whole grains, and low-fat foods, including dairy. Replacing carbohydrates and animal fat with vegetables is a smart move. It improves survival in patients with cancer.3
Being diagnosed with cancer brings up many questions. Should I change my diet? Should I gain or lose weight? What diet will help me lose weight? Would I benefit from taking a multivitamin or other dietary supplements? Do healing diets work, and if so, which is best? You may also have heard inconsistent or confusing answers to these kinds of questions. That’s because some promises are false and because some definitive data are not yet in place, but the goal of this chapter is to provide you with an overview of what we know today.
Dietary Fats
As outlined on the Mayo Clinic website,4 there are two main types of harmful dietary fat: saturated fat and trans fats. These are solid at room temperature and include beef fat, pork fat, shortening, stick margarine, and butter.
Saturated fat. This comes mainly from animal sources of food. Saturated fat raises total blood cholesterol levels and low-density lipoprotein (LDL) cholesterol levels, which increase your risk of disease and could impact survival after cancer.
Trans fat. This occurs naturally in some foods, especially foods from animals. But most trans fats are made during food processing through partial hydrogenation of unsaturated fats, which creates fats that are easier to cook with and less likely to spoil than are natural oils. However, that can increase unhealthy LDL cholesterol and decrease healthy high-density lipoprotein (HDL) cholesterol, increasing the risk of disease.
Healthier dietary foods contain mostly monounsaturated and polyunsaturated fats. They are liquid at room temperature and include olive oil, safflower oil, peanut oil, and corn oil.
Monounsaturated fat. Found in a variety of foods and oils, studies show that eating foods rich in monounsaturated fats improves blood cholesterol levels, which can decrease your risk of disease and produce better health.
Polyunsaturated fat. Found mostly in plant-based foods and oils, eating foods rich in polyunsaturated fats improves blood cholesterol levels, which can decrease risk of heart disease and type 2 diabetes. Omega-3 fatty acids, found in some types of fatty fish, appear to be especially healthy.
First, when living with cancer, eating a wholesome diet and maintaining a healthy body weight are priorities. Such lifestyle factors, along with regular physical activity (discussed in the next section), can help maximize the effectiveness of your treatments and help maintain good quality of life, all while minimizing unwanted side effects. In the longer term, they can help reduce your risk of cancer recurrence and your risk of other chronic diseases, and they promote longevity.
As we start our discussion about diet and nutrition, a few guidelines are worth mentioning:
• No food, vitamin, mineral, or other supplement is going to immediately and miraculously cure your disease or cause you to drop 50 pounds. That’s not to say the benefits of a healthy diet are insignificant, just that eating well is not an immediate fix. To achieve the benefits—and there are many—it takes regular, long-term commitment to a healthier lifestyle. The key is to choose a way of eating that makes the most sense for you, given your personal goals and tastes. Short-term bouts on a healthy diet aren’t likely to do much good. But sticking to a healthier diet long term, even if you don’t follow it perfectly all the time (moderation is always important!), can make a significant improvement to your health.
• If you are overweight or obese, weight loss is critical. The importance of achieving or maintaining a healthy body weight cannot be overstated. Evidence is beginning to accumulate in support of what doctors have long suspected: that losing weight, even after diagnosis, can lead to longer survival. Being overweight is associated with increased risk of recurrence and decreased disease-free survival. Moreover, gaining weight after diagnosis is a frequent complication of treatment, which must be avoided. Managing your weight requires a combination of diet and exercise. It doesn’t have to be as daunting as it sounds—the tips in this chapter and the activity chapter will help.
• Vitamin supplements do not produce the same benefits as diets high in those vitamins. This has been demonstrated time and again in single-vitamin studies over the past 25 years. Whole-foods diets rich in vegetables, fruits, whole grains, beans, and fish or lean meats, and low in refined sugar, red meat, and high-fat foods, have protective effects against cancer. But the benefits are most likely due to synergistic effects of the many nutrients and phytochemicals present in whole food and not as the result of any one or two nutrients. Supplements can be useful in some cases, such as to meet recommended levels of any vitamins or minerals lacking in your diet, but they cannot replicate the benefits of whole foods. Vitamin D is an example of a nutrient that cancer patients (and others) are frequently deficient in and that may require supplementation (discussed later in this chapter).
• It is important to make sure you are getting enough protein. This is important for everyone, but all the more so for cancer patients during all stages of treatment, recovery, and long-term survival. When selecting sources of animal protein, it’s best to choose foods that are low in saturated fat, such as fish, lean meat, skinless poultry, eggs, or low-fat dairy. Plant sources of protein, such as beans, nuts, and seeds, have the added benefit of being high in fiber and rich in antioxidants and other healthy plant compounds.
• Consider seeking individualized nutrition advice. We all have unique needs, and those of cancer patients are particularly variable depending on the nature of your disease and treatment. As a result, personalized advice can be invaluable. This can be from a doctor who is knowledgeable about nutrition or from a registered dietitian (RD) who has experience with the unique needs of cancer patients. Ask for a referral to an RD who is also a Certified Specialist in Oncology (CSO).
Body Mass Index
Body mass index (BMI) is a good way to determine if you are at a healthy weight or are overweight or obese. There are many free automatic calculators online, such as the U.S. National Institutes of Health website (http://apps.usa.gov/bmi-app.shtml). Simply insert your height and weight in their calculator and your BMI will appear. The website contains information about how to interpret and, if necessary, to reduce your BMI.
Specific Dietary Regimens
In choosing a diet to follow, it’s helpful to consider your priorities—whether you need to lose weight or gain it, for instance. Some diets are particularly focused on preventing chronic diseases such as diabetes and heart disease, and that is particularly important if you have a family history of these illnesses or are otherwise at increased risk. And it goes without saying that you’ll want to decrease your risk of secondary cancers or recurrences. It’s a good idea to consult with a dietitian who can help you consider your options and develop the best plan for you. In this next section, we provide an overview of a few diets that cancer patients may hear about and consider. Some have little, if any, value but are popular among some cancer patients. However, a Mediterranean-type diet is considered by experts as the absolute best so we’ll start with that one.
Mediterranean Diet
The Mediterranean diet has become an established eating regimen for decreasing the risk of cancer and its recurrence, as well as the risk of many other chronic diseases. The hallmark of this dietary regimen is low consumption of meat and dairy products. Participants consume fruits, vegetables, legumes (beans, lentils, and the like), and
