Why has fat, a natural, whole macronutrient, become vilified? I believe that this demonisation of foods that come straight from Mother Nature is not only misleading but also detrimental, especially when it comes to our menstrual cycle health! Why? Because it leads us down a path of extremes, and extremes in nutrition can result in real harm. Plus, a lot of the generalised nutrition information out there is not aimed at women and fertility issues. When it comes to fats, especially saturated fats, the myths have perpetuated for decades, causing a significant impact on women’s health—especially their menstrual cycles and fertility.
A Common Story: Misguided Advice on Cholesterol
Here’s a true story: A woman visits her doctor to investigate her PMS symptoms, fatigue, and overall low health. Her blood tests show a low HDL cholesterol level, but instead of addressing the real issue, the doctor advises her to “reduce fatty foods”?! When most of us think about “fatty foods,” we picture butter, cream, and the fat marbled in a juicy steak—not the margarine that’s heavily marketed as “heart-healthy.” But because she’s been told to cut back on fat, she reduces her intake of these natural foods, opting for low-fat alternatives and vegetable oils.
Her goal was to improve her menstrual cycle health, but now she’s on a path that could actually worsen it.
The Myth of Saturated Fat and Its Impact on Women’s Health
Since the 1950s, saturated fat has been labelled the enemy, accused of causing heart disease. But this demonisation of a key macronutrient has serious implications beyond just heart health—especially for women.
Cholesterol, often viewed negatively, is essential for hormone production. Without enough cholesterol, the body cannot produce adequate levels of sex hormones like estrogen and progesterone, which are vital for reproductive health. Women with low HDL cholesterol are more likely to experience menstrual cycle issues and infertility.
What many don’t realise is that it’s not naturally occurring fats, like those found in meat, butter, and eggs, that are problematic. Rather, it’s the processed vegetable oils, high in omega-6 fatty acids, that pose a threat to both heart and reproductive health. These oils are often marketed as “healthy” despite their contribution to inflammation, oxidative stress, rise in LDL cholesterol levels, and reduction of protective HDL cholesterol.
The Dark History of Dietary Guidelines
The fear of saturated fat can be traced back to the 1960s, when major health organisations in the U.S. and U.K. launched campaigns against it. The dietary guidelines at the time advised that fat should make up no more than 10% of the diet, without accounting for gender differences. These recommendations were largely based on flawed research, including the work of Ancel Keys, whose study suggested that Mediterranean populations with low saturated fat intake had lower rates of heart disease.
But this advice wasn’t founded on solid evidence. Instead, it served the interests of industries like sugar and vegetable oil, which capitalised on the opportunity to fill the void left by reduced fat intake. The 1961 American Heart Association’s advice to limit saturated fat became one of the most influential pieces of nutrition policy ever, shaping public perception of fat for generations.
This guideline, however, was aimed at men. Women—especially those looking to support their menstrual cycles and fertility—had no such tailored advice.
How These Guidelines Hurt Women’s Health
As a result of these misguided guidelines, women turned to low-fat, highly processed foods, filled with polyunsaturated fats and sugars. This dietary shift has contributed to an array of health issues, including menstrual cycle irregularities, infertility, and conditions like PCOS and endometriosis.
The consequences are even more pronounced when you consider the role fats play in nutrient absorption. Many essential vitamins, including vitamins A, D, E, and K, are fat-soluble. This means that without adequate fat intake, even women consuming healthy diets can face nutrient deficiencies, ultimately affecting their menstrual cycle health.
The Different Types of Fats
It’s crucial to understand that not all fats are created equal. In their book Real Food for Fertility, Lily Nichols and Lisa Hendrickson-Jack recommend that fats should make up at least 40-45% of our daily calories. They emphasise that the type of fat matters:
- Saturated fats (found in tallow, lard, ghee, coconut oil, and palm oil) are stable at high temperatures, making them great for cooking. These fats contain nutrients like stearic acid, which has been linked to a lower risk of PMS, and butyric acid, which supports estrogen and progesterone production.
- Monounsaturated fats (found in olive oil, avocado oil, and macadamia oil) are perfect for salad dressings and support fertility through compounds like oleic acid, which has been linked to embryo development.
- Polyunsaturated fats, especially the processed ones found in vegetable oils like canola, rapeseed, and margarine, should be avoided. These oils are high in omega-6, which raises LDL cholesterol and contributes to inflammation and menstrual cycle disorders.
Omega Fatty Acids and Menstrual Cycle Health
Omega-6 isn’t inherently bad, but the problem is that our modern diets are overloaded with it. A diet balanced in omega-3 and omega-6 fatty acids is essential for reproductive health, yet the ratio of omega-6 to omega-3 has skyrocketed from 1:1 to as much as 30:1 over the past 80 years.
Omega-3s, particularly DHA and EPA, are critical for improving egg quality, supporting progesterone production and potentially even delaying ovarian aging. A higher fat intake, especially from omega-3 and saturated fats, has been linked to a lower risk of PMS, quicker conception times, and enhanced fertility markers.
Conclusion: Embrace Natural Fats
The key takeaway? Don’t be afraid of dietary fat—especially naturally occurring fats. If you tolerate dairy, opt for full-fat versions. Enjoy the fat on your meat, drizzle butter on your vegetables, and sip the rich broth from your soups. Your body, hormones, and menstrual cycle will thank you.
Let’s ditch the processed oils and low-fat fads. Instead, nourish yourself with real, whole foods, and let your body thrive as it was designed to.
References
- Colpo, A., 2005. LDL Cholesterol:” Bad” Cholesterol or Bad Science?. Journal of American physicians and surgeons, 10(3), p.83.
- Heileson, J.L. “Dietary saturated fat and heart disease: a narrative review.” Nutrition Reviews 78(6) (2020): 474–485
- Teicholz N. A short history of saturated fat: the making and unmaking of a scientific consensus. Curr Opin Endocrinol Diabetes Obes. 2023 Feb 1;30(1):65-71. doi: 10.1097/MED.0000000000000791. Epub 2022 Dec 8. PMID: 36477384; PMCID: PMC9794145.
- “How The Sugar Industry Lobbied Harvard Scientists to Blame Saturated Fats.” Analyze and Optimize. 2020. https://youtu.be/EvqKpvBesRE
- Harcombe Z. US dietary guidelines: is saturated fat a nutrient of concern? Br J Sports Med. 2019 Nov;53(22):1393-1396. doi: 10.1136/bjsports-2018-099420. Epub 2018 Aug 14. PMID: 30108061.
- Nichols, L., Hendrickson-Jack, L. 2024. Real Food For Fertility. Fertility Food Publishing. Pp. 35-44.
- Nichols, L., Hendrickson-Jack, L. 2024. Real Food For Fertility. Fertility Food Publishing. Pp. 8.
- https://www.healthline.com/nutrition/5-studies-on-saturated-fat
