Which fat is good for fertility? A guide to making healthy dietary choices

October 27, 2025 •

3 min read

According to a Harvard study, women with the highest intake of monounsaturated fats were 3.4 times more likely to have a live birth during IVF than those with the lowest intake. When considering a nutrition diet, knowing which fat is good for fertility is crucial for couples preparing to conceive. The right fats play a critical role in hormonal balance, egg and sperm quality, and reducing inflammation in the body.

Quick Summary

Healthy fat choices significantly impact reproductive health for both men and women by regulating hormones, improving blood flow, and enhancing egg and sperm quality. Focusing on beneficial monounsaturated and omega-3 fats while eliminating trans fats is a key nutritional strategy for those trying to conceive.

Key Points

Prioritize Omega-3s: Increase your intake of omega-3 fatty acids from sources like oily fish, walnuts, and seeds to enhance egg and sperm quality and reduce inflammation.
Embrace Monounsaturated Fats: Incorporate more MUFAs from avocados, olive oil, and nuts to improve insulin sensitivity, which is vital for ovulation.
Eliminate Trans Fats: Completely avoid trans fats found in processed and fried foods, as they are strongly linked to ovulatory infertility.
Balance Omega-6s: While some omega-6s are necessary, maintaining a balanced ratio with omega-3s is important for managing inflammation.
Follow the Mediterranean Diet: Adopt a Mediterranean-style eating plan, which emphasizes healthy unsaturated fats and has been associated with improved fertility outcomes.
Choose Full-Fat Dairy (for some women): Some research suggests that women may benefit from consuming full-fat dairy products instead of low-fat options to reduce the risk of ovulatory infertility.
Be Mindful of Saturated Fat: Limit excessive intake of saturated fats from animal products and processed foods, as high levels can negatively impact fertility.

The critical role of healthy fats in reproductive function

Fats are not all created equal when it comes to reproductive health. Healthy fats are a foundational building block for hormones, including estrogen and testosterone, which are essential for ovulation and sperm production. They are also integral components of cell membranes, ensuring that eggs and sperm can function correctly. A balanced intake of the right fats can also help manage inflammation and improve insulin sensitivity, two factors that significantly impact fertility. Conversely, the wrong kinds of fat can disrupt this delicate balance, leading to negative outcomes.

Omega-3 fatty acids: The 'fabulous fats' for fertility

Omega-3 polyunsaturated fatty acids (PUFAs), especially DHA and EPA, are vital for both male and female fertility. The human body cannot produce these essential fats on its own, so they must be obtained through diet or supplements.

Benefits of omega-3s for fertility:

Improved blood flow: Omega-3s boost circulation to the reproductive organs, which is essential for successful conception and implantation.
Hormone regulation: They help regulate key hormones required for ovulation and overall reproductive function.
Enhanced egg and sperm quality: Omega-3s, particularly DHA, are structural components of egg and sperm cell membranes, and supplementation has been shown to improve sperm count, motility, and morphology.
Reduced inflammation: The anti-inflammatory properties of omega-3s can reduce systemic inflammation that may impair reproductive organ function.
Delaying ovarian aging: Research suggests a link between omega-3 intake and prolonging the female reproductive lifespan by improving oocyte quality.

Sources of omega-3 fatty acids:

Oily fish (salmon, sardines, mackerel, herring)
Walnuts
Flaxseeds and chia seeds
Hemp seeds
Soybeans and tofu

Monounsaturated fats (MUFAs): Improving insulin sensitivity

Monounsaturated fats are another type of healthy fat linked to better fertility outcomes. They play a significant role in improving insulin sensitivity, which is particularly beneficial for women with insulin resistance or polycystic ovary syndrome (PCOS).

Benefits of MUFAs for fertility:

Improved insulin sensitivity: Maintaining stable insulin levels is crucial for healthy ovulation.
Associated with better outcomes: Some studies have shown an association between higher MUFA intake and higher birth rates, particularly during IVF.

Sources of monounsaturated fats:

Avocados
Olive oil
Nuts (almonds, cashews, pecans)
Seeds (pumpkin, sesame)

The harmful impact of trans fats

While healthy fats support fertility, trans fats are profoundly detrimental. Found in processed and fried foods, trans fats create inflammation and insulin resistance, both of which can negatively impact ovulation. A Harvard study linked a 2% increase in trans fat calories with a 73% higher risk of ovulatory infertility. Avoiding these fats is a critical step in any fertility-focused diet.

Sources of trans fats to avoid:

Fried foods and fast food
Baked goods (cakes, cookies, doughnuts)
Margarine and shortening
Processed snacks containing partially hydrogenated oils

A comparison of fats for fertility


Feature	Omega-3 (PUFA)	Monounsaturated (MUFA)	Trans Fat (TFA)	Saturated Fat (SFA - excessive)
Effect on Fertility	Positive: Improves egg/sperm quality, regulates hormones, reduces inflammation.	Positive: Improves insulin sensitivity, linked to better IVF outcomes.	Negative: Increases ovulatory infertility risk, causes insulin resistance.	Negative (Excessive): Linked to reduced sperm count and fewer mature oocytes.
Hormone Regulation	Regulates reproductive hormones like estrogen and progesterone.	Improves insulin sensitivity, which impacts hormonal balance.	Disrupts ovulation by inducing insulin resistance.	Excessive intake can lead to inflammatory issues impacting hormones.
Inflammation	Reduces inflammation throughout the body.	Has anti-inflammatory properties.	Directly promotes systemic inflammation.	Excessive amounts can promote inflammation.
Best Sources	Oily fish, walnuts, chia seeds, flaxseeds.	Avocados, olive oil, nuts, seeds.	Processed foods with partially hydrogenated oils, fried foods.	Red meat, butter, cheese, processed items.

The Mediterranean diet model for fertility

The Mediterranean-style diet, rich in fruits, vegetables, whole grains, and, importantly, healthy unsaturated fats like olive oil, is often recommended for reproductive health. This dietary pattern naturally emphasizes the intake of good fats while minimizing harmful processed foods, aligning with key nutritional advice for couples trying to conceive.

Conclusion

Ultimately, making conscious dietary choices regarding fat intake can significantly support fertility. Prioritizing omega-3 and monounsaturated fats from whole food sources like fish, nuts, seeds, and avocados helps to create a fertile environment for both egg and sperm development. Just as importantly, eliminating trans fats found in processed and fried foods can reduce inflammation and insulin resistance, directly addressing potential causes of infertility. For those looking to support their reproductive health, focusing on the quality of fats, rather than simply restricting them, is a powerful nutritional strategy.

For more in-depth information on nutrition and fertility, the American Journal of Clinical Nutrition offers a wealth of research on the topic.

Frequently Asked Questions

When cooking for fertility, it's best to use oils rich in monounsaturated or omega-3 fats. Extra virgin olive oil is an excellent choice for general cooking and dressings, while canola oil contains both MUFAs and omega-3s. Avoid oils high in omega-6s and trans fats.

Yes, fish oil supplements can be a great way to ensure adequate intake of omega-3 fatty acids, especially if you don't regularly consume oily fish. Multiple studies suggest omega-3 supplementation can improve sperm quality, egg quality, and overall pregnancy rates.

The key is the type of fat, not necessarily the total amount. A diet high in healthy unsaturated fats (MUFAs, PUFAs) has been linked to better fertility, while a diet high in harmful trans fats and excessive saturated fats is associated with increased infertility risk.

You can easily incorporate healthy fats by snacking on a handful of nuts or seeds, using avocado in salads or sandwiches, and replacing butter with olive oil. Drizzling flaxseeds or chia seeds into smoothies and oatmeal is another simple method.

While excessive saturated fat intake has been linked to poorer reproductive outcomes, a moderate amount is not necessarily harmful. The issue is overconsumption, especially when it replaces healthier unsaturated fats. It's best to prioritize healthy fats and get saturated fats from responsibly sourced, less processed foods.

Trans fats harm ovulation by causing insulin resistance and promoting inflammation. High insulin levels can disrupt the hormonal balance needed for regular ovulation, a key factor in ovulatory infertility.

Yes, research suggests that the Mediterranean diet, with its emphasis on healthy fats, can also improve measures of semen quality, including sperm morphology, motility, and concentration.