Scientific American asked the question back in 2015 if non-alcoholic fatty liver disease (NAFLD) was America’s greatest health risk of the times. In that year, the American Liver Foundation estimated that up to 25 percent of Americans were living with the disease.
Researchers have echoed that concern. In a 2015 study, they stated that there was a worldwide epidemic of NALFD. As far back as 2011, they predicted that the prevalence of the disease would increase by 50 percent by the year 2030.
In 2016, researchers reported that as the epidemic of obesity and its related metabolic conditions increase, “the clinical and economic burden of NAFLD will become enormous.” Indeed, NAFLD is closely related to the other major health conditions we’re all facing today: diabetes, obesity, and heart disease.
Most women don’t give our livers a second thought, but it’s time we did. The health of the liver is extremely important to our overall health, and NAFLD can cause liver damage without us even being aware of it. At its most severe, it can lead to the need for a liver transplant for survival.
Estimates are that if we keep going the direction we’re going, NAFLD will become the main cause of liver transplants in the country, with demand continuing to outpace supply.
What is NAFLD?
NAFLD is an umbrella term describing those liver diseases that aren’t related to alcohol consumption. Whereas consumption of too much alcohol over a period of several years is known to damage the liver, NAFLD is directly related to fat. Though there are various sub-forms of the disease, they’re all caused by too much fat in the liver cells.
As the fat builds up, it can eventually start to cause inflammation, which in turn, leads to liver damage. Since the condition rarely causes symptoms at this point, the person remains unaware of what’s happening. As the inflammation continues, it can cause scar tissue to form. This leads to a disease called “cirrhosis,” which is a scarring of the liver that can lead to liver failure.
In most cases, NALFD proceeds in the following stages:
- Initial fat buildup: The liver gradually experiences a buildup of fat. This is directly related to overweight or obesity. The disease is usually undetectable at this point.
- Inflammation: The fat builds up to the point it starts to cause inflammation in the liver. This condition is also called “non-alcoholic steatohepatitis (NASH),” which is liver inflammation and damage caused by fat buildup.
- Scar tissue: Persistent inflammation causes scar tissue to form in the liver and in the surrounding blood vessels. This is also called “fibrosis.”
- Cirrhosis: The most serious stage of the disease, cirrhosis occurs after years of inflammation-related scarring. The liver can actually become misshapen or even “lumpy,” and will no longer be able to function correctly. Cirrhosis can lead to liver failure and liver cancer.
What are the Risk Factors for NAFLD?
Overweight and obesity are the primary risk factors for NAFLD. Fat around the middle—the “apple” shape—is more likely to lead to fatty liver than fat around the hips and thighs (“pear” shape).
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDKD) states that more than 2 in 3 adults are overweight or obese today. As we’ve gained weight as a nation, our livers have suffered. Harvard Health estimates that about 20 percent of Americans have some degree of fatty liver disease.
Turns out that excess fat may be just as dangerous to the liver as excess alcohol. A diseased fatty liver looks much the same as a liver damaged by a lifetime of drinking. That’s why the disease is so dangerous.
The Mayo Clinic reported in 2012 that NASH-related cirrhosis was increasing in frequency in liver transplant recipients, while other types of liver disease like hepatitis C and alcohol-related liver disease were decreasing. They estimated that NASH would become the leading cause of liver disease in the transplant population in the coming years.
Fat doesn’t work on its own to harm the liver, though. Research has shown that a number of related conditions encourage and accelerate liver damage. These are all conditions that are naturally related to being overweight. At this time, the most dangerous one appears to be diabetes.
The Diabetes-NAFLD Connection
The American Society for Metabolic and Bariatric Surgery (ASMBS) calls diabetes and obesity “twin epidemics.” More than 90 percent of type 2 diabetics are also overweight or obese.
Diabetes, unfortunately, can increase the odds that fat will harm the liver. Obesity can cause insulin resistance, which results in a buildup of blood sugar. It can also increase the amount of free fatty acids circulating in the blood, and those fatty acids accumulate inside the liver cells. That’s what leads to inflammation and liver damage.
The Hepatitis B Foundation also notes that buildup of fat in the liver is common in those with type II diabetes, and that it can increase the risk of liver cirrhosis and liver cancer. Obesity is a risk factor for diabetes, which in turn, can increase the chance of fatty liver and liver inflammation. The three conditions work together to create a very unhealthy situation.
In fact, the partnership is so common that Daniel Einhorn, M.D., clinical professor of medicine at the University of California, San Diego, said to Everyday Health that fatty liver disease is so common that “it’s present arguably in a majority of type 2 diabetics.”
The problem is that until it becomes quite severe, NAFLD has no symptoms. That means if you have it, you most likely aren’t aware of it.
Female-Specific Risk Factors: Hormones
Some studies have suggested that women may be at a higher risk for NAFLD, while others have found that men are more susceptible. Scientists are still looking into this, but we do have some helpful information.
First of all, as with heart disease, it seems that female hormones have a protective effect. That means that once we go through menopause and our estrogen levels drop, we may be more at risk. In a 2013 study, for instance, researchers found that out of 251 women, NAFLD was present in 37.1 percent of those who were postmenopausal. In addition, hormone replacement therapy seemed to help. NAFLD was present in:
- 26.4 in those taking hormone replacement therapy
- 39.9 of those without hormone replacement therapy
An earlier study found similar results—that NAFLD was more frequent in postmenopausal women who had not received hormone replacement therapy. Researchers suggested that estrogen may play a protective role.
In 2012, scientists reported on an analysis of over 4,000 women aged 20 to 65 years. They found that the prevalence of NAFLD was lower in women using birth control pills than in those not using them. In fact, current users had 50 percent lower odds of developing the disease than those who never used the pills.
We need more evidence before we can say for sure that female hormones affect risk, but for now, women should be aware that they may need to be more careful after menopause.
Female-Specific Risk Factors: Polycystic Ovarian Syndrome
Polycystic ovarian syndrome (PCOS) is a condition in which women have imbalanced levels of the female hormones estrogen and progesterone. In general, the level of these hormones is decreased. This causes the growth of ovarian cysts, as well as other issues like irregular menstrual periods, excess hair on the face and chest, acne, and sometimes, infertility.
Women with PCOS often have other health issues too, including overweight, diabetes, high blood pressure, and high cholesterol levels. Thus it starts to make sense that women with PCOS may also be at a higher risk for NAFLD.
A 2014 study found just that. Researchers reviewed the scientific literature, and reported that PCOS is a potential risk factor for fatty liver disease. They advised doctors to be aware of the connection. They added that PCOS could cause liver disease to develop at a much younger age than usual.
In a 2016 study of 600 women with PCOS matched with a group of controls without the disease, scientists again noted that NAFLD was more prevalent in women with PCOS. They noted that these women had higher measurements for waist circumference, higher levels of triglycerides in their blood, and higher total cholesterol levels, as well.
Fatty Liver Disease and Metabolic Syndrome
Underneath all these connections is a condition called “metabolic syndrome.” Researchers have found this to be frequently present in those with NAFLD—and in those with PCOS and diabetes.
Metabolic syndrome is the name for a group of risk factors that increases risk for heart disease and all these related problems we’ve been talking about: diabetes, stroke, fatty liver disease, and more. Risk increases as you age, and is believed to affect one out of every six people.
The main characteristics of metabolic syndrome are:
- high blood pressure
- high blood cholesterol (and low HDL “good” cholesterol)
- high blood sugar
- abdominal (belly) fat
- high blood triglycerides (fats)
In a 2015 study, for instance, researchers reported that almost 25 percent of the women with PCOS were diagnosed with NAFLD, and that metabolic syndrome was present in between 32.7 percent and 44.6 percent of the patients with PCOS. They concluded that in women with both PCOS and NAFLD, metabolic syndrome was “highly prevalent.”
But even without PCOS, metabolic syndrome is dangerous for women’s livers. Research published in 2015 on over 1,400 women found that postmenopausal women were more at risk for NAFLD, and that metabolic syndrome—specifically, diabetes, belly fat and high levels of fat in the blood—were specifically associated with the disease.
How Women Can Reduce Their Risk of NAFLD
As noted earlier, NAFLD doesn’t create symptoms until the very last stages. A blood test, however, can detect it. If you have any of the other risk factors listed here—obesity, diabetes, metabolic syndrome—check with your doctor. Detecting fatty liver early is the best way to avoid complications down the road.
Currently, we have no drugs made specifically to treat NAFLD. Instead, doctors will recommend lifestyle changes like losing weight, exercising more, eating a nutritious diet, and controlling blood sugar and triglycerides. Some diabetes medications may also be effective.
After all this research, what are we left with? The main conclusion is that our health is more interactive and holistic than many have believed for years. One issue, such as diabetes, doesn’t operate on its own. It affects the whole body, and can cause a number of other problems if it’s not controlled.
Your best bet is to recommit yourself to a healthy lifestyle. Eating right, exercising more, and losing a few pounds are still really worthwhile goals. If you have any risk factors for disease, do your best to keep them under control to limit their impact on your health as a whole.