A New Idea for Me About Evolution: Body Weight, Insulin Resistance, and Fructose

July 28th, 2011 by Amy Gonsalves Leave a reply »

This paper is fascinating me right now despite being sidetracked yesterday. Dr. Richard Johnson of Denver Colorado is the presenter and researcher; he presented at the World Congress on Insulin Resistance, Diabetes, and Cardiovascular Disease in November 2010.

(This is one of what seems like an infinite number of instances wherein “diabetes” means type two diabetes, by my figuring.)

Full disclosure here: I’m not a scientist.  One of the reasons I’m not a scientist is that I have to read science terms very slowly and I’m not patient enough to do so.  So please remember I’m pointing to words, terms, and phrases in the online work itself rather than paraphrasing in large part because I’m not familiar enough with what I’m writing about.  (Not that that stops me from writing about it.) 

Johnson believes that “fructose may not be simply an energy source, but may have specific metabolic effects that may aid in increasing fat stores.”

He goes on to say that islet injury from fructose is in part mediated by urate, and uricase deficiency is a genetic mutation that may just have saved our ancestor’s lives. (I can’t fully explain how the islet injury occurs to begin with, or why.)

So, in a world where fruit and fruit sugar is a main source of energy, those with a uricase deficiency would have had a tough time of insulin management, which would today appear as insulin resistance (one of the hallmarks of type two diabetes).

Until  you consider Survival of the Fittest: those best able to survive periods of famine were those who had the genetic propensity to insulin resistance.


Because a body resistant to insulin makes more insulin to manage glucose in the blood.    It also in turn increases fat storage since that’s one of the functions insulin serves in our bodies.  More body weight (fat) means more insulin required, which means more insulin made, which starts the cycle all over again.

So those who carried extra body fat and body weight due to a uricase deficiency would have been those best equipped to survive a famine.

Wacky, isn’t it?

Our ancestor’s propensity to increase fructose consumption without proper genetic tools to manage that consumption helped them survive, and here we are in the twenty first century with insulin resistance and type two diabetes as one of the world’s most alarming health crises.

It’s important to keep in mind that the amount of fructose our ancestors consumed is NOWHERE NEAR the amount we consume today.  Johnson points out that in our lifetimes we have seen an incredible increase in the amount of sugar we consume compared to just three hundred years ago:
“…from a mean of 4 pounds of sugar intake per year in 1700 in the United Kingdom and United States, to greater than 150 pounds per year today….we found that 25% of the population was ingesting over 130 g of fructose per day, which equates to over 200 pounds of sugar per year …some individuals are ingesting more than 50 times the mean amount of sugar than was being ingested just 300 years ago.”

So while we owe our ancestors a debt of gratitude for surviving as well as they did, we need to make some changes in our own lives and in our own world so that our children and grandchildren and 10-times-great-grandchildren can thank us, too.

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