By Dr. Mercola
Mounting evidence shows that exercise can not only help cancer patients get well but also help keep their cancer from recurring. Yet, few oncologists tell their patients to engage in exercise beyond their simple daily, normal activities.
And many cancer patients are reluctant to exercise, or even discuss it with their oncologist.
A recent study1 by the Mayo Clinic investigated exercise habits among cancer patients and their clinicians' roles in providing related counseling, and found that:
"Participants overwhelmingly cited usual daily activities as their source of 'exercise.' Symptoms, particularly treatment-related, discouraged participation, with fear of harm being a significant concern only among younger women. Exercise was recognized as important for physical and mental well-being, but seldom as a means to mitigate symptoms.
...Although respondents preferred to receive guidance from their oncologist, none reported receiving more than general encouragement to 'stay active.' A lack of direction was typically accepted as a sanction of their current activity levels. Participants appeared less receptive to guidance from ancillary health professionals."
An Important Conversation You'd Be Wise to Have With Your Oncologist
Fear that exercise might be harmful appears to be largely unfounded, though it's certainly understandable. It can be difficult to be enthusiastic about exercise if you struggle with nausea, fatigue, and other detrimental side effects from the treatment. However, it may be helpful to focus on the benefits you can reap from exercise. For example, research has shown that exercising during and after cancer treatment can:
- Reduce your risk of dying from cancer
- Reduce your risk of cancer recurrence
- Boost energy and minimize the side effects of conventional cancer treatment (see additional listing below)
The fact that most oncologists overlook this vital aspect of their patients' care is highly unfortunate, especially considering how most patients defer to their recommendations. However, it's not unexpected. Conventional doctors are trained to prescribe drugs, not exercise.
Ideally, they'd prescribe exercise in the same manner drugs are prescribed – in specific "doses" and intervals. To do this properly, oncologists would be wise to develop relationships with personal trainers, and prescribe training sessions for their patients. If you have cancer, I would highly recommend discussing exercise with your oncologist, and/or work with a trained fitness professional who can help you devise a safe and effective regimen.
Exercise Needs to Be Part of Standard Cancer Care
A recent report issued by the British organization Macmillan Cancer Support2 argues that exercise really should be part of standard cancer care. It recommends that all patients getting cancer treatment should be told to engage in moderate-intensity exercise for two and a half hours every week, stating that the advice to rest and take it easy after treatment is an outdated view.
The organization offers loads of helpful information about the benefits of exercise for cancer patients on their website, and also has a number of videos on the subject, available on their YouTube channel.3
Professor Robert Thomas discusses the benefits of physical activity after cancer treatment.
According to Ciaran Devane, chief executive of Macmillan Cancer Support:4
"Cancer patients would be shocked if they knew just how much of a benefit physical activity could have on their recovery and long term health, in some cases reducing their chances of having to go through the grueling ordeal of treatment all over again..."
Indeed, the reduction in risk for recurrence is quite impressive. Previous research has shown that breast and colon cancer patients who exercise regularly have half the recurrence rate than non-exercisers.5 Macmillan Cancer Support also notes that exercise can help you to mitigate some of the common side effects of conventional cancer treatment, including:
|Reduce fatigue and improve your energy levels||Manage stress, anxiety, low mood or depression||Improve bone health|
|Improve heart health (some chemotherapy drugs and radiotherapy can cause heart problems later in life)||Build muscle strength, relieve pain and improve range of movement||Maintain a healthy weight|
|Sleep better||Improve your appetite||Prevent constipation|
How Exercise Can Improve Cancer Outcome
This topic is near and dear to my heart, as I went to medical school in large part because I wanted to use exercise as a therapeutic tool to help people get healthier. I strongly believe that without fitness, it is virtually impossible to achieve optimal health. Lack of exercise can also severely hamper your recuperative efforts once disease has set in.
A 2005 study6 by researchers at Harvard Medical School found that breast cancer patients who exercise moderately for three to five hours a week cut their odds of dying from cancer by about half, compared to sedentary patients. In fact, any amount of weekly exercise increased a patient's odds of surviving breast cancer. This benefit remained constant regardless of whether women were diagnosed early on or after their cancer had spread.
Similarly, researchers investigating the impact of physical activity on cancer recurrence and survival in patients with stage III colon cancer found those who were more active cut their risk of recurrence in half.7
One of the primary reasons exercise works to lower your cancer risk is because it drives your insulin levels down, and controlling your insulin levels is one of the most powerful ways to reduce your cancer risks. It's also been suggested that apoptosis (programmed cell death) is triggered by exercise, causing cancer cells to die. This theory was demonstrated in two studies published in 2006. In one, mice who used running wheels developed fewer and smaller skin tumors.8 The second study found that exercise reduced the number and size of intestinal polyps.9
The studies also found that the number of tumors decreased along with body fat, which may be an additional factor. This is because exercise helps lower your estrogen levels, which explains why exercise appears to be particularly potent against breast cancer.
If you're male, be aware that athletes have lower levels of circulating testosterone than non-athletes, and similar to the association between estrogen levels and breast cancer in women, testosterone is known to influence the development of prostate cancer in men. Strength training may be of particular benefit. In one 2009 study10, men who regularly worked out with weights and had the highest muscle strength were between 30 percent and 40 percent less likely to lose their life to a deadly tumor.
Other research has shown:
- Exercising moderately for six hours a week may reduce colorectal cancer mortality11
- Three hours per week of moderate-intensity physical activity may lower risk of prostate cancer mortality by about 30 percent12, and lower the rate of disease progression by 57 percent13
Of course, exercise also improves the circulation of immune cells in your blood, whose job it is to neutralize pathogens throughout your body. The better these cells circulate, the more efficient your immune system is at locating and defending against viruses and diseases, including cancer, trying to attack your body.
Exercise Tips for Cancer Patients
I would strongly recommend you read up on my Peak Fitness program, which includes high-intensity exercises that can reduce your exercise time while actually improving your benefits.
Now, if you have cancer or any other chronic disease, you will of course need to tailor your exercise routine to your individual circumstances, taking into account your fitness level and current health. Often, you will be able to take part in a regular exercise program – one that involves a variety of exercises like strength training, core-building, stretching, aerobic and anaerobic – with very little changes necessary. However, at times you may find you need to exercise at a lower intensity, or for shorter durations.
Always listen to your body and if you feel you need a break, take time to rest. But even exercising for just a few minutes a day is better than not exercising at all, and you'll likely find that your stamina increases and you're able to complete more challenging workouts with each passing day. In the event you are suffering from a very weakened immune system, you may want to exercise at home instead of visiting a public gym. But remember that exercise will ultimately help to boost your immune system, so it's very important to continue with your program, even if you suffer from chronic illness or cancer.
Intense Workouts May Also Be Safe for Heart Patients
Another group of people often discouraged from exercise are those suffering with heart problems, but even here the mindset is starting to change. In an about-face in the way patients recovering from heart attacks or heart surgery are typically treated, a new study14 suggests high-intensity workouts may in fact be a safe choice. The study followed 4,800 Norwegian heart patients who did aerobics. Only three cardiac arrests occurred in over 170,000 hours of intensive exercise in these patients.
According to Reuters:15
"The number was too small to say for sure that high impact workouts are just as safe as moderate ones, but they show the overall risk of exercise bringing on cardiac arrest is fairly low, according to the authors. There is plenty of evidence that the harder people work out, the more benefit they gain in cardiovascular function, said Oeivind Rognmo, a researcher at the Norwegian University of Science and Technology in Trondheim and lead author of the study..."
The participants completed both moderate- and high-intensity workouts, spending a combined total of 129,456 hours working out at moderate intensity and 46,364 hours at high intensity. Moderate intensity workouts included an hour of walking, or other exercises resulting in exertion at 60-70 percent of maximum heart rate. The high-intensity workouts consisted of four-minute-intervals (cycling, running, or cross country skiing), pushing their heart rate up to 85-95 percent of maximum, followed by four-minute-long rest periods.
During the more than 129,000 combined hours of moderate exercise, one person died from cardiac arrest. And during over 46,000 combined hours of high-intensity workouts, two suffered cardiac arrest during or within an hour of exercise, but both survived. According to the lead author:16
"We found that both types of intensities were associated with low event rates... I think (high-intensity training) should be considered for patients with coronary heart disease."
Remember to Listen to Your Body
One of the key principles I teach and believe in is to listen to your body. This applies no matter what your current state of health is. If your body will not allow you to exercise, either due to pain or worsening of your underlying condition, then you have no practical option but to honor your body's signals and exercise less.
Even though your body desperately needs the exercise to improve, you will only get worse if you violate your current limitations. So you may have to start with as little as just minutes a day. That's okay. As your body gradually improves so will your tolerance to exercise, and you'd be wise to do as much as your body will allow in order to achieve a high level of health.
Additional Strategies to Help Prevent Cancer
While exercise is an important facet of cancer prevention and treatment, it's certainly not the only one. I believe the vast majority of all cancers could be prevented by strictly applying the healthy lifestyle recommendations below:
- Avoid sugar, especially fructose. All forms of sugar are detrimental to health in general and promote cancer. Fructose, however, is clearly one of the most harmful and should be avoided as much as possible.
- Optimize your vitamin D. Vitamin D influences virtually every cell in your body and is one of nature's most potent cancer fighters. Vitamin D is actually able to enter cancer cells and trigger apoptosis (cell death). If you have cancer, your vitamin D level should be between 70 and 100 ng/ml. Vitamin D works synergistically with every cancer treatment I'm aware of, with no adverse effects. I suggest you try watching my one-hour free lecture on vitamin D to learn more.
- Avoid charring your meats. Charcoal or flame broiled meat is linked with increased breast cancer risk. Acrylamide – a carcinogen created when starchy foods are baked, roasted or fried – has been found to increase cancer risk as well.
- Avoid unfermented soy products. Unfermented soy is high in plant estrogens, or phytoestrogens, also known as isoflavones. In some studies, soy appears to work in concert with human estrogen to increase breast cell proliferation, which increases the chances for mutations and cancerous cells.
- Improve your insulin receptor sensitivity. The best way to do this is by avoiding sugar and grains and making sure you are exercising, especially with Peak Fitness.
- Maintain a healthy body weight. This will come naturally when you begin eating right for your nutritional type and exercising. It's important to lose excess body fat because fat produces estrogen.
- Drink a quart of organic green vegetable juice daily. Please review my juicing instructions for more detailed information.
- Get plenty of high quality animal-based omega-3 fats, such as krill oil. Omega-3 deficiency is a common underlying factor for cancer.
- Curcumin. This is the active ingredient in turmeric and in high concentrations can be very useful adjunct in the treatment of cancer. For example, it has demonstrated major therapeutic potential in preventing breast cancer metastasis.17 It's important to know that curcumin is generally not absorbed that well, so I've provided several absorption tips here.
- Avoid drinking alcohol, or at least limit your alcoholic drinks to one per day.
- Avoid electromagnetic fields as much as possible. Even electric blankets can increase your cancer risk.
- Avoid synthetic hormone replacement therapy, especially if you have risk factors for breast cancer. Breast cancer is an estrogen-related cancer, and according to a study published in the Journal of the National Cancer Institute, breast cancer rates for women dropped in tandem with decreased use of hormone replacement therapy. (There are similar risks for younger women who use oral contraceptives. Birth control pills, which are also comprised of synthetic hormones, have been linked to cervical and breast cancers.)
If you are experiencing excessive menopausal symptoms, you may want to consider bioidentical hormone replacement therapy instead, which uses hormones that are molecularly identical to the ones your body produces and do not wreak havoc on your system. This is a much safer alternative.
- Avoid BPA, phthalates and other xenoestrogens. These are estrogen-like compounds that have been linked to increased breast cancer risk
- Make sure you're not iodine deficient, as there's compelling evidence linking iodine deficiency with certain forms of cancer. Dr. David Brownstein18, author of the book Iodine: Why You Need It, Why You Can't Live Without It, is a proponent of iodine for breast cancer. It actually has potent anticancer properties and has been shown to cause cell death in breast and thyroid cancer cells.
For more information, I recommend reading Dr. Brownstein's book. I have been researching iodine for some time ever since I interviewed Dr. Brownstein as I do believe that the bulk of what he states is spot on. However, I am not at all convinced that his dosage recommendations are correct. I believe they are too high.