Elizabeth A. Reid, MD Fatty Livers
OR thousands of years, humans have known how to make a tasty delicacy called foie gras from the livers of certain animals. Foie gras, which means “fatty liver” in French, is made by force-feeding animals, usually geese or ducks, a mash consisting of fat-soaked grain. Fatty livers are most easily in- duced in animals that regularly store extra fat for energy before migration. Humans also store en- ergy easily, and modern lifestyles, including
F diets heavy in fat-
soaked carbohydrates, have in- advertently created an epidemic of
fatty livers in people. Some researchers estimate that the problem now affects one-third of the US population.
Doctors have long been famil- iar with fatty livers in alcoholics, in whom a combination of the toxicity of alcohol and dietary de- ficiencies converts liver cells into fat-laden bubbles. This condition is known as alcoholic steatosis and is the first step along a road that can lead to
cirrhosis and
liver failure. Alcoholic steatosis can be reversed if the patient stops drinking. If not, it can be- come progressively worse, lead- ing to an inflammation of the liver called alcoholic steatohepatitis. Ultimately, this inflammatory de- generation can lead to a scarred and shrunken liver (cirrhosis) and to liver failure.
By 1980, the appearance of T H E E L K S M A G A Z I N E
M. Apicius [Marcus Gavius Apicius, a first century AD Roman gourmet] made the discovery that we may employ the same artificial method of increasing the size of the liver of the sow, as of that of the goose; it consists in cramming them with dried figs, and when they are fat enough, they are drenched with wine mixed with honey, and immediately killed. —PLINY THE ELDER, THE NATURAL HISTORY, BOOK VIII, CHAPTER 77
fatty livers and the kinds of prob- lems that are associated with them in nondrinkers forced doc- tors to devise a new diagnosis— nonalcoholic fatty liver disease (NAFLD). As in alcohol-fueled liver disease, NAFLD can also lead to inflammation, a condition called nonalcoholic steato- hepatitis (NASH), and to cirrho- sis and liver failure in some pa- tients. Progression from NAFLD to NASH seems to require the additional effects of viral hepati- tis or of toxic substances, like certain medications, both of which also play a role in some alcoholic liver disease progression. Since the 1980s, the preva- lence of NAFLD has been climb- ing in parallel with the numbers of people affected by the meta- bolic problems of obesity, insulin resistance, and type 2 diabetes. Like these problems, NAFLD is now affecting younger people, even children. By 2006, NAFLD and NASH were the main reasons
patients were referred to liver spe- cialists and were also the lead- ing causes behind diagnoses that led to 4 to 10 percent of liver transplants. While it is very diffi- cult to make accurate estimates about the overall prevalence of NAFLD, it is clear that it is very common in people who have ab- dominal obesity,
insulin resis-
tance, and type 2 diabetes—per- haps affecting as many as 75 percent of such individuals. In a state of good health, the liver functions silently. Tucked up under the ribs on the right side of the abdomen, it is the size and shape of a deflated football and is the second largest organ in the body (the skin is the largest). The liver coordinates energy stor- age and regulation and makes the proteins and cholesterol nec- essary to the health of all cells in the body. It also makes and se- cretes the bile needed to absorb fats from the intestine and filters toxins from the blood to destroy
them or ship them out with bile. The liver also stores vitamins and regulates the blood’s ability to clot in a fine-tuned range. Sometimes, the liver stores fat in its cells. Generally, this is a temporary state, and the fats are transported back to the body for use as an energy source or for storage in fat tissue. Obesity, in- sulin resistance, and diabetes, however, work together to keep fat in liver cells. Despite this stored fat, the liver can continue to function well, producing no symptoms, unless other factors produce inflammation and scar- ring. Thus, NALFD is often dis- covered incidentally, because of abnormal liver function blood tests or a scan of the abdomen for other problems.
When fat accumulation in the liver is accompanied by inflam- mation or occurs in someone who already has a scarred liver from other problems, like heavy alco- hol use or hepatitis, liver failure and cirrhosis may follow. It is estimated that 20 percent of those with NAFLD have inflammatory changes in their livers, moving them from a diagnosis of NAFLD to a diagnosis of steatohepatitis, or NASH, which increases their risk of developing liver failure and cirrhosis. Unfortunately, there are no easy tests to determine the presence or absence of inflam- mation in the liver, and patients (Continued on page 80)
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