Hi everyone, Dr K here, back from a long summer holiday. Today we’re going to discuss a much misunderstood organ, the mysterious liver.
Just what does the liver do, Doc? How much booze is too much? I heard Tylenol is bad for your liver, is that true? How do you get hepatitis? I’m hearing an awful lot about fatty liver lately, what’s up with that? And what can I do to keep my liver healthy? Those are all good questions and I’ll try to get to all of them today. Keep in mind that hepatology, the study of liver disease, is a big, big subject. As always, I’ll try to not get bogged down in the minutiae, but rather, stick to the facts, “just the facts, Ma’am”.
What does the liver do? Think of it as the concierge, kitchen and housekeeping staff of a luxury hotel. Concierge? The liver takes just about anything you put into your body (food, drink, medications and other substances) and tells it where to go and what to do. Kitchen? The liver takes raw substrates and turns them into exquisite delicacies to fuel the rest of the body. Housekeeping? It breaks down unwanted and unneeded stuff and helps get rid of it. Is this analogy a bit of a reach? Yeah, probably.
What I’m trying to say is, the liver takes all the food presented to it from the small intestine and either stores it or distributes it. The liver is the central producer of proteins and glucose needed by every cell in your body. And it breaks down medications, after they do their thing, of course, and removes them through the bile.
Sir William Osler (1849-1919) is widely regarded as the quintessential clinician of Western medicine. As wise a sage as there ever was, he was quoted as saying “Jaundice is a disease that your friends recognize”. Now, not to correct Dr Osler, after all who am I, but… jaundice is a sign that can be seen in many different diseases. Jaundice, as you probably know, is the yellowing of the eyes and skin that often suggests liver dysfunction. This condition reflects the accumulation of bilirubin that occurs if your hepatocytes (liver cells) are sick. (Increased serum bilirubin can also occur with obstruction of the bile ducts and in certain blood disorders.) To get even more technical, bilirubin comes from the breakdown of hemoglobin from the normal turnover of your red blood cells. One of the many jobs your liver does is to process this bili (that’s what we call it, bili) and ship it out via your bile ducts and ultimately, your stool. What’s that you say? TMI? Ready to move on? Me too.
How much booze is too much? If you’re asking, then you probably drink too much. Ha! The official answer, for your liver health, is more one drink per day for women, two for men. One drink is defined as 5 oz of wine, a 12 ounce beer or one shot (1.5oz) of liquor. Anything above that increases your risk of developing alcoholic liver disease. Binging (5 drinks in a 2 hour period), even occasionally, is also risky. Now that doesn’t mean everyone who has three drinks at dinnertime every day is going to develop cirrhosis. Only about 15% of hard drinking alcoholics (like a fifth of vodka every two days, that kind of drinking) develop cirrhosis; this is surprising, but tells us there are factors in addition to excessive alcohol in play. Things like genetics, poor nutrition, coexistent diseases and maybe just plain luck. Just remember, “We cannot tempt fate without eventually getting scorched by it”. (Ana Veciana-Suarez)
This would be a good time to discuss liver injury in general. Anything that harms the liver- too much drink, viruses like Hep C, excessive fat in the liver, autoimmune attack, to name a few- first causes hepatitis, meaning inflammation of the liver. The liver, like every other body tissue, reacts to chronic inflammation by attempting to heal itself, but at the expense of fibrosis. Fibrosis is scar tissue that replaces previously normal tissue. The liver has a large reserve, but if you replace enough of it, say >50%, with fibrotic tissue, then there are not enough functioning hepatocytes to do all that work we spoke of earlier (the hotel, remember?). This is what we call cirrhosis. As a result, not enough needed proteins are made, nutritional stores suffer, and maybe too much bilirubin, which causes what? That’s right, jaundice! You were paying attention!
I told you this was a big topic. We may have to come back in a part 2 for liver disease, but for today, I’ll wind up by finishing my answers to those questions posed earlier.
Tylenol (acetaminophen) can be bad for you IF: 1) you OD, which requires taking 20 or more pills at one time. This sadly remains a common means of suicide attempt, especially in places like the UK without free access to firearms (not a problem in the good old US of A), OR 2) you are someone who abuses alcohol and also takes the upper end of recommended Tylenol (2 extra strength pills every 6 hours) semi-regularly. Why? Alcohol abuse increases an enzyme pathway in liver cells that turns acetaminophen into a metabolite that is quite toxic. But if you are a social drinker and take acetaminophen occasionally, no problemo.
We touched on hepatitis earlier. There are many causes of hepatitis, or liver inflammation- viruses (like Hep A, B or C), medications, alcohol, autoimmune disorders, and genetic conditions like hemochromatosis (iron overload) and Wilson’s disease (copper overload). So other than viral hepatitis, you don’t really “catch” it.
Fatty liver should be a post onto itself. It’s a HUGE problem. 25% of the population, one in four people, has increased fat in their liver cells. But fat alone is no big deal. In some people, and we don’t know exactly why, an inflammatory reaction occurs that leads to scarring (fibrosis, remember?) and cirrhosis. We call this kind of hepatitis nonalcoholic steato-hepatitis, or NASH for short. NASH occurs in maybe 10-20% of people with fatty liver. So, ginormous numbers worldwide. In fact, we are bracing for a flood of chronic liver disease (cirrhosis and liver cancer) related to fatty liver. Think about it. The obesity epidemic in the US and elsewhere has been going on for at least 20 years. It typically takes 10-20 years for chronic hepatitis (like NASH) to develop into cirrhosis in those susceptible. Do the math.
You don’t have to be overweight to get fatty liver. How does your doctor know if you have it? If your liver blood tests are elevated (ALT and AST are included in most “routine” blood work), further testing- blood and ultrasound- must be done to determine why. And as in real estate, suspicion, suspicion, suspicion! Common things are common! If you have any risk factors such as Type 2 diabetes, hypertension, elevated cholesterol, sleep apnea, polycystic ovary syndrome, and of course obesity, you should be evaluated, even if your ALT and AST are normal.
So how do you love your liver? Everyone’s favorite doctor advice- moderation! Watch your alcohol, keep your weight down, exercise regularly, and work with your doctor. Be involved in your health care!
But there may be some things you just can’t prevent. So in closing, “You will find, Brumm,” said Earl Lavender, “that one of two things must be sacrificed by every man who lives to be over sixty- the mind, or the liver.” (John Davidson 1895)