The Human Foie Gras: A Fatty Liver Story
Have you heard of foie gras? A staple of French cuisine, this controversial dish is made from the liver of a goose or a duck fattened by force-feeding, intentionally giving it fatty liver disease. But did you know that birds are not the only animals to develop fatty liver? In humans, fatty liver disease is widespread. Between 25 and 30% of the Western population is estimated to be affected. So you may have fatty liver without even knowing it!
Usually, you won’t even know it when you have fatty liver. You might see a doctor for a completely unrelated issue, get prescribed an ultrasound, and be told that your liver is hyperechogenic, meaning that it is exhibiting an increased echo during the exam, the hallmark of fatty liver. There is nothing to worry about for the moment as for most, fatty liver is asymptomatic. It is estimated that 25 to 30% of the Western population are affected by this disease. Nonetheless, you might want more information, so you ask your doctor to tell you more about it!
Sick without knowing it
“Well, it is exactly the same as foie gras,” your doctor says. However, that doesn’t reassure you. Comparing one of your organs to a well-known delicacy is not what you expected. Your liver works as the waste disposal unit of your body, on top of storing sugars and vitamins, and supporting energy production for the entire body. While efficient, it can become overwhelmed if you give it too much garbage. Our Western diet, with its high content of sugars and fats, will lead to an unhealthy accumulation of lipids inside the liver cells, called the hepatocytes. When more than 30% of your liver hepatocytes are filled with fat, you would be diagnosed with steatosis, the scientific name of fatty liver disease. This mechanism is precisely the one that happens with geese and ducks through the process of gavage, leading directly to foie gras. Force-feeding birds for gastronomy has been mastered by humanity for thousands of years. The only difference with humans is that you don’t plan on eating your own liver.
Nothing to worry about? Really?
“The good news is that you have nothing to worry about for the moment,” your doctor adds. Indeed, you might not show any symptoms when you first learned about fatty liver, but the situation can get worse. If you keep up your unhealthy diet habits, the fat contained in your liver will start to become toxic to the surrounding cells. In a process similar to alcoholic poisoning, your hepatocytes die progressively, creating a highly inflamed area. Of course, your body can repair the damaged area, and a healing response will kick in, replacing dead cells with scar tissues.
If you injure your skin repeatedly, the scars that form become more and more extensive, and your skin would end up looking nothing like it did before. Just like the scars on your skin, those scars in your liver will also grow more prominent and hard with continued inflammation, eventually leading to cirrhosis. You probably have already heard of this disease, usually tied with alcohol consumption, but an unhealthy diet can also lead to it. It describes a liver so altered by the scarring process that it can no longer function normally. Liver cirrhosis is a dangerous disease that can lead to death on its own, but also greatly increases the risk of developing liver cancer. Two deadly conditions for the price of one.
Preventing the disease
“It is not too late for you,” your doctor continues gently. Of course, you would now be panicking after receiving that much dire information. But they reassure you: if the condition is detected early, it is reversible! The entire pathology is dynamic in the beginning, which means that if you eliminate the causal factor, your liver can heal on its own. The best way to do so is to have a healthier diet. Less fast foods and soda! Your best course of action would be to act now and not wait until it gets worse. If cirrhosis gets too advanced, you may reach a point of no return. Talented scientists around the world are looking into promising solutions, but sadly there is no cure for the moment once you reach that point. The only solution is to avoid damaging your liver too much, so do be careful with what you eat. You might prefer only keeping foie gras on your plate from time to time and not in your body!
1. EASL–EASD–EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease. J Hepatol (2016), http://dx.doi.org/10.1016/j.jhep.2015.11.004
This article was specialist edited by Dr. Rachel Golub and copy edited by Dr. Cassandra Koh.