It is even worse that we are adopting the primitive dietary style. I was appalled by this idea after I meticulously digested the 2005 Dietary Guideline. For instance, the Guideline suggests that almost all vegetables should be eaten in raw or minimally cooked. Fruits should be eaten without peeling. Should I forget about the exquisite Chinese cuisine? Should I eat like a gorilla, biting fruits without appreciating the delicacy of nature?
Furthermore, whole grain, the big star in this Guideline, is particularly gross. Everybody who is sensitive to the color, smell, and texture of breads will boycott the dark and coarse whole grain breads, let alone those faked whole grain breads covered with flakes of oatmeal. They are tough to my mouth, harsh to my esophagus, and harmful to my stomach. I miss the tasty white breads.
So why did those stupid experts advocate whole grains, or whole foods in general? Let’s again get armed with modern knowledge. We know the main ingredients in grains, vegetables and fruits are carbohydrates plus many vitamins and minerals. Let’s tackle carbohydrates in this post and leave vitamins and minerals to the next post.
Carbohydrates can be broadly grouped into simple carbohydrates and complex carbohydrates (what a dumb classification!). Simple carbohydrates consist of one or two sugar molecules. Glucose, fructose (fruit sugar), and galactose (in milk) are typical single sugars. Lactose (stuff causes diarrhea after drinking milks), sucrose (table sugar) and maltose (sweetness in beer) are common double sugars.
On the other hand, complex carbohydrates consist of long chains of sugar molecules (polysaccharides). They have to be digested and broken down to single/double sugar to be absorbed and fuel our body.
After the invention of water powered mill, refined grains are appreciated by all civilized human beings. The refine process reconstructs the complex carbohydrate structure so that glucose chains are nicely aligned and bound together. The product, starch, can be quickly broken down to single or double sugar and easily absorbed. Unfortunately, most vitamins, minerals, fibers, and other nutrients are likely lost during the process.
We all know that blood glucose level will increase quickly after having a chocolate snack. The same thing occurs after you finish a plate of foods. However, due to the different structure of complex carbohydrates, different foods raise blood glucose level at different speed. White bread and white rice, which mainly consist of glucose in easily digested forms, can raise blood glucose level very fast, even faster than eating a spoon of table sugar (sucrose=glucose+ fructose). Fructose has to be converted to glucose to be useful.
A rapid increase of blood glucose will cause an increased secretion of insulin, a hormone made by pancreatic beta cells. Insulin can reduce blood glucose level by facilitating the usage and storage of glucose. Knowledgeable readers may point out that a malfunction of insulin stuff will cause diabetes, one of the leading risk factors in heart diseases. Diabetes mellitus can also cause blindness and amputation of extremities such as foot.Probably one or two of your relatives already have diabetes.
So it indeed makes some sense to treat carbohydrate seriously. The speed of raising blood glucose by foods is called Glycemic Index (GI). GI is standardized against glucose and scaled at 0-100. The rule of thumb is that you should always look for GI below 50, called low GI foods if you are worrying about your glucose. In general you should avoid eating too much foods with GI greater than 70.Potatoes and watermelon are among high GI foods. There was also a comprehensive table in American Journal of Clinical Nutrion by Australian researchers three years ago.Google it. The concept of GI is getting popular.
But wait. There is another important carbohydrate I didn’t mention. Yes. The fiber. There are two types of fibers: water soluble fiber and insoluble fiber (again a dumb classification). Water soluble fiber includes gum and pectin, and insoluble fiber includes cellulose, hemicellulose and lingnin. Human beings can’t digest fibers (if we can, we will live like cows, constantly munching straws). They most likely increase the bulk of stool instead.
In modern point of view, fibers are more important than many other carbohydrates. Eating a lot of fibers can make your stomach full, thus preventing more energy intake. Sticky fibers such as gum or pectin can delay the digestion of other carbohydrates, retain dietary fat in intestines, reduce cholesterol, stimulate bowl movement, and most of all, prevent colon cancer and heart diseases. Can you imagine other stuff that won’t contribute your energy intake while reduce the risk of death?
Most vegetables and fruits are rich in fibers, but not in refined grains. That is, Chinese white rice is not good for you. If you understand that white rice also has lower percent of protein than other grains, the small body of Chinese can be attributed to white rice. What a bummer!
The take home message is this: be gross, live primitively, man.
PS. Prune juice can relieve constipation because it has lots of soluble fibers. But be prepared, the taste of prune juice may give you a surprise.
The next topic: move your butt, let’s go back to jungle!