When most hear the term “fatty liver”, what immediately comes to mind is a condition driven by excessive alcohol consumption. While excess fat in/around the liver can be caused by consistent and excessive alcohol consumption, more frequent instances of fatty liver are being observed in people who are not consuming excessive alcohol. A fatty liver not caused by excessive alcohol consumption is called non-alcoholic fatty liver disease (NAFLD).
This Berkeley Wellness article outlines two types of (NAFLD):
- Nonalcoholic fatty liver (NAFL), which has few or no symptoms and is thought to be harmless. The liver normally contains some fat, but when the percentage passes the 5 to 10 percent mark, the liver is considered to be fatty (a condition called steatosis). In NAFL, the liver functions normally despite fat accumulation. Most people with NAFLD have this form of the disease and don’t even know they have it. However, NAFL can occasionally progress to a more serious form of NAFLD.
- Nonalcoholic steatohepatitis (NASH), in which the accumulation of fat is accompanied by inflammation. NASH can lead to the development of scar tissue in the liver (cirrhosis), which can prevent liver cells from functioning properly and result in liver failure. NASH can also lead to liver cancer. It’s usually symptomless but might cause fatigue, a general feeling of illness, and vague discomfort in the upper-right abdomen. It affects about 3 to 5 percent of Americans with NAFLD and is most common in adults between ages 40 and 60.
Isn’t NAFLD Caused by Eating Too Much Fat?
One of the misconceptions of NAFLD is that it is caused by a high fat diet. The thought process is eating high fat causes a build-up of fat in/around the liver. In reality, that is not the case at all. The below extract from PubMed Central (PMC) where some excellent medical and life sciences literature can be found, highlights how carbohydrates (fructose & glucose) are major drivers of NAFLD. Here’s a direct quote:
High fructose corn syrup (HFCS)-containing beverages were associated with metabolic abnormalities, and contributed to the development of NAFLD in human trials. Ingested carbohydrates are a major stimulus for hepatic de novo lipogenesis (DNL) and are more likely to directly contribute to NAFLD than dietary fat. Substrates used for the synthesis of newly made fatty acids by DNL are primarily glucose, fructose, and amino acids.
Journal Extract: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4405421/
Causes of NAFLD
While we are still learning about what exactly are the root causes of NAFLD, it is interesting to review what are believed to be key contributors & linked factors. Notice any commonalities?
- Severe overweight or obesity
- Insulin resistance
- Abnormally elevated cholesterol or triglyceride levels
- Large waist size
- High blood pressure
- Elevated blood sugar levels
- Type 2 diabetes
- Metabolic syndrome (having three or more of a cluster of risk factors: high blood pressure; excess abdominal fat; high blood sugar; low HDL, or good cholesterol; and high triglycerides)
Our dietary choices drive most of the above conditions. Consider:
- Insulin resistance is a pre-cursor to becoming pre-diabetic, as blood sugar levels remain elevated and insulin is unable to move blood sugar into the cells. Some of this sugar is then converted to fat, and stored in the liver. This insulin resistance is prevalent in people who are pre-diabetic, which if not reversed, leads to becoming a type 2 diabetic.
- Insulin resistance is a core contributor to obesity (BMI > 30) & a larger waist size (fat accumulation around the waist/gut). The more fat you have around your mid-section, the more likely you are to have a fatty liver. In fact, as you lose weight, the body will seek to reduce the fat around the liver first, which is why some who go on weight loss plans do not see the physical manifestation of that weight loss right away. The weight is coming off from within.
- Insulin resistance, obesity and type 2 diabetes are linked to coronary heart disease (CHD), which includes high triglyceride levels and high blood pressure.
- Insulin resistance is driven by three core behaviors:
- Poor Quality of Foods we Eat
- Poor Quantity / Mix of Macronutrients
- Excessive Frequency of Consumption
Even the article, which highlights solutions/suggestions to reduce this risk, mentions two core issues to address: “But several single metrics stood out as being especially important. Failing to control blood pressure, for example, explained 52.8 percent of deaths in people with NAFLD. Uncontrolled blood sugar levels were also associated with significantly increased risk.“
For more on the role of insulin resistance, and how to begin to reverse a fatty liver through better dietary choices, please refer to my previous post.