What Should Cancer Patients Pay Attention to in Their Diet?

People often ask me what cancer patients should pay attention to in their diet. Until now I have mostly given advice face-to-face to patients who come to me, tailoring it to their specific condition and constitution. Too many people ask for me to answer each one individually, so today I write this article for readers' reference.

I believe that, among all foods and drinks, the first thing cancer patients should avoid are foods that easily trigger allergic reactions—such as seafood, fish and shrimp, alcohol, and spicy food. Such foods often cause sudden allergic reactions in patients. I have seen quite a few patients whose condition deteriorated sharply after an allergic reaction, developing complex complications, with the tumor progressing rapidly until it was beyond rescue.

Patients with allergic constitutions should be especially careful not to eat allergenic foods. People's allergens differ; for example, someone in my own family is allergic to honey—every time he takes pills containing honey or cakes of that sort, a severe allergic reaction with gripping abdominal pain is triggered. Allergenic foods vary from person to person and are hard to enumerate; only the patient knows his own allergens best.

The "fajie" (fa-wu, "graphic-dispelling") foods TCM often speaks of are mostly allergenic foods. Patients with poor digestion have even more foods that easily trigger allergic reactions; even drinks like tea and coffee can cause allergic reactions in their bodies. Whenever I myself drink tea or coffee, I develop itchy skin.

When doctors take a history and write a chart, one piece of information is very important: the patient's allergy history. Most doctors only ask about drug allergies; few ask about food allergies. In fact, dietary allergies objectively exist. As someone who once had asthma, I know this from personal experience.

Let me expand on this. Some patients like to go to health resorts to recuperate; in fact, many patients are also allergic to climate. A resort that suits others may not suit certain allergic patients, so cancer patients should not be too rigid when choosing a place to recuperate.

Second, cancer patients should stay away from conventional carcinogenic foods: pickled foods, grilled foods, fried foods, most industrial foods, hotpot, alcohol, and high-salt, high-sugar, high-fat foods are all carcinogenic. So I often tell my own patients: whatever you eat, be sure it is fresh; for vegetables and fruit it is best to eat what is in season; keep the diet light and fresh; avoid pickled and grilled foods, hotpot, and unhealthy high-salt, high-sugar, high-fat foods.

The large number of digestive-tract cancers in China has a great deal to do with our Chinese dietary habits. Our love of pickled foods, smoked foods, grilling, fried foods, and hotpot is a culinary tradition of thousands of years. Many patients have eaten these things all their lives, so asking them to give up such carcinogenic foods is quite difficult. Some patients lose their appetite without such foods, so they always violate medical orders and sneak them—this is really not treasuring one's own life.

Third, avoid leftover food and overly hot food. Leftovers contain high levels of nitrite, and nitrite is an important carcinogen; those who regularly eat leftovers are prone to cancer. Patients who like their food very hot are also prone to digestive-tract tumors.

Fourth, cloying, sticky foods should not be eaten to excess; patients with already-poor digestion should avoid them altogether. Shen Congwen once wrote an essay about a relative who, after falling ill, ate a zongzi (sticky rice dumpling) and died because of that single zongzi. Sticky foods are hard to digest; once they accumulate in the stomach and intestines, they can trigger acute gastroenteritis or even intestinal obstruction—acute, life-threatening conditions. Slightly mishandled, or without timely emergency care, they can cause the patient's death.

Fifth, eat fewer raw and cold fruits and melons, especially those just taken from the refrigerator in summer. Such foods do patients more harm than good; raw, cold fruits easily cause gastrointestinal emergencies. If the patient is also taking medicine, these hard-to-digest foods that easily cause gastrointestinal reactions will also bring various other discomforts.

So what should cancer patients eat?

Overall, eating fresh, easily digested organic foods does more good than harm for cancer patients. Many family members, once a patient has cancer, always want to "tonify" the patient. In fact, tonifying foods are mostly hard to digest, and cancer patients' digestive and excretory functions are mostly poor; eating such foods backfires. Great tonification ultimately becomes great harm.

As for so-called anti-cancer foods—with all due respect, the great majority are nonsense; they do little to fight cancer and should not be taken too seriously. They are only psychological comfort. Some patients eat large amounts of ginger and garlic because many irresponsible popular-science articles recommend them as anti-cancer; such heavily stimulating foods mostly end up causing constipation and "shanghuo" (internal heat), which really is a poor trade-off.

There are also legends that alkaline foods like water chestnuts or potato juice fight cancer; such tales are mostly absurd. I have seen plenty of people who, after eating such foods, developed chronic diarrhea that did not stop all year round.

Eating a normal diet through the seasons, choosing light, fresh ingredients, having no abnormal reactions in the body, and keeping a calm mind is better than anything one could eat.