Nonalcoholic Fatty Liver Disease

9 Oct 2017

When you think about liver disease, what cause pops into your mind? Alcohol? Viral hepatitis? Drugs? Genetic? Autoimmune? While all of these can cause liver disease, the most common liver disease in America and the world over is not caused by any of these agents. Rather, the most common cause of liver disease affecting us has only been around for the past few decades and it is increasing by the millions annually. This liver disease is known as nonalcoholic fatty liver disease, or NAFLD.

Nonalcoholic fatty liver disease is a disease that is caused by the conversion of fructose to triglyceride in the liver and leads to deposition of fat in the liver and abdomen. This then causes the liver to get inflamed and begin to scar. Once scarring occurs, it progresses to cirrhosis of the liver. Once you have developed cirrhosis of the liver, the disease progresses to liver cancer and/or liver failure. the first publication of fatty liver disease occurred in 1980 for adults and 1983 for children. This disease now affects nearly 90 million adults and 12 million youth in America.

There is a metabolic pathway in the liver that lies dormant in us until it is challenged by excess fructose consumption on consecutive days. It only takes six days to activate this metabolic pathway but once turned on, it may take weeks to months to turn it back off. The longer it has been activated, the harder it is to stop it. And, what’s worse, once activated, other digestible sugars are absorbed in the small intestine and transported to the liver where more conversion of sugar to triglyceride fat occurs.

Not all people who have opened up this metabolic pathway will develop cirrhosis for various reasons; but, for those that do develop liver disease, the process is reversible if cirrhosis is not present. This requires the removal of digestible carbohydrates (those that can be absorbed in the small intestine and transported to the liver) from the diet for several weeks so that the sugar to fat metabolic pathway can be put to sleep. Once that has occurred, then you can safely add back garden greens and pick a treat day every week or so and it will not reactivate the pathway.

Fructose is the key though. The liver can only process a small amount of fructose on a daily basis without activating this sugar to fat pathway. For women, that amount is about 8-10 grams per day; for men, it is about 10-15 grams per day. It varies for each of us but we all have an upper limit. A study that I published earlier on this web site demonstrated that 25 grams of fructose for six days activates the pathway in 100% of men. That is the amount of fructose that is in a modern day hybridized apple. Fruits and berries contained much less fructose in the first half of the twentieth century but hybridization and genetic modification have dramatically increased the sugar content.

We used to consume about 10 grams of fructose per day in America. That quantity began to increase in the 1960’s for a number of reasons but it is now up to 85 grams per day on average. If you strictly limit your sugar intake, you can see how others may be consuming twice the national average. The big five sources of fructose are: fruit, fruit juice, honey, table sugar and high fructose corn syrup. While many want to blame high fructose corn syrup for all our ills as it relates to fatty liver, fructose is same chemically no matter the source. I worked with a nurse who ate fruit smoothies for breakfast and mid morning snack and she developed this problem. It totally reversed itself once she could wrap her head around the fact that her 100 grams of fructose derived from organic, fresh fruit was the culprit. A hard concept to accept when fruit and berries taste so good.

Our intestinal system was not designed to chronically handle large quantities of digestible sugars, especially fructose, without suffering metabolic consequences for this excess consumption. I hope this helps you understand fatty liver disease a bit better. Feel free to send me questions, if I have not made this clear enough. Sign up for automatic updates of new posts. Have a great week.
Dr. Lyons