This article is from Canada’s national paper, The Globe & Mail, and is written by one of our nationally known nutritionists, Leslie Beck.
If you favour meat over vegetarian fare, you might want to reconsider your menu. According to a study published this week in the British Journal of Cancer, vegetarians are less likely than meat eaters to develop cancer.
The most striking difference was in cancers of the blood – leukemia, multiple myeloma and non-Hodgkin lymphoma.
It’s estimated that 4 per cent of Canadians follow a vegetarian diet, a number that’s expected to rise over the next decade. More people are embracing a meat-free lifestyle for ethical reasons: not wanting to be cruel to animals or to harm the environment. Others go the vegetarian route because they view it as healthier.
It seems that the notion of a vegetarian diet being better for you does, in fact, have strong scientific backing.
The most recent study compared the risks of 20 different types of cancer among 61,556 meat eaters and vegetarians living in Britain who were followed for more than 12 years.
The researchers found that vegetarians were 12 per cent less likely to be diagnosed with cancer than the meat eaters – even after accounting for other risk factors including smoking, alcohol intake and obesity.
When the researchers compared the risk for specific cancers, the vegetarian diet offered significant protection for some. Compared to meat eaters, vegetarians’ risk of stomach cancer was reduced by 64 per cent, bladder cancer by 53 per cent, multiple myeloma (cancer of the bone marrow) by 75 per cent and non-Hodgkin lymphoma by 43 per cent.
This isn’t the first time research has suggested a meatless diet as an effective measure for fighting a myriad of diseases and health conditions. Previous studies have linked vegetarian diets with lower blood cholesterol and blood pressure, lower body weights and a reduced risk of cancer.
The current study comes days after the American Dietetic Association published an evidence-based review showing a vegetarian diet is associated with numerous health advantages, including a lower risk of dying from heart disease. In the report, the association concluded that well-planned vegetarian diets – including the totally vegetarian vegan diet –are healthful not only for adults, but also for infants, children, teenagers, athletes and pregnant women.
There are several ways in which a meat-based diet might contribute to cancer. Compounds in cooked meat called heterocyclic amines (HCAs) have been shown to promote tumours in animals. Preliminary research also suggests HCAs can trigger the growth of precancerous colon polyps in humans.
Processed meats including ham, bacon, corned beef, bologna and wieners also contain sodium nitrite, a preservative added to prevent botulism food poisoning and to give cured meats their characteristic red colour. During cooking, nitrites are transformed into N-nitroso compounds, several of which have been associated with certain cancers in humans and animals.
While giving up red meat may improve the health outcomes of vegetarians, it’s not the whole story. A steady diet of whole grains, nuts, vegetables, fruit, beans and soy foods is also low in fat and offers plenty of protective plant chemicals, antioxidants and fibre.
Vegetarian diets range from those that avoid all animal foods to others that include a few. Vegans shun all animal products. Semi-vegetarians avoid only red meat. Pesco-vegetarians eat fish, dairy products and eggs but avoid meat and poultry. Lacto-vegetarians eat dairy products, but avoid meat, poultry, fish and eggs. Lacto-ovo-vegetarians include dairy and eggs, but no meat, poultry or fish.
If you’re a vegetarian, or would-be vegetarian, planning and variety can ensure a meatless diet is balanced and nutritionally adequate.
Vegetarians get protein from five main food groups: dairy and eggs, beans and lentils, soy and soy products, nuts and seeds, and grains and cereals. Aim to include a source of protein at every meal.
Include a variety of protein foods in your diet to meet daily requirements for essential amino acids, the building blocks of protein that your body can’t make on its own.
(While animal foods contain large amounts of all essential amino acids, plant proteins are low in or missing some. Eating a variety of grains, nuts, seeds and legumes throughout the day will make up for this deficit.)
Lacto- and lacto-ovo vegetarians can meet their daily calcium requirements by including three to four servings of milk, yogurt or cheese in their diet. Vegetarian calcium sources include fortified soy beverages, fortified fruit juice, almonds, soybeans, tofu prepared with calcium, bok choy, broccoli, kale and figs.
If you’re concerned you’re not meeting your daily calcium requirements, take a supplement. (Teenagers require 1,300 milligrams of calcium per day, adults aged 19 to 50 need 1,000 milligrams and older adults 1,500 milligrams.)
Vegetarian diets often lack vitamin D because milk, oily fish and fortified soy beverages are the main food sources. Based on the fact that few foods contain vitamin D – and our skin produces little from sunshine in the fall and win-ter months – the Canadian Cancer Society advises taking a 1,000 IU vitamin D supplement in the fall and winter, and all year round if you are over 50, have dark-coloured skin, or do not expose your skin to sunshine in the summer months.
Vegetarians require almost twice as much iron as meat-eaters because the body absorbs iron from plant foods less efficiently. Good sources of iron include beans, lentils, nuts, leafy green vegetables, whole grains, breakfast cereals and dried fruit.
Iron absorption can be increased by eating vitamin-C-rich foods such as citrus fruit, strawberries, red peppers and tomato juice.
It’s only found in animal and fortified foods, so vegetarians should include three servings of B12-rich foods n their daily diet: milk, yogurt, eggs, fortified soy beverage, nutritional yeast, fortified breakfast cereal or fortified soy “meat.” Vegans should choose fortified foods and take a B12 supplement.
Vegetarians who don’t eat fish need a daily helping of alpha-linolenic acid, the omega-3 fatty acid plentiful in walnuts, ground flax, chia, and flaxseed and canola oils. Supplements of flax oil or docosahexaenoic acid, an omega-3 fat derived from algae instead of fish, are other sources.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV’s Canada AM every Wednesday. Her website is lesliebeck.com.