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Issues in Liver Health

Are you feeding your liver too much sugar?

Livewell Newsletter

Alcohol has always been considered the liver’s worst enemy. Lately however, there is increasing evidence that refined sugar and its manufactured cousin – high fructose corn syrup -- may actually do just as much damage to the liver when consumed in excess.

Who is at risk for fatty liver disease?

Like many forms of liver disease, fatty liver disease can develop silently but cause increasing damage to liver tissue. Fat build-up in the liver is also linked to Type II diabetes and heart disease. Obesity (particularly excess weight around the waist) is the major cause of fatty liver disease. According to statistics, more than 50% of Canadians are overweight. It is estimated that 75% of obese individuals are at risk of developing a simple fatty liver and up  to 23% of obese individuals are at risk of developing fatty liver with inflammation.

Besides obesity, other risk factors include:

  • starvation and protein malnutrition,
  • long term use of total parenteral nutrition (a feeding procedure that involves infusing nutrients directly into the blood stream),
  • intestinal bypass surgery for obesity,
  • rapid weight loss.
  • diabetes mellitus,
  • hyperlipidemia (elevated lipids in the blood),
  • insulin resistance and high blood pressure.
  • genetic factors,
  • drugs and chemicals such as alcohol, corticosteroids, tetracycline and carbon tetrachloride.
According to a 2011 Statistics Canada report, one in five calories consumed by Canadians comes from sugar. Fruits and vegetables contain naturally occurring complex sugars that are healthy (and are metabolized slowly) but processed or sweetened foods – think packaged cereal, pop, baked goods, some flavoured yogurts -- have added simple sugars (which are metabolized very quickly), often in disproportionate amounts.  When added together over the course of a day, these different forms of sugar can amount to a whopping 110 grams or the equivalent of 26 teaspoons.

So what effect does too much sugar have on the liver?  A diet laden with simple sugars can lead to fat build-up in the liver. While this fat may not cause any problems, in some cases it can cause the liver to become inflamed (swollen) eventually leading to the development of scar tissue (cirrhosis). The technical terms for this progression are: fatty liver (simple fat buildup), non-alcoholic fatty liver disease (inflammation), non-alcoholic steatohepatitis (severe inflammation & scarring). In its severest form, non-alcoholic steatohepatitis – or NASH for short – can lead to cirrhosis of the liver or liver cancer. In the U.S., NASH is becoming a frequent cause of liver transplants.

Consuming too much alcohol on a consistent basis can also lead to fatty liver disease. Since alcohol is already subject to age restrictions and government regulations, some experts are now calling for the same type of rules to apply for simple sugar.  

According to Dr. Diana Mager, a professor of Clinical Nutrition from the University of Alberta and  a member of the CLF’s National Education Advisory Committee, regulators need to move carefully when considering restrictions on sugar. “It is important to pay close attention to what we mean by  dietary sugars (i.e. those that occur naturally vs those added for sweetening),” says Dr. Mager.  “Milk for example is composed of lactose (a simple sugar); but it contains many other important nutrients such as protein, vitamin D and calcium and therefore restricting these sources of foods could have a major impact on the nutritional content of your diet.”

In the meantime, Dr. Mager feels that the best approach is to strive for a balanced diet. “Eating fresh fruits and vegetables are a great way to get healthy sources of complex carbohydrates , fibre and vitamins in your diet and will contribute to your overall liver health.  When eating packaged foods, choose foods that have added fruit (rather than fruit flavoring) without extra sugar or sugar coatings. An even better idea is to add fresh fruit to unflavored foods for both variety and added taste.”

Fatty liver disease is already the most common form of liver disease in Canada and as obesity rates continue to rise, so will the incidence of fatty liver disease. Although sugar is not the only culprit, it plays a significant role in the development of this condition. Unfortunately, since sugar is added to nearly all processed foods and occurs naturally in many fruits and vegetables, moderating your sugar intake can be a challenge. To learn more about how to recognize the sources of sugar in your daily diet and how cut down on your daily consumption, check out this month’s LIVERight Tip. For more information on fatty liver disease, click here or call our National Help Line at 1-800-563-5483.   

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