Navigating the tenuous relationship between food and cancer can be a daunting task. As a society, we are constantly being bombarded with messages about which foods we should and should not eat. The info is continuously changing and often contradictory. There are new trends, old practices that come back into fashion, and sometimes groundless claims. And yet even as we know there is a strong connection between food and disease, it is often overlooked by the medical community when discussing treatment plans.
Here’s a look at three of the most popular food plans and their effect on cancer prevention and treatment.
Vegetarian/Vegan/Plant-Based Diets
Spend more than a few minutes on social media and quickly discover just how popular plant-based diets have become. From celebs to athletes to Michelin-star restaurants, saying no to meat and/or dairy projects has become all the rage. And it is, without a doubt, a healthier way to treat both our bodies and the planet. But did you know that a whole food plant-based lifestyle can have a huge impact on cancer risk as well as recovery? First of all, there is compelling evidence that certain kinds of meat can cause cancer. Current research shows that specific chemicals in red and processed meats – both added and naturally occurring – cause these foods to be carcinogenic (having the potential to cause cancer). The research on dairy and cancer isn’t as conclusive, but some studies have shown an increased cancer risk for people who consume large amounts of dairy, particularly in non-western countries.
Conversely, a plant-based diet, consisting of fruit, vegetables, whole grains, beans, nuts, and seeds, maximizes the consumption of anti-cancer compounds found in food. This leads to a healthier gut microbiome, lower inflammation and cellular stress levels, and a healthier body weight, all of which can help prevent cancer. In fact, a large study published in the International Journal of Cancer found that those who ate the most plant foods and the least animal foods reduced their risk of cancer by 15%. Cruciferous veggies, like broccoli, rocket, cabbage, brussel sprouts, mushrooms, nutritional yeast, and the allium family of vegetables which includes onions, garlic, and leeks, have all been shown to contain anti-cancer properties.
Whatsmore, a slew of scientific literature shows that a healthy plant-based diet can improve your chances of remission and survival even after a cancer diagnosis.
Breast cancer, colorectal, and prostate cancer have all been shown to have longer remission and survival rates among patients who consume more fruits, vegetables, and whole grains. And while there aren’t necessarily any magic foods that can guarantee to cure cancer, some certainly stand out for their health benefits related to the disease. For example, blueberries, strawberries, apples, oranges, peaches, onions, tomatoes, cauliflower, carrots, sweet potatoes, kale, broccoli, grapes, and spinach; grains and seeds including brown rice, oats, and whole grains; and beans and legumes including chickpeas and lentils are among those foods which have been shown to aid in anti-angiogenesis, that is the process of preventing the growth of blood vessels that feed tumors and cancer.
Mediterranean Diet
The Mediterranean Diet, as the name suggests, is a lifestyle plan inspired by the eating habits of people who live near the Mediterranean Sea. It was initially formulated in the 1960s, and based on the cuisines of Greece, Italy, France, Spain, and the Ottoman Empire. The diet is rich in fish, olive oil, vegetables, whole grains, nuts, and legumes, and it limits but does not completely eliminate red meat, dairy, and alcohol consumption. The Mediterranean Diet has long been lauded as one of the healthiest ways of eating on the planet. In addition to weight loss and maintenance, it can lower your risk of cardiovascular disease, support healthy blood sugar, blood pressure, and cholesterol levels, and even slow brain function decline as you age.
In terms of cancer, the Mediterranean Diet is considered a powerful and manageable method for fighting the disease. The foods included in the diet are generally chock full of antioxidant and anti-inflammatory properties, which aid in preventing and counteracting DNA damage and slow down the development of various forms of cancer and cancer cell proliferation. A slew of studies associated the Mediterranean Diet with a reduced risk of overall cancer mortality and a reduced risk of several cancer types.
A small sampling of these studies includes:
- Colorectal Cancer: A 2018 study found that three key elements of the diet – a large amount of fish, a large amount of fruit, and a low amount of soft drinks – were associated with an over 30% reduced odds of a person having advanced, precancerous colorectal lesion when compared to those who did not consume any of these components.
- Breast Cancer: 15,000 women in Greece were studied for nearly a decade, where it was found that the postmenopausal women in the group on the Mediterranean Diet had a lower risk of breast cancer than those who didn’t.
- Prostate Cancer: A study conducted in the United States looked at 410 men who were diagnosed with prostate cancer and their food choices. After adjusting for age and clinical characteristics, researchers saw a significant association between a high baseline diet score and a lower risk of cancer-grade progression. For every one-point increase in the Mediterranean diet score, researchers observed a 10% lower risk of progression.
The Ketogenic Diet
In the past few years, the ketogenic diet, or keto for short, has become incredibly popular as a weight loss method. It involves significantly reducing your carb intake and replacing it with fat and protein. Think of a juicy cheeseburger with melted cheese and lots of mayo… but no bun. When this happens, your body becomes incredibly efficient at burning fat for energy, a process known as ketosis. It also turns fat into ketones in the liver, which can supply energy to the brain. Ketogenic diets can cause significant reductions in blood sugar and insulin levels. This, along with the increased ketones, is known to have health benefits beyond just weight loss. The ketogenic diet reduces IGF-1 levels and the risk of diabetes and obesity. These factors may lead to a reduced risk of developing cancer in the first place.
In order to understand the relationship between the keto diet and cancer treatment, we have to think about the role of blood sugar in cancer. Nearly all cancer cells share one common trait: they feed off carbs or blood sugar to grow and multiply. The keto diet drastically reduces blood sugar levels through the process of ketosis, which can effectively “starve” the cancer cells, causing them to grow more slowly, decrease in size, or possibly even cause them to die. In addition, reducing carbs reduces the energy available to your body which may, in turn, slow tumor growth and cancer progression.
Researchers have studied the ketogenic diet as an alternative cancer therapy for decades, primarily in animals. For example, one study of mice with metastatic cancer tested a ketogenic diet. When compared with a standard diet, the ketogenic diet resulted in a significant decrease in tumor growth. Another study found that using a very low-carb diet to restrict glucose levels prevented the growth of squamous cell carcinoma tumors in mice with lung cancer or esophageal cancer. Recently, scientists have also begun studying keto diet results in human cancer patients. The data is still emerging, but limited research seems to show that a ketogenic diet may reduce tumor size and the progression rate of certain cancers.
Despite clear general health benefits and emerging research suggesting that a ketogenic diet can contribute to cancer prevention and treatment, it is not without its risks. It is very high in fat, and many foods allowed on the diet, such as red meat, have been shown to increase the risk of some cancers. The diet is also very limiting regarding foods known to prevent cancer, such as whole grains, fruits, and some vegetables. It can be challenging for those undergoing traditional cancer therapies to consume enough calories while on the diet. Anyone considering a keto diet should consult with their medical professional first.
Conclusion
Although it is not yet possible to provide quantitative estimates of the overall risks, it has been estimated that 35% of cancer deaths may be related to dietary factors. Diets that include fruits, vegetables, and spices may provide substantial health benefits in cancer prevention and treatment by suppressing the inflammatory processes that lead to transformation, hyperproliferation, and the initiation of carcinogenesis. Diet is clearly an important component, but it is not a replacement for a complete treatment regimen. Any food program should be discussed with your physician and implemented under the guidance of a qualified integrative healthcare professional/nutritionist.