What types of fat are good for fertility?
by Kayleah Scarborough, dietetic intern
Do any of these sound familiar to you?
“I've heard canola oil is really bad for me.”
“My doctor told me to cut back on the butter.”
“I was told oil is really disruptive to your hormones.”
These may be some of the things you hear when you are surrounded by diet culture. In reality, there are many benefits to lots of different types of oils and fats. Though nutrition science is constantly changing, you likely don’t need to throw out all the oil in your pantry. So, let's do some myth busting around different types of fats!
What are the different kinds of fats?
There are a lot of different types of fats that each serve different functions in the body. The four main categories of fats are:
Monounsaturated Fats: Can help maintain a healthy level of cholesterol; found mostly in plant oils (ex. canola oil, olive oil, sesame oil)
Polyunsaturated Fats: In plant and some animal based foods (ex. fish, nuts, avocados). This category includes both Omega-6 and Omega-3 fats; both of which are very important for bodily functions.
Saturated Fat: Most are in animal foods, solid at room temperature (ex. Butter, coconut oil)
Trans Fat: Naturally or Artificially made. (ex. Fried foods, partially hydrogenated vegetable oil). Trans fats are no longer intentionally used in processed foods in the US due to health risks, but may spontaneously form due to cooking or food processing methods.
What can fats do for me and my fertility?
Fat is essential in creating hormones, absorbing nutrients (vitamin A, D, E, K), protecting organs, and providing energy. Unsaturated and saturated fats are used as energy during the process of maturation of an egg and early embryo development. These fats also help create certain steroids and hormones used in fertility including:
Prostaglandins – increases the chances of sperm survival, motility, and fertilization
Estrogen – thins your cervical mucus allowing sperm to swim through to the egg
Progesterone – helps prepare the uterus for pregnancy
Testosterone – required for sperm production
Without fats, these hormones would not be able to play their vital role in attaching a fertilized egg into the uterine lining (implantation) and overall pregnancy maintenance.
Are saturated fats and trans fats bad?
The American Heart Association suggests plant based fats for cooking such as:
Canola
Corn
Olive
Peanut
Safflower
Soybean
Sunflower
These are all unsaturated cooking fats. Many worry that saturated fats are going to increase their “bad cholesterol” (LDL) levels and in turn create heart problems. Though saturated fat isn’t recommended by the AHA, there is newer research suggesting that there is not a link between saturated fat and certain chronic conditions. It seems to some researchers that there has been an exaggeration in what LDL is actually capable of doing to our bodies. According to one systematic review: “LDL cholesterol is not associated with cardiovascular disease.”
It’s important to note that this area of research is still developing, and those with genetic risk factors for heart disease may benefit from lowering their intake of saturated fat, but we also know that cholesterol is artificially elevated in pregnancy and lactation as your body works to transport fat and other nutrients to your growing baby through the placenta and breast milk. For all of these reasons, here at Feed Your Zest we don’t focus on cholesterol too much with clients who are trying to conceive or currently pregnant, and don’t recommend they limit saturated fat either.
In contrast, trans fats do seem to have some correlation with coronary heart disease. Trans fat is also associated with higher risks of ovulatory infertility and laparoscopically confirmed endometriosis. Those with PCOS also have increased sensitivity to trans fats - meaning that lowering trans fats in your eating pattern when you have PCOS can have a big effect on managing your symptoms. This does not mean that eating trans fat is going to guarantee heart disease and worsened endometriosis or PCOS; however, being mindful of your intake of fried and highly processed foods can help limit adverse health outcomes.
Do oils high in Omega-6 cause inflammation?
Many plant based oils are high in Omega-6 fatty acids including seed oils– which are just like what they sound like, oils made from seeds. Some common ones used regularly are canola, sunflower, grapeseed, safflower and cottonseed oil. Other oils high in omega-6 fatty acids include corn, vegetable and soybean oil. You may have heard that seed, corn and soy oils cause inflammation, but this claim is false. Current evidence suggests that higher intake of Omega-6 fatty acids does not increase inflammatory markers. While many have posited that the standard Western diet is too high in Omega-6 fatty acids and that this is responsible for the increase in chronic diseases, the issue may actually be a lack of Omega-3 fatty acids instead. Choosing a seed oil high in Omega-3 fats like canola for cooking can help you increase your intake of Omega-3 fats without fearing Omega-6 fats.
What do Omega-3 fatty acids do for me?
There is loads of evidence showing the benefits of Omega 3 fatty acids on cardiovascular health, gut health, and brain function, but what about fertility and pregnancy? Higher intake of Omega-3 fats has been shown to improve embryo morphology for people undergoing IVF treatment. In pregnancy Omega-3 fatty acids are important in forming the fetus into a baby, improving the babies cognitive function, and decreasing the chances of a premature birth. Foods that are high in Omega-3 fats include:
Seafood (especially cold water fish like; salmon, sardines and mackerel)
Walnuts, chia, and flax seeds
Avocado and olives
Canola and extra virgin olive oil
However, an Omega-3 supplement could be helpful in addition to making additions to your eating pattern. A study conducted on fertility and omega-3 fats showed that women who were supplementing with Omega-3’s had 1.51 times the probability of conceiving. Talk to your dietitian about whether an omega-3 supplement is right for you.
So what does this mean?
When we educate ourselves on what is ACTUALLY happening with the fats that we are eating, we can make informed decisions that are not based out of fear. Instead, we can move towards eating a well rounded and joyful diet without thinking twice about what diet culture has told us. Focusing on building a balanced plate with carbs, protein, fat, and fiber allows you to eat nutritious and fulfilling meals while utilizing intuitive eating techniques.
Looking for more information about how to properly nourish yourself for your fertility and pregnancy journey? Our group coaching program Fully Nourished Pregnancy walks you through how to ADD foods for fertility and pregnancy according to evidence-based nutrition science without a restrictive diet. Enroll in Fully Nourished Pregnancy today!