A final note, even those who eat semi-vegetarian diets experience health benefits, so it is not necessary to avoid all animal foods entirely unless you feel inclined to do so.
Dangerous Diets—Some Promoted as Cancer Cures
Macrobiotics
The macrobiotic diet is plant based, comprised largely of whole grains, beans, soups (such as miso soup), and sea vegetables. It excludes meat and dairy, but fish is permitted occasionally. Fruits, nuts, and seeds also are consumed at times, along with vegetable pickles and non-caffeinated teas. More than a diet, however, macrobiotics traditionally encompasses both a philosophy and a way of life. It emphasizes balance in the selection, preparation, and consumption of foods, as well as in day-to-day life.
In a 2009 report, the American Dietetic Association concluded that “appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases.”6 That said, your nutritional needs may vary compared to the average person, which is why it is important to discuss diet with your doctor and/or another nutrition-trained health professional.
Macrobiotic theory is based largely on the yin-yang principle of balance that was integral to ancient Chinese medicine. Yin and yang are seen to be equal but opposite forces that describe all components of life and the universe. The diet and philosophy were initially developed and popularized by Japanese philosopher George Ohsawa in the early twentieth century. An early disciple, Michio Kushi, led the macrobiotic movement from the mid-1900s. The macrobiotic diet was promoted as a cancer cure in the United States for many years, but that effort eventually waned as scientific studies failed to support the claims.
No diet or combination of foods, in fact, has ever been shown to cure cancer. Moreover, practicing macrobiotics and other extreme diets can lead to nutrient deficiencies, such as vitamin B12 and calcium, and inadequate caloric intake.
Gerson Regimen and Metabolic Therapies
Developed in the 1930s by German physician Max Gerson, the Gerson regimen involves a strict metabolic diet, as well as coffee enemas and various supplements intended to aid in detoxifying the body. The diet is vegetarian and emphasizes fresh fruit and vegetable juice; each patient consumes about 20 pounds of fruits and vegetables each day, largely in the form of fresh juice. Supplemental digestive enzymes are frequently given, as well as coffee enemas, which are claimed to stimulate the excretion of bile from the liver and eliminate toxins from the body. This and many other extreme diets are based on the incorrect idea that cancer is caused by a buildup of toxins in the body, and that detoxification will cure the disease. The Gerson clinic advertises its cancer therapy as “a natural treatment that activates the body’s extraordinary ability to heal itself through an organic, vegetarian diet, raw juices, coffee enemas, and natural supplements.” Along with many other fanciful “therapies” for cancer, the Gerson clinic is located in Tijuana, Mexico, a hotbed of nonviable “alternative” disproved cancer treatments that do not work.
Fasting and Juice Therapies
Fasting eliminates all solid food and generally limits dietary consumption to certain liquids. Juice cleanses or juice fasts, during which only freshly juiced fruits and vegetables are consumed for a period of time that can vary from a few days to weeks, are very common today. Such therapies are promoted for general health maintenance, as well as for healing diseases. Advocates believe they facilitate internal cleansing and support the immune system.
Fresh fruit juice, in moderation, can be healthy as well as delicious. But regimens such as this, especially when continued over an extended period, can be dangerous, especially for cancer patients.
In summary, eat healthfully; seek professional advice if you have special swallowing or digestive issues; beware of bogus dietary or other cancer “cures”; enjoy the beneficial and delicious Mediterranean-type diet rich in fruits, vegetables, seafood, olive oil, beans, and whole grains.
Important Vitamins and Foods
When researching nutrition for cancer patients online, some vitamin and food entries can create more questions than answers. It is worth spending a bit of time discussing some of those common items.
Soy
Soy can be a confusing topic for cancer patients. On the one hand, it is widely touted as a health food. It contains compounds called isoflavones, which may help decrease the risk of heart disease and cancer and reduce menopausal symptoms in women, among other benefits. Soy foods are also an excellent source of plant-based protein, particularly valuable for vegetarians. As a result, soy protein is being added to all kinds of processed foods and is becoming ubiquitous in the food supply.
But the very same isoflavones credited with many of these benefits are similar in structure to the hormone estrogen. Doctors and scientists are therefore concerned that they may mimic estrogen’s activity in the human body, potentially encouraging hormone-sensitive tumors (such as estrogen receptor (ER)–positive breast cancer) to grow. So, the question is, how do these benefits and risks balance out? Is soy something you should be eating at all, and if so how much is too much?
Soy’s journey to mainstream began decades ago, when researchers observed that rates of breast and other cancers were significantly lower in Asia than in Westernized countries. They assumed that diet was a factor and zoomed in on soy as a possible source of this health disparity. Since soy foods were eaten all the time in Asia but were almost entirely absent from the Western diet, it seemed a solid hypothesis. Fast-forward 20 years, however, and the research results have been mixed.
Regular consumption of soy foods has been associated with a reduced risk of cancer in many studies, but some laboratory and animal research suggests that soy can promote growth of estrogen-sensitive tumors. It’s worth underscoring that virtually all of the studies showing harm were conducted using isolated cells growing in a petrie dish or in rodents—not in humans. And most of them used isolated soy isoflavones, not the soy in its whole-food form. So the degree to which such findings apply to us is not clear. No conclusions can be drawn without considering results in humans.
In recent years, there have been several large public health studies of soy consumption in humans, and all have found it to be safe and perhaps beneficial, even in women with ER-positive breast cancer. Three large studies, two in U.S. breast cancer patients and one in Chinese patients, found no adverse effects of soy consumption on outcome, and suggested it may even offer some protection against recurrence and cancer-related death. The largest of these followed 9,514 U.S. and Chinese breast cancer survivors and found that patients who consumed at least 10 milligrams of isoflavones (about 3 grams of soy protein) per day had a significantly lower risk of cancer recurrence.7
Interestingly, it appears that soy is most beneficial when it is eaten regularly early in life and through puberty. Studies suggest that this may decrease the risk of breast cancer, but that introducing soy into the diets of adult women may not do much to change their cancer risk, either positively or negatively.
The bottom line, considering all of the findings so far, is that eating moderate amounts of soy should be fine. In its most recent set of guidelines, the American Cancer Society concluded that for breast cancer patients “current evidence suggests no adverse effects on recurrence or survival from consuming soy and soy foods.”
That said, it is wise to avoid supplements that contain high doses of isolated soy isoflavones. Stick to soy-containing foods, such as miso soup, tofu, tempeh, soymilk, edamame, and even soybeans in their original form.
Vitamin D