Recent research
has demonstrated the importance of protective antioxidant nutrients
in the diet found in fresh fruit and vegetables. These antioxidant
nutrients include the beta-carotene form of vitamin A, vitamin
C and E. Many researchers now believe that these nutrients play
a major role in reducing the risk of chronic diseases such as
heart disease and cancer. A high consumption of fresh fruit
and vegetables is a benefit of vegetarian diets.
All these factors contribute to the proven health of vegetarians
although it is difficult to account for the exact contribution
of each nutrient. All vegetarian diets are not necessarily healthy,
for example if too high a proportion of high fat dairy products
are consumed.
Part
2
Heart Disease
Cardiovascular
disease is the major cause of mortality in Britain, being responsible
for around 50% of all deaths. The majority of these deaths are
from coronary heart disease. Vegetarians suffer markedly lower
mortality from coronary heart disease compared to non-vegetarians
(Key et al (1999). This reduced risk may be related to the lower
blood cholesterol levels of vegetarians. Findings from the Oxford
Vegetarian Study, a 12 year study of 6000 vegetarians and 5000
meat-eater found that the incidence of coronary heart disease
mortality was 28% lower in vegetarians compared with matched
omnivores, after all non dietary factors had been taken into
consideration (Thorogood, 1994).
Burr & Butland (1988) found vegetarians to suffer
significantly lower mortality from heart disease than health
conscious non-vegetarians. Mortality from ischaemic heart disease
was 57% lower in vegetarians than the general population, and
18% lower than in non-vegetarians following a healthy lifestyle.
Deaths due to cerebrovascular disease was 43% lower in the vegetarians
compared with the general population.
A study of nearly 28,000 Seventh Day Adventists in California
noted a clear trend of increasing incidence of heart disease
with rising frequency of meat consumption (Snowdon, 1988).
The Coronary Artery Risk Development in Young Adults
(CARDIA) Study examined diet in relation to health in over 5,000
young adults aged 18 to 30. Vegetarians were found to have greatly
improved cardiovascular fitness and a lower risk of heart disease
(Slattery, 1991). A low level of meat consumption was linked
to improved general health.
An
eleven-year study of 1,900 German vegetarians has found mortality
from cardiovascular disease to be 61% lower in male vegetarians
and 44% lower in female vegetarians than the general population.
For ischaemic heart disease, mortality was reduced still further,
to only one-third of that expected (Claude-Chang, 1992). The
protective effect of a vegetarian diet is believed to be related
to the lower blood cholesterol levels seen in vegetarians. Repeated
studies have demonstrated the low blood cholesterol levels of
vegetarians (Resnicow, 1991). Thorogood (1990) found vegetarians
to have cholesterol levels 10% lower than health conscious meat-eaters.
High blood cholesterol is a primary risk factor in heart disease.
Significantly, vegetarians have lower levels of low-density-lipoprotein
(LDL) cholesterol. This is the cholesterol fraction particularly
associated with heart disease.