Cholesterol and Fertility: How High and Low Cholesterol Affect Your Hormones, Ovulation, and Egg Quality [EP 81]
Cholesterol is one of those words that can immediately make you think, “I need to lower that.” But cholesterol is also essential for fertility. Your body needs cholesterol to make reproductive hormones, build healthy cells, produce bile, and support vitamin D production. So what happens when cholesterol is too high—or potentially too low—when you're trying to conceive?
In this episode, I'm breaking down what your cholesterol numbers can actually tell you about fertility, metabolic health, and hormone function. We'll look at LDL, HDL, triglycerides, ApoB, Lp(a), thyroid health, fasting insulin, nutrition, exercise, and the important difference between dietary cholesterol and blood cholesterol. Most importantly, we'll talk about why your cholesterol numbers need to be interpreted in the context of your whole body—not in isolation.
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“Your body needs cholesterol to make the hormones you need to get pregnant.”
What You’ll Learn:
Why your body needs cholesterol to make estrogen, progesterone, and testosterone
How cholesterol, thyroid health, blood sugar, and insulin resistance are connected
What your LDL, HDL, and triglyceride levels can tell you about metabolic health
Why ApoB and Lp(a) can provide additional context beyond a standard lipid panel
How insulin resistance can affect cholesterol, ovulation, and reproductive hormone signaling
Why elevated cholesterol doesn't automatically mean you should follow a low-fat or highly restrictive diet
Why dietary cholesterol and blood cholesterol are not the same thing
How eggs, healthy fats, fiber, and omega-3s can fit into a fertility-supportive diet
What unusually low cholesterol can tell us when it's combined with under-eating, irregular cycles, or low energy
Why thyroid health deserves a closer look when cholesterol is elevated
How cholesterol medications fit into the fertility conversation and why you should never stop medication on your own
What comprehensive preconception blood work can reveal about your fertility and long-term health
“Cholesterol is one piece of a much bigger picture.”
Lab Markers Mentioned:
Total cholesterol
LDL cholesterol
HDL cholesterol
Triglycerides
ApoB
Lp(a)
Fasting insulin
Fasting glucose
Hemoglobin A1C
TSH
Free T4
Free T3
Thyroid antibodies
Inflammatory markers
Liver enzymes
Links Mentioned:
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“You shouldn’t choose between your cardiovascular health and your reproductive health.”
Transcript:
What if I told you that one of the most feared numbers on your blood work is also essential for making the hormones you need to get pregnant?
I'm talking about cholesterol.
Yes, the same cholesterol you've probably been told to lower, avoid eating certain things because of, or worry about every time you get your annual blood work.
And here's the thing: your body needs cholesterol to make estrogen, progesterone, and testosterone.
It needs cholesterol to build healthy cells, produce bile, and even support vitamin D production, which are all really important for fertility.
But that doesn't mean higher cholesterol is always better.
And it definitely doesn't mean that we should ignore overall elevated cholesterol, especially when we're talking about LDL or triglycerides.
When I'm looking at cholesterol and someone who's trying to conceive, I'm asking two separate questions.
First, is your body getting what it needs to make hormones and support reproduction?
And second, what is your lipid panel telling us about your metabolic and cardiovascular health?
Because that impacts fertility too.
These two things are connected, of course.
So today we're going to dive in and talk about why cholesterol matters for fertility, what your lipid panel can actually tell us about your hormones, why your thyroid and blood sugar deserve a seat at this table, and what you can actually do to support healthy cholesterol levels without compromising your fertility.
So let's go ahead and start with a little biology because once you understand what cholesterol actually does, the rest of this conversation makes a whole lot more sense.
What Cholesterol Actually Does
First of all, cholesterol is a fat-like substance found in every cell in your body.
Your liver makes most of what you need.
And you also get cholesterol from animal foods like eggs, meat, and dairy.
One of its most important jobs is actually serving as a starting material, or like the backbone, for your steroid hormones.
Your body takes cholesterol and converts it into pregnenolone, and from there it can actually produce progesterone, estrogen, testosterone, and DHEA.
Think about that for a second.
Your body cannot make these hormones without cholesterol.
And when we're talking about fertility, these hormones are very important.
Estrogen helps us build your uterine lining and supports follicular development.
Progesterone helps prepare your uterus for implantation and supports early pregnancy.
Testosterone also plays a role in ovarian function.
And we obviously need adequate testosterone production for healthy sperm development on the male side too.
Why More Cholesterol Isn't Automatically Better
But here's where I want to make a really important distinction.
Just because cholesterol is a starting material for those hormones doesn't mean that eating more cholesterol will automatically increase your progesterone or improve egg quality.
Unfortunately, your body is a little more complicated than that.
You need healthy hormone signaling, adequate energy, functioning mitochondria, proper thyroid function, and many nutrients that are involved in all of these hormone production processes too.
And of course, you actually need to ovulate in order to produce meaningful amounts of progesterone in the first place.
This is why we don't look at low progesterone and immediately jump to progesterone supplementation.
It's much more complex than that.
I want to understand why you're not producing enough in the first place.
Are you ovulating consistently?
Are you eating enough?
Are you getting adequate protein and carbohydrates?
Is your thyroid functioning properly?
Are you dealing with insulin resistance or chronic inflammation, for instance?
Cholesterol is one piece of a much bigger picture.
And here's something else worth understanding.
Even if your cholesterol is low, that doesn't automatically mean your body doesn't have enough cholesterol to make hormones.
Your cells can produce cholesterol, and hormone production is regulated.
Your body does its best to keep it tightly regulated, but it all depends on the environment that it's being created in.
When Low Cholesterol Deserves a Closer Look
When I see unusually low cholesterol alongside irregular cycles, chronic dieting, or signs of undernutrition, I want to investigate further.
Not because the specific cholesterol number diagnoses a hormone problem, but because I want to understand what's happening overall metabolically.
Because it all is connected.
Your reproductive system needs adequate energy and nutrients.
And if you've spent years under-eating, avoiding entire food groups, or exercising excessively, that's something that we need to address.
All of those things are going to impact cholesterol and then the downstream effects of what cholesterol supports.
Which definitely includes all of those hormones.
Understanding Your Cholesterol Blood Work
All right.
So let's talk about blood work because I think this is where a lot of women are missing really important context.
You get your annual blood work done, or maybe it's with your fertility doctor, and you're seeing that your total cholesterol is coming back at 215.
And suddenly you're being told that you need to lower it.
But what about your HDL?
What's your LDL?
What are your triglycerides looking like?
How's your blood sugar?
How's your thyroid?
How's your inflammation?
Do you have a family history of cardiovascular disease?
All of these things matter because we have to put every single lab marker in context.
And certainly cholesterol is no different.
Your total cholesterol is one number.
It does not tell us the whole story.
So let's break down the markers I want you to understand.
LDL Cholesterol
LDL is commonly called your bad cholesterol, but technically it's a lipoprotein that transports cholesterol through your bloodstream.
Your body needs this transport system.
However, elevated LDL, particularly when you have a high number of ApoB-containing particles, increases the risk of plaque accumulating in your arteries over time.
And we definitely want to take that into consideration and take it seriously.
But when I'm working with someone who has elevated LDL, I also want to know why.
Why are you transporting more cholesterol on this lipoprotein?
Is your thyroid underactive?
Do you have insulin resistance?
Is there a genetic component?
Has your diet changed significantly?
Or maybe you're taking medications that are influencing cholesterol regulation?
Because understanding the contributing factors to the LDL helps us create a more individualized plan.
And if your LDL is 190 or higher, it's going to prompt a more holistic evaluation.
Standard lab ranges are a little tight when we're talking about fertility, so LDL coming up a little bit above 100 is not as concerning when we're looking at the whole context and understanding the full cholesterol regulation picture.
HDL Cholesterol
After LDL, we also have HDL.
HDL is commonly called your good cholesterol, and its job is also to transport cholesterol, but it's transporting it back towards the liver where it can be reused or eliminated.
HDL is often lower in people who have insulin resistance, lower in people who have metabolic syndrome, or low levels of physical activity.
We want HDL to be higher, ideally above 70, which is a little bit higher than our standard lab ranges are looking at.
But this is something I see quite frequently in women with POMS.
And we've been discussing POMS on this podcast also.
So if you're not familiar with what that is, it used to be called PCOS, and it has a whole new diagnosis.
Go back and listen to previous lessons if you have a PCOS diagnosis because there's more context for that specific diagnosis on that episode.
But you may have irregular cycles, elevated insulin, higher triglycerides, and lower HDL when there's a metabolic syndrome involved.
These are not completely unrelated problems.
They're often different signs of the same underlying metabolic dysfunction.
I also want to point out that higher HDL isn't endlessly better.
Having a very high HDL doesn't cancel out elevated LDL or ApoB.
But the balance, and again, the context of all of it, is definitely important to look at.
We always have to look at the entire picture.
Triglycerides and Insulin Resistance
Triglycerides is another marker that we want to pay close attention to, especially when we're dealing with fertility challenges.
Triglycerides are a form of fat that your body uses and stores for energy.
Elevated triglycerides frequently accompany insulin resistance.
For example, let's say you're a 35-year-old woman who's been struggling to conceive, your triglycerides are 180, your HDL is 42, and your fasting insulin is elevated.
I'm absolutely going to investigate your metabolic health.
Even if your fasting glucose and hemoglobin A1C are technically within standard reference ranges.
Because insulin resistance can develop long before—actually, a decade before is estimated—your blood sugar even becomes abnormal.
So before that fasting glucose or hemoglobin A1C becomes out of range, fasting insulin can give us big red flags of insulin resistance.
And metabolic dysfunction can absolutely interfere with ovulation and reproductive hormone signaling.
This is why I encourage comprehensive preconception blood work rather than relying on a basic metabolic panel.
ApoB and Lp(a)
Let's talk a little bit more about ApoB.
This is a marker I wish more people knew about.
Apolipoprotein B, or ApoB, gives us an estimate of the number of potentially atherogenic lipoprotein particles circulating in your blood.
Each LDL particle carries one ApoB protein, as do several other cholesterol-carrying particles.
Why do I care about this?
Because two women can have identical LDL cholesterol levels but different numbers of LDL particles.
And those particle numbers can actually tell us something important about cardiovascular risk.
ApoB can be particularly helpful when someone has insulin resistance, elevated triglycerides, or a family history of cardiovascular disease.
If your lipid panel is concerning, this is one of the additional markers worth discussing with your healthcare provider.
I also want to mention apolipoprotein A, or Lp(a).
This is a largely genetically determined cardiovascular risk marker.
Most adults should have it measured at least once, especially if there's a family history of premature cardiovascular disease.
Neither of these tests replaces your standard lipid panel.
They just give us more context, more information for how to approach the lipid panel.
Why Thyroid Health Matters for Cholesterol
Next, we have to talk about thyroid because thyroid and cholesterol are very closely connected too.
This is really one of the first things I investigate when I see elevated cholesterol in someone who's trying to conceive.
The thyroid.
If you're listening to this, or if you've listened to this podcast for a while, you know how much I talk about thyroid health.
Your thyroid does so much more than regulate your metabolism.
Thyroid hormones influence ovarian function, menstrual cycles, ovulation, and your body's ability to process cholesterol.
Here's how.
Your liver has receptors that help remove LDL cholesterol from your bloodstream.
Thyroid hormones help regulate those receptors.
When thyroid hormone levels are low, your liver may not clear LDL as efficiently.
As a result, your LDL and total cholesterol can actually increase.
And this is why hypothyroidism is a recognized secondary cause of elevated cholesterol.
Now think about the woman who's trying to conceive, struggling with fatigue, constipation, irregular periods, and elevated cholesterol.
If you're only looking at her cholesterol, you're missing a potentially important piece of the puzzle.
This is why I want to see a comprehensive thyroid panel.
I want to understand what your TSH and free T4 are, and also your free T3 and your thyroid antibodies.
We want a full thyroid picture.
And if we identify hypothyroidism, we need to address it.
Treating an underactive thyroid can improve cholesterol levels while also supporting reproductive health.
And I want to be clear: not every woman with elevated cholesterol has a thyroid problem, and thyroid treatment doesn't replace appropriate cardiovascular care.
But the point is that your cholesterol can give us valuable information about other systems in your body.
And those systems all matter for fertility.
The Blood Sugar and Cholesterol Connection
All right, let's talk a little bit more about the blood sugar and cholesterol connection.
This is a really important connection with fertility as well.
Your blood sugar and your insulin.
If you're dealing with insulin resistance, there's a good chance your lipid panel is giving us clues.
Insulin resistance changes the way your liver processes fats, and your liver may start producing more triglyceride-rich particles.
Your HDL can actually decrease, and your LDL particles can become smaller and more numerous.
You can actually have a relatively normal LDL cholesterol number while still having an elevated ApoB.
This is a reason why I don't like relying on total cholesterol alone.
But what does this have to do with getting you pregnant?
A heck of a lot.
Elevated insulin can interfere with ovarian hormone production and contribute to excess androgen production, particularly in women with POMS.
And this can actually disrupt follicular development and ovulation.
And if you're not ovulating consistently, you're not producing progesterone consistently either.
So when someone comes to me with irregular cycles, low progesterone, elevated triglycerides, and low HDL, we're going to spend some time evaluating metabolic health further.
I want to see fasting insulin, fasting glucose, hemoglobin A1C, and the rest of your lipid panel as well.
And depending on history, we may need additional glucose testing.
And we're going to look at what you're eating, how you're sleeping, how you're moving, and whether you're adequately nourishing yourself.
What does nutrient status look like?
One of the simplest places to start to improve all of this is actually breakfast.
Building a Fertility-Supportive Breakfast
If you're waking up, drinking coffee, skipping breakfast, and then grabbing something quick at noon because you're starving, we have some work to do.
We have to lay that foundation to support overall insulin response and then cholesterol management.
Also, we want to start building that balanced breakfast with at least 30 grams of protein, fiber-rich carbohydrates, and healthy fats.
For instance, eggs with veggies, avocado, and fruit can be a good combination.
Or Greek yogurt with berries, seeds, and nuts, or whatever works for your dietary needs and preferences.
But think fiber and protein as a good focus.
Then work on getting regular movement throughout the day.
Even a 10- to 15-minute walk after meals can support your blood sugar response in really helpful ways.
And don't forget strength training.
Movement Without Overdoing It
Exercise and movement should all be looked at in context too because it's easy to overdo.
So if you're already doing a lot of it, we may actually need to scale back and really increase or shift around the eating pattern.
But strength training is very, very helpful for improving glucose regulation.
So if we know that insulin resistance is an issue, if blood sugars are wonky, strength training or building muscle can be really supportive.
Because it improves insulin sensitivity, which supports overall metabolic health too.
These are not complicated interventions, but consistency really does matter.
So if you're looking for support in individualizing these pieces, please seek additional support on your team.
Because knowing what to prioritize can make all of the difference for how consistent you can be.
Should You Avoid Eggs Because of Cholesterol?
All right, let's talk about eggs.
Because I know some of you have been avoiding egg yolks for years because you were told they would raise your cholesterol or are the reason why your cholesterol is elevated.
But here's what I want you to understand.
Dietary cholesterol and blood cholesterol are not the same thing.
Your body makes most of its cholesterol internally.
When you eat more cholesterol, your body can adjust to how much it produces, although that response varies from person to person.
And also, dietary cholesterol doesn't directly turn into blood cholesterol either.
So, for many people, dietary cholesterol has a very small effect on blood cholesterol, especially when compared with saturated fats.
Eggs contain some very important nutrients for preconception health too.
We're talking choline, protein, B12, selenium, and other nutrients that are important for reproductive health.
Choline, in particular, is important for early fetal development.
So I don't want you automatically eliminating nutrient-dense foods because you're afraid of cholesterol.
I also don't want you interpreting this as permission to eat unlimited amounts of saturated fat because saturated fat can raise your LDL cholesterol.
And some people are particularly sensitive to it.
Finding the Right Balance With Dietary Fat
But we don't want too little saturated fat either because we need enough cholesterol to support all of the hormone building for reproduction.
If you do have elevated LDL or ApoB, we need to look at your overall dietary pattern.
That might mean adjusting the amount of butter, cream, fatty cuts of meat, and other concentrated sources of saturated fat that you're consuming.
It doesn't mean you have to eliminate them.
I do not recommend eliminating animal foods or starting to eat a very low-fat diet either, because those over-restrictions are going to negatively impact fertility in a lot of ways.
You can eat eggs.
You can include animal protein.
And you can still build a dietary pattern that supports healthy cholesterol.
I encourage including more unsaturated fats or omega-3 fatty acids, like avocados, olive oil, and fatty fish.
Fatty fish is going to provide those omega-3 fatty acids, which can help lower elevated triglycerides by supporting HDL cholesterol levels.
And please don't forget about fiber.
Soluble fiber from oats and beans, lentils, apples, and other plant foods can help lower LDL cholesterol by influencing bile acid recycling.
This is one of the reasons I encourage a diverse whole-food diet rather than focusing exclusively on individual nutrients.
We want it to support your cardiovascular health and your reproductive health together.
You shouldn't choose between them because of how interconnected they are.
What If Your Cholesterol Is Too Low?
All right, on the flip side, what if your cholesterol is too low?
We've talked quite a bit about elevated cholesterol, but I also want to address the other end of the spectrum.
Because occasionally I'll see someone who's been dieting for years, avoiding dietary fat, and dealing with significant digestive issues, and her total cholesterol is unusually low.
Maybe she's experiencing irregular cycles, low energy, or difficulty maintaining her weight.
I'm not going to look at that cholesterol number and automatically conclude that she has a hormone deficiency.
But I am going to ask some questions.
Is she eating enough calories?
Is she consuming adequate dietary fat?
Is she having any symptoms of malabsorption?
What's going on with the thyroid?
Is it overactive?
Does she have an underlying medical condition or take any medications that could be explaining low cholesterol?
And importantly, is she ovulating?
Here's what I don't want to do.
I don't want to look at cholesterol of 150 and decide that you need to eat more butter to make more progesterone because that's again not how this works.
Low cholesterol doesn't automatically cause low progesterone.
But inadequate energy intake absolutely can disrupt reproductive function.
And if you're chronically under-fueling your body, that's something we need to correct.
Energy Availability and Fertility
Your reproductive system requires adequate energy to be available.
And if you're exercising too intensely, skipping meals, restricting carbs, and constantly trying to lose another five pounds, then your body may respond by reducing reproductive hormone signaling.
And in that situation, the solution isn't necessarily a cholesterol supplement or a particular food.
It's addressing the energy deficit and whatever else is contributing to your symptoms.
And this also applies to male fertility too.
Men need adequate energy, dietary fat, and micronutrients to support testosterone production and healthy sperm development.
Both partners need to be part of the preconception conversation around cholesterol too.
Cholesterol Medications and Trying to Conceive
All right, and you might be wondering about medications, cholesterol medications specifically, when you're trying to conceive.
So this is an important conversation, especially if you've recently been prescribed a statin or your doctor has recommended one.
Statins reduce cholesterol production in the liver, and they can substantially lower LDL and reduce cardiovascular events in people who need them.
They can also reduce your body's production of CoQ10, which plays a role in mitochondrial energy production.
You might know CoQ10 from a common supplement that's recommended for egg quality and sperm quality.
And you know how often we talk about mitochondrial health when we're discussing egg quality and sperm quality.
Reduced CoQ10 levels don't automatically mean statins impair fertility.
We don't have enough evidence to make that conclusion.
But what we do know is that cholesterol management needs to be individualized when you're planning a pregnancy.
Most of the time we can avoid a statin.
And most women are advised to discontinue statins before pregnancy and during pregnancy.
There are exceptions that exist.
But if you're taking a statin, have a conversation with your prescribing provider before trying to conceive.
Hopefully, add to your team to help understand the full cholesterol regulation picture a little bit more.
Don't just discontinue it on your own.
And if you're being told to start cholesterol medication, ask about your complete cardiovascular risk.
Talk about your family history, ApoB, Lp(a), thyroid function, and metabolic health.
We want to understand the whole picture while making sure that you're receiving appropriate support.
Hopefully, holistic support.
What to Do With Your Cholesterol Results
So what do you actually do with all of this information?
If you're trying to conceive and your cholesterol is elevated and you're concerned that it might be, or you're concerned that it might be too low, here's where I would start.
First, get comprehensive blood work.
I want you to understand your total cholesterol, LDL, HDL, and triglycerides.
Depending on your results and your family history, adding in ApoB and Lp(a) can also provide really helpful context.
Then look beyond your cholesterol.
What's going on with your thyroid?
What's happening with your fasting insulin?
Are there signs of inflammation?
Are your liver enzymes normal?
How does all of this line up with your menstrual cycle, your ovulation, and your overall health?
Second, take a look at your nutrition.
Are you eating enough?
Are you getting adequate protein, carbohydrates, and healthy fats?
Are you consuming enough fiber?
If you have elevated LDL, pay attention to your saturated fat intake.
If your triglycerides are elevated, let's investigate insulin resistance, refined carbohydrate intake, alcohol consumption, and other contributing factors.
And if you're under-eating, we need to address that rather than adding more restrictions.
Third, move your body consistently.
Strength train.
Walk regularly.
Find forms of movement that you actually enjoy.
And of course, don't forget to prioritize your sleep.
Your sleep affects insulin sensitivity, appetite regulation, and reproductive hormone signaling.
Aim for seven minimum hours, ideally closer to nine hours of quality sleep.
Maintain a consistent sleep schedule and get outside for morning light, which is going to help your nighttime sleep quality too.
Don't Forget Your Partner
And of course, don't forget about your partner.
Male metabolic health matters too.
Insulin resistance, obesity, and metabolic dysfunction can affect testosterone regulation and are all associated with poorer semen parameters.
If you're both preparing for pregnancy, these habits are worth working on together.
The Bigger Picture
Here's what I want you to take away from this episode.
Cholesterol is essential for fertility, but more isn't automatically better.
Your body needs it to make reproductive hormones, but your blood cholesterol levels are also important indicators of cardiovascular and metabolic health.
And when we're trying to improve fertility, we need to understand both.
I don't want you fearing every cholesterol-containing food.
I also don't want you ignoring your elevated LDL because you've heard that cholesterol is necessary for hormone production.
Both things can be true, and it's all about balance and context.
Your body needs cholesterol, and excessive amounts of certain cholesterol-containing particles can be harmful.
And this is why we look at the whole person.
Your thyroid, your blood sugar, your nutrition, your inflammation, your family history, and reproductive health all deserve attention.
And if you're trying to conceive and have been told that your cholesterol is abnormal, I encourage you to ask more questions and work with your healthcare team—or add to it—to be able to understand what's contributing to these results.
How to Get Additional Fertility Support
And if you want help understanding your preconception blood work and building a plan that supports both your fertility and your long-term health, please don't hesitate to reach out.
You can apply for a Fertility Strategy Session, which is a phone call where we can chat to make sure we're a good fit to work together.
Otherwise, I hope to see you back in our next episode of The Fertility Dietitian Podcast.
Thanks for tuning in.