Life Extension Magazine®
Most people take liver health for granted. After all, the liver is one of the body’s most resilient organs and the only one capable of regenerating itself. Regrettably, most doctors are unaware of a liver ailment that strikes a significant portion of the population. It is called nonalcoholic fatty liver disease. Researchers say it has become the most common liver disorder in the United States, affecting an estimated 24% of us, according to a recent study at Johns Hopkins University School of Medicine.1 What’s even more frightening is that, like diabetes and hypertension, this usually silent liver condition sneaks up and can cause life-threatening health problems years down the line. If staying alive were easy, everyone would be doing it. People usually associate liver disorders with alcoholism or viral hepatitis. The facts reveal that nonalcoholic fatty liver disease is the villain that will most likely attack your liver The words “nonalcoholic fatty liver disease” describe this condition well: an accumulation of fat in the liver, making up at least 10% of the organ2—in people who drink little or no alcohol. The latter distinction is an important one, say experts, because in the past, fat buildup in the liver has typically been associated with alcohol abuse. Nonalcoholic fatty liver disease is the name given to a broad spectrum of liver disease that encompasses several stages of hepatic pathologies.
Who’s at Risk? Nonalcoholic fatty liver disease is much more prevalent in obese and diabetic people than in the general population. An estimated 90% of obese people are at risk for the development of chronic liver injury.7 Moreover, about half of the estimated 16 million Americans with type II diabetes have nonalcoholic fatty liver disease.8 Combine obesity and diabetes, and a person’s risk climbs even higher: just about all of those with both conditions have some degree of nonalcoholic fatty liver disease,9 almost half have nonalcoholic steatohepatitis, and 20% suffer from cirrhosis.8 Even more important than the fact that a person is obese is where excess fat is stored on the body. Research has shown that people who carry excess weight around their middle (abdomen or waist) are most prone to developing insulin resistance. And recent studies have revealed that the majority of people with nonalcoholic fatty liver disease have central (abdominal) obesity.10,11 What’s Behind the Problem? The pathogenesis of NAFLD is not well understood. Production of tumor necrosis factor-alpha (TNF-a) has been reported to be one of the early events in the many types of liver injury, and together with other TNF-a-dependent cytokines (inflammatory messengers), it may mediate a process of chronic liver injury. During chronic liver injury, proliferation and migration of activated hepatic stellate cells are involved in the pathogenesis of hepatic fibrosis. Recent studies have demonstrated that oxidative stress stimulates production of collagen, which drives the development of fibrosis. Hepatic stellate cells are the main source of the abnormal collagen-derived extracellular matrix material that represents the biochemical hallmark of the disease process.
Dyslipidemia (high LDL and triglycerides; low HDL), insulin resistance, and other components of the metabolic syndrome (see sidebar, on p.56, “The Syndrome X Connection”) increasingly are recognized as being associated with NAFLD. Adding weight to the theory that insulin resistance plays a leading role in the development of a fatty liver is that high insulin levels have been shown to block the oxidation (burning off) of fat in liver cells (hepatocytes), contributing to the buildup of harmful fatty acids and triglycerides in the organ.13-15 In fact, triglyceride fat is the very type of fat stored in tiny sacs inside a fatty liver.7 High concentrations of fatty acids (which help produce the triglycerides that can build up in the liver) are not only toxic to liver cells, but also may be directly tied to the oxidative stress that leads to the inflammation and scarring in the second stage of NAFLD.13,16 A recent study shows that 58% of patients with severe hypertriglyceridemia had elevated liver enzymes indicative of nonalcoholic steatohepatitis.17 Intriguingly, as we will see later, PPC has shown potent triglyceride reductions in human clinical studies. A new study shows that insulin resistance is associated not merely with NAFLD, but with its more serious form, nonalcoholic steatohepatitis. The study employed a measure of insulin resistance known as the homeostatic model assessment (HOMA), which is calculated as the fasting insulin level times the fasting glucose level, divided by 405 (for blood tests reported in US numerical units; for European numerical units, divide by 22.5 instead of 405). A HOMA level greater than 2.2 indicates insulin resistance. Patients with simple fatty liver (steatosis) had an average HOMA level of 1.61, whereas patients with nonalcoholic steatohepatitis averaged 3.67 and were therefore insulin resistant.18 As noted earlier, dyslipidemia, including elevation of triglyceride levels, insulin resistance, and other components of the metabolic syndrome increasingly are recognized as being associated with NAFLD.
Signs, Symptoms, and Complications If the disease progresses to the more-advanced cirrhosis stage, however, a patient can suffer any number of symptoms, including blotchy red palms, prominent veins on the abdomen, star-shaped spider veins on the upper torso, thinning hair, swelling of the legs (edema), abdominal fluid retention (ascites), and even mental confusion, as well as irregular or absent menstrual periods in premenopausal women and enlarged breasts (gynecomastia) in men.7 Studies show that as many as 20% of patients with nonalcoholic steatohepatitis may progress to cirrhosis within a 10-year period,19,20 and 3% may progress to liver failure, eventually requiring liver transplantation.21 Because cirrhosis is typically diagnosed so late in NAFLD patients compared to those with other chronic liver diseases, it is more likely to be fatal.22 And compared to simple fatty liver sufferers, patients with advanced nonalcoholic steatohepatitis are more than 10 times more likely to die from the disease.23,24 Most worrisome is mounting evidence that nonalcoholic steatohepatitis can progress to hepatocellular cancer (liver cancer). A new study finds that Ki-67 staining, a marker of liver cell proliferative activity, is virtually absent in the normal liver but is seen in 54% of fatty liver patients and in 100% of nonalcoholic steatohepatitis patients. In nonalcoholic steatohepatitis, the Ki-67 index correlates with grades of necro-inflammation in the liver.25
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Can NAFLD Be Treated or Prevented? Phosphatidylcholine (the main component of lecithin) is an integral part of cell membranes, essential for their structural and functional integrity. Cell membranes act like gatekeepers, allowing nutrients into the cells but blocking damaging toxins from gaining entrance. PPC has been shown to enhance cell membrane function throughout the body.
PPC already is approved for the treatment of chronic liver diseases in many European countries and is being investigated for treatment of hepatitis (see sidebar on p. 55, “PPC in Viral Hepatitis”). PPC is listed in the Physician’s Desk Reference (PDR) commonly used by US physicians. An accumulating body of research suggests that PPC’s umbrella of protection may extend from the liver to the stomach, pancreas, and cardiovascular system. PPC is well absorbed in humans and animals when taken orally and has no known contraindications, side effects, or interactions with other drugs, even when consumed in large quantities. In one pilot study, researchers found that daily doses of PPC halted the progression of liver fibrosis,27 and a Czech study showed that taking the supplement every day (along with low doses of fatty acids, B vitamins, and vitamin E) reduced fatty-liver symptoms within six months in more than half of the study participants.28 PPC also appears to increase the breakdown of collagen, the connective-tissue protein that tends to accumulate in liver disease, promoting the scarring behind fibrosis and cirrhosis.29 PPC’s protective effect is believed to be the result of its ability to be incorporated in normal and damaged cell membranes. Animal studies have indicated that PPC, which is a polyunsaturated phosphatidylcholine, becomes incorporated in the membranes of liver cells as a substitute for native saturated phosphatidylcholine molecules.30 This substitution is shown to result in an increase in membrane fluidity and active transport activity across the membrane. Similarly, PPC is incorporated in blood lipoproteins such as cholesterol, leading to lipid-lowering properties. In one Russian clinical trial, the supplement lowered total and LDL (“bad”) cholesterol by about 15%, decreased triglyceride levels by 32%, and raised levels of “good” HDL cholesterol by 10%.31 PPC also appears to have antioxidant properties, which means it may effectively reduce the oxidative stress (cellular changes that generate cell-damaging free radicals) shown to be a contributing factor in the inflammation and scarring of nonalcoholic steatohepatitis.32 Experts point out that simply losing weight often will result in a significant reduction of excess fat in the liver. But they add that it is best to lose weight slowly—at a rate of no more than 1 to 2 pounds a week—because rapid weight loss has been shown to exacerbate a fatty liver condition, causing inflammation and even resulting in liver failure.33-35 Keeping high glucose levels under control also is critical for NAFLD patients, as research has shown that a fatty liver improves as glucose levels are controlled.36 A preliminary study found that a drug called metformin (Glucophage®), which improves insulin sensitivity and is used to treat type II diabetes, also significantly lowered liver enzyme levels and decreased fatty deposits in the liver in people with NAFLD.7 Additional studies are now under way. Doctors say that NAFLD can probably be largely prevented and even eliminated in the future by encouraging the adoption of healthy eating habits and more-active lifestyles. For those who already have nonalcoholic fatty liver disease, encouraging discoveries show that the use of natural products may potentially alter the course of this serious consequence of aging and unhealthful lifestyles.
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