I recently had someone ask me why she had been found to have high cholesterol levels when she had watched her diet very carefully for years, always being sure to choose low fat or fat free foods.

The cause of her high cholesterol may not be dietary fat as she understandably thinks, but rather sugar (added sugar in particular).

Sucrose is found naturally in fruit, vegetables and honey and in higher amounts as added sugar in processed foods such as breads, cereals, processed meats, cool drinks and sauces. Sucrose is made up of the simple sugars glucose and fructose. The way in which glucose is digested is completely different to the way fructose is digested. While nearly every single cell in our body uses glucose as a fuel, only the liver cells can metabolise fructose.

Once fructose enters the liver, a series of chemical processes converts it into fat. If there is a regular high intake of fructose, fat droplets accumulate in the liver causing a condition called non-alcoholic fatty liver disease.


Research has found that people with NAFLD are more likely to have plaque build-up in their arteries, increasing their risk of cardiovascular disease. In addition to this, the metabolism of fructose to fat in the liver increases your blood triglyceride and LDL cholesterol (i.e. the “bad” cholesterol) levels; increases the build-up of fat around the organs (visceral fat) and increases blood pressure. These are all risk factors for heart disease.

In the early 1900’s, we had very little fructose in our diet, mainly from vegetable and seasonal fruit. Now that sucrose is added in high amounts to nearly every processed food (especially those which have had the fat removed i.e. your fat free/low fat options) we are having approximately four to five times more. This explains the high rate of NAFLD we are seeing.

It has been found that more than 70 % of people with type 2 diabetes have NAFLD, yet many doctors do not test for it and it is left undiagnosed, which increases the risk of the person developing cardiovascular disease. It is concerning that because of the link between cardiovascular disease and diabetes, diabetics have for years been advised to follow a low fat diet. It may be this very diet that is increasing their risk further, if you consider the fact that may low fat foods contain added sucrose.

High fructose corn syrup (HFCS) is a cheap man-made sweetener added to a plethora of foods and drinks. Its fructose content is extremely high compared to foods naturally containing fructose. Fizzy drinks, breakfast cereals, ice-creams, yoghurt, sweets and even savoury foods can all contain HFCS and regular consumption of these can soon overwhelm the liver.

If you are battling high cholesterol levels, remember it is important to look at your diet as a whole, rather than just focusing on eliminating one thing.