Hormonal Update Volume 3 Number 11

Colon Health and Hormones

Colon cancer is diagnosed four times more frequently than other cancers and it has the second highest death rate. The good news is that in women over the last thirty years the incidence of death from colon cancer has declined by thirty percent. Interestingly, during this same time period the use of estrogen hormone replacement therapy (HRT) has been on the rise. Many in the scientific community believe there is a link between lowered colon cancer risk and estrogen replacement. While it is not yet known exactly what role estrogen plays in the health of the colon, studies continue to show that it is protective. In this hormonal update we take a look at hormones and your colon.

The Importance of Your Colon

Many who study the gastrointestinal tract, which includes the colon, believe it plays a primary role in a person's health status throughout his or her life. In a complex system of absorption and elimination the gastrointestinal tract and colon enable the body to absorb water and nutrients, prevent toxins from entering the bloodstream, and eliminate waste that is the byproduct of digestion and metabolism. 

Toxins are accumulated from the air we breathe, the food we eat, and the water we drink. A healthy gastrointestinal tract helps us process these toxic substances quickly and efficiently thus protecting the body from the harm they can do. A healthy colon usually means a healthy immune system. 

Colon cancer develops from small benign tumors, or polyps, that form on the walls of the colon and grow slowly over twenty to thirty years. When diagnosed early, colon tumors can be cured. Early detection is the best chance for arresting this deadly disease.

Risk factors for colon cancer include a poor diet that is low in fiber (fruits and vegetable) and high in animal fat, sedentary lifestyle, family history of colon cancer or other hereditary colon disorders, long history of colon inflammation such as ulcerative colitis, and a history of colon polyps. Excess alcohol consumption and smoking also increase risk.

The Estrogen Connection

As early as 1980 studies were showing that estrogen hormone replacement was influencing colon cancer risk. Science has not yet determined the exact role that estrogen plays in decreasing colon cancer but there are some theories. It is possible that estrogen helps the body produce the bile acids necessary for proper digestion and elimination. And, because estrogen interacts with specific receptors in the colon it may help suppress the growth of abnormal cells. More studies are necessary to define the specific action of estrogen in the colon. 

Over the years estrogen research has yielded some conflicting evidence, however, most of the data shows that women who take estrogen replacement can reduce their colon cancer risk by as much as half. One study found a seventy-five percent reduction in risk in women who were of normal weight and taking hormone replacement. Another study found that even women who only took HRT for a short time to help manage menopausal symptoms had a twenty percent lower lifetime colon cancer risk. 

Of course, this does not mean that all women are candidates for estrogen replacement in order to protect against colon cancer. All forms of hormone replacement should be considered only if needed and then administered in the lowest possible dose required to achieve results.

Strong Bones, Safe Colon

Phyto-estrogens, the estrogen-like substances found in foods such as soy and certain whole grains, appear to have a protective effect against many cancers, including colon cancer. Many of phyto-estrogenic foods are high in fiber. More studies will be needed to determine if the phyto-estrogens themselves are providing protection or simply reflecting a diet that is healthier for the colon. 
Based on the findings of the Framingham study, which included nearly three thousand New England women, Boston University researchers have found an association between the density of a woman's bones and her risk for colon cancer. It appears that the denser a woman's bones are the less likely she is to develop this deadly cancer. In fact, women with thinner bones are twice as likely to develop cancer of the colon as women with good strong bones. The Framingham study did not measure estrogen levels; however, x-rays of bone density were taken. When Boston epidemiologists compared those x-rays with the x-rays of fourteen hundred postmenopausal women who had taken estrogen they found a striking correlation. After making adjustments in the study for alcohol consumption, smoking status and other factors that influence bone density, only one case of colon cancer per thousand women was found in the group with the strongest bones - a sixty percent lower risk for colon cancer than in the low bone density group. 

This is not intended to suggest that a woman can lower her colon cancer risk by building up her bones. More likely it suggests that bone density measurement may be a way of assessing a woman's exposure to some of the factors that are associated with cancer risk. For example, lower estrogen levels are often associated with increased risk for osteoporosis, a disease that manifests in weak bones and increased risk for fracture. On the other hand, a healthy lifetime exposure to estrogen is often associated with good bone density and fewer fractures. If you have osteoporosis or are at high risk for it, you may want to talk to your doctor about colon cancer screening.

Growth Hormones

Human Growth Hormone, a hormone produced by the pituitary gland, helps stimulate our body to grow. It is also believed to be important for tissue repair, muscle growth, healing, brain function, physical and mental health, bone strength, energy and metabolism. When we are young our body produces a great deal of HGH. As we age production declines. It recent years supplementation with this hormone has become popular because of its purported anti-aging benefits. 

One of the effects of human growth hormone is to raise blood levels of IGF-1, or insulin growth factor type 1, which animal studies show cause cancer. In fact, exposure to 
IGF-1 causes colon cancer cells to grow faster...

Researchers in England investigated the lifetime medical records of children, now adults, who took human growth hormone (hGh) for health reasons during the years between 1959 and 1985 and found that they had a higher rate of developing colon cancer. 

Human Growth Hormone Deficiency (GHD) is recognized as a specific clinical syndrome by the FDA with characteristic signs and symptoms that resemble many aspects of aging. For example, loss of muscle and lean tissue mass, as well as increased fat accumulation are often associated with aging. In August 1996, the FDA approved Human Growth Hormone for use in adult patients. Because of the English study, there is an ongoing and very spirited debate among scientists, researchers, and physicians regarding this treatment. Some believe the natural decline in growth hormone production produces an appropriate balance and in fact supplementation may stimulate cancer cells to grow. Others have found that if the dosage administered helps a patient achieve 'normal' levels of HGH then it is both safe and effective.

Testing, Monitoring, and HRT