CW: Pass the Brownies

Oops. I screwed up.

This week’s Cycling Wednesday entry didn’t get posted last night. As we used to say in fellowship training, it was a “rookie mistake.” An example of an electrophysiologist getting too fancy with WordPress–a failure to use the KISS method.

Sorry.

Here’s the entry:

After spending an entire vacation reading stories, I would like to start tonight’s post with a tiny dose of fantasy. Can we try using a daydream to learn something about the challenge of making good nutrition choices?

The fantasy goes something like this…

You have just been sentenced to eternal life on a far-away sun-drenched island. This island has mountains, paved roads, wide bike lanes, and mountain bike trails. You get to take two bikes, a couple riding buddies and your family—if they’ll go. You also get to take one Apple product.

Sounds good so far.

The kicker is that you only get four food choices—and liquids count.

You are a cyclist, so after coffee and beer there are only two food choices remaining. Obviously, you will need a protein source. Smart choices here would include nuts, mercury-free fish or organically-fed animals. The protein isn’t the point, let’s keep moving.

Now we are down to the carbohydrate source.

Choose one of the following:

A.) Arugula
B.) Quinoa
C.) Cranberries
D.) Fruit Loops

Herein lies the primary hurdle that smart-nutrition advocates face: unhealthy simple sugars taste really good. To all but a tiny minority of pale-skinned, pony-tailed Whole-Foods shoppers, avoiding simple sugars is nearly impossible. Even my arugula-consuming uber-healthy wife falls prey to M and Ms. The biology of pleasure draws most of us of to the middle aisles of the grocery store. Abstinence may work for preventing teen pregnancy and STDs, but it sure looks like a futile strategy in our struggle with sugar consumption.

The biologic problem with consuming too much sugar is that it causes high levels of the hormone, insulin. And insulin is a baddie. On this point, I agree with the famous nutrition author Mr Gary Taubes. His piece in the NY Times Magazine details the toxicity of sugar.

I’ll boil his 9-page treatise down for you in a few sentences. (But for those with a few minutes, and even the slightest interest in nutrition, I highly recommend reading the entire essay.) Sugar ingestion causes insulin release from the pancreas. Insulin promotes uptake of sugar into the working cells. That’s a beneficial effect, because in the absence of insulin, blood sugar levels rise—as in Type I diabetes. Unchecked high blood sugar causes death quickly.

Insulin also promotes fat storage. Simply stated, insulin puts the fat into fat cells. You can see this effect at any State Fair or Shopping Mall. The more sugar one eats, the more insulin is released. High levels of insulin causes the body to develop resistance to the effects of insulin, and as a result the pancreas releases yet even more insulin–you see the vicious cycle.

But there’s more bad news about high levels of insulin. Now, there exists substantial data suggesting that insulin acts as a “growth-factor” inside blood vessels (and perhaps even in cancer cells.) Promoting the growth of cells inside blood vessels causes heart disease. Diabetes is one of the strongest predictors of heart disease, and diabetic patients with heart disease suffer more complications.

On the cancer note, in the final section of his NY Times piece, Mr Taubes provides a solid argument that insulin facilitates tumor cell growth. His premise is strengthened by the well known fact that diabetics and obese people have higher rates of cancer. A connection between sweets and cancer seems likely.

The final point to make on sugar metabolism is that individuals vary in their tolerance to carbohydrates. Some seem to handle sugars well, burning them off quickly as fuel. Others aren’t so lucky; even modest amounts of sugar cause high levels of insulin and expanding waistlines, blood vessel disease and possibly even cancer. Why people vary this way is yet to be determined.

I’m no nutritionist, but when I want to go uphill fast on the bike, I eat fewer sweets and drink less fermented-wheat products.

It works like magic, but I just can’t seem to abstain for long. I’m glad my livelihood doesn’t depend on prolonged will-power.

Now where did we put those Pop-Tarts?

JMM