Does eating a high-fat diet raise cholesterol?
For decades, dietary fat has been villainised as the cause of high cholesterol and heart disease. Even though researchers have long disproven this notion, myths surrounding fat and cholesterol continue to dominate headlines, and doctors as well as government guidelines continue to recommend low-fat diets to the public.
Based on years of contradictory advice, you may rightly be confused.
In this blog, I’ll clear up the confusion surrounding fat, cholesterol and their role in health and heart disease once and for all.
What is cholesterol?
Cholesterol is a waxy, fat-like substance that's found in ALL the cells in your body. It’s actually super important for your health. Your body needs cholesterol to make hormones, convert sunlight to vitamin D, make synapses connecting brain cells and to make bile which helps you digest food. We need lots of cholesterol to live and to heal, which is why our body manufactures it all on its own in the liver. In fact, the body makes more cholesterol than what you can eat, so avoiding foods that are high in cholesterol won’t impact your blood cholesterol levels significantly. So, as you can see cholesterol isn’t the bad guy lurking in your eggs and bacon, ready to pounce and cause you a sudden stroke.
So, why are so afraid of cholesterol?
Certain types of cholesterol (LDL) can become sticky and build up as plaque in our arteries leading to obstructions of blood flow leading to heart attack or stroke. What leads to the increase and build-up of sticky cholesterol has been the subject of much debate and confusion perpetrated by none other than the sugar industry. Big surprise!
In the 1960s the sugar industry paid a couple of Harvard scientists to play down the link between sugar and heart disease and promote saturated fat as the culprit instead(1). This means that decades of research into the role of nutrition in heart disease, including many of today’s government dietary guidelines, have been largely shaped by the sugar industry.
Davinia Taylor - "Don't be afraid of healthy fats and cholesterol in your diet"
Does eating fat cause high cholesterol?
As with everything in life, nothing is black and white, and the answer is more complex than a simple yes or no. General advice to cut fat from your diet isn’t nuanced enough to distinguish between a plate of chips swimming in canola oil and the unsaturated good fat found in avocado.
Recent research has shown no consistent link between dietary fat intake and heart disease. Saturated fat, the most unnecessarily demonised of all fats has not been found to increase levels of the worrisome sticky cholesterol that can clog up our arteries(2). In fact researchers found that a high-fat diet was actually associated with an increase in good (HDL) cholesterol levels.
When it comes to fat, what matters most is the type of fat you eat. Some fats will contribute to your health while other will detract from it, knowing the difference is crucial to preventing disease and living a healthy life.
The key is to eat mostly “good” unsaturated fats, moderate amounts of saturated fat, and avoid “bad” trans fats like the plague itself. For more on different types of fats have a read of my previous blog Fats – The Good, The Bad, and The Ugly.
Excess sugar - the most powerful driver of sticky cholesterol production
Sugar, in all its forms including bread, pasta, crackers, bagels, fruit juice, soda and alcohol create insulin spikes which increase weight gain, sticky cholesterol production and inflammation in your arteries. Inflammation leads to the thickening of the walls of your blood vessels and plaque formation, ultimately resulting in heart attack or stroke.
For those of us who haven’t damaged their blood vessels by mainlining processed, carb-laden food, cholesterol flows through the body unobstructed and is allowed to go about its business of being essential to our health.
What affects the amount of inflammation in your body is what you eat, how active you are, your level of stress, and other lifestyle-related factors such as smoking.
How to decrease your risk of heart disease & stroke
Instead of worrying about your cholesterol numbers, adopt a healthy lifestyle focused on reducing inflammation. Eat more anti-inflammatory omega 3s from fatty fish and olive oil, and less omega 6s and trans fats.
When it comes to saturated fat, stick to grass-fed beef, coconut oil and MCT oil rather than fried food or processed meat. MCT oil has actually been found to increase good cholesterol while decreasing the sticky type we don’t want to clog our arteries. I love to add mine to my morning coffee to protect my heart health and for an extra boost of energy.
As well as adding in the good stuff make sure to limit the amount of processed carbs in your diet and replace them with antioxidant rich vegetables and whole grains.
In short; eat well, stay active, keep your stress to a minimum and support your body in performing functions that it’s meant to do, and you won’t have to worry about your cholesterol levels.
PS. There are certain genetic conditions such as familial hypercholesterolemia that may require medication or a different dietary approach.