Vegetarian and Vegan Diets
A vegetarian diet refers to a diet that does not include meat, poultry or fish. A vegan diet only contains plant foods and excludes all animal products such as meat, poultry, fish, dairy and eggs. You can meet your nutritional needs with vegetarian or vegan diets, but it's important to include foods that provide the protein, vitamins and minerals that might otherwise have come from animal foods. For those cancer survivors who are trying to regain lost weight and muscle, you may benefit from expert advice. Especially if you follow a vegan diet, a consultation with a registered dietitian nutritionist can help you make sure your calorie, protein and nutrient needs are adequate.
AICR's recommendation for cancer prevention is to eat a plant-based diet, primarily vegetables, fruits, grain products, beans, nuts and seeds, with some animal foods. This allows you to get a variety of the plant foods' cancer-protective nutrients such as fiber, vitamins, minerals and phytochemicals.
What research shows for cancer survivors
Research shows that cancer survivors should follow the same diet recommendations as those for cancer prevention: a varied, plant-based diet. It does not appear that vegetarian or vegan diets are any more protective than plant-based diets that include moderate to small amounts of animal foods. AICR recommends that you fill your plate with 2/3 (or more) plant foods and 1/3 (or less) fish, poultry or meat, and dairy.
In addition to focusing mostly on plant foods, one of AICR's recommendations is to limit red meat, like beef, pork and lamb, to 18 ounces or less of cooked meat a week, and to avoid processed meat like sausage and bacon. High amounts of red meat increase risk for colorectal cancer and small amounts of processed meat, eaten regularly, increase risk for both colorectal and stomach (non-cardia) cancer.
The emerging research
AICR's continuous update report on breast cancer survivorship found emerging, but limited, evidence that eating foods containing fiber and soy link to improved survival. There are also indications that women eating high amounts of fat and saturated fat before developing the disease may have an increased risk of dying following a diagnosis of breast cancer. This research is tentative and ongoing; while the findings are intriguing, evidence is not strong enough to make recommendations.
However, research has found that eating moderate amounts of soy foods are safe for breast cancer survivors and that eating foods high in fiber help lower risk for colorectal cancer.