As a registered dietitian who works with cancer patients on a regular basis, I frequently get questions about the role that certain foods and ingredients have in prevention, treatment, and survival of the disease. Answering these questions is difficult these days because of misinformation in the media. Everyone thinks they are a nutrition expert and has an opinion on what causes cancer and what doesn’t.
While we are all entitled to our own opinions and beliefs, as a nutrition expert and professional, it is my job to help my clients and the public understand the scientific evidence behind food and cancer risk. What is the research behind the headlines really telling us?
I can’t sum up ALL of the evidence behind food and cancer risk in one blog post (that would take forever) but my goal is to help clear up some of the confusion so you can have peace of mind next time you are eating something thinking, “am I going to get cancer from this?” I also want to dive into some of the big reasons WHY spreading misinformation about foods and cancer risk is so harmful, especially in the vulnerable populations in my community that I work with every single day.
Long story short: there is NO conclusive scientific evidence that any food or ingredient causes cancer. None. Sure, there have been studies that suggest certain foods and eating patterns are correlated with increasing or decreasing cancer risk. But correlation does not = causation, and we have to remember the multitude of other factors that may contribute to disease, including genetics, sleep, stress levels, relationships, socioeconomic status, environment, to name a few. Keep in mind that many of the studies out there do not take all of these into consideration, and thus research findings often have to be taken with a grain of salt (as convincing as some studies can be!). Another important thing to keep in mind is that conducting studies on cancer in humans is not always ethical, and therefore, a lot of the research out there regarding food and cancer is based on animal studies. We are not mice, and the results from these types of studies cannot be applied directly to you.
Let’s take red & processed meat, for example. A couple years ago, the International Agency for Research on Cancer (IARC) classified processed meat as a Group 1 carcinogen, or a “definite” cause of cancer, placing processed meat into the same group that includes smoking and alcohol. The same organization classified red meat as “probably” carcinogenic. Both red and processed meats have an established link to colon, prostate and pancreatic cancers. The announcement that these foods are “cancer-causing” caused an uproar—it was as if this was the first time we had ever heard that these foods play a role in cancer risk. When really, this topic has been studied for decades.
If you dive a little bit deeper into the research, you’ll learn that the risk of cancer when eating these foods is “dose-specific.” This means that if you consume it in high amounts for a long period of time, then yes, you may have a greater risk of cancer. Key words: “greater risk.” That does not mean you will automatically get cancer if you eat these foods on a regular basis, but you are more likely to…especially in combination with other unhealthy habits, such as smoking, drinking excessive amounts of alcohol, and high stress levels. However, if you eat red meat and maybe a little bit of processed meat here and there, in combination with an otherwise healthy and balanced diet, you are most likely going to be fine. I say “most likely,” because nothing is ever guaranteed. The truth is that there are people out there who eat extremely healthy and exercise every single day who still get cancer. Telling someone that avoiding a specific food or eating a certain way will prevent them from getting cancer is a complete lie. That’s not to say that someday we won’t have a cure for cancer that involves food, but right now, there is no food or ingredient that is 100% known to prevent, treat, or cure cancer.
I also feel the need to mention that there are components of almost every food that can be linked to cancer risk, even healthy, plant-based, vegan, “green” foods. Asparagus, tomatoes, potatoes, eggplant –with a simple Google search you’ll find arguments from both ends of the spectrum about whether or not you should eat these vegetables to lower cancer risk. How confusing is that? Now, I wouldn’t recommend that you eat loads of the exact same vegetable at every single meal for a variety of reasons…but I would never tell someone to avoid a certain type of vegetable to prevent cancer, nor would I say the same thing for any other foods.
What people who promote cancer-fighting foods and diets and supplements and ingredients do not realize is that they are actually doing more harm than good. In my work, I come across clients who struggle with many other programs and social issues in addition to a cancer diagnosis. Most of our clients struggle with at least one of the following:
- Food insecurity (the state of being without reliable access to a sufficient quantity of affordable, nutritious food)
- Financial instability
- Social isolation
- Lack of transportation (or none at all)
- Unstable housing or homelessness
- Stressful living arrangements
- Mental illness (addiction, depression, anxiety, etc)
And the list goes on, and on, and on. Imagine you have just been diagnosed with cancer. You can’t work due to your illness yet you’re buried with medical bills. You can barely afford housing, not to mention you were told by an “expert” on the internet that basically all the foods you have in your cupboard are cancer-causing. You don’t have the finances to buy any of the foods that this “expert” recommended, such as organic produce (or any produce for that matter). What’s a person to do?
We must STOP promoting fear and misinformation around food and cancer (and all other diseases) but rather look at the big picture. The stress associated with all of the factors listed above will lead to cancer before eating any specific type of food ever will. And we must work together to increase access to healthy food for ALL people, so that everyone can have the same privilege to improve health and lower risk of disease.
Now you might be wondering, is there anything I can do with my diet to help reduce my risk of getting cancer? I’ve said it about 3 times in this post, and I will say it again: there is no one food, ingredient, or diet to follow to prevent, treat, or cure cancer. But there are a few things that you can do with your lifestyle to keep you healthy overall and lower risk of all disease, including the following:
- Consume a balanced diet that includes a variety of plant-based foods. This includes fruits, vegetables, legumes, nuts/seeds, and whole-grains.
- Eat plenty of healthy fats, including avocados, olive oil, flaxseed, fatty fish, and nuts/seeds.
- Pay attention to where you get your protein. You don’t have to completely avoid meat, but try not to have it at every single meal or even every single day. Include some plant-based sources of protein in your diet, such as beans, lentils, tofu, tempeh, and so on.
- Limit your intake of fried foods, added sugar, processed meats, and refined grains.
- Avoid smoking and drinking excessive amounts of alcohol.
- Keep your stress levels under control: yes, chronic stress will lead to cancer more quickly than a certain food ever will.
- Make time for fun and good relationships in your life.
- Get plenty of sleep and rest.
And here’s what you can do to keep your neighbors healthy, who may be less fortunate than you are:
- Donate nutritious foods that YOU would eat to food pantries and food banks. Many of these organizations now provide fresh produce to their clients, so if you have some produce laying around in your fridge that you know you’re not going to use…donate it before it goes bad!
- Volunteer for an organization that has an aim to improve health among food insecure populations, such as Open Arms of Minnesota.
- Do your research and vote for political candidates who have an agenda that supports healthcare, good nutrition, and food access for all.
- Support programs that aim to improve food access, such as SNAP and WIC.
- Avoid spreading misinformation about food and nutrition. You can have your own nutrition beliefs and dietary practices – all the power to you. But remember that one person’s experience does not apply to all people and doesn’t take the place of science.