There is a lot of misinformation out there about the role of nutrition in cancer. It seems such a logical connection, but for a variety of reasons, it has been shuttled to the sidelines. Compared to the highly technical aspects of today’s cancer treatment, with robotic surgeries, exacting radiation therapy and chemotherapy drugs that target specific types of cancers’ genetic profiles and cell surface markers, the types and quantities of food we consume can seem simplistic. Funding for cancer therapies through research or insurance rarely covers nutritional needs to avoid off-loading grocery costs to the study of insurance coverage. Compounding this misunderstanding are the many unfounded claims of miracle cures by businesses who want to sell their products, such as vitamins, enemas, teas or cleansings, with little proof of effectiveness.
Nutrition in Prevention or Treatment
That foods may be able to delay or prevent cancer gets confused with the good nutrition vital to sustain our energy and reduce fatigue throughout treatment. Certain foods have a reasonably good track record, according to the American Institute for Cancer Research, where diet matters. For example, they cite whole grains as protective against colorectal cancer, and vitamin A containing carotenoids from carrots or squash as protective against pharynx, larynx and mouth cancers. Be wary when one substance of any kind is said to be protective against all cancers. Cancer is a set of varying diseases, each with its own nutritional profile. Misunderstandings abound in that certain foods may be helpful, but the quantities and purity of the substances contained in the foods may be out of reach for any dietary intake, leading to over-expectations and subsequent disappointment that foods alone can prevent cancer.
When it comes to nutrition during treatment, there is a more solid scientific ground. What is striking is that the Dietary Guidelines for Americans, 2010 produced by the US Department of Health and Human Services, the current American Heart Association’s Diet and Lifestyle Recommendations, and the American Cancer Society’s Nutrition for the Person with Cancer during Treatment are surprisingly similar. The principles in these guidelines can then be tailored to each patient’s needs based upon many factors: starting weight, the kind of cancer diagnosed, the types of treatment to be had and whether a feeding tube will be needed, at least temporarily. Accredited cancer treatment programs have access to or make referrals for professional oncology nutritional counseling as part of comprehensive patient-centered care. Often times, these requests are made late in treatment, after too much weight has been lost or gained, making the recovery effort even more daunting, but certainly possible.
As a general rule, as for all of us, we need to be aware of the quantity of calories we need, and the quality of these calories from its optimal sources.
Why Do We Lose (or Gain) Weight During Cancer?
Although cancer cells may arise in certain organs or tissues, their effect is felt by the whole system. Recent advances help our understanding of this effect. When cancer grows in a certain part of the body (“local extension”), it needs nutrition and oxygen, so it easily finds it through local blood supply, when cells enter it due to the pressure in our blood vessels caused by the blood’s circulation. These cells can deposit elsewhere and then start to grow (metastases). Cells can also lodge in our lymph nodes as they cleanse the body, also needing calories and energy. These same cells also produce cell proteins or cytokines (cyto = cell; kine = protein) that rev up our metabolism, putting further demands on our energy supplies. The body naturally responds by accessing stored energy in the form of carbohydrate, then protein, leaving fat since it has to work the hardest to get calories (energy) from stored fats. That leaves our protein-rich muscles compromised. It is these muscles we need for the regular activities of daily life.
Typically, breast and prostate cancers are intimately involved with hormones (estrogen and progesterone in women and testosterone in men) and they directly affect weight retention, as women learn early in life with the start of their periods and monthly thereafter, and men learn as they gain muscle weight as teenagers and beyond.
The goal during cancer treatment is to preserve lean body mass. Our lean body mass is made up mostly of muscle. Keeping lean body mass at its ideal level, we can sustain most important body functions at their peak efficiency. Virtually everyone undergoing treatment gets tired and out of shape, reinforcing the feelings of discouragement. The “secret” trifecta: good nutrition, some tailored physical activity and good quality rest are the best winning combination of things we can do when so much is determined by our treatment teams.