Digestive Wellness: Strengthen the Immune System and Prevent Disease Through Healthy Digestion, Fourth Edition (8 page)

Genes + Environment = Health Status

Figure 1.1
Causes of digestive imbalance.

In fact, the only factor we can’t control is our genetic makeup, and even that is more malleable than we previously believed. To illustrate this point, here are two recent studies on the effect of lifestyle and diet on how our genes behave. The Functional Genomics and Nutrition Study (FUNGENUT) looked to see whether different carbohydrate sources would change the way genes worked. Participants ate 25 percent of their calories either as rye bread and dark pasta or as oat-wheat bread and potatoes. Those who ate the rye and dark pasta diet had 62 genes that were up-regulated (turned on). The genes that were affected were related to better handling
of stress and reductions in inflammatory markers. Dean Ornish, M.D., performed genetic testing on 30 men who had low-risk prostate cancer. Eighteen of these men’s cancer-protective genes were down-regulated (turned off) and 388 of their cancer-promoting genes were up-regulated. For three months, they changed their lifestyles to include a low-fat, whole-foods, plant-based diet; daily stress-management techniques; moderate exercise; and participation in a support group. At the end of the study, the cancer-protective genes were significantly turned on and the cancer-promoting genes had been significantly turned off. While so far no genetic studies of this type have been done on digestive issues, we can anticipate many of them in the future. The few studies that we do have illustrate that small changes in lifestyle can have dramatic impacts on how genes express themselves.

“The surface area of the digestive mucosae, measuring up and down and around all the folds, rugae, villi, and microvilli, is about the size of a tennis court.”

—Sydney Baker, M.D.

The digestive system is self-running and self-healing. Because this beautiful, intricate system works automatically, the average person knows very little about it. Let’s take a trip through the digestive system to see what miraculous events occur inside us every moment of our lives.

The digestive system (also called the alimentary system, the gut, and the gastrointestinal system) comprises the mouth, pharynx, esophagus, stomach, small intestine, and large intestine (colon) (
Figure 2.1
). There are also accessory digestive organs that are outside of the digestive tract and these include our teeth, tongue, salivary glands, gall bladder, pancreas, and liver. Think of the digestive tract as a 16-to 23-foot tubular set of muscles that runs from the mouth to the anus. At its most basic, its function is to turn food into molecules that our cells can use for energy, maintenance, growth, and repair and waste products. On a deeper level it helps run our metabolism and protects us from infections and foreign substances that may come in on our food.

The digestive system is like an irrigation system. A large source of water gets narrower and narrower, finally getting water to each tiny portion of a field. If the water becomes blocked upstream, the plants wither and die. In the body, the unblocked flow of nutrients is critical for optimal health and function. Along the way, the body breaks down food protein into amino acids, starches into glucose, and fats into fatty acids and glycerol. Enzymes, vitamins, and minerals are also absorbed. The cells use these raw materials for energy, growth, and repair. If digestive wellness is compromised, our cells lose their capacity to function fully. Unlike a field, the body is innovative and will try to find ways to make things work. Eventually, however, its ability to seek new pathways fails, and we feel unwell. This is especially apparent in the lining of the digestive tract, which repairs and replaces itself every three to five days.

Figure 2.1
The digestive system.

THE DIGESTIVE SYSTEM IS WEBLIKE

The digestive system is complex. While we think of it as just something that digests food, here are some of its other less obvious functions.

Muscular:
The digestive structure is muscles.

Immune:
Most of the immune system lies in the digestive system.

Neurological:
The enteric nervous system has more nerve endings than our spines and more neurotransmitters than our brains. There is a direct gut-brain connection.

Endocrine:
There are more than 16 known digestive hormones, such as gastrin, ghrelin, and secretin.

Cardiovascular:
Probiotic bacteria help normalize cholesterol and triglyceride levels.

Metabolic:
The commensal bacteria in the digestive system drive the body’s metabolism.

Eating healthful foods is the right place to start, and that’s where we focus much of our attention, but many people eat all the “right” foods and still have digestive and other health problems. Typically we digest and absorb 90 to 97 percent of the food that we eat. The rest is typically plant fibers that serve to create bulk and to create short-chain fatty acids in our colon. Yet, the best diet in the world won’t help if you aren’t digesting properly. You must be able to digest foods; break them down into tiny particles; absorb the food mash; take that through the intestinal lining and into the bloodstream; assimilate nutrients and calories into the cells where they can be used; and eliminate waste products through the kidneys, bowels, lymph system, and skin. Health can and does break down at any of these phases. For example, people with lots of intestinal gas are often fermenting their food rather than digesting it. Difficulty with absorption can cause people to have food sensitivities, fatigue, skin rashes, and migraine headaches. In people with celiac disease, the gut may be so inflamed that they have malabsorption issues. Diabetics have a problem with assimilation of glucose into the cells. Constipation and diarrhea are problems of elimination.