Fatty liver has become astonishingly common in the United States. As much as 30% of the US population has fatty liver. Most estimates are from data collected several years ago, so chances are fatty liver is even more common now, given the trends in obesity and diabetes. To state the obvious, this is not good.
The full name of the condition is nonalcoholic fatty liver disease (NAFLD) and basically means that there’s an increased amount of fat throughout the liver in liver cells. Just like we have fat on the outside of our bodies, which we all can see, we also have fat build up around and in our organs. Most of the time, fatty liver will never cause direct harm, but a rather large minority of people do have progressing problems. 20% of individuals with fatty liver disease progress to something called nonalcoholic steatohepatitis (NASH). That’s a mouthful! NASH is basically fatty liver that has progressed to inflammation and injury in the liver cells. Under magnification, it’s easy to see how liver cells have ballooned up with fat (triglycerides). Sometimes the liver becomes scarred (fibrosed). One in five people who have these inflamed livers, full of fat, will develop liver cirrhosis, which can lead to liver failure and death.
Even though only about 4% of people with fatty liver will develop cirrhosis, the condition is so common that 4% represents a lot of people. In fact, the most common reason that women need liver transplantation is now fatty liver that has progressed to liver failure, and it’s almost the common reason men need liver transplantation, with alcoholism.
Fatty liver also can lead to liver cancer. And people with fatty liver have a higher risk of heart disease and cancer.
Because it’s such a common condition and most people are not in danger from the condition, doctors may gloss over it at a patient visit. There’s no drug or procedure to prescribe to treat fatty liver, which reduces the likelihood of doctors spending much time talking about it. But as you can see, it’s not something to be taken lightly.
Most people find out they have fatty liver by either elevated liver enzymes (AST or ALT) on lab tests, or by an imaging test of their belly or chest done for some other reason. Sometimes these other imaging tests incidentally mention fatty liver in the results. Fatty liver doesn’t really cause symptoms, so it’s almost diagnosed by a lab or imaging finding. An ultrasound can be helpful to confirm and characterize the fatty liver, but unfortunately, you can’t fully be sure whether the condition is progressed to the more inflammatory NASH without a liver biopsy. Biopsies are not done for everyone because they carry small but potentially serious risks.
If your doctor has told you that you likely have fatty liver disease, how do you treat it?
The fantastic news is that diet and lifestyle changes are really effective. There are couple types of foods and beverages that are particularly problematic, but the most important therapy is weight loss.
Things to avoid include saturated fat, added sugars (fructose, in particular), and alcohol. Americans load up on saturated fat by consuming cheese, milk, meats, and added oils, butter, and margarine. Fructose is found in sodas, fruit juices, and all the foods high in added sugars. Cut back on these foods and your liver will thank you, along with other organs in your body.
And cutting back on foods rich in fat, oils and solid fats, and added sugars will help with weight loss, as well, which is really the ‘sledgehammer’ of treatments here. The benefits of weight loss for your liver are astounding.
In one study, 58% of subjects with the more dangerous NASH who lost just 5% of their body weight saw their NASH resolve. Of those who lost 10% of their body weight, 90% saw a resolution of NASH. Perhaps even more remarkably, almost half of the people who lost more than 10% of their weight saw regression of their fibrosis (scarring), which occurs in advanced disease. These are remarkable numbers, showing that the liver can heal even after scarring is present, with the right diet and lifestyle.
Another intervention study found that weight loss reduced fat (triglyceride) in the liver to a remarkable degree in subjects with obesity. A 5% weight loss was associated with a 13% reduction in liver fat. A 10% weight loss led to a 52% reduction in liver fat, and a 15% body weight loss led to a 65% reduction in liver fat.
What does all this add up to? There are many tens of millions of Americans with fatty liver, and tens of millions of them will have some degree of progressive disease. This means that sizable numbers of Americans will get cirrhosis, liver failure, or liver cancer as a direct result of their fatty liver.
But we now know the cure – a diet that promotes a healthy weight while minimizing saturated fats and added sugars. This means a diet comprised of whole foods that limits or avoids processed foods (where a lot of added fat and added sugar is found), and a diet predominantly based on plants. Exercise is excellent, as well, as this independently improves several metabolic processes that keep your liver healthier.
In my own practice I have seen many patients with fatty liver change their diet to a strict whole-food, plant-based diet and I see their elevated liver enzymes improve and normalize over time. The benefit doesn’t stop with the liver, of course. Even greater is the fact that as the liver improves, the risk of heart disease is reduced, certain cancers become less likely, and you might feel better and move better throughout your day.
I encourage patients to use fatty liver as a serious red flag that their metabolic health is badly compromised. It is a red flag, and an increasingly common cause of life-threatening problems. While most patients will never be directly harmed by fatty liver, it is a crucial opportunity to change their future, avoid progressive ‘medicalization’, and realize dramatic health improvements by diet and lifestyle alone.