Nutrition: Fighting Cancer With Food (cont.)
Scroggs: Someone has done their research! Radiation treatment works on an oxidative process as well as a proposed mechanism for some chemotherapy agents. Adriamycin, which is a chemotherapy agent often used with breast cancer treatment, is in that category where it is proposed, not proved, that it works on an oxidative process. An oxidative process is where free radicals are introduced that increase cell death, and a cascade of these free radicals can promote cell death, which is what your goal is for chemotherapy treatment or radiation treatment, to kill the cancer cells.
Now I'm going give two sides to this: One side says don't overdo antioxidants. An example would be the vitamin E that was referred to, plus vitamin C, vitamin A, and selenium are all nutrients with antioxidant properties. Taking large amounts, mega-antioxidant supplements, may stop the cascade of cell deaths because antioxidants help reduce the free-radical activity. They help stabilize the cells.
On the other side, there is some research going on looking at the role of antioxidants with some cancer treatments at some specific cancer sites, in mostly test-tube and animal studies and very small numbers of human studies, looking at having an antioxidant with a treatment, hoping to show fewer toxic side effects. Some of the research indicates that less of the chemotherapy treatment needs to be given because it makes the treatment more effective, so you can use less of the chemotherapy drug.
These studies are not conclusive. They seem to be very specific. It's going take a lot of research in this new science to see which antioxidants are best for which chemotherapy treatments for which cancer diagnosis. When these studies get to a phase II clinical trial the subjects in the studies will be monitored for adverse effects, tolerance, organ function, etc.
So that's very different from someone buying over-the-counter supplements, where mega-doses can be purchased. For example, I have had patients who are taking an antioxidant supplement, a mega-dose multivitamin supplement, an immune-system booster, and a stress-relief supplement, which added up can be above the upper limits recently establish by the National Academy of Science. And the upper limit can be defined as an amount taken over time that can result in adverse effects. So there could be side effects like taking a drug because you're taking such high amounts and there can be nutrient interaction.
The American Cancer Society recently published an article, Nutrition During and After Cancer Treatments, and they recommend staying below the upper limit. And this gives a very broad range with the dietary reference intake including an RDA (recommended dietary allowance) and then a broad range to an upper limit. An example would be selenium, a potent antioxidant mineral. The RDA is 55 mcg and the upper limit is 400 mcg. So as long as your food intake and supplements don't exceed the upper limits, then you're in a safe range. However, you would need to discuss this with your oncologist, regarding supplements to take with treatment or not to take with treatment. After treatment, it's a different story.
Member: So where does that leave me right now, as to how to introduce antioxidants to my diet?
Scroggs: A healthy balanced diet is loaded with antioxidants. I analyze patients' intakes and, for example, vitamin C, just from the diet, may be as high as 400% above the RDA. This would still put you well below the upper limit of 2000 mg for vitamin C. I appreciate that it can be a challenge to eat or consume all the foods you know you need when receiving treatment.
Member: Would a low-carb diet be appropriate?
Scroggs: Research for cancer prevention indicates that we can reduce the risk of cancer by 30-40% with feasible dietary means. The American Institute for Cancer Research estimates that 33-50% of breast cancers are preventable by diet. In their guidelines for reducing risk, they recommend five or more servings of fruits and vegetables a day and more than seven portions of cereals or beans, starchy foods. To do this, you would have more of a plant-based diet that would provide 50% or more of your calories coming from carbs.
Research is being done on why this seems protective. Is this because plant-based diets are nutrient dense? It's where those great antioxidants come from. It's where the phytochemicals come from (phyto is the Greek word for plant). The phytochemicals show promise in disease reduction from initiation, promotion, and progression as well as reducing risk from heart disease. A plant-based diet has more fiber, so this may play a role. A plant-based diet is lower in fat and this may play a role.
The National Cancer Institute estimates that by simply getting the five a day, three vegetables, two fruits, one can reduce their risk of cancer by 20%. So the research supports a plant-based diet, which contributes carbohydrates to your total caloric intake. As I said earlier, if you are eliminating carbs and still needing to maintain calories then you have fats, protein, and alcohol left. And the cancer-fighting properties are coming from a plant-based diet that provides the nutrients, antioxidants, and phytochemicals. Again simple carbs, as discussed earlier, provide only empty calories.
Member: Does it matter if those "five a day" are fresh, frozen, or canned?
Scroggs: Excellent question. Research has been done on nutrients available in fresh produce vs. frozen vs. canned, and the results were interesting in that they were pretty much equal. Some speculation is that the reason is frozen and canned produce are picked at their peak of ripeness and preserved. Fresh produce may be picked before it's ripe, can sit in a truck, be shipped cross country, and sit on the produce counter with less nutrients and/or losing nutrients. What's important is that you eat your fruits and vegetables. If fresh produce is available, that's a choice. But if it's not always convenient with limited shopping time or accessibility. Have frozen on hand as well as canned.
Member: That is good to know because living in northern Wisconsin, there is a very short growing season for fresh produce.
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