Exercise With Oxygen Therapy (EWOT)

Exercise With Oxygen Therapy (EWOT)

An excellent and safe way to get massive amounts of oxygen into your bloodstream. In a nutshell, you breathe an oxygen mixture while you walk on a treadmill. There is a book on the subject: Stop Aging or Slow the Process, How Exercise With Oxygen Therapy (EWOT) Can Help, by William Campbell Douglass. Oxygen, of course, is the archenemy of cancer cells. There are dozens of different oxygen therapies in the alternative camp.

Exercise Therapeutics Update & Commentary: Exercise and Cancer

Exercise and resistance to neoplasia
Can J Physiol Pharmacol 76:581, 1998

Summary: This recent article summarizes a large number of studies which have been conducted regarding exercise and cancer. These include epidemiological or population studies, animal studies, exercise as adjunct therapy for patients with cancer, and mechanistic studies. The vast majority of studies investigating the relationship of physical exercise and cancer tend to strongly support a beneficial effect of regular exercise in the prevention of cancer.
The vast majority of human studies and cancer have been population based or survey type of studies (epidemiological). The two types of cancer which have shown the strongest correlation between increasing levels of exercise and decreased rates of cancer are colon and breast cancer. There is no evidence that exercise has any protective role for skin cancer For colon cancer a risk reduction of between 50-100% has been found for persons who engage in moderate to strenuous regular exercise. For women who regularly exercise the reduction in risk for breast cancer is between 10-50%. Risk for other female reproductive cancers such as ovarian, uterine, and endometrial has generally been reported to be lower in women who exercise, however, the degree of risk reduction has not been established.

The association between physical activity and prostate cancer has proven to be variable. Nine of 17 studies found a reduced risk of prostate cancer with exercise, while 3 actually found an increased risk. After adjusting for smoking, physical activity does appear to reduce the risk of lung cancer (a 20-50% risk reduction). Whereas, exercise appears to have no protective value for stomach, bladder and pancreatic cancer.

The author summarizes a number of studies which have investigated the possible mechanism which might account for the positive relationship between exercise and most common cancers. For colon cancer, exercise is known to decrease gut transit times and hence may lessen the time colon cells are exposed to the mutagenic effects of fecal toxins. For breast cancer and other female reproductive cancers, exercise has the ability to keep estrogens at a lower level which may contribute to the way regular physical activity becomes protective against these types of "hormone-dependent" cancers.

Commentary: This is a good review paper regarding all aspects of what we know regarding exercise and cancer Although the epidemiological (population) studies provide strong evidence that regular exercise can lower one's risk for most major types of cancer, we are a long way from understanding how much, how long and what types of activities are most beneficial. At this time it seems prudent to engage in any type of regular exercise just to help stack the cards in favor of preventing cancer, especially since the incidence and deaths from the major types of cancers are on the rise.
It is interesting to consider the mechanism by which regular exercise may be beneficial. Besides the fact that exercise helps maintain regular bowel movements and lessens total estrogen exposure, it also improves antioxidant defense systems, improves cancer immune defenses, decreases negative lifestyle behaviors (i.e. people that begin exercise tend to improve their diet and decrease their smoking), and decreases exposure to testosterone (a prostate cancer concern). Since we have no definitive understanding of the multiple factors which contribute to a particular type of cancer, it is hard to come to an understanding of how exercise might help decrease risk of cancer. Despite a poor mechanistic understanding of how exercise works to decrease cancer risk, it is clear that regular exercise can affect many body systems in a positive way. No drug or supplement can even come close to having the wide reaching impact of regular exercise.

Effect of exercise intensity and duration on the induction of mammary carcinogenesis

Cancer Res 54(suppl):1960s, 1994

Summary: These authors used a rat model to try and determine the effect of different intensities and duration of treadmill exercise on the incidence of breast tumors. Since cancer can take many years to develop, it is unreasonable to conduct longitudinal studies of the effects of prescribed exercise programs on the development of human cancer. Two types of chemicals were used in this study to induce breast cancer One chemical (MNU) directly causes breast cancer in animals, another chemical (DMBA) indirectly leads to breast cancer.

None of the exercise regimens had any effect on MNU-induced tumors, while exercise at a higher intensity did reduce the incidence of DMBA-induced cancers. If the exercise program was started after the initiation stage of the tumor then exercise programs of higher intensity and duration were positively correlated with fewer tumors in the animals. This would suggest exercise has a greater ability to positively impact tumor progression rather than initiation.
Commentary: It would appear from this small animal study that more intense (i.e. exercise that gets your heart rate up higher) exercise bouts are better than slow, long exercise bouts at reducing the progression of breast cancer In other words it looks like running bouts are more effective than jogging bouts. This study is too small and had too much variability to really say that their results are conclusive. It is interesting to consider that our ancestors (hunter gatherers) would have had this type of exercise. Short duration (less than 15 minutes), but fast running is what would be needed to effectively hunt wild game. Also it is interesting in the overtraining literature to note that some studies have found that high level endurance athletes will not become so easily overtrained if extra speed work is added, but will succumb to overtraining syndrome when extra distance work is added. For now, just consider adding in some speed work at the end or middle of your regular aerob ic workout.

Effects of diet and exercise on insulin, sex hormone-binding globulin, and prostate-specific antigen
Nutr Cancer 31(2):127, 1998.

Summary: High levels of testosterone and low levels of sex hormone-binding globulin (SHBG) are both considered to be important risk factors for prostate cancer. The more SHBG in the blood the less bioavailable testosterone. High blood insulin is correlated with low blood SHBG. Insulin is also known to be able to stimulate the growth of a prostate cancer cell line in tissue culture. These authors wanted to test the effects of a 3-week diet (low fat, high-fiber, complex-carbohydrate diet) and exercise program in 27 obese men. Prostate-specific antigen (PSA), SHGB, and blood insulin were measured in these men before and after the diet and exercise program. The exercise program consisted of 30-45 minutes of daily walking plus participation in a supervised exercise class.

Blood insulin levels dropped 43% while SHBG increased 39% from the diet and exercise program. PSA levels tended to decrease, but not significantly.

Commentary: This study is taking a well-established approach in the world of cardiovascular studies and applying it to prostate cancer. Since cancer takes so many years to develop researchers need to come up with some "markers" to determine if specific interventions have the potential to actually decrease the incidence of prostate cancer. The "risk markers" for prostate cancer are not nearly as well established as those for heart disease (i.e. high blood cholesterol, high blood LDLs, high blood triglycerides).(*) Very long term studies are needed using diet and exercise interventions and using incidence and death rates from prostate cancer as the end points. Instead of waiting for the results of those types of studies, these authors propose that blood insulin and blood SHBG levels may be good "markers" to assess a patient's risk for prostate cancer.

It would appear that the diet/exercise program was quite successful at favorably altering the "risk" of prostate cancer for these obese men. Actually it is surprising the significant changes these authors report in insulin and SHBG levels after only 3 weeks. It would have been far more informative if they had carried out the study for at least 6 weeks and tested the change in cardiovascular fitness with these men. It also would have been more informative if they had not given all the men dietary changes, but just an exercise prescription. The diet they used was very restrictive, only 10% of calories as fat. It is questionable whether they needed to be that restrictive, especially if they had focused on increasing fruits and vegetables rather than just "complex carbohydrates."

Fatigue-reducing strategies used by patients receiving treatment for cancer

Cancer Nurs 18(1): 23, 1995

Summary: Fatigue is a common complaint of patients being treated for cancer using radiation or chemotherapy. Although most patients recover from this fatigue it can have a huge impact on both quality of life and mood. Only one previous study actually assessed the effectiveness of increased rest and decreased activities to relieve chemotherapy or radiation induced fatigue; they were rated at moderately effective. This study is designed to assess the effectiveness of self-initiated interventions to relieve fatigue in 99 women undergoing treatments for breast, ovarian, endometrial or cervical cancer.

Interviews were conducted with each of the women at the start and mid-point of any chemotherapy cycle and at the beginning and end of a full course of radiation. At each interview the patient was asked to complete a fatigue rating scale and a Fatigue Relief Scale (FRS). The strategies used included reducing or ceasing activity, increasing physical or social activity, distraction (i.e. listen to music, read, etc), or other. Sleep and exercise were rated as the most effective fatigue relieving strategies. Not surprisingly, the strategies the women employed were more effective at relieving fatigue at the second time point. This means that it is easier to see an effect on fatigue level when they are worse, i.e. after radiation or chemotherapy treatment.

Commentary: The problem of radiation and chemotherapy induced fatigue is a large one. Most oncologists will recommend decreased activities and more rest as the solution, yet these strategies have been found to be only moderately effective. In fact, at least one study found that the more sedentary a person becomes, the less energy the person has for activity (a vicious cycle). This may be due to both structural and biochemical changes which occur with prolonged muscle inactivity. Although not compelling evidence, the results of this study do suggest that a short daily walk may be beneficial in relieving cancer treatment induced fatigue.

Clearly, relieving this fatigue is important to the patients' quality of life while they are undergoing radiation or chemotherapy. However, there may be far wider implications than a period of several months. How good a patient feels while undergoing treatment may have a significant impact on the success of the therapy. A patient's fatigue level could easily contribute to feelings of depression and apathy and their will to live.

Do urinary oestrogen metabolites predict breast cancer? Guernsey IH cohort follow-up

Brit J Cancer 78(9): 1250, 1998.

Summary: During 1977-85, 5104 women aged 35 and older living in Guernsey participated in a population-based survey on factors considered to be important for breast cancer risk. These women filled out questionnaires, had mammograms and urine samples collected and frozen. These urine samples were analyzed from 40 women who had been diagnosed with breast cancer and 40 women who had no signs of breast cancer 9.5 years after the samples were collected. The researchers were measuring the levels of estrogen metabolities in the urine.

Estrogen breakdown occurs in the liver as well as breast tissue. In breast tissue one of the breakdown products is 16-alphahydroxyestrone (16-E), the other is 2-hydroxyestrone (2-E). A strong correlation between the level of 16-E and the incidence of breast cancer in a mouse model has been reported as well as high levels in women at high risk for breast cancer. The levels of 2-E appear to be decreased in animal models of breast cancer.

Although not statistically significant the highest ratio of 2-E/16-E did correspond to about a 30% lower risk for breast cancer. This was true for both pre- and postmenopausal women. The authors note that this is not conclusive evidence, but rather supportive evidence that these urinary estrogen metabolities might become important "biomarkers" for the assessment of breast cancer risk.

Commentary: Identifying biomarkers for breast cancer risk is a very exciting possibility. Using these biomarkers (as discussed in the prostate study in this column) as an intermediate endpoint is an excellent way to study the effects of different natural interventions in the possible prevention of breast cancer, including exercise prescriptions.

At least one study found that a high level of physical conditioning was associated with an increase in 2-E/16-E ratio. In other words the effect of exercise on estrogen breakdown may be a major way to understand the numerous studies which have found that regular exercise is associated with a decreased incidence of breast cancer.

Column Summary:

Regular aerobic exercise appears to be beneficial for preventing breast, colon, endometrial, uterine, ovarian and lung cancer. It is less clear for prostate cancer and does not seem to make a difference to stomach or pancreatic cancer. So far this information mainly comes from population or epidemiological studies, supported by a few animal studies. The amount, intensity or type of exercise to achieve the greatest cancer protective benefits is totally unclear. Human studies which may help clarify this issue would need to use biomarkers (if known) for individual cancers at an intermediate endpoint. It is possible, but unlikely, that any researcher will ever be able to prescribe an exercise program to a large group of individuals and hope to keep them on that exercise program for 10 years or more to see who ends up getting cancer and who does not.

Besides preventing cancer it appears that exercise needs to be considered as an adjunct cancer treatment. Besides fatigue a number of side effects of conventional cancer treatment may be ameliorated or prevented by regular, mild aerobic exercise. These would include depression, anxiety and muscle weakness. Specific range of motion, stretching and strengthening exercises can be crucial to prevent and treat limb swelling (lymphedema) associated with surgical removal of the breast or prostate gland or radiation.

(*) Despite the fact that these blood fats are considered standard risk factors for cardiovascular disease, this author finds them way too limiting and too much weight being given to these "markers" when blood coenzyme Q and blood vitamin E levels may actually be more accurate risk markers for heart disease.

Winningham ML. How exercise mitigates fatigue: implications for people receiving cancer therapy. In: Carroll-Johnson RM, ed. The Biotherapy of Cancer V. Pittsburgh: Oncology Nursing Press, 1992-16-21.
Snow RC, Barbieri RL, Risch RE (1989) Estrogen 2-hydroxylase oxidation and menstrual function among elite oarswomen. J Clin Endocrin Metab 69:369-376.

MacIntosh AM. The role of exercise in treating lymphedema following cancer treatment. Townsend Letter Doc patients Jan 1997:26-28.

Article copyright Townsend Letter for Doctors & Patients.
By Anna MacIntosh

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