The Role of Protein During Cancer Treatment

Receiving a cancer diagnosis turns your world upside down. That initial shock is usually accompanied by a search for information regarding your diagnosis. What you should or shouldn’t put in your mouth will almost always show up in your search results. And as you dig deeper, the choices you make when it comes to your diet can appear daunting and overwhelming.

One of the hallmarks of cancer is that is a highly catabolic disease. Catabolic means “to break down”, which in this case means that your body continually breaks down nutrients — mainly protein and carbohydrates — to meet the demands of fighting off cancer. While this is happening, your cancer is simultaneously rerouting those newly broken-down nutrients to support its own needs.

Essentially, your body is in a state of requiring the amount of nutrients it would need when training for a marathon, making unexplained weight loss prior to diagnosis a common occurrence. When experiencing this sudden loss of weight, people often think, “this is great, I could stand to lose some weight.” Sadly, this is far from the actual truth.

When people lose weight at a rapid pace, they are not only losing fat mass but muscle mass as well. There are several reasons this weight loss occurs, one being that muscle is metabolically expensive to maintain and relatively easy to break down to use to meet our energy needs. Another reason is that there is an increased demand on the body to build new cells, especially immune cells to help fight cancer. This requires amino acids, which are the building blocks of protein.

In general, people diagnosed with cancer have an increased need to consume protein to help maintain their muscle mass whether they have just been diagnosed, are about to start treatment, or are in the middle of treatment. One of the best ways to meet your protein needs is to include a protein source with each meal and snack you consume throughout the day.

We recommend getting your nutrients from food sources whenever possible and some good sources of protein in the diet include meat, fish, eggs, and dairy products.

If you are vegetarian or vegan, you can still easily meet your protein needs. There are a few plant-based protein foods that are complete protein sources, including soy, quinoa, buckwheat, amaranth, nutritional yeast, hemp, and chia seeds. Some plants do not contain all of the 8 amino acids that are considered essential, so it is important to pair your plant-based protein sources. Be sure to pair your beans and legumes with nuts, seeds, and grains if you are consuming other plant sources of proteins. These foods don’t need to be paired at every meal; it is more important to consume them within one day.

Can I use a protein supplement?

Many people going through treatment struggle to meet their daily protein needs through food alone. If you are unable to meet your protein needs through foods, a protein supplement may help you meet your daily protein goals. Be sure to choose a protein supplement that has the fewest ingredients possible; a good option is whey, which tends to be the best tolerated for most people. Other options include soy, rice, egg, pea, pumpkin, and hemp, but these will carry more of a taste than whey and may not be as well tolerated. Be sure to check the label for unwanted ingredients such as added vitamins or minerals, spirulina, creatine, bee pollen, or herbs. If possible, aim to purchase plain protein powder, as it may be better tolerated — especially if someone is experiencing taste changes, as the flavored powders may be off-putting or come across as metallic-tasting. Also, plain protein powder is much more versatile when adding it to a variety of foods.

How are they used?

If you need extra calories in addition to protein, you can mix protein powder into your favorite beverage or add it to a variety of soft foods such as mashed potatoes, cereals, soups, stews, and casseroles. It is also is a nice addition to smoothies, milkshakes, hot cocoa, chai tea, and even your coffee. You can even add it to milk for an easy boost. Protein powders can sometimes be used as an egg replacement in baked goods, too.

A few of our favorite protein-rich meals are Quinoa Porridge, Turkey Meatballs, and Fish en Papillote, plus we have plenty of protein-rich vegetarian meals and snacks.

If you are concerned that you are not eating enough protein and/or are losing weight due to treatment, it is important to speak to your doctor, dietitian, and the rest of your cancer care team, as they will be able to advise you on the need for a supplement and other interventions.