Why Low Cholesterol Isn’t Always a Good Thing, Especially If You’re Trying to Conceive
Do you remember your very first doctor’s visit that wasn’t in a pediatrician’s office? Where it wasn’t your mom calling the office, and setting up the appointment for you, and going to the appointment with you, and talking to the doctor for you?
Because I remember mine! It was a little nerve-wracking being in a cold, grey office with elderly adults sitting in the waiting room. Worlds apart from the lime green and neon blue wall paper of my pediatrician’s office. My doctor scanned my annual labs, tapped the screen, and told me my cholesterol was low. She said “it’s fantastic!” and practically handed me a gold star.
For the longest time I believed her, because why wouldn’t I? Low cholesterol is supposed to be the goal of course. I learned it in high school health class and again in nursing school. I never once asked what “low” might be costing someone.
Years later, struggling to conceive my second babe, I then came across a blog post by Dr. Mark Hyman that laid out a whole new idea completely novel to me. Cholesterol that’s too low isn’t automatically a win. It can actually be a sign your body doesn’t have enough raw material to build the hormones it needs, including the ones required to get pregnant.
That one post sent me down a research hole that changed how I ate and, eventually, changed my fertility.
Few doctors will warn you that “low” isn’t automatically “good.” Let’s talk about what’s actually going on.
Your Eggs Are Made of Fat
Want to hear a fun fact? Your egg cells contain a large amount of saturated fat -close to 80%- those “bad” fats we’ve all been warned about since the inception of 90s diet culture and the food pyramid.
One of the main saturated fats is called stearic acid, which is present in animal fat, coconut oil, palm oil, and cocoa butter. Egg cells contain other types of fat too, but saturated fat plays a major structural role.
That raises an important question: what happens when we spend years avoiding many of the foods that provide the building blocks our bodies use?
It does not mean that eating more fat will automatically solve fertility problems. Fertility is far more complicated than that. But it does mean fat should not be treated as nutritionally unnecessary, especially during the months leading up to conception.
We Cut Fat, And Something Broke
Between 1980 and 1997, Americans cut their fat intake by 41%. During that same time period, soybean oil use shot up more than a thousand times over. American moms swapped butter for vegetable oil and whole milk for skim under the promise this would make us healthier, and skinnier.
But the results didn’t pan out as promised. Reducing saturated fat while dramatically increasing the intake of highly processed vegetable oils has not eliminated heart disease or obesity. Some studies suggest it may even raise the risk of heart disease. Vegetable oils can raise the harmful, oxidized version of LDL, lower your protective HDL (your “good” cholesterol that we want to be high), and stir up inflammation in the body.
In the process of becoming afraid of fat, many women may also have reduced their intake of foods that support hormone production and provide nutrients needed before pregnancy.
We did not only remove calories from our plates. In some cases, we may also have removed important hormone building materials.
Cholesterol Isn’t the Villain! It’s the Starting Point.
Every single sex hormone in your body starts as cholesterol. Your body uses it to produce steroid hormones, including estrogen, progesterone, and testosterone. These hormones influence the menstrual cycle, ovulation, implantation, libido, mood, and many other processes.
Cholesterol also sits inside the fluid surrounding your developing egg. Too little of it, and the egg may not get what it needs to grow properly.
Your body needs cholesterol to build a baby.
What Happens When Women Restrict Fat on Purpose
Very-low-fat diets can affect reproductive hormones.
In some women, severe or prolonged restriction may contribute to irregular cycles, delayed ovulation, or the loss of ovulation altogether.
Research examining diet and ovulatory infertility has also suggested that dietary patterns matter. Adequate energy, protein, and fat intake appear to support reproductive function more effectively than chronic restriction.
This does not mean every woman needs to follow a high-fat diet. It means the body needs enough nourishment to feel safe enough to reproduce.
Ovulation is not essential for immediate survival so when the body senses that resources are limited, reproductive function may be one of the first systems it downregulates.
Why the Type of Fat Matters
Not all fat plays the same role inside your body.
Saturated fat is stable, meaning it doesn’t break down easily when heated, which makes it a smart choice for cooking. It also resists oxidation (a rusting effect on your cells), which is likely why your body chooses it to build your egg cells in the first place. One type in particular, stearic acid, has been linked to a lower risk of PMS. Two others, butyric acid and caprylic acid, found mostly in dairy fat and tropical oils, appear to support progesterone production and healthy early pregnancy in animal studies.
Monounsaturated fat are found in in avocado and olive oil, macadamia nuts, hazelnuts, almonds, lard, and poultry fat. This fat also plays a supportive role.
Omega-6 fat, which is found heavily in vegetable and seed oils, is where things get tricky. Your body only needs a tiny amount, about 1 to 2% of your daily calories, to avoid a deficiency. However, most Americans eat far more than that. Omega-6 fat oxidizes easily, which creates harmful byproducts that can damage egg cells. Women going through IVF with high omega-6 levels have shown poorer egg quality. The ratio of omega-6 to omega-3 fat in the American diet has shifted from roughly 1 to 1, all the way up to 30 to 1 in some cases!
Egg Development Begins Months Before Ovulation
One of the most important things I learned during my fertility journey was that egg development does not happen entirely in that cycle. An egg goes through a long maturation process before it is released and the final 71 days before ovulation are the most sensitive to nutrition. Whatever you’re eating in those months shapes the quality of the egg that gets released.
It doesn’t stop there. Before the placenta even forms, your embryo is nourished by your uterine lining. Most of the critical early development happens before you get a positive pregnancy test. A lot of early miscarriages and pregnancy complications trace back to problems with egg quality, implantation, or those very first stages of development.
In other words, the fat you eat months before you conceive may matter just as much as anything you do once you’re pregnant.
So How Much Fat Do You Actually Need?
There is no single percentage that works for every woman.
Your needs depend on your activity level, total calorie intake, metabolic health, digestion, cycle patterns, medical history, and the rest of your diet. But a fat intake around 40-45% of your daily calories or higher is what I generally like to see.
The goal is not to force-feed yourself butter. It is to stop treating fat as something that must always be minimized.
A practical approach is to include a satisfying source of fat with meals and snacks.
That might look like:
- Eggs with the yolks
- Full-fat dairy, when tolerated
- Avocado or olive oil
- Butter, ghee, tallow, or coconut oil for appropriate cooking methods
- Nuts and seeds
- Fatty fish
- Meat with its natural fat
- Olives or nut butter
Fat also helps the body absorb fat-soluble nutrients from vegetables. A dry salad is not necessarily healthier than one dressed with olive oil.
For many women, eating enough total food, protein, cholesterol, and fat can be more supportive than continuing to restrict.
Fun fact: a study of over 9,000 women found that vegetarians and semi-vegetarians reported more period irregularity, more PMS, more painful periods, and more mental health struggles than women who ate meat. The strongest predictors of a regular cycle in that study were simple. Enough protein and enough cholesterol.
But Eating More Fat Isn’t Enough If You Can’t Absorb It
I would be doing you a disservice if I left out this part…
It is not only about how much fat you eat. Your body also has to digest and absorb it!
Bile plays a major role in this process. The liver produces bile, the gallbladder stores it, and the body releases it when fat enters the digestive tract.
Bile helps break fat into smaller particles so the body can absorb it. It also supports the absorption of vitamins A, D, E, and K, the same nutrients involved in hormone production, egg health, and pregnancy.
When fat digestion is impaired, simply adding more butter, eggs, or meat may not solve the problem.
Possible signs that fat digestion needs attention can include:
- Nausea after fatty meals
- Bloating after eating fat
- Pale or greasy or floating stools
- Constipation
- Upper abdominal discomfort
- A history of gallbladder problems
- Previous gallbladder removal
These symptoms can have many causes, so they should not be self-diagnosed. But they are worth discussing with a qualified nutritionist.
For me, increasing fat intake only became helpful once I also addressed digestion and bile flow. That turned out to be a major missing piece in my own health, and the health of my clients. It’s something I see over and over and over again.
What This Means for Your Plate
If you’ve spent years avoiding butter, eggs, and red meat because you thought it was the healthy choice, you’re not alone. Almost every one of us was taught the same thing. Thank you to kindergarten teachers across America circa 2001 teaching the food pyramid!
But your ovaries, your eggs, and your hormones were never asking you to fear fat. They were asking for it!
Add a real source of fat to every meal. Cook with butter, tallow, or coconut oil instead of vegetable oil. Eat the egg yolk. Choose whole milk over skim.
This one dietary change won’t fix everything on its own. Fertility is layered, and fat is one piece of a much bigger picture. But it’s a piece that’s been ignored for far too long, and it’s one you have full control over starting with your very next meal.
My “good” low cholesterol wasn’t good at all. It took raising my fat intake and fixing my bile flow before I finally got pregnant. If your labs have always come back “normal” or “low” and nobody’s asked any further questions, it might be time to ask them yourself.
If you need help applying these ideas to your cycle, nutrition, and fertility goals, this is the kind of root-cause work we support our clients with. You can book a discovery call and learn how personalized, root-cause support could help you in your fertility journey.
This post is for learning purposes only and is not medical advice. If you have symptoms that worry you, please talk with your healthcare provider.
