Drs David Ryde and Tony Wardle

There are three separate factors which contribute to causing cancer - heredity, environmental pollution and diet. It's difficult to put percentages on them but diet ranks extremely highly and accounts for possibly 30-50 per cent of all cancers. One thing is certain, cancer is very much a Western disease. One half of all cancers in the world afflict just one-fifth of the population - the fifth that lives in the industrialised countries (41). And the rate is increasing.

One set of figures which illustrates this is for colon cancer. Americans are four times more likely to develop it than Japanese. But when researchers looked at Japanese who had moved to the US they found that their risk of colon cancer shot up to near that of Americans. The main difference between the two groups was identified as diet - a traditional Japanese diet being low in animal products while a typical US diet is extremely high in them. Japanese Americans tended to adopt the US style of eating once they moved to that country (42).

One scientific method of looking at diseases such as cancer is to establish how different foods affect them, both good and bad - those foods that may cause the disease (positive) and those that may prevent it (negative). They're called correlation studies.

One of these studies looked at 37 countries and established a strong positive link between meat and meat protein and intestinal cancer while vegetable protein was negative - it provided protection (43). Another correlation study carried out in Israel followed the growth of the population from 1.17 million to 3.5 million. Over this period, meat consumption increased dramatically by more than 400 per cent and cancers doubled (44).

Two other studies, one of breast cancer and one of cancer of the uterus, found similar links between animal protein and fat and cancers. When complex carbohydrates - starchy vegetable foods - were considered, the result was negative (protective) (45, 46). In 1981, a massive study looked at cancer in 41 different countries and found that diets based on beans, maize and, to some degree, rice are good at preventing breast and colon cancer while meat promotes both (47).

In 1990, the diets of 88,000 women were examined and it became clear that those who eat beef, pork or lamb as a main dish every day are two-and-a-half times more likely to develop colon cancer than those who eat meat only once a month (48). In 1994 came the Oxford Study (mentioned earlier) and its conclusion that vegetarians have a 40 per cent less chance of dying from cancer than do meat eaters. There are many other studies that show vegetarians are less at risk (49, 50) by between 25 and 50 per cent. The ADA and BMA have both found that vegetarians are less likely to develop cancer.

Interestingly, other studies have found that eating increased amounts of fruit and vegetables contributes to vegetarians' better chances but doesn't fully account for it. In other words, there appears to be something in meat which actually causes cancer (51, 52).

The WHO has produced a list of dietary pluses and minuses which affect cancer. Fat, it says, plays a part in breast, colon, prostate and rectum cancer while fruit and vegetables offer protection from lung, colon, bladder, rectum, oral cavity, stomach, cervix and oesophagus cancers. On breast cancer it says there is a direct association between the numbers who die and the intake of high quantities of calories and dietary fats such as milk and beef.

In a test carried out in the US, researchers investigated the cancer forming compounds (carcinogens) produced in cooking. All foods when heated to cooking temperatures produce these agents but some produce more than others. Researchers compared soya-based burgers, beef burgers and bacon, which were all cooked until well done. The beef burger produced 44 times more carcinogens than the soya burger and the bacon produced 346 times more (53).

Diabetes

Diabetes mellitus is a condition in which the mechanism that turns sugar into energy no longer functions properly. The outcome is that the body can't control the amount of sugar in the blood. In virtually every developing country in the world, diseases associated with affluence are becoming the new health problem. As processed and fat-rich animal foods are increasingly seen as desirable foods so the diseases develop. And they follow a pattern according to the WHO. One of the first to show itself is diabetes, followed several decades later by heart disease and gall stones, then cancer and finally chronic disorders of the gastrointestinal tract.

A major risk factor is obesity and about 80 per cent of non-insulin dependent diabetics are obese. People who are moderately overweight are twice as likely to develop the disease as people of normal weight (WHO).

In a little over a generation, diabetes mellitus has increased six-fold and there are factors at work other than obesity - including heredity. However, heredity wouldn't account for the fact that almost all Sumo wrestlers are diabetics - but their weight and extraordinarily high-fat diet might.

Diabetics can benefit from a high-fibre, vegetarian diet and people who are already eating this kind diet have a 45 per cent reduced chance of developing the disease. Heavy meat eaters on the other hand - those who eat meat six or more times a week - are nearly four times as likely to develop diabetes (54). The ADA states that diabetes is much less likely to be a cause of death in vegetarians than it is in meat eaters and puts it down to vegetarians' higher intake of complex carbohydrates (starchy foods) and the fact that they tend to be lighter. Again, the science is consistent, that diabetes is up to 90 per cent higher in meat-eating men and 40 per cent higher in women. Even allowing for the fact that vegetarians tend to be lighter than meat eaters, they still face less risk (55, 56, 57).

Diabetes usually begins in middle age and strongly increases the risk of developing coronary heart disease, kidney failure, eye and neurological (nerve) damage (WHO). More good news for vegetarians is that a plant-based diets often eliminates or reduces a diabetic's need to take medication and reduces the chance of developing both nerve and eye (retina) damage (58, 59, 60, 61 62).

In 1999, the British Diabetic Association issued a staggering warning - the number of cases of diabetes in the UK will double by 2010 to a staggering 1.5 million - another clear reason to adopt a vegetarian diet.

Contents

Introduction
The Offical Position
Coronary Heart Disease
Cholesterol
Clogged Arteries
High Blood Pressure
Strokes
Cancer
Diabetes
Gallstones
Obesity
Osteoporosis
Iron Deficiency Anaemia
Protein Deficiency
Vitamin B12 Deficiency
Zinc Deficiency
Eating Disorders
Rickets
Saturated Fats
Free Radicals
Antioxidants
Folate
Fibre
Dairy
Mothers & Babies
Children
Conclusions
References