Forty years ago, the term non-alcoholic fatty liver disease (NAFLD) didn’t even exist. Today, a staggering 30 to 40 percent of Americans have this undesirable condition.
This fatty liver epidemic parallels the obesity epidemic. Both conditions have similar causes: sugar, vegetable oils, and challenges with things like the regulation of the hormone insulin (i.e. metabolic syndrome and type 2 diabetes).
You’re probably aware that the ketogenic diet can help with obesity. But can keto help with fatty liver too?
You’ll learn what the science says here. First, though, let’s talk more about NAFLD.
What Is Non-Alcoholic Fatty Liver Disease?
Non-alcoholic fatty liver disease (NAFLD) is the buildup of excess fat (called visceral fat) in the liver (hepatic steatosis). Unlike with alcoholic fatty liver disease, the fat accumulation that defines NAFLD is not due to alcohol consumption.
NAFLD is diagnosed via ultrasound testing, usually after the patient presents with elevated levels of the enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Your levels of ALT and AST, also called your “liver enzymes,” are easily identified via blood tests. If more advanced liver disease is suspected, the doctor may order a liver biopsy.
Most of the time, NAFLD is not dangerous. Most people with fatty liver have neither symptoms nor complications. The danger increases, however, when simple fatty liver progresses into a form of hepatitis called nonalcoholic steatohepatitis (NASH), which is essentially NAFLD with inflammation. When inflammation is combined with liver fat, the whole organ goes up in flames, and liver damage is inevitable. NASH also often progresses to cirrhosis, a scarring (fibrosis) of the liver which portends liver failure.
Unfortunately, the development of fatty liver is often the first, silent step of this hepatic disease process. In America, between 30 and 40 percent of the population has this condition, and one of the causes is insulin resistance, which inspires fatty acids to be released from fat cells and for sugar to build up in the blood.
Why are there so many fatty livers? The answer is simple: bad nutrition.
Causes Of Fatty Liver
There are four main causes of NAFLD, with fructose leading the way:
Fructose doesn’t just raise your carbohydrate intake, cholesterol, and blood glucose. Believe it or not, researchers are calling fructose a “weapon of mass destruction” for causing liver fat too.
Here’s how that weapon works. When you eat fructose, it heads straight to your liver to be packaged into fat molecules called triglycerides. This fat, unfortunately, tends to stick around in the liver. Multiple animal and human studies confirm: Diets high in fructose cause fatty liver.
But wait, fruit contains fructose. Does that mean fruit is bad for your liver?
Not necessarily. Yes, fruit has fructose, but, unless you’re eating lots of ripe bananas, the amounts are relatively small. The real problem is the high-fructose corn syrup that sweetens sodas, juices, cookies, and most other packaged foods. Remove high-fructose corn syrup from the food supply and you take a huge step towards stopping NAFLD.
#2: Vegetable Oils
Along with fructose, veggie oils must take some blame for the NAFLD epidemic. That’s because oils like soybean oil, corn oil, and safflower oil are high in an omega 6 polyunsaturated fat called linoleic acid. When you feed animals diets high in linoleic acid, they develop fatty liver. In one study, mice fed soybean oil developed more fatty livers than mice fed coconut oil.
#3: Obesity and Insulin Resistance
The same foods that cause fatty liver – sugar and vegetable oils – also causes obesity. High sugar consumption, in particular, leads to insulin resistance, a condition which underlies obesity, diabetes, and NAFLD.
Insulin resistance means that insulin has become lousy at managing your blood-sugar levels. You need more insulin to do the same job. As a result, your pancreas releases more insulin, insulin levels rise, and insulin resistance worsens.
Insulin, by the way, is a fat-storage hormone, and high levels of insulin (hyperinsulinemia) contribute to both obesity and NAFLD. Unfortunately, the type of fat stored when you’re insulin resistant tends to be organ (visceral) fat, not the safer jiggly (adipose) fat.
#4: Not Enough Choline
Choline is a nutrient that helps your liver process fat. Specifically, your body requires choline to make very low-density lipoprotein (VLDL) particles. VLDL particles, in turn, function to export fat from your liver – crucial for preventing fat accumulation.Though human trials on choline for NAFLD are a bit thin, research in animals has shown that choline supplementation reverses fatty liver disease.
Unfortunately, most people don’t eat enough choline. That’s because the primary dietary source of choline – the egg – has been demonized for its saturated fat content. People also tend to avoid beef liver, another excellent source of choline. Other good sources of choline include caviar!, fish like salmon, tuna and cod, and shitake mushrooms.
Can A Keto Diet Help with Fatty Liver?
The ketogenic diet is the opposite of a low-fat diet; in fact, it’s a high-fat low-carb diet best known for stimulating weight loss. On a keto diet, you follow carbohydrate restriction through eating the right macronutrients and antioxidants for your specific body (the amounts are based on your body mass index and other factors). Also, your daily calorie intake is at least 60 percent fat, 20 to 30 percent protein, and 10 percent carbs so that you maintain “ketosis,” which is when your body relies on ketones (made by your body from both body fat and fat from your diet) as its primary fuel source.
The research on keto for NAFLD is early, but promising. The meta-analysis from clinical trials suggest:
- Two weeks of keto dieting reduced liver fat by 42 percent in 18 people with NAFLD.
- A six month keto diet reduced liver inflammation in obese people.
- A low-carbohydrate diet led to reductions in liver fat in 10 healthy people. (A more recent study, however, found that a keto diet didn’t affect liver fat in a similar population).
It seems counterintuitive that a high-fat diet would improve fatty liver. But when you look at the causes of NAFLD, it makes more sense.
First, the keto diet is low in fructose. Eliminate fructose and you eliminate a primary cause of fatty liver. Second, a whole-foods keto diet doesn’t contain vegetable oils; instead liver-friendly fats like olive oil, coconut oil, and butter are prioritized. Third, the keto diet has been shown in study after study to reverse insulin resistance and stimulate weight loss in obese people. These are also risk factors for NAFLD.
Finally, choline is encouraged on keto, not shunned. Eggs are an ideal ketogenic food.
The Final Word
The same things that cause obesity and cardiovascular disease/heart disease also cause fatty liver. Preventing (or reversing) fatty liver means cutting down on fructose, eliminating vegetable oils, losing body weight, and getting enough of the nutrient choline.
Early research suggests that a keto diet can reverse fatty liver, promote healthy liver function, and improve insulin sensitivity, at least in obese populations. A proper keto diet has other beneficial effects: it’s high in choline, an essential nutrient for liver health, and, of course, it can reverse problems for type 2 diabetics.
For more on low-carb therapy for NAFLD, check out this illuminating video with Dr. Jean-Marc Schwarz, the director of the Metabolic Research Center in Touro University California.
Also, when considering dietary lifestyle changes, whether it’s to mitigate weight gain/excessive body mass always consult with your healthcare provider.