By Dr. Mercola
If you are like most people, when you think of reducing your risk of cancer, exercise probably isn't at the top of your list. However, there is compelling evidence that exercise can not only help slash your risk of cancer, but can also help cancer patients get well sooner, and help prevent cancer recurrence.
Research has also shown it may help minimize the side effects of conventional cancer treatment.
A preliminary study presented at The Integrative Biology of Exercise VI meeting in mid-October1 helps shed light on why exercise is so effective for decreasing the risk of secondary cancers in survivors, or why it can decrease your risk of getting cancer in the first place.
Exercise Improves Your Immune System's "Cancer Surveillance"
Sixteen cancer survivors who had just completed chemotherapy participated in the three-month long study. The fitness program, which was tailored to each individual, included:
- Strength training
- Endurance training
- Cardiovascular exercise
- Exercises for flexibility, balance and posture
The researchers examined the immune cells in the participants' blood before and after completion of the 12-week program, and the analysis showed that a large portion of the T cells were altered into a more effective disease-fighting form, called "naïve" T cells. As reported by Medical News Today:2
"[Lead researcher] Bilek explained, 'What we're suggesting is that with exercise, you might be getting rid of T cells that aren't helpful and making room for T cells that might be helpful.'
This research is important because it not only emphasizes the advantages of exercise for cancer patients and cancer survivors, but it also demonstrates how it can benefit healthy individuals. However, the increased 'cancer surveillance,' or the power of the immune system to stop emerging cancers, is particularly beneficial for those struggling with cancer, or who have just survived it.
Bilek concluded: 'There's a litany of positive benefits from exercise. If exercise indeed strengthens the immune system and potentially improves cancer surveillance, it's one more thing we should educate patients about as a reason they should schedule regular activity throughout their day and make it a priority in their lives.'"
Viewing Exercise as a Drug
Besides altering your immune cells into a more potent disease-fighting form and improving circulation of those immune cells in your blood, another primary way exercise lowers your risk for cancer is by reducing elevated insulin levels. This creates a low sugar environment that discourages the growth and spread of cancer cells. It's also been suggested that apoptosis (programmed cell death) is triggered by exercise, causing cancer cells to die.
The trick though, is understanding how to use exercise as a precise tool. I like to suggest viewing it as a "drug" that needs to be carefully prescribed to achieve its maximum benefit. This ensures you're getting enough to achieve the benefit, not too much to cause injury, and the right variety to balance your entire physical structure and maintain strength, flexibility, and aerobic and anaerobic fitness levels.
Ideally, doctors would prescribe exercise 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.
Unfortunately, many public health guidelines still focus only on the aerobic aspects of exercise, and this exclusive focus can lead to imbalances that may actually prevent optimal health.
It's important to include a large variety of techniques in your exercise routine, such as strength training, aerobics, core-building activities, and stretching. Most important of all, however, is to make sure you include high-intensity, burst-type exercise, once or twice a week, in which you raise your heart rate up to your anaerobic threshold for 20 to 30 seconds, and then you recover for 90 seconds. These exercises can increase your body's natural production of human growth hormone.
Compelling Evidence in Support of Exercise as Cancer Prophylactic
In the 1980s the notion that exercise may help prevent cancer started getting its due attention. According to a study published 12 years ago in the British Medical Journal,3 which explored the relationship between exercise and cancer, exercise affects several biological functions that may directly influence your cancer risk. These effects include changes in:
Cardiovascular capacity Energy balance Pulmonary capacity Immune function Bowel motility Antioxidant defense Hormone levels DNA repair
In 2003, a paper in the journal Medicine & Science in Sports & Exercise4 reported that "more than a hundred epidemiologic studies on the role of physical activity and cancer prevention have been published." The authors noted that:
"The data are clear in showing that physically active men and women have about a 30-40 percent reduction in the risk of developing colon cancer, compared with inactive persons … With regard to breast cancer, there is reasonably clear evidence that physically active women have about a 20-30 percent reduction in risk, compared with inactive women. It also appears that 30-60 min·d-1 of moderate- to vigorous-intensity physical activity is needed to decrease the risk of breast cancer, and that there is likely a dose-response relation."
Cancer Groups Recommend Making Exercise Part of Standard Care
In recent years, a number of cancer groups have started taking exercise seriously. For example, a recent report issued by the British organization Macmillan Cancer Support5 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.6
Professor Robert Thomas discusses the benefits of physical activity during after cancer treatment.
According to Ciaran Devane, chief executive of Macmillan Cancer Support:7
"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.8 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
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.
Just remember that 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.
That said, 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.
Protein Intake Also Crucial for Cancers
I recently interviewed Dr. Ron Rosedale for nearly fifteen hours and i hope to be able to start posting those articles very soon. He is one of the first physicians in the U.S. that started measuring leptin levels clinically and was far ahead of the curve on this one. In our interview, he helped me understand the major importance that excessive protein intake can have on cancer growth.
The mTOR pathway is short for mammalian target of rapamycin. This pathway is ancient but relatively recently appreciated and has only been known for less than 20 years. Odds are very high your doctor was never taught this is medical school and isn't even aware of it. Many new cancer drugs are actually being targeted to use this pathway. Drugs using this pathway have also been given to animals to radically extend their lifespan. But you don't have to use drugs to get this pathway to work for you.
You can biohack your body and merely restrict your protein intake and replace the decreased protein with healthy fats as this will provide virtually identical benefits as these dangerous and expensive drugs.
Eating excessive protein can be an additional synergistically powerful mechanism. Dr. Rosedale believes that when you consume protein in levels higher than one gram of protein per kilogram of LEAN body mass you can activate the mTOR pathway, which will radically increase your risk of cancers. It is very easy to consume excess protein and my guess is that most people reading this are. I know I was, and as a result of this new insight I have reduced my protein intake by about half.
To determine your lean body mass find out your percent body fat and subtract from 100. So if you are 20% body fat you would have 80% lean body mass. Just multiply that times your current weight to get lean body mass. For most people this means restricting protein intake from 35 to 75 grams. Pregnant women and those working out extensively need about 25% more protein though.
Of course when you reduce protein you need to replace it with other calories, so the key is to replace the lost calories with high-quality fats such as avocados, butter, coconut oil, olives, olive oil, nuts and eggs. It is also very helpful to avoid eating anything for three hours before going to bed as this allows you to have relatively low blood sugars while you are sleeping. This is another good trick to move your body to fat burning mode.
Nearly everyone is primarily in carb burning mode because of the amount of carbohydrate content that they consume. The beauty of shifting over to fat burning mode is that it virtually eliminates hunger. Intermittent fasting is one way to help achieve this, but radically cutting back on non-vegetable carbs is also very important. Coconut oil is particularly useful to use in making the transition to fat burning mode as it is primarily short and medium chain fats which break down very quickly and can be used as an energy source which is important for countering the decreased energy and other physical challenges that many encounter in the several weeks it typically takes to make the transition to fat burning mode .
Cancer Prevention Begins with Your Lifestyle Choices
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.
- Limit your protein. Newer research has emphasized the importance of the mTOR pathways. When these are active, cancer growth is accelerated. The best way to quiet this pathway is by limiting your protein to one gram of protein per kilogram of lean body weight, or roughly a bit less than half a gram of protein per every pound of lean body weight. For most people this ranges between 40 and 70 grams of protein a day, which is about 2/3 to half of what they are currently eating.
- 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 and leptin receptor sensitivity. The best way to do this is by avoiding sugar and grains and restricting carbs to mostly fiber vegetables. Also 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 pint to 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.9 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 Brownstein10, 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.
- 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.