Dietary Fats and How They Relate to Cancer Risk

31 Aug 2014 by Krystal Barter
Dietary Fats and How They Relate to Cancer Risk

Carolyn McAnlis, Dietitian and Pink Hope Ambassador, discusses the different sorts of dietary fats and how they relate to cancer risk.

Saturated fats vs unsaturated fat, trans fats, heart-healthy fats, what’s the difference? In this post I’ll go through each kind of dietary fat and discuss which are better (and which are worse!) for you, and how they can affect the risk of some cancers.


We actually do need some fats in our diet, as they are necessary to provide the coating around nerve cells, cushioning around joints, and elasticity in the skin. They also help keep us warm and balance hormone levels. But the type of fat we consume has different effects on the body.


To start with, what does saturated or unsaturated mean? The difference lies in the structure of the molecule. Looking at the graphic below, you can see that the carbon chain of saturated fat is completely filled with hydrogen atoms (it is “saturated” with hydrogen atoms). Unsaturated fats contain one or more double bonds between carbon atoms, making it “unsaturated” with hydrogen atoms. That variation means they act differently in the body and cause different reactions. They are also found in two forms; saturated fats are generally solid at room temperature (like butter), while unsaturated fats are typically found as liquids (like olive oil).

Saturated fats are mostly found in animal products like red meat, poultry, eggs, and dairy. There are a few plant sources as well, like palm and coconut oils. Saturated fats have been shown through many studies to lead to an increased risk of cardiovascular disease, high blood pressure, and high cholesterol. Because of this strong evidence, they should be reduced as much as possible. Choose low-fat dairy products, remove visible fat and skin from poultry, or try to have a few vegetarian meals throughout the week. Opt for lean cuts of beef and pork, which include those that end with “-loin,” like tenderloin. You can also simply look at the visible fat to compare different options.

I’ve had a few people ask lately, “I heard coconut is healthy – is that true?” This a great question as coconut has recently become a bit of a “fad food.” Coconut has a very high percentage of saturated fat, so dietitians advise following the recommendations for saturated fat; that is, to use it only in moderation. It may have some health benefits – but this has not yet been proven in major research studies. So for now, the recommendation is that less than 10 percent of total calorie intake should come from saturated fat. Like other seeds and nuts, it is a good alternative for vegans who need to obtain dietary fats through non-animal sources.

Next, trans fats. These are the ones to avoid completely. They are entirely man-made, formed in the process of turning an unsaturated fat into a saturated one in order to increase its shelf life – this is called hydrogenation. Due to this chemical process, and the creation of an unnatural molecule, the body has trouble recognizing and processing it. The end result is an increase in blood cholesterol and inflammation, as well as potentially clogged arteries. They are most often found in highly processed baked goods like store-bought pastries, cookies, and cakes. A simple way to avoid these is to make as much from scratch as possible, as opposed to buying these items.


Unsaturated fats are the good guys. Also referred to as “heart-healthy fats,” these are found in nuts, seeds, seed oils, avocados, and fish. There are polyunsaturated and monounsaturated fats included in this category. Again, the names are based on the molecular structure. Overall, they help reduce inflammation in the body, and help lower blood cholesterol, which lowers the risk of cardiovascular disease.

Now, how does this relate to us as high-risk women? Many studies have shown an inverse relationship between unsaturated fat consumption and breast cancer risk. That is, as the amount of unsaturated fats you consume increases, your risk decreases. With higher saturated fat intake, breast cancer risk is raised.

Dietary fats should make up less than 30 percent of your total caloric intake, so the aim isn’t to consume a large amount of any type of fat, but instead to alter the type of fat we eat. Try these simple swaps to reduce your intake of saturated fat and increase your unsaturated fat intake:

Instead of mayonnaise on a sandwich try mashed avocado
Instead of sour cream try plain low-fat Greek yogurt
Instead of steak try fish
Instead of creamy salad dressing try balsamic vinegar and olive oil
Instead of cream based sauces try tomato based sauces
Instead of anything fried try grilled
Instead of butter while cooking try other seek oils

Keep in mind that some fat is necessary, so eliminating fats altogether is not recommended.
Not only does the type of fat we eat affect breast cancer risk, but it also affects the entire cardiovascular system. Making small changes like these can make a big difference in the long term towards overall health.

Further reading
The Mayo Clinic – Dietary fats: Know Which Types to Choose
More on unsaturated fats from The CDC (USA): http://www.cdc.gov/nutrition/everyone/basics/fat/unsaturatedfat.html


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