AICR 2021 Session Recap: Food for Thought: A Conversation About the Role of Diet in Cancer

This presentation was given by: 

Dr. Karen H Vousden: British medical researcher at the Francis Crick Institute

Dr. Matthew G. Vander Heiden: Medical doctor and researcher at the Koch Institute for Integrative Cancer Research at MIT

“What diet should I follow?” 

This is a common question asked by cancer patients to their oncologists. Patients want to do everything in their power to ensure their treatment is effective, and that they ultimately achieve remission or a cure. Because nutrition is a component of treatment that patients can control, it’s no wonder this is a popular, and extremely important question to ask. While there is research showing that certain nutrition interventions play a positive role in cancer treatment outcomes, unfortunately, there is not as much detailed data on this topic as people think. Nutrition and cancer are both big subjects with a lot of variation within each area. Despite what you may read in the media, in books or online, the answer to the question of what exactly a cancer patient should eat is not so black and white.

The ultimate goal for cancer nutrition recommendations would be to mimic what is done with targeted drug therapy. Just as FLT3 inhibitors are given to AML patients with FLT3 mutations, it would be ideal to also give personalized nutrition recommendations that improve the outcomes of those specifically with FLT3-mutated AML. While cancer nutrition research is not advanced enough to currently provide completely personalized recommendations like this, there are many researchers like Dr. Vousden and Dr. Vander Heiden who are working towards the answers we need in order to practice and provide more effective and personalized nutrition strategies to cancer patients.

Dr. Vousden and Dr. Vander Heiden provide a very thorough explanation as to why there is not just one diet that benefits all cancers. Diet, whole-body metabolism and cancer is very complex. We know that this relationship is influenced by hormones such as insulin and insulin-like growth factor which are involved in cell growth, but these hormones appear to act differently in various cancer types. While there is growing evidence that diet-induced changes can impact the growth of tumors and influence response to some therapies, we still have a long way to go to tease out all of the details. Dr. Vousden and Dr. Vander Heiden reviewed their research to provide examples that reveal why nutrition is not a one-size-fits-all approach in cancer therapy.

Dr. Vousden’s Research: 

Dr. Vouseden presents her lab’s research which looks at how the absence of certain nutrients can inhibit tumor growth. She states that in order to know how to interfere with a certain cancer, it is important to determine how an individual cancer uses metabolism to grow. Her work aims to answer the question: Can we use selective nutritional limitations for cancer therapy? 

In her study, she used a serine and glycine-free diet in mice to see if a lack of these amino acids would slow the growth of various tumor types. She found that this type of diet worked in some tumors such as breast cancer that had metastasized to the brain, but it did not work in pancreatic tumors. This is because the location of the tumor influences the type of nutrients the tumor needs to survive. Brain tissue has a very low need for serine while pancreatic tissue needs high amounts of serine so the body is able to produce it from other amino acids, bypassing the effectiveness of a serine and glycine-free diet on tumor growth. 

Dr. Vouseden concludes that we must take into account the genetics of a patient’s cancer cells and the tumor environment in order to determine what diet interventions would be an effective therapy. 

Dr. Vander Heiden’s Research:

Dr. Vander Heiden presents his lab’s research which looks at diets that have different macronutrient ratios and their effects on tumor growth. He found that the manipulation of fats had the most effect on tumor growth. He explains that a standard ketogenic diet was not able to impair tumor growth but once he started manipulating the types of fats provided within the ketogenic diet he was able to induce an impairment in tumor growth. He states this is because cancer cells have the ability to make their own lipids but cannot perform a process called desaturation in order to utilize them for energy.

He proposed that because of this, an imbalance of saturated to unsaturated fatty acids in the diet may be effective in slowing tumor growth. Because a standard ketogenic diet is typically high in both saturated and unsaturated fatty acids, the diet will provide fuel to the tumor and will not be able to impair tumor growth. However, if the ketogenic diet is manipulated by providing only saturated fatty acids from palm oil, this modification appeared to slow tumor growth. 

This research shows that just modifying macronutrient ratios may not be enough to have an effect on tumor growth. We may need to consider the types of foods we eat that make up these carbohydrate, fat and protein ratios to have a more profound effect on cancer progression. 

Main Takeaways from the Session: 

Before we can begin to recommend serine-free diets or ketogenic diets with the fat content coming primarily from saturated fatty acids, we must first better understand in which patient circumstances these types of recommendations provide the most significant outcomes. Additionally, we must determine in what situations these diet modifications do not cause harm. A serine and glycine-free diet may have consequences such as impaired immunity that have not fully been studied.

Nutrition recommendations such as eating fruits and vegetables high in antioxidants, choosing lean, non-processed animal proteins and cooking with anti-inflammatory fats like olive oil all promote wellness and may help patients have better treatment outcomes, but the downside to these recommendations is that they are general and are often made to people with any type of cancer diagnosis. In order to drill down further and be able to achieve more significant and positive outcomes, we need to be able to provide personalized nutrition recommendations based on tumor type and cancer genetics.

Hopefully one day there will be a roadmap clearly outlining what to eat for AML that will specifically target and affect the growth of leukemia cells, but until then it is still advantageous to apply more general nutrition recommendations in order to reduce the risk for adverse outcomes like treatment interruptions, malnutrition and infection. We can also use various nutrition strategies to help cope with treatment-related side effects such as nausea, constipation and mouth sores. Meeting with a registered dietitian can be extremely beneficial to you in your cancer journey. These healthcare specialists are pros at being able to condense the growing body of cancer nutrition research and provide you with tips and tricks to keep you eating well and feeling your best!