Do Vegetable Oils Cause Hormonal Imbalance and Infertility?

You are what you eat. There are no better times than these to really take these words to heart and question everything we eat or drink. Genetic modifications, hybrids, and pesticides – we get so much more than we bargain for in the food we eat. Our food also largely determines the hormonal balance in our body ‒ and that extends to the fats and oils we cook with as well.

Does Fatty Food Affect Your Hormones?

Fatty foods definitely have an effect on your hormones and not in a good way.


Fat is one of the three main nutrients for the body, the other two being carbohydrate and protein. Fats are made of fatty acid chains and oil is just a type of fat that is liquid at room temperature.

Research shows that a diet high in fat leads to an increased level of the female sex hormone estrogen in the body. Men and women require a certain level of estrogen in the body but if beyond that, it has been linked to the increased incidence of breast cancer.1 A vegetarian diet is typically lower in fat content but animal fats and vegetable oils can be villains when it comes to increased estrogen levels, as studies show. A diet heavy in animal fats or a diet cooked largely in vegetable oils also leads to the consumption of what we call fatty foods.2


What Harm Does Vegetable Oil Cause?

When cooking with oil, a basic requirement is that the oil shows stability under high temperatures. You don’t want the oil to oxidize, that is, combine with the oxygen in the air, and create dangerous free radicals. The fat in oils is categorized into three forms: saturated fat – a single bond in the fatty acid molecules; monounsaturated fats – one double bond in the molecules; and polyunsaturated fats – multiple double bonds. The trouble is with the double bonds, which tend to be highly sensitive to heat and become chemically reactive. So it is recommended that polyunsaturated fats be avoided in cooking.

Given the high level of polyunsaturated fats in vegetable oils, cooking with them leads to oxidation and release of cancer-causing free radicals. Studies have shown that high levels of polyunsaturated fats, like those found in vegetable oils, are contributing to the increased occurrence of breast cancer in women. Other effects could be polycystic ovarian syndrome or infertility.3


This is essentially due to the increased estrogen and resultant hormonal imbalance in the body.  Polyunsaturated fats have found to have an impact on pregnancy (conception, uterine activity, preterm labor) and male infertility.4

So are men at risk too? Male fertility, measured by the sperm quality and quantity, was found to be impacted under conditions of excess polyunsaturated fats. While the presence of polyunsaturated fat aids in the sperm fluidity needed for fertilization, in excess it can cause oxidative stress and have a negative impact on fertility.5


Studies show that the consumption of polyunsaturated fats has changed over the years with so much thrust being given to vegetable oils. Our ancestors used to consume the two types of polyunsaturated fats omega-6 and omega-3 in a 1:1 ratio but today consumption of these is almost in the range of 20:1 up to as much as 25:1. This significant change, due to increased use of vegetable oils, has resulted in a higher incidence of inflammatory diseases like cardiovascular disease,6 metabolic syndrome, and arthritis in men and women. An increased omega-6 to omega-3 ratio also negatively impacts sperm density and successful fertilization. 7

Are All Vegetable Oils Bad For Health?

Vegetable oils are mainly extracted from seeds like soya bean, peanuts, sunflower, corn, canola, sesame, safflower, rice bran, etc. The extraction is not a very natural process and involves intense use of chemicals like bleaches, deodorizers, and toxic solvents. Such oils contain high levels of polyunsaturated fats. The human body does not need these fats for normal functioning.


The oils with higher levels of good fat are coconut oil, with 92% saturated fat; butter with 68% saturated fat and 28% monounsaturated fat; olive oil with 75% monounsaturated fat; and palm oil with about 50% saturated fat and 37% monounsaturated fat.

So the next time you are in the supermarket, do read the labels carefully and perhaps opt for cooking oil that is higher in saturated fats. Might just be a safer bet!