Vegan for Life - Jack Norris [68]
The reasons why vegan diets could help lower blood pressure aren’t completely understood. Lower body weight and sodium intake account for some but not all of the difference. Diets high in fruits and vegetables are associated with lower blood pressures, and that may be part of the explanation for the protective effects of plant-based diets. Most experts believe that it is a combination of multiple factors that explains the protective effects of plant-based diets.
BODY WEIGHT
Scientists assess body weight by looking at the body mass index (BMI), which is a measure of weight based on height. It’s not a perfect assessment, however, because it doesn’t account for muscle mass (which weighs more than fat), but it is a helpful tool for comparing populations.
A BMI of 20 to 25 is considered healthy. Above 25 is overweight and over 30 is considered obese. The two tables below display findings from Seventh-day Adventists and British vegetarians. You can see that in both groups, vegans have lower BMIs than people following either lacto-ovo or semi-vegetarian diets.
BODY MASS INDEXES OF SEVENTH-DAY ADVENTISTS6
BODY MASS INDEXES OF BRITISH VEGETARIANS (FROM THE EPIC-OXFORD STUDY)7
OTHER CHRONIC DISEASE CONDITIONS
The preliminary data from the newest study of Adventists shows that vegans were less than half as likely to have diabetes when compared with meat-eaters. While being overweight raises the risk for diabetes, the lower BMI of vegans in this study was determined not to be the only reason for their lower diabetes risk.
Research suggests that vegetarians are less likely to form either renal stones or gallstones, and as we would expect from their higher fiber intake, vegetarians are only about half as likely as omnivores to develop intestinal problems like diverticular disease. Among Seventh-day Adventists, vegetarians are also less likely to develop dementia. So far, we don’t have any information about the effects of a vegan diet on these conditions.
VEGETARIAN DIETS AND CANCER
The relationship of diet to cancer has proven to be extremely difficult to study. It’s a complex disease and there aren’t many markers for cancer risk. That is, we can measure the effects of diet on blood-cholesterol levels and make predictions about how that will affect heart disease risk. But we don’t have many blood parameters related to cancer risk that are as straightforward.
There is evidence that how people eat in childhood is linked to their risk later on for developing cancer, which means that it is hard to uncover the links between diet and cancer risk without studying lifelong eating habits And because cancer is such a complex disease, it’s possible that the disease process is affected by interactions among different food components and by food components that aren’t well-understood. As a result, we have a very poor grasp of what type of diet protects against cancer. A few studies have found that vegetarians have lower cancer rates compared to omnivores, but most haven’t shown any difference between the two groups.
The environment of the colon in vegetarians—including the levels of different bacteria and enzymes—differs from meat-eaters in ways that appear to be protective against colon cancer. This is due in part to a higher intake of fiber, which is linked to a lower risk for cancer. Vegetarians and vegans also eat more fruits and vegetables and have a higher intake of antioxidants than omnivores. But while it’s generally believed that this lowers cancer risk, the evidence has weakened over the past few years as some recent studies haven’t supported a link between fruit and vegetable intake and cancer. Soyfoods are linked to reduced risk for both breast and prostate cancer although this, too, is an area that needs more study.
In contrast to the possible protective effects of plant foods, certain animal foods may raise cancer risk. Red and processed meats are linked to a higher risk for colon, stomach, and possibly bladder cancer. Some researchers believe that eliminating meat from the diet is more beneficial for