The diagnosis of cancer can shatter lives and put families into turmoil. All of us know someone with, or have lost a loved one, to the disease. Rates of cancer are highest in developed countries, with Australia being at the top of the list. Breast and prostate cancer rates are more than double those of developing nations and colon cancer is more than five times more prevalent in Western countries.
While genetics play a small role in the development of cancer, diet and other lifestyle factors – like obesity, smoking, alcohol use and a sedentary lifestyle – fuel the development and growth of cancer. This article aims to outline how this occurs and what steps you can take to reduce your cancer risk.
What is cancer anyway?
Cancer is a multi-stage process resulting from uncontrolled proliferation of damaged cells. Cancer is typically labeled in stages from one to four, with four being the most serious as it has spread (or metastasized) to other parts of the body.
At some stage of our lives most of us will develop pre-cancerous cells. However, our immune system is amazing at recognising and removing these cells before they develop into tumors and spread to the rest of the body. We are only beginning to see how our immune system works in such sophisticated and complicated ways to remove cancer. It can either be stimulated or dampened by environmental factors, including our diet.
Nutrition is crucial for a functioning immune system as it provides our cells with everything they need to fight disease. If our diet is not high in powerful antioxidants and phytonutrients then cancer cells can go unchecked. The gut microbiome is also highly important in cancer prevention as it’s where much of our immune cells originate. And a healthy gut microbiome comes from what we put in our mouths.
Cancer rates across the world
The burden of cancer worldwide is not uniformly distributed. In developed nations, where diet is dominated by animal based and processed foods, cancer rates are high. Developing nations, as they become “Westernised”, are seeing an increase in cancer rates. At the same time their intake of meat, dairy and processed foods is skyrocketing as they are becoming more affluent.
The China Study, by T. Colin Campbell, was based on the most comprehensive study of nutrition conducted to date. It examined the link between the consumption of animal products and chronic illness, cancer being one of them. Traditionally, the people living in rural China have consumed a diet low and fat and high in fibre. The study found that people living in rural settings had a low prevalence of cancer compared to larger cities. The authors showed a clear correlation between increased incidences of cancer with a high intake of animal products in the diet.
How exactly does food cause cancer?
There are a number of dietary factors working to make the Western diet so powerful at promoting cancer. The consumption of ultra-processed foods, a lack of antioxidants and phytochemicals, large amounts of animal protein and environmental toxins are the key players.
There are many potential mechanisms to explain the cancer risk associated with eating meat. Meat contains pro-inflammatory omega-6s, more cancer-associated methionine, heterocyclic amines, trans fat, endogenous hormones like IGF-1 and artificial hormonal growth-promoters.
Methionine is an essential amino acid that has the highest concentration levels of all animal protein. Some cancers are dependent on methionine for survival and proliferation. In humans, plant-based diets, which are naturally low in methionine, may prove to be a useful nutritional strategy in cancer prevention and tumor growth control.
Our body has an amazing defense system called angiogenesis that keeps microscopic cancers from developing into tumors by starving them of a blood supply and nutrients that they require to grow. This defense system can be optimised by the foods we choose to eat. Animal protein fuels angiogenesis by developing vascular tissue. Plant foods such as soy, tomatoes, berries are your best weapon to keep tumors at bay and can be found in your supermarket, vegetable garden and local farmers’ market.
IGF-1 (Insulin-like growth factor 1) s an important growth promoter produced in our liver and helps us to grow as children. Having high levels as adults however tells our cells to just keep growing and proliferating. When we consume too much animal protein, the body increases its production of IGF-1. The more IGF-1 we have in your bloodstream, the higher our risk for developing cancer. By decreasing our consumption of animal products our IGF-1 levels lower. After just a few days of eating whole plant foods our IGF-1 levels drop low enough to reverse cancer cell growth.
So what are the best plant foods for reducing our cancer risk?
Soy plays a role in cancer development, right? Wrong. Soybeans were one of the first foods shown to have anti-angiogenic effects and cancer-fighting properties. Similarly, epidemiological studies have revealed that a high consumption of soy products is associated with low rates of hormone-dependent cancers, including breast and prostate cancer. Soy phytoestrogens have been given a bad wrap, but studies have actually shown these to reduce the risk of developing cancer.
Alliums contain sulfur and organic compounds that restrict cancer growth. So eat garlic, onions, leeks, chives, and shallots as often as you can.
Cruciferous vegetables such as broccoli, broccoli sprouts, cauliflower and kale, contain powerful protective micronutrients and phytochemicals. These sulfur-containing compounds, isothiocyanates, have powerful immune-boosting and anti-cancer activities.
Mushrooms, although not technically plants, have recently been highlighted as containing powerful anti-cancer and anti-tumor agents. The polysaccharide, beta glucan, is the best known and most potent mushroom-derived substance with anti-tumor and immunomodulating properties.
Interestingly, nutritional yeast is also high in beta glucan and can help prevent cancer by modulating the immune system and suppressing tumor growth.
Berries, including blackberries, strawberries and raspberries, have anti-proliferative effects on cancer cells and they can slow down cancer growth. They are also very powerfully anti-angiogenic and can restrict blood supply to tumors.
A daily dose of beans may not only decrease our cancer risk but also increase our longevity. A common ingredient in the diet of centenarians is legumes, such as chickpeas, beans and lentils. High in fibre, protein and sulfur containing compounds, these qualities give legumes their amazing chemo-protective properties.
There are many more cancer-protective examples of whole plant foods. The key is to buy your produce locally and fresh, and eat them in large quantities. Try to include every colour of the rainbow in your meals and eat leafy greens in abundance.
Eating to live cancer-free
It’s always best to prevent, rather than cure a disease like cancer. Unfortunately the current anti-cancer and chemotherapy drugs that are available pose several detrimental side-effects and complications. This then highlights the urgent need for less-toxic, evidence based approaches to preventing cancer development and proliferation.
Eating a diet rich in whole plant foods isn’t a cure, nor is a panacea, for all cancers. However if you could minimise your or your family’s risk of developing many types of cancer in the first place by eating a whole food, plant based diet, why wouldn’t you?
