Animal-based protein recommended for people being treated for cancer
If you're being treated for cancer, don't leave meat, fish and dairy off your plate, University of Alberta experts advise.
Though it may seem healthier to avoid animal-based proteins like red meat, relying on plant-based protein alone isn't a good plan while fighting cancer, said Carla Prado, a nutrition expert in the Faculty of Agricultural, Life & Environmental Sciences.
"When you have cancer, the majority of protein in your diet should be animal-based, and it is safe to eat."
Proteins like red meat or pork tend to get a bad rap when lumped in with their highly processed cousins like cured ham, bacon and salami, which have been linked to causing cancer.
"Unfortunately, there's this misconception that if one type of meat is bad, then all meat is bad, but this is certainly not the case."
In a new opinion paper, Prado and her co-authors—cancer nutrition experts from around the world—reviewed available scientific data and suggest that meat, fish, eggs, poultry and dairy offer better muscle-building properties than plant-based proteins, such as legumes.
Animal-based protein is higher in amino acids, which are vital for building and growing new muscle tissue, as well as helping people better tolerate cancer treatments like chemotherapy.
"Our research has already shown that the more muscle you have, the less severe the toxicity of cancer treatment, your quality of life is better and you can live longer," said Prado, a professor in the Department of Agricultural, Food & Nutritional Science.
Cancer treatments can also erode muscles through poor appetite, bedrest or the stress of surgery, so people undergoing treatments need more protein than healthy individuals, said dietitian Katherine Ford, a Ph.D. candidate in nutrition and metabolism and co-author on the paper.
Many people don't realize the body's nutritional needs differ during cancer treatment, versus eating for cancer prevention, Ford said.
"The amount of protein a person needs to maintain muscle goes up significantly during treatment."
The researchers recommend that at least 65 percent of total protein intake during treatment be from animal-based foods.
"Combined with plant protein, it's likely the best way to support muscles and avoid malnutrition," said Ford.
People being treated for cancer would have to eat significantly more plant-based proteins to get the same benefits of also including meat, fish, dairy or eggs on their plates, she noted.
Current recommendations suggest people should consume 1.2 to 1.5 grams of protein for every kilogram of body weight daily during cancer treatment. The easiest way to increase intake is to include a protein source in every meal and snack, Ford suggested.
Adding tuna or leftover chicken to a salad or casserole, pairing some cubed cheese with fruit or whole-grain crackers, or adding yogurt to a snack or as a dessert are all easy ways to include animal-based protein sources.
"By doing that, you're well on your way to meeting your nutrition needs."
The researchers also recommend that those sticking to an entirely or mostly plant-based diet during cancer treatment should see a dietitian to ensure they are getting enough protein.
"It's important for making sure they're getting adequate nutrition to properly support muscle health," Prado said.
More information: Katherine L. Ford et al, The importance of protein sources to support muscle anabolism in cancer: An expert group opinion, Clinical Nutrition (2021). DOI: 10.1016/j.clnu.2021.11.032