Tag Archives: NAFLD

How a single high-fat “meal” (palm oil) affects liver metabolism 

Posted on January 24, 2017 | 2 comments

I thought we were through demonizing saturated fats.

I put my headline’s “meal” in quotes because the only item in the meal was palm oil. That doesn’t look like one of my meals.

From MNT:

“Individuals who consume higher levels of saturated fats are more likely to feel the effects of a range of health conditions, including non-alcoholic fatty liver disease. Although this link is well-known, exactly how and why it develops is not yet clear.

Recent research investigates the effects of a single high-fat meal on the liver.Non-alcoholic fatty liver disease (NAFLD), as the name suggests, is a condition in which excess fat is stored in the liver of an individual who drinks little or no alcohol.

Marked by liver inflammation, NAFLD most commonly affects people in their 40s and 50s, and especially those who are obese. It can cause scarring of the liver and permanent damage. At its worst, it can lead to liver failure.NAFLD is primarily characterized by an increased buildup of fat in the liver, and this buildup is often accompanied by insulin resistance, thereby increasing the risk of type 2 diabetes and cardiovascular disease.”

Source: How a single high-fat meal affects liver metabolism – Medical News Today

German researchers fed a single palm oil meal to 14 healthy men, and some mice.

The article writer doesn’t make it clear whether results apply to the men, the mice, or all combined. Anyway, they found

  • Elevated blood triglycerides
  • Increased glucagon (a pancreas hormone that raises blood sugar)
  • Whole body insulin sensitivity decreased 25 percent
  • Hepatic insulin sensitivity decreased 15 percent
  • Adipose (fat) tissue insulin sensitivity decreased 34 percent
  • Triglycerides in the liver – the main constituent of body fat in humans  – also rose by 35 percent

All of these changes would tend to promote not only NAFLD but also type 2 diabetes.

Whether these adverse changes would be see with other saturated fats or polyunsaturated fats is left unstated in the report.

From UpToDate.com: “The pathogenesis of nonalcoholic fatty liver disease has not been fully elucidated. The most widely supported theory implicates insulin resistance as the key mechanism leading to hepatic steatosis, and perhaps also to steatohepatitis. Others have proposed that a “second hit,” or additional oxidative injury, is required to manifest the necroinflammatory component of steatohepatitis. Hepatic iron, leptin, antioxidant deficiencies, and intestinal bacteria have all been suggested as potential oxidative stressors.”

I’ve been hearing for years that NAFLD is going to be a big deal. At least every other shift I work in the hospital, I see someone with evidence for fatty liver on ultrasound or CT scan.

The mainstay of therapy for NAFLD is weight loss for those who are obese or overweight. It’s probably a good idea to avoid all alcohol consumption, too.

If you need to lose weight, check out my books.

Steve Parker, M.D.

Steve Parker MD, Advanced Mediterranean Diet

Two diet books in one

 

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Too Much Mouse and Molecular Biochemistry!

Posted on July 7, 2013 | 1 comment

That’s my primary assessment of an article I read in Current Opinion on Clinical Nutrition and Metabolic Care.  The title is “Low-carbohydrate ketogenic diets, glucose homeostasis, and nonalcoholic fatty liver disease.”

Don't assume mouse physiology is the same as human's

Don’t assume mouse physiology is the same as human’s

The article’s more about mice than my patients.

The authors share some stats about nonalcoholic fatty liver disease (NAFLD):

  • the earliest stage is fat build-up in the liver
  • 15% of the nonobese population has NAFLD
  • 65% of the obese have NAFLD
  • it can progress to an inflammatory disorder (nonalcoholic steatohepatitis (NASH)
  • about two out of 10 NASH patients progress to cirrhosis within 10 years
  • NAFLD is an independent predictor of heart and vascular disease, an even stronger predictor than overall body fat mass (even visceral fat)
  • insulin resistance is strongly linked to NAFLD

The Washington University School of Medicine authors say good things about low-carbohydrate ketogenic diets for weight loss and seizure control.  They spend the rest of the article talking about rodent physiology and lab chows—right up Carbsane Evelyn‘s alley.  But not mine.  Bores me to tears.

They do mention the small Browning study that showed a very-low-carb ketogenic diet superior to a calorie-restricted diet for reducing liver fat in humans. Weight loss by various methods is a standard recommendation for humans with NAFLD; I wouldn’t be surprised multiple different diets worked.  It may be the weight loss, not the diet, that does the trick.  We have just one human study thus far indicating a ketogenic diet is more effective short-term.

Here’s the full Browning study if you care to read it yourself.

If I were obese and had NAFLD, I’d go on a very-low-carb ketogenic diet (like this one).

Steve Parker, M.D.

Reference:  Schugar, Rebecca, and Crawford, Peter.  Low-carbohydrate ketogenic diets, glucose homeostasis, and nonalcoholic fatty liver disease.  Curr Opin Clin Nutr Metab Care, 2012, vol. 15.  doi: 10.1097/MCO.0b013e3283547157

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Low-Carb Diet Beats Low-Calorie for Treating Fatty Liver

Posted on April 9, 2012 | 3 comments

Loss of excess weight is a mainstay of therapy for nonalcoholic fatty liver disease. A very-low-carb diet works better than a reduced-calorie diet, according to a study in the American Journal of Clinical Nutrition.

Nonalcoholic fatty liver disease (NAFLD) occurs in 20 to 40% of the general population, with most cases occuring between the ages of 40 and 60. It’s an accumulation of triglycerides in the liver. For every week I work in the hospital, I see five or 10 scans (either CT scans or sonograms) that incidentally show fat build-up in the liver.

Nonalcoholic steatohepatitis (NASH) is a subset of NAFLD, perhaps 30% of those with NAFLD. Steatohepatitis involves an inflammatory component, progressing to cirrhosis in 3 to 26% of cases.

Researchers at the University of Texas Southwestern Medical Center assigned 18 obese subjects (average BMI 35) to either a very-low-carb diet (under 20 grams a day) or a low-calorie diet (1200 to 1500 calories a day) for two weeks. Liver fat was measured by magnetic resonance technology. The low-carb groups’ liver fat decreased by 55% compared to 28% in the other group. Weight loss was about the same for both groups (4.6 vs 4 kg).

Bottom Line

This small study needs to be replicated, ideally with a larger group of subjects studied over a longer period. Nevertheless, it appears that a very-low-carb diet may be one of the best dietary approaches to nonalcoholic fatty liver disease. And I bet it’s more sustainable than severe calorie restriction. The Ketogenic Mediterranean Diet, by the way, provides 20-30 grams of carb daily.

Steve Parker, M.D.

Reference: Browning, Jeffrey, et al. Short-term weight loss and hepatic triglyceride reduction: evidence of a metabolic advantage with dietary carbohydrate restriction. Am J Clin Nutr, May 2011 vol. 93 no. 5 1048-1052. doi: 10.3945/ajcn.110.007674

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