Modifying the Gut through Diet

 Our gut is apparently modified by what we eat. This makes a lot of sense. If we usually eat a lot of some food and the body ramps up the enzymes that digest that food, then we should get more energy from that food, and until relatively recently, getting as much energy from our food as posible was the body's goal. It's only in the recent past that most of us have too much food available so that obesity and not starvation is the problem.

Here is a study showing that if you eat a lot of food, your gut expands so you can digest more food. It had previously been shown that cold does the same, which makes sense because you need to burn more calories to stay warm when it's cold. The interesting thing is that this process seems to be reversible, meaning that if you limit your food intake for a bit, your gut may change its structure again (reducing the number of absorptive villi and hence surface area) so that it absorbs fewer calories.

Interestingly, fructose seems to do the same thing, increasing the villus length: "the increase in villus length was associated with increased nutrient absorption, weight gain and fat accumulation in the animals" wrote the authors of this study. They note that this makes sense evolutionarily because fruit, which contains a lot of fructose ("fruit sugar"), is most available in the fall, when animals want to fatten up so they can survive the lean times of winter.

Eating a peach is not likely to fatten you up, but overeating fructose by drinking a lot of high-fructose corn syrup--sweetened sodas could.

The abstract of the paper can be found here. Note that the authors suggest that fructose also promotes tumor growth.

Of course, if you have diabetes, any sugars like glucose, sucrose, or fructose are not a great idea.

New Hormone Complex Affecting Diabetes

Sometimes it seems as if a new factor that affects diabetes is announced every week. The latest one is called fabkin, which sounds to me like a detergent or a new diet craze. And fabkin is not one factor but a complex of of several. The name comes from fatty-acid-binding protein 4 (FABP4), which forms a functional hormone complex with two kinases, adenosine kinase (ADK) and nucleoside diphosphate kinase (NDPK) to regulate extracellular ATP and ADP levels.

It's postulated that fabkin affects beta cells, blunting their effects. The interesting thing is that using antibodies to neutralize fabkin improves beta cell function in both type 2 and type 1 diabetes. In fact, it has been suggested that neutralizing fabkin could "spell the end of diabetes."

This is an exaggeration, although of course anything is possible. A lot more research needs to be done before fabkin wipes out diabetes.

But it's another factor to keep an eye on.

 

 

The Demise of NuSI

 I don't know how many people have been following this, but NuSI (the Nutrition Science Initiative) was founded in 2011 with the goal of improving the quality of nutrition research, which would allow clarification of which diet was best for weight loss.

Gary Taubes, author of Good Calories and Bad Calories as well as many articles in various media supporting low-carb diets for weight loss, and Peter Attia, a physician interested in longevity, were the founders, and thanks to the John Arnold Foundation, they were able to throw a lot of money at studying the issue. They completed a few studies, but the results were not earth shaking.

 Unfortunately, like so much these days, the organization soon became embroiled in controversy and science politics, and Taubes has just announced its dissolution. 

This won't have much effect on most of us patients. What we want to do is find an eating plan that controls our blood glucose levels and lets us lose weight if we need to, or maintain our weight if we don't need to lose. Diet politics is of less importance to us.

If I were a physician prescribing diets to patients, I'd want to know the results of big controlled trials on many people, so I could first prescribe a diet with the greatest chance of succeeding and then if that didn't work, prescribe something else. But I'm not. So although it's too bad, the demise of NuSI doesn't have much effect on people like me. 

The success of any diet depends on many factors. No diet works well if the subject doesn't follow it, and different people have different tastes. A diet of 100% sea slugs might work 100% of the time, but how many people would be willing to eat nothing but sea slugs? A more reasonable diet might work most of the time if people adhered to it, but even then adherence would vary.

So although the demise of NuSI is sad, it won't have a huge effect on most of us patients. We'll just keep plugging away with the knowledge we have now.

 

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