Cancer – Genetic or Environment?

By Nikki Doering, RD, LD
March 5, 2019

Cancer is a word that (rightfully so) scares most people. A recent Dishing Up Nutrition podcast took a closer look at what causes an increased risk of getting cancer, how to prevent it and what may help during treatment. If one thing is certain, cancer is a controversial topic, and it is difficult to shift through all the information at times. Search any cancer topic and you’re certain to find conflicting viewpoints on the subject.

Dr. Robert Rakowski, a cancer expert and guest on the recent podcast, mentioned that only 5-10% of cancers are caused by genetics, meaning there is a significant amount of environmental factors at play. The American Cancer Society states that at least 30% of cancer is caused by smoking and about 20% of cancer cases are caused by diet. Experts argue about the cause of the remaining cases of cancer.

Cancer experts do agree that preventing cancer is of utmost importance, and many are researching how to stop cancer before it starts. Medical treatments have come a long way, and the survival rates of cancers are improving, but our goal should be to continue to prevent cancer first.  

Dr. Rakowski summarized several things that may help prevent cancer and things which help during cancer treatment. He stated nutrition, stress, sleep, and reducing environmental toxins play important roles in cancer outcomes. Let’s spend a little time with each of these topics.

Nutrition’s Impact on Cancer 

Many have heard the phrase “Sugar feeds cancer,” but what does that really mean? It depends on who you ask, but in short, the body’s response to sugar intake has the most impactful role in cancer’s metabolism.

It gets a little complicated, but our sugar intake changes the amount of insulin our body releases and the rate at which sugar enters our cells. After we consume high sugar foods (or foods that turn into a lot of sugar), insulin is released from the pancreas in response to the increased glucose (sugar) levels in our blood. Think of insulin as the key that unlocks the door to our cells to allow glucose to enter the cells and be used as energy. This is an amazing and delicate process, but it does not take much sugar to cause an influx of insulin into our blood stream. If all our cells use glucose (sugar) to thrive, than why would cancer cells be any different? One theory is cancer cells contain more insulin receptors making glucose uptake quicker than non-cancer cells.

Since insulin response plays a role in cancer, (though not well understood at this time), nutrition and blood sugar balance are important for cancer prevention and cancer treatment. In other words, we don’t want huge fluctuations in insulin levels caused by eating foods that turn into a lot of sugar. The simplest way to control insulin release is to eat in balance every 2.5-3.5 hours. Balanced eating means that each meal and snack should contain protein, healthy fat, and vegetable or fruit carbohydrates.  

Most experts agree that vegetable intake is critical for health during cancer treatments and for prevention. Vegetables, specifically cruciferous vegetables (broccoli, Brussels sprouts, cabbage, cauliflower, etc.), have been shown to reduce the risk of some cancers. Needless to say optimal nutrition can be very difficult to achieve during cancer treatments – and very confusing– but it can be critical to health outcomes. Adding a dietitian or nutritionist to your care team is important. Note that Dr. Rakowski shared that juicing fruits and vegetables may not be a good option because it can have a detrimental effect on blood glucose balance. Juice, specifically fruit juices, spike blood glucose quickly and in turn increase insulin in the bloodstream.

Sleep’s Impact on Cancer

Essentially, we sleep to heal. Dr. Rakowski reiterated how important sleep is to the healing process for cancer prevention and during cancer treatments, saying that sleeping 7.5 to 9 hours a night for most people is a necessity, and less than that is known to hinder our immune system. When fighting cancer we do not want to subject ourselves to a stunted immune system!

Melatonin is a great option for individuals who find getting a good night’s rest difficult. Dr. Rakowski shared that melatonin helps with sleep and also with the body’s response to stress, which we’ll touch on below.

Stress’s Impact on Cancer

Again, experts disagree on the topic of stress and cancer, questioning whether stress alone causes cancer or if stress increases cancer risk behaviors. Either way you look at it, stress reduction is important and essential to having a strong immune function to fight cancer. Dr. Rakowski spoke in detail about how melatonin can be used to buffer the stress response because our natural melatonin production is blocked by stress.  

Decreasing stress is of course based on individual needs. Each person needs to determine what stress is present in their life and what the best way to de-stress is. This Dishing Up Nutrition podcast entitled Conquering Your Stress can be a helpful resource. Balanced nutrition will also help by balancing hormones, which make dealing with stressors much more manageable. Finding calming activities like reading, walking, yoga, or meditation can also have a positive impact. And one more time, getting enough sleep and exercise also decrease our body’s response to stress.

Toxins’ Impact on Cancer + How to Reduce Your Exposure

According to the National Cancer Institute we have daily exposures to cancer- causing environmental toxins in the air we breathe, the water we drink, the foods we eat, and the materials we use. Many of these toxins cause chronic inflammation which is linked to cancer risk. Here are a few ways to help reduce overexposure to environmental toxins:

• Drink filtered water in glass, steel, or ceramic containers
• Avoid cooking foods in plastic containers – heating plastic releases harmful chemicals into the food
• Reduce alcohol consumption
• Avoid getting too much sun
• Avoid eating burned foods or deep fried foods
• Quit smoking

Full Team of Support

Overall, a cancer diagnosis can seem extremely overwhelming, but with support from family, friends, and medical providers it can be more manageable. Remember that nutrition, sleep, stress, and environmental toxins all impact your health even with a cancer diagnosis. Our nutritionists and dieticians are always here for a phone, video visit, or in-person consultation to help. If your goal is cancer prevention, taking a few steps to improve your general health can go a long way. 

References:
Acrylamide and Cancer Risk (National Cancer Institute): https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/acrylamide-fact-sheet
Acrylamide and Cancer Risk (American Cancer Society): https://www.cancer.org/cancer/cancer-causes/acrylamide.html
Cancer-Causing Substances in the Environment: https://www.cancer.gov/about-cancer/causes-prevention/risk/substances
Consumption of Deep-Fried Foods and Risk of Prostate Cancer: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3756514/
Cruciferous Vegetables and Cancer prevention: https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/cruciferous-vegetables-fact-sheet
Distribution, function and physiological role of melatonin in the lower gut: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3198018/
Drinking Water and Cancer: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1518976/
Exposure to Chemicals in Plastics: https://www.breastcancer.org/risk/factors/plastic
The Genetics of Cancer: https://www.cancer.gov/about-cancer/causes-prevention/genetics
Health Risks of Smoking Tobacco: https://www.cancer.org/cancer/cancer-causes/tobacco-and-cancer/health-risks-of-smoking-tobacco.html
Sugar and Cancer: https://www.oncologynutrition.org/erfc/healthy-nutrition-now/sugar-and-cancer
Tobacco: https://www.cancer.gov/about-cancer/causes-prevention/risk/tobacco