I’ve had quite a few requests to do a blog post on this topic, but I’ve avoided it for a while because the subject is extremely complicated and there seems to be quite a lot of contradictory information out there. The whole thing seems to boil down into a couple of simple misunderstandings.
First, is the idea that you are what you eat. At the atomic level, this may be true, but our entire digestive process is designed to break down the foods we eat into molecules that can be used by our cells and sometimes those molecules look nothing like they did when we swallowed them. Two examples here are dietary fat and dietary cholesterol. I get the impression that many people believe that dietary fat is transported directly to our fat tissue and dietary cholesterol immediately goes to work depositing itself in our arteries. But in actuality, digestion and metabolism of fats and cholesterols are pretty complicated things. Fat is an extremely dense source of energy for our bodies and is necessary for a whole host of processes in the body, including creation of numerous hormones. The same is true of cholesterol which is a precursor of vitamin D, makes up a significant portion of the structure of the brain and is necessary for the uptake of numerous hormones. Our bodies have a variety of ways of synthesizing these and eating lots of them in the diet has not been shown to produce adverse health effects.
The second big fallacy is the idea that because a bad thing is made up of a particular substance, that substance is bad to have in our bodies. For example, arterial plaque is made up mostly of cholesterol, therefore cholesterol is bad, right? This makes about as much sense as saying that cancer patients should stop drinking water because cancer tumors are mostly water. The problem isn’t high levels of cholesterol in the blood or the ratio of HDL to LDL, those are symptoms.
So, what’s the cause? The most likely candidate seems to be hyperinsulinemia which in turn is caused by– you guessed it– excessive carbohydrate intake. For those of you who haven’t been following along, carbohydrates are broken down into glucose which triggers your body to release insulin. Insulin is a transport hormone that moves glucose from the bloodstream into cells where it can be used for energy, stored as glycogen in muscles and the liver, or stored as triglycerides in fat cells. The body responds to regularly high levels of insulin in the same way that it responds to regularly high levels of any other drug or hormone, by developing a resistance to it. Insulin resistance (AKA, metabolic syndrome) is strongly associated with a whole host of nasty conditions, including atherosclerosis and heart attack. Weird how that works.
There’s a whole lot more to this– like the roles of Omega 3 and 6 fatty acids, Vitamin D, exercise, inflammation and so on– but that’s the general idea. I encourage you to do your own research, but here’s a few places to start:
If you’re unfamiliar with basic biochemistry as it relates to human metabolism, the Wikipedia entries on Carbohydrate Metabolism, Fatty Acid Metabolism, Lippoproteins and Triglycerides are a good start. FAQ.org’s article on Carbohydrates is good, as well, and less technical. You can also visit modern-diets-and-nutritional-diseases.com, and cholesterol-and-health.com. Finally, you can check out the movie, “Fat Head,” if you want– though there is a lot in there that is irrelevant entertainment — or more to the point, just visit the website and check out their useful links and recommended reading sections.