Updated: Sep 11, 2020
The words ‘fat’ and ‘cholesterol’ immediately trigger a negative connotation thanks to years of media telling us to eat a low fat diet and to stay away from animal fat and egg yolk which is typically high in cholesterol which will clog our arteries and cause heart disease. However, researchers are finally putting together pieces of the puzzle to explain why so many studies which show some patients with high cholesterol and no heart disease against patients with low cholesterol who then suffer a heart attack. For years this data has been disregarded due ‘small study sample size’ or an unexplained exception the rule that high cholesterol causes heart disease.
If you look at trends in fat and carbohydrate consumption in the past 30 years, you will see a dramatic decline in saturated fat consumption and an increase in carbohydrates, due to the message for a healthy heart being to reduce cholesterol found in saturated fats. Interestingly, during this time, heart disease has significantly INCREASED. So if the general population is eating LESS fat, yet suffering MORE heart attacks, what does that tell you? There is more to the story than meets the eye.
What is the function of cholesterol?
Cholesterol is so important that the body makes its own. Synthesized in the liver, it is essential for maintaining neurotransmitter and brain function, building nerves and tissue, and nourishing the immune system. It is needed for normal cell function and to help digest fat-soluble vitamins A, D, E and K. It also plays a key role in hormone production, particularly oestrogen and progesterone.
What’s the deal with HDL, LDL and VLDL Cholesterol?
You may have heard of HDL (high density lipoprotein) being referred to as ‘good’ cholesterol and LDL or VLDL (Low density and very low density lipoprotein) referred to as ‘bad’ cholesterol. This is partly true, but there is more to it than simply being labelled good and bad. HDL cholesterol is not easily oxidised, where as LDL and VLDL is a lot more prone to oxidation. Think of oxidation as a fire, and anti-oxidants as the hose that puts out the fire. When LDL cholesterol comes into contact with oxygen, if there are not enough anti-oxidants to put out the fire, it will cause damage to the cells. This is what leads to plaque build up and hardening of the arteries. So, as you can see, it is not mealy the presence of cholesterol that causes plaque build up. Cholesterol can sit there quite happily doing its job, but when you have a lot of LDL cholesterol which are prone to oxidation and little HDL cholesterol which contain anti-oxidants, you are then more susceptible to cardiovascular disease. Pair this with a diet low in anti-oxidants and high in pro-inflammatory mediators such a vegetable oils, refined carbohydrates and sugar and you have a recipe for disaster.
The role of saturated and unsaturated fat in heart disease
The chemical structure of saturated fat contains a double carbon bond between two hydrogen molecules. This double bond makes it a very stable molecule as there are no exposed hydrogen molecules seeking another molecule (it is saturated) meaning that it does not oxidize readily when exposed to oxygen. This stability is what gives saturated fat its hard texture (think of a stick of butter). Then you have monounsaturated fats (mono meaning one, i.e. one carbon bond) found in nuts, avocado, sesame and olive oil and polyunsaturated fats found in fish, walnuts and flax seeds. These are slightly less stable, making them more sensitive to oxidation when exposed to air or high temperatures. Following the trend to reduce saturated fats, the current western diet is extremely high in vegetable oil, typically lower in fruits and vegetables and high in carbohydrates. So basically, it is overloaded with unstable molecules seeking to attach to something to make it more stable, and a the lack of anti-oxidants, it attaches to free radicals.
The main concept to take on board here is: It is better to have more HDL and less LDL cholesterol because HDL will not oxidize as easily as LDL cholesterol will. However, the rate of oxidation depends on what else you are putting in to your body. If you have high cholesterol and low anti-oxidant status, the risk of heart disease is increased. However if you have high cholesterol and high anti-oxidants, you may not be at risk of heart disease. Similarly, if you have low cholesterol, high poly-unsaturated fat intake and low anti-oxidant intake, you may be at a higher risk for heart disease when compared with someone who has overall higher cholesterol levels.
Saturated fat intake alone is not a predictor of cardiovascular disease.
High cholesterol levels alone are not a predictor of heart disease.
Increased seed oil and reduced saturated fat intake reduces cholesterol, but increases heart disease
Low fat, high carbohydrate and high fructose diets have a dramatic effect on the development of obesity and cardiovascular disease.
Polyunsaturated (good) fats, in particular oily fish, increases HDL cholesterol and decreases LDL cholesterol.
Statin drugs (cholesterol lowering medication) reduces the body's CoQ10 levels – a potent natural anti-oxidant which cannot be obtained through the diet (remember with out anti-oxidants cholesterol will oxidize) Patients taking statin medications should supplement CoQ10.
Eating for cardiovascular health
Eating a healthy fat, low carbohydrate diet will help decrease your risk of cardiovascular disease and improve your general health and wellbeing. Fat is satiating, which means when you eat it, your brain registers as being full and satisfied, therefore sends a signal to stop eating. The end result being that you do not over eat and feel generally more satisfied, reducing the risk of binge eating and feelings of deprivation. So, even though you are eating more fat that does not mean you will get fat! Quite the contrary, as matter of fact.
Now, don’t get too excited there. This is not a free pass to indulge in doughnuts and chips because they contain fat. That is the wrong kind of fat and you're not fooling your body into thinking it’s full and nourished from a packet of doritos. Cakes, biscuits, pastries, chips etc contain trans fats and yes, a lot unstable vegetables oils, so stay away! Not to mention that they are completely devoid of any nutritional value.
Approved saturated fats include whole fat dairy products, butter (grass fed is best), un-processed meats. Stay away from deli meats such as salami, ham, bacon, chorizo, sausages etc.
Good sources of healthy fats include oily fish such as sardines, mackerel, salmon, trout and herring, avocados, nuts and seeds (especially walnuts and flaxseeds).
Extra virgin olive and coconut oil are especially good for cholesterol as well as for weight management and are ideal to use for cooking and salads. Tip: to raise the smoke point of olive oil when cooking (smoke point refers to the temperature at which the oil starts oxidize when heated), combine with a saturated fat such as coconut oil or butter.
Foods for lowering total cholesterol:
Oats (rolled oats, oat bran, oat milk)
Fibre (Psyllium husk)
Beans and Legumes