High-Fat, High-Fructose Combination Worse Than High-Fat Or Low-Fat Alone

I’ve been saying this for years1,2 … a diet that is both high in fat and high in refined carbohydrates is worse (that is, leads to more metabolic disorders such as weight gain, diabetes, fatty liver, cancer) than a diet high in one or the other. The combination is particularly deleterious. (Although diets high in fat alone come with their own risks related to their higher levels of fat-soluble environmental toxins, increased systemic inflammation, and, as this study found, promotion of insulin resistance and fatty liver.)

This new study found that:

Fructose Supplementation Worsens The Deleterious Effects Of Short Term High Fat Feeding On Hepatic Steatosis And Lipid Metabolism In Adult Rats, Experimental Physiology, 27 June 2014

RatsHighFat2014Adult male rats were fed either a low-fat, high-fat, or high-fat/high fructose diet for 2 weeks. The high-fat/high-fructose diet was worse than the high-fat diet, which was worse than the low-fat diet. Another way of saying that … the low-fat diet was the healthiest.

Some significant bits:

“From our results, it appears that hepatic mitochondrial impairment is an early event induced by increased lipid content of the diet, since it is already evident after 2 weeks of dietary treatment, and that the presence of fructose does not have a further impact on mitochondrial function.

Significantly lower mitochondrial oxidative capacity but significantly higher oxidative stress was found in rats fed high fat and high fat-high fructose diet compared to rats fed low fat diet.”

During high fat feeding an increased lipid supply to peripheral organs, and particularly to the liver, arises mainly from dietary lipids.”

They say that mitochondrial impairment is linked to insulin resistance, and that it is dietary fat which initiates insulin resistance. It occurs because there is a reduced capacity by mitochondria to deal with the increased lipid supply. The extraneous fat is deposited ectopically or outside of the cell, leading to a fatty liver, which exacerbates insulin resistance. Adding fructose to this impaired state compounds the problem.

This is exactly what Dr. McDougall says happens. (Insulin Resistance Is A Normal Adaptation To A Rich Diet)

By the way, the rats fed a low-fat, high-carbohydrate diet (from cornstarch) by the end of the study weighed less, had less body fat, less liver fat, fewer plasma free fatty acids, and lower plasma cholesterol than the rats fed a high-fat diet, even though they ate the same amount of food (in calories) as the high-fat rats.

1 High-Fat High-Sugar Dietary Pattern (“Meat & Potatoes”) Linked To Colon Cancer, Diabetes, Fanatic Cook, July 2010
2 “Meat And Potatoes” Dietary Pattern And Risk For Colon Cancer, Fanatic Cook, May 2010

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s