Less Heart Risks from Vegetarianism?
The results come from a small study that looked at how different dietary patterns related to the prevalence of metabolic syndrome. Metabolic syndrome is a cluster of disorders, including raised blood pressure, cholesterol and blood sugar, which increase the risk of cardiovascular disease and diabetes. The research was conducted in 773 members of the Seventh-day Adventist faith, a Christian denomination that places emphasis on staying healthy and limiting intake of meat. The researchers found that 35% of participants who considered themselves vegetarian were less likely to have metabolic syndrome or its associated risk factors than non-vegetarians.
This relatively small study is of limited value due to both its size and the fact that it assessed a very specific group of people who may not be representative of the population as a whole. Also, it only looked at people at one point in time, meaning that their past behaviors may have influenced the prevalence of metabolic syndrome.
It has long been recognized that there may be health benefits from following a diet low in saturated fats and high in vegetables, fruit and unsaturated fats such as nut and seed oils. These health benefits include a reduction in the risk of obesity, high blood pressure and diabetes. This study does not change current healthy eating advice.
The study was performed by researchers from the Karolinska Institute in Sweden, Loma Linda University and the School of Public Health, Loma Linda, California. Funding was provided by the U.S. National Institutes of Health. The study was published in the peer-reviewed medical journal Diabetes Care.
This was a cross-sectional survey of participants taking part in The Adventist Health Study 2, an ongoing research project studying followers of the Seventh-day Adventist religious denomination. People who follow this Christian belief system have been studied in dietary research because many adhere to special dietary habits, for example not consuming meat. Their religion also places emphasis on looking after health, particularly through avoiding habits such as smoking and drinking. Their tendency to avoid certain unhealthy lifestyle choices means that researchers can potentially discount the influence of these behaviours when performing analyses.
In this study researchers surveyed the dietary patterns of 773 participants (average age 60 years) and assessed how their diets related to their risk of metabolic syndrome or their risk of having its individual composite risk factors (for example, cholesterol, blood pressure and high BMI). Metabolic syndrome is a cluster of disorders associated with an increased risk of diabetes and cardiovascular disease.
Metabolic syndrome was defined according to established cut-off levels for glucose (fasting glucose above 100mg/dL), and they considered people to have high blood pressure or diabetes if they were taking medications appropriate to these conditions.
The average age of participants was 60 years. Some 35% were vegetarians, 16% semi-vegetarian and 49% non-vegetarian. Body mass index (BMI) was lower among the vegetarians (25.7kg/m2) than in the semi- (27.6kg/m2) and non-vegetarians (29.9kg/m2). A BMI of 18.5 to 25 is considered to be ideal weight, and a BMI of over 25 is considered to be overweight.
Risk factors for metabolic syndrome included high levels of cholesterol or glucose, high blood pressure, a large waist circumference or a high BMI. Vegetarians were less likely to have metabolic risk factors (12% of the group had three or more risk factors), compared with semi- and non-vegetarians (in both of these groups 19% had three or more risk factors). After adjusting for other lifestyle risk factors, age and sex, the researchers found that levels of blood cholesterol, blood glucose, blood pressure, waist circumference and BMI were all significantly lower among vegetarians compared with non-vegetarians. There was also a significantly higher prevalence of metabolic syndrome among non-vegetarians than among vegetarians (39.7% vs. 25.2%). Relative to non-vegetarians, vegetarians had a 56% reduced odds of having metabolic syndrome (odds ratio OR 0.44, 95% confidence interval 0.30 to 0.64, p<0.001).
From the April 28, 2011, Prepared Foods' Daily News.