Does Eating a High-Fat Diet Raise Cholesterol?

For decades, dietary fat has been villainised as the root cause of high cholesterol and heart disease. Even though researchers have long disproved 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, quite understandably, be confused. Let’s clear up the confusion surrounding fat, cholesterol and their role in health and heart disease once and for all.

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. Your brain is made from it too and without it, we would die. 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 consume, 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 or heart attack. 

Certain types of cholesterol (LDL) can become sticky and build up as plaque in our arteries, leading to obstructions of blood flow and resulting in a heart attack or stroke. What leads to the increase and build-up of sticky cholesterol has been the subject of much debate and confusion, which has been 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. 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. 

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 that there is 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. 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 whilst others will detract from it - knowing the difference is crucial to preventing disease and living a healthy life.

The key is to eat mostly “good” animal and dairy fats along with high levels of Olive oils which are anti-inflammatory, and avoid “bad” trans fats like the plague itself. For more on different types of fats, have a read of our Fats: The Good, The Bad, and The Ugly.