Monday, September 22, 2008

How to Fatten Your Liver

Steatohepatitis is a condition in which the liver becomes inflamed and accumulates fat. It was formerly found almost exclusively in alcoholics. In the 1980s, a new condition was described called nonalcoholic steatohepatitis (NASH), basically steatohepatitis without the alcoholism. Today, NASH is thought to affect more than 2% of the adult American population. The liver has many important functions. It's not an organ you want to break.

This week, I've been reading about how to fatten your liver. First up: industrial vegetable oil. The study that initially sent me on this nerd safari was recently published in the Journal of Nutrition. It's titled "Increased Apoptosis in High-Fat Diet–Induced Nonalcoholic Steatohepatitis in Rats Is Associated with c-Jun NH2-Terminal Kinase Activation and Elevated Proapoptotic Bax". Quite a mouthful. The important thing for the purpose of this post is that the investigators fed rats a high-fat diet, which induced NASH.

Anytime a study mentions a "high-fat diet", I immediately look to see what they were actually feeding the animals. To my utter amazement, there was no information on the composition of the high-fat diet in the methods section, only a reference to another paper. Apparently fat composition is irrelevant. Despite the fact that a high-fat diet from coconut oil or butter does not produce NASH in rats. Fortunately, I was able to track down the reference. The only difference between the standard diet and the high-fat diet was the addition of a large amount of corn oil and the subtraction of carbohydrate (dextrin maltose).

Corn oil is one of the worst vegetable oils. You've eaten corn so you know it's not an oily seed. To concentrate the oil and make it palatable, manufacturers use organic solvents, high heat, and several rounds of chemical treatment. It's also extremely rich in n-6 linoleic acid. The consumption of corn oil and other n-6 rich oils has risen dramatically in the US in the last 30 years, making them prime suspects in NASH. They have replaced the natural (more saturated) fats we once got from meat and milk.

Next up: fructose. Feeding rats an extreme amount of fructose (60% of calories) gives them nonalcoholic fatty liver disease (NAFLD), NASH's younger sibling, even when the fat in their chow is lard. Given the upward trend of US fructose consumption (mostly from high-fructose corn syrup), and the refined sugar consumed everywhere else (50% fructose), it's also high on my list of suspects.

Here's my prescription for homemade foie gras: take one serving of soybean oil fried french fries, a basket of corn oil fried chicken nuggets, a healthy salad drenched in cottonseed oil ranch dressing, and wash it all down with a tall cup of soda. It's worked for millions of Americans!


.^ said...

Interesting. I've been reading Dr Eades's archives recently and he had a related observation way back in July '05 - foie gras cest moi

Stephan Guyenet said...


Thanks. It's insane how common NAFLD and NASH are in the US. It's a real epidemic. Once your liver is fatty and insulin-resistant, the rest of your metabolism is toast.

Debs said...

How frustrating that it was just described as a "high-fat diet" without that distinction! Aside from the n-6 content and processing in corn oil, and the fructose and processing in HFCS, it's also interesting that both these triggers were from corn.

Of course, maybe our population is getting NASH specifically because we're not eating rat chow. Look at the evidence: Did you know over 99.9% of people with NASH have never included rat chow in their diets?

Food Is Love

Anna said...

This was one of my concerns when I looked into agave syrup. You can't imagine how many recommendations I hear for it, from "natural" health food store employees to well-intentioned moms looking for a "healthy" sugar. When I looked into it, I found some brands are as high as 92% fructose and AFAIK, all brands have a higher fructose content than HFCS!

And agave syrup, while still a fringe sweetener, is showing up more frequently. Trader Joe's is carrying a bottle of it (and I wouldn't be surprised if AG starts to show up on the ingredient labels of Trader Joe's products, too. It is a frequent sweetener ingredient in sweetened nutty spreads at the "natural" foods stores, as well as an ingredient in "healthy" ice cream, yogurt, and baked goods. Very worrisome, IMO.

And I have seen some moms use agave syrup with abandon, in a way they never would apply granulated table sugar to their childrens' food. The marketing of this "healthy" sweetener is proving to be quite successful, unfortunately. And it's a fine line telling people about it, because I'm sure I sound like Chicken Little or a killjoy at times to the folks that want to believe that agave syrup/nectar is the answer to their prayers for a safe sweetener.

Stephan Guyenet said...


It's typical in the nutrition research field to massage the interpretation a bit to make it confirm your bias. In this case, the investigators wanted to blame fat for NASH. Specifying that it was PUFA corn oil that caused the NASH would make them butt heads with the conventional wisdom that all fat is bad. All they needed to add was one little sentence about it in the methods section. It's really disheartening to see researchers obscuring relevant data like that. That style of wishful interpretation/misleading omission that pervades the nutrition research field is a big part of what got us where we are today.

Stephan Guyenet said...


I share your concern about agave syrup. Way too much fructose. Plus it's very inefficient to make compared to cane sugar and HFCS. Actually, I'm not sure people realize the process of making agave syrup is pretty similar to how they make HFCS. Enzymatic processing.

People want a sweetener they can eat with abandon without harming their health. In my opinion, there are none. The only solution is moderation.

Robert Andrew Brown said...

Thanks Stephan

An interesting clear post as usual.

The acerbic comment at the end made me laugh.

How many reasons do people need to moderate Omega 6 intake? And yes it is too simple an answer for many. They will not even even open their minds to the idea.

I sent a copy of my book to the MD of UK's premier medical think tank the Kings Fund. I got a letter back saying they could not consider the book as they had no expertise in the field (lipids.) I did very gently hit my head on the desk a few times (-:.

I can personally testify reducing Omega 6s and increasing long chain 3s will reduce NAFLD makers significantly. Feeling your living shrinking is a very weird sensation (-:.

Anna - thanks for the information on Agave. That is seriously concerning.

Robert Brown


Omega Six the Devils Fat

Unknown said...

I've never been a fan of Hersheys milk chocolate products but I just read they've started using vegetable oils instead of cocoa butter as a cost-cutting measure.
In this article they briefly mention health benefits of cocoa butter but say nothing of the effects of vegetable oils.

Stephan Guyenet said...


Did you have NAFLD at one point?


I took a look at the article. There was one part at the end that left me confused:

"“Chocolate lovers need not be alarmed about the future of their favorite product,” the FDA said in a consumer update. “Cacao fat, as one of the signature characteristics of the product, will remain a principal component of standardized chocolate.”"

Yet they are allowing the replacement of cocoa butter with veg oil. Am I crazy or is that a frank contradiction?

Unknown said...

I noticed that too and figured he meant to say cacao paste or cacao solids. Then again, I wouldn't be surprised if that was an outright lie.

What also bothered me was this deceptive statement from the spokesperson:

“there are high-quality oils available which are equal to or better than cocoa butter in taste, nutrition, texture and function, and are preferred by consumers.”

Unknown said...

I just read the last few paragraphs again and it seems the FDA person could be talking about their definition of chocolate in general and not in reference to the products that were the focus of the article. So it might not be a falsehood but still a bit misleading from the way that quote was tacked on.

Anonymous said...

Rober: "I can personally testify reducing Omega 6s and increasing long chain 3s will reduce NAFLD makers significantly."

I think we should remove variables, rather than adding them. First, get rid of refined sugar, high fructose corn syrup, etc. Second, get rid of high PUFA oils and limit or cut out foods with a high PUFA content, ex: most nuts and seeds. I suspect that most health problems would cease to exist if everyone took these simple steps, but most people would rather use drugs and expensive supplements the rest of their lives apparently. It's hard to understand.

Lee FG (Yogipanda) said...

But what about fruit? Why is it that fruit is so good for you when it has a high level of fructose?

new guy said...

I like to drink alcohol, usually Crown Royal or Jack Daniels, in moderation of course. Is there some form of alcohol, that still tastes great and doesn't kill your liver due to fat?

Rafael said...

I was diagnosed with fatty liver 2 years ago. At first, they told me DOn´t worry is nothing just try lo lose weight. then, afer doing my own research i went to a specialist who recomended a very low fat diet and increase exercise. No mention about sugars

Alex J said...

It's funny that you mentioned fois gras. The first thing that came to mind when I started reading about NAFLD was that I should apply all of this wonderful newfound knowlege to give geese NAFLD without having to resort to force-feeding. Look a little further, and what do you know, the French have already worked this out:

Still plotting, might have some apple fattened goose liver coming to a farmer's market near you!


skibunny said...

Hi.... What do you think about using L-Carnitine to reduce fat in the liver ? It helps burn fat at a higher rate in the body and helps the mitocondira as well.... please tell me what you know about L-Carnitine? and its effects on fatty liver disease?

Unknown said...

Hey Stephan,

A bit late to the party I know. But I was hoping you could help me out. I know you mention that fats such as coconut oil and Butter will not produce NASH. I'm wondering if this is dependent on choline intake. Unless the MCT's do not need lipoprotein transport. I know they are directed to liver through the portal vein, but do you know if fat stored from coconut oil increases the necessity for choline?

Thanks in advance,
Kyle K.