Sunday, November 28, 2010

Tuesday, November 23, 2010

Preventing Fatty Liver

Fatty Liver II.
A couple weeks ago I wrote a little bit about how children as young as five years old are getting Non-alcoholic Fatty Liver Disease (NAFLD) and discussed how fructose appears to be a causative factor (not the only one). It's kind of an important issue considering that as many as 100 million Americans probably have some stage of fatty liver disease.

Chris Masterjohn just published an article on his blog, The Daily Lipid, looking in to the research on what actually causes fatty liver. It's a bit technical, but the information is simply fantastic. In fact, Chris' work in general is some of the best there is on nutrition and health, and I highly recommend his blog. Anyway, I suggest you read his full analysis here, but I'll give a quick summary of his findings. 

Sugar, fat, alcohol and choline. 
In his review of the literature the evidence shows that alcohol, fat, and sugar/fructose intake ALL contribute to fatty liver, but only in the presence of a choline deficiency. It appears that a deficiency of choline impairs the ability of the liver to export the fat it creates from alcohol, fat, or sugar, effectively trapping it in the liver and leading to fatty liver disease. Adequate choline intake prevents this pathogenesis, even in the presence of sugar, fat, or alcohol. Chris wraps it up nicely here:
I have to conclude from all these studies that choline deficiency plays a role in virtually every type of diet-induced fatty liver model. The fat has to be provided to the liver through either dietary fat or dietary lipogenic substrates like ethanol and fructose, and the fat has to be trapped by impaired export of fats from the liver. And choline deficiency seems to be the preeminent cause of this.

Take home points.
  • Fatty liver needs a choline deficiency to develop.
  • Make sure you are getting adequate amounts of choline in your diet, especially if you are consuming large amounts of alcohol, fat, or sugar.
  • The best food sources of choline are... Egg yolks and liver! Yum!
Any thoughts?

Wednesday, November 17, 2010

ADA is coming around? Low fat diets increase heart disease risk

Today a report from the recent American Dietetic Association (ADA) conference was released with several experts reporting that replacing saturated fat with carbohydrates in the diet probably increases heart disease risk. Maybe this will be the straw that breaks the camel's back... 

Here's the report- thanks to Jamie at Primal Muse for pointing this out. 

Low fat diets could increase heart disease risk, say nutrition experts

By Caroline Scott-Thomas, 16-Nov-2010
Related topics: Fats & oils

Many Americans aim to eat low-fat foods but there is strong evidence that replacing fat with carbohydrates could be harmful to health, according to nutrition experts at the ADA conference in Boston last week.

Recommendations to reduce saturated fat intake are largely based on the notion that high levels increase risk of cardiovascular disease, but unless saturated fat is replaced with other fats, many studies have suggested that fat reduction could increase risk of heart disease.
During a symposium called “The Great Fat Debate: Is There Validity In the Age-Old Dietary Guidance?” at the American Dietetic Association’s (ADA) Food and Nutrition Conference and Expo, four leading experts presented evidence suggesting that low fat diets may be less healthy than those containing at least a moderate amount of fat. In particular, all four agreed that replacing saturated fat with carbohydrates – as has been widely recommended in the United States – is likely to raise the risk of cardiovascular disease.
The low fat message
Director of the cardiovascular health laboratory at Tufts University Dr. Alice Lichtenstein said dietary advice to adhere to a low fat diet is based on an oversimplification of recommendations.
“The emphasis should be on displacing saturated fat and trans fat with unsaturated fat because that is where the data is,” she said. “…‘Displace saturated fat with polyunsaturated fat’ was simplified to ‘low fat’. Then ‘low fat’ became ‘low calorie’. The low fat message is still very pervasive, especially in the lay press.”
‘Massive distraction’
Chair of the Harvard School of Public Health’s nutrition department Dr. Walter Willett takes this even further.
“If anything, the literature shows a slight advantage of the high fat diet,” he said. “The focus on fat in dietary guidelines has been a massive distraction…We should remove total fat from nutrition facts panels on the back of packs.”
He added that while the pervasive dietary guidance given to consumers has been to eat fats sparingly, to load up on starch and eat non-fat products, “the food industry quickly realized sugar was cheaper than fat and laughed all the way to the bank.”
“It was really the type of fat that was important,” he said. “If you replaced saturated fat with polyunsaturated fat there was a reduction of risk.”
American eating behavior
Meanwhile, distinguished professor of public health and professor of epidemiology at the University of Pittsburgh’s Graduate School of Public Health, Dr. Lewis Kuller, said that dietary guidance to reduce saturated fat should not change, considering that too much of the fat in the American diet is saturated and not enough is unsaturated.
“The biggest problem in America at the moment is eating behavior,” he said. “…Eating is a social pleasure and not a therapeutic challenge. We have done a great job of confusing the public.”
The importance of overall diet
Assistant professor of medicine at Harvard Medical School Dr. Mozaffarian agreed with the other speakers about a lack of evidence linking total fat consumption and cardiovascular disease risk.
High levels of low density lipoprotein (LDL cholesterol) and high triglyceride levels have both been linked to increased risk of cardiovascular disease, but Mozaffarian said there has often been overreliance on single biomarkers in drawing conclusions about fats’ impact on heart health, “even one as hallowed as LDL cholesterol”.
“Overall dietary quality is very important for cardiovascular risk,” he said. “Saturated fats may raise LDL cholesterol but increasing levels of all fats lowers triglycerides…You can’t look at data across countries and draw conclusions. Nor can you look at animal studies or a single biomarker and draw conclusions from that.”
Concluding the discussion, Dr. Lichtenstein warned against focusing on single nutrients for disease risk reduction.
She said: “We need to stop focusing on individual dietary components because when one goes down, another goes up.”

Thursday, November 11, 2010

Cognitive dissonance in government institutions

The System.
Jamie Scott runs a great blog called Primal Muse and writes articles on evolutionary medicine and nutrition. In this post, he displays a correspondence between himself and "Dr Doug Lush - Principle Advisor on Human Health and having held previous positions with the Ministry of Health and the New Zealand Heart Foundation".

Cognitive Dissonance.
The exchange is about the conflict between evolutionary nutrition principles and government/institutional recommendations. Despite being in New Zealand's system, it's incredibly applicable to our own predicament in the United States. Jamie writes and awesome letter and "attached a meta-analysis that spanned 21 studies and ~350000 subjects, and a Cochrane Collaboration report" to back up his stance, after which the former government official replies that his stance should be backed up by evidence based meta analysis and information from the Cochrane Collaboration... did he even read Jamie's email? The absurdity of this is killing me and I feel Jamie's frustration.

Check it out here: