) – 3.2g of fibre for 1/2 cup
Carrots – 3g of fibre for 1 large carrot
Lentils (cooked) – 10.4g for 2/3 cup
Black beans (cooked) – 7.5g for 1/2 cup
Peanut butter (chunky) – 2.6g for 2 tbsp
Brown rice (cooked) – 1.8g for 1/2 cup
Rolled oats (cooked) – 4.2g for 3/4 cup
Ideally people with PCOS should be aiming for 30-35g of fibre per day. As you increase your fibre intake, be sure to make sure you’re also increasing the amount of water you’re drinking per day (this is because fibre can bind water).
Cutler, D., Pride, S., & Cheung, A. (2019). Low intakes of dietary fiber and magnesium are associated with insulin resistance and hyperandrogenism in polycystic ovary syndrome: A cohort study. Food Science & Nutrition, 7(4), 1426-1437. doi: 10.1002/fsn3.977
It’s not just a woman’s issue. And what you’re eating (or not eating), can affect your fertility success. Let’s dive into a couple of things that can help improve sperm parameters in men.
Fatty Acids and Fertility
The sperm cell membrane high in fatty acids, and these acids are necessary for sperm function. The membrane is pretty important when it comes to fertilization – it helps with cell maturation, penetrating and fusing with the egg.
The fatty acids that you need to do these jobs can’t be made by your body, so you need to either eat fish, supplement with fish oil, or eat nuts and seeds. Studies have shown that male fertility patients who have a higher intake of omega-3, have more normal sperm. A study looking at walnuts (which are a great source of omega 3s) have been related to higher sperm parameters – vitality, motility (how sperm move), and morphology (how sperm look). Another study showed that men’s fish intake was related to shorter time to pregnancy and a lower risk of infertility.
It is important to pay attention to mercury levels in fish, and consider avoiding fish with high mercury levels as it may impact fertility.
Soy and Fertility
Women aren’t the only ones cautious about soy. From my experience, men are pretty fearful too. When we look at the research on dietary soy and men’s health it’s pretty conflicting. While one study mentions that dietary isoflavone intake is associated with higher sperm count and motility, another says that soy intake is associated with lower sperm concentration.
Here’s the thing, if you’re vegan or vegetarian and soy makes up a large part of your diet, aim for non-GMO and organic sources.
Dairy & Meat and Fertility
Research on diary and sperm parameters is pretty mixed. One study looking at young men and dairy consumption showed that intake of dairy products (like milk) have been related to lower testosterone, FSH and LH levels.
When it comes to meat, the same results exist. Some studies show that meat is unrelated to sperm parameters, some show that processed meat affects sperm counts.
Something to consider though is your cardiovascular health. While that Double Big Mac might not do anything to your sperm, it might affect your heart health! Keep in mind that your body
Fruits & Vegetables and Fertility
Unsurprisingly, fruits and vegetables are cornerstone of good health. But, many of them are sprayed with pesticides. One study showed that consumption of high-pesticide-residue fruits and vegetable was associated with poor sperm quality in men attending a fertility clinic.
So what does this mean? Choose organic when eating foods off the Dirty Dozen list.
Overall, the review that I read didn’t go into as much detail as the female version. However, it did mention that if you’re going to abide by a diet, then the Mediterranean Diet is a good bet. It’s high in seafood, vegetables and fruits, whole grains, etc. Basically you’re not eating processed and packaged foods.
Changing a diet can be pretty difficult. I’m of the mind of taking it a week at a time, so if you’re introducing a new food or avoiding an old (but problematic) favourite, do it in weekly increments.
When I was giving up gluten, cow dairy and eggs, I picked one and committed to that for a week, then gave up another, etc. When introducing new foods like salmon, commit to eating it once a week, find different ways to prepare it, etc. Changing your habits around food don’t need to be difficult. But like all things, it does take some work.
For more information on how you can boost your fertility and improve your sperm parameters, consider working with a naturopathic doctor. If you have any questions, feel free to get in touch!
Nassan, F., Chavarro, J. and Tanrikut, C. (2018). Diet and men’s fertility: does diet affect sperm quality?. Fertility and Sterility, 110(4), pp.570-577.
Many people in the health arena talk about a “fertility diet,” like the top 10 things you should eat to get pregnant. And the truth is, there really isn’t a true fertility diet. In fact, many people get pregnant by eating whatever they want – which is great, but can be incredibly frustrating for those people who’ve been trying a long time to become pregnant and are tracking everything – including the food they eat.
However, diet does play a huge role in how we feel and function, and provides the necessary building blocks to support conception.
Carbohydrates and Fertility
Carbohydrates typically make up a significant part of a persons diet. It’s made up of many components like monosaccharides (single sugars: glucose, fructose, galactose), disaccharides (two sugars combined: sucrose and lactose), and polysaccharides (complex sugars: starch and dietary fibre).
Most of our processed food these days often contain a significant quantity of artificial sugars which can lead to negative outcomes.
Studies have shown that eating whole grains have been correlated to increased implantation and live birth rates, possibly because they help to thicken the endometrial lining.
In women undergoing IVF and who regularly consumed artificial sugars experienced lower success rates. In those using ICSI, drinking beverages higher in artificial sweeteners also had a negative impact.
Additionally, the glycemic index and load have been associated with fertility outcomes.
The glycemic index is a value assigned to a particular food on how fast or slow it causes an increase in your blood glucose level.
The glycemic load combined quality and quantity of carbohydrates. It’s calculated by the amount of food you eat and the glycemic index of the particular food.The glycemic load is also associated with higher risks of ovulatory infertility.
In PCOS, it’s been found that women will often consume foods with a higher glycemic index. When women reduce their carb intake (or perhaps choose carbs with a lower index and load), their insulin sensitivity will improve, testosterone will decrease, and ovulation will occur (this is important, because anovulation is a key symptom in PCOS).
Fats, Fatty Acids and Fertility
Let’s clear something up. Fat isn’t bad. Yes, some are better than others and there are some you should avoid completely. But you need fat to make hormones, help your eggs mature and to get that tiny blastocyst to implant! Fats provide energy for all your daily activities, and they help to make up your cell membranes.
Fats can be divided into two types based on their structure – saturated and unsaturated. Animal foods are largely made up of saturated fats, while plants are largely made up of unsaturated fats.
Unsaturated fats can be broken up into omega 3 fatty acids – EPA and DHA, omega-6 and omega-9 fatty acids. Omega 3 fatty acids are associated with progesterone production in the luteal phase and a reduced risk of anovulation. In women undergoing IVF, omega 3 fatty acid intake was associated with better embryo quality and implantation, and linked to high live birth rates.
Unsurprisingly, there is a particular fat you should be avoiding – trans fat. This is a type of unsaturated dat that can increase insulin resistance, may prevent ovulation from happening, and decrease your chance of getting pregnant.
Dairy and Fertility
It’s been thought that dairy can negatively impact fertility, however no relationship between full-fat dairy foods and anovulation has been found.
Protein and Fertility
Protein intake is not just important for fertility, but it’s important for your overall health. Ideally you should be eating at least 1g of protein per kg of body weight (more if you’re active).
Protein comes in different forms: animal and vegetable. Animal proteins can be further divided into red and white meat. Red meat often gets a bad rap because it contains saturated fatty acids and can also contain hormones, antibiotics and toxins.
Seafood is thought to be a better protein source because it also contains omega-3 fatty acids. If you’re going to start incorporating more fish in your diet, be mindful that eating fish that’s exposed to more toxins (like mercury – which can interfere with hormones), might offset its actual benefits.
Studies show that women who eat a large amount of vegetables and fish had higher rates of blastocyst formation; whereas women who ate more red meat, drank alcohol and smoked had lower rates of blastocyst formation. Obviously it would have been interesting to see a direct comparison between fish and red meat without including alcohol and smoking to the mix.
I often get asked if soy is a suitable protein for fertility, because its affect as a phytoestrogen. Studies have shown that soy causes little harm in women, and in fact might be beneficial. Soy isoflavone supplements were associated with improvement in reproductive outcomes, increased live birth after clomiphene administration, and higher endometrial thickness and ongoing pregnancy rates after IVF and ICSI.
Before ordering your soy latte – choose organic, non-GMO soy. And if you have a thyroid condition, it may be best to avoid dietary soy altogether.
Antioxidants and Fertility
Many people believe that antioxidants can be helpful for fertility, the reasons why they’re often used is because oxidation regularly occurs in the body. When nutrients are used in the body, the mitochondria use them for energy, which also produces oxidation and an abundance of reactive oxidative species can cause damaging effects in the body if there aren’t enough antioxidants to “quench” them and repair the damage the cause.
When produced in high amounts, reactive oxidative species can lead to DNA damage and cell death. In cells associated with fertility, the most common cause of oxidative stress are environmental pollution, smoking, alcohol, poor nutrition, and obesity.
Although many studies don’t agree on the ‘best’ antioxidant outcomes leading to live births, or the dosage – there are many antioxidants to choose from. We’ll focus on this in a future blog post.
Vitamins and Fertility
The family of B vitamins are needed for energy production. Studies have specifically looked at folate. We know that this important B vitamin is needed for neural tube defects – which is why many people will start to take folate when planning a pregnancy.
Studies have shown that using folate in the preconception period may increase chances of becoming pregnant and hopefully result in a live birth. In a Danish study, folic acid was associated with a shorter time to pregnancy. In addition, a Polish IVF study demonstrated that supplementation led to better quality and more mature eggs – compared to women who did not have folic acid supplementation.
Oftentimes, folic acid and folate are used interchangeably. Methylfolate is the active form of folic acid, and while it does the same thing as folic acid, the active form may be better absorbed and used.
Vitamin D is an important vitamin, with receptors on the ovary, endometrium, and placenta. Studies have shown that a vitamin D deficiency in women undergoing IVF, can negatively impact egg and embryo quality and reproductive function. A vitamin D deficiency was also higher in women with recurrent miscarriages – although recurrent miscarriages can happen for a variety of reasons (ex. hypothyroidism).
Vitamin D is also thought to support endometrial receptivity and implantation of the embryo. In women older than 40, there was a relationship between decreased AMH and a vitamin D deficiency.
Mediterranean Diet and Fertility
I mentioned in the intro that there’s no true fertility diet. That said, a lot of people turn to the Mediterranean diet as a standard because it has been shown to be beneficial in those using IVF. The Mediterranean diet consists of fish, monounsaturated fats from olive oil, fruits, vegetables, whole grains, legumes/nuts, and moderate alcohol consumption (read: red wine). Unlike other diets, it does not limit foods or calories.
In non-obese women under 35, the live birth rate was 20% higher in those following a Mediterranean diet, compared to other diets. There wasn’t any difference in women older than 35; as well as no difference in egg collection or embryo grades.
So while the Mediterranean diet has been shown to be helpful for fertility, it’s often studied in people who go on to use IVF. Again, that doesn’t mean this will be the right diet for you, but if you are looking to improve outcomes – particularly if you feel it’s taking you a ‘long’ time to get pregnant, it may be worth exploring this diet further.
It might be obvious that a diet that leans towards fast food/processed foods and few fruits and vegetables is probably not ideal. Reviewing the Mediterranean diet may be a good idea if you’re hoping to improve outcomes.
That said, no matter what you may be eating, be mindful of pesticides and other chemicals in your foods as they also affect reproductive success. Therefore, if possible, choose organic when you can. Basically, if any of the fruits and vegetables that you eat appear on the Dirty Dozen, eat the organic version instead. For the foods that appear on the Clean Fifteen, you don’t need to choose organic versions of these products.
Keep in mind that when choosing organic version of products, you want to look for a specific seal – otherwise you can’t be certain that the product you’re buying is indeed organic. The picture below demonstrates a Canada Organic seal, as well as a USDA organic seal. The Non GMO project seal may be good to remember when choosing products containing soy.
When choosing meats, aim to get your meats from local farms if possible. Choosing grass-fed and antibiotic-free are great options too. I haven’t been able to find a seal for this (I’m not sure one exists), but in my experience the packaging will usually state if a product is grass-fed or antibiotic free.
Lastly, you may also be considering taking some supplements during the preconception period. This may include a prenatal that includes methylfolate, a fish oil supplement that contains EPA and DHA, and vitamin D – although you may want to get your level assessed by a Naturopathic Doctor to see if you’re experiencing any deficiencies.
Chiu, Y., Chavarro, J. and Souter, I. (2018). Diet and female fertility: doctor, what should I eat?. Fertility and Sterility, 110(4), pp.560-569.
Gaskins, A., & Chavarro, J. (2018). Diet and fertility: a review. American Journal Of Obstetrics And Gynecology, 218(4), 379-389. https://doi.org/10.1016/j.ajog.2017.08.010
Koga, F., Kitagami, S., Izumi, A., Uemura, T., Takayama, O., Koga, T., & Mizoguchi, T. (2020). Relationship between nutrition and reproduction. Reproductive Medicine And Biology, 19(3), 254-264. https://doi.org/10.1002/rmb2.12332
Lu, J., Wang, Z., Cao, J., Chen, Y., & Dong, Y. (2018). A novel and compact review on the role of oxidative stress in female reproduction. Reproductive Biology And Endocrinology, 16(1). https://doi.org/10.1186/s12958-018-0391-5
Smits, R., Mackenzie-Proctor, R., Fleischer, K., & Showell, M. (2018). Antioxidants in fertility: impact on male and female reproductive outcomes. Fertility And Sterility, 110(4), 578-580. https://doi.org/10.1016/j.fertnstert.2018.05.028