Each year, about 14 million people are diagnosed with cancer and 8 million people die of the disease worldwide. This year's World Cancer Day on 4 February takes an inspiring approach to tackling the disease with the theme "We Can. I Can", highlighting the positive impact everyone can have -- both individually and collectively -- on preventing cancer. As a nutritionist, I'm pleased that people are becoming empowered to protect themselves, and I know that eating plant-based foods is an essential part of cancer prevention.
Did you know that according to the US National Cancer Institute, 80% of all cancers are caused by known factors? That means that more than three-quarters of all cancers are potentially preventable. While it's no surprise that cigarettes are responsible for 30% of cases, it's significant that food causes up to 50% of cancers. In other words, the key to good health is on our dinner tables.
People who don't eat meat are between 25-50% less likely to suffer from cancer, even after controlling for other factors, such as smoking.
Vegetables, whole grains, legumes and fruits help prevent cancer and deter tumour growth because they're packed with nutrients such as pectin and phytochemicals, which strengthen the immune system and destroy harmful substances before they can do any damage. Fruits and vegetables are full of good-for-you beta-carotene, flavones and indoles. They also contain vitamin C, which acts as an antioxidant, neutralises carcinogenic chemicals and blocks the conversion of nitrates into cancer-causing nitrosamines in the stomach.
Plant-based foods are also high in fibre, which helps to eliminate carcinogens from the digestive tract. Researchers have found that people who don't eat meat are between 25-50% less likely to suffer from cancer, even after controlling for other factors, such as smoking. That's why one of the primary recommendations in the American Cancer Society's nutrition guidelines for prevention is to eat a diet "with an emphasis on plant foods".
Not only do plant foods help prevent cancer, animal-derived foods actually cause it. A recent World Health Organization study created quite a stir with its finding that processed meats -- such as bacon, ham and sausage -- are carcinogenic. The report said that eating just 50 grams of processed meat a day (less than two slices of bacon) increases the chances of developing colorectal cancer by 18%. But processed meats aren't the only dangerous foods to avoid: eggs and milk products are also full of saturated fat, excess protein, hormones and other harmful substances that can raise a person's cancer risk.
Countries whose populations consume a high percentage of calories from meat and dairy foods have increased numbers of breast cancer cases.
According to Dr T Colin Campbell, professor emeritus of nutritional biochemistry at Cornell University and director of the China Project, the most comprehensive study of health and nutrition ever conducted, "No chemical carcinogen is nearly so important in causing human cancer as animal protein".
A 2011 Harvard study found that by consuming just two and a half eggs per week, men increased their risk of developing a lethal form of prostate cancer by a staggering 81%, compared with men who consumed less than half an egg per week. Intake of dietary fat, which is abundant in meat and other animal-derived foods, increases men's testosterone production and in turn increases prostate-cancer risk. Western nations whose diets consist of large amounts of animal-derived foods also have the highest rates of colon cancer.
Furthermore, countries whose populations consume a high percentage of calories from meat and dairy foods have increased numbers of breast cancer cases. In Japan, people get far fewer calories from animal-derived foods, and breast cancer rates are low. But when Japanese women are raised on Western diets, their breast cancer rates surge. In India, breast cancer rates are rising in tandem with increased obesity, especially among younger women.
Plant-based foods are conducive to both prevention and healing, which is why vegans enjoy lower overall cancer rates. It's as simple as that.
If we're serious about fighting a disease that kills millions every year, then it's imperative to acknowledge that meat, eggs and dairy foods increase the risk of developing cancer. According to Dr Jane Plant, a British scientist, cancer survivor and author of The No-Dairy Breast Cancer Prevention Program, "Undoubtedly, the best anti-cancer diet would be to go completely vegan".
World Cancer Day is a reminder that what we choose to eat can be a powerful ally in the fight against cancer -- or it can lead to poor health. As Hippocrates, the father of medicine, famously said, "Let food be thy medicine and medicine be thy food." Plant-based foods are conducive to both prevention and healing, which is why vegans enjoy lower overall cancer rates. It's as simple as that.
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