Search Health Studies

Search Results

Vegetarian Diets and Childhood Obesity

Scientists at Loma Linda University conducted a meta-analysis to explore the health effects of vegetarian diets and the potential biological reasons for the protective effects of plant foods as a potential approach for preventing childhood overweight and obesity.  The review of the literature found that vegetarian children tend to have lower BMIs than non-vegetarian children. The authors advocate for food policies that support vegetarian diets and that “reduce the cultural and economic forces that make it difficult to promote plant-based dietary patterns.”
American Journal of Clinical Nutrition. May 2010; 91(suppl):1525S–9S. [Sabate J and Wien M]

Vegetarian Diet to Reduce Heart Disease

Heart disease is the primary cause of death in the United States.  The risk factors for heart disease include high BP, elevated cholesterol, diabetes, tobacco use, lack of exercise, and obesity.  Through a review of the literature, scientists at the University of Tennessee evaluated possible links between cardiovascular disease and vegetarian diets.   Research indicates an inverse relationship between fruits, vegetables, and fiber consumption and the risk of heart disease.  Diets low in saturated fat are also associated with decreased risk of heart disease.  Vegetarian diets follow these rules and vegetarians tend to have fewer chronic diseases such as heart disease, obesity, and diabetes. The authors conclude that a well-planned vegetarian diet with adequate supplementation may be effective for primary prevention of heart disease.
Journal of the American Academy of Nurse Practitioners.  March 2010; 22:134-139. ([Stitcher MA et al.]

Vegetarians May Have Lower Bone Mineral Density

Researchers from Pham Ngoc Thach University of Medicine in Ho Chi Minh City, Vietnam compiled data from nine different studies on bone mineral density (BMD) and diet type. While two of the nine showed vegetarians to have significantly lower average BMDs than omnivores, thus putting them at greater risk for osteoporosis, the pooled data showed no significant statistical difference. The results did suggest that vegetarian diets, and especially vegan diets, are associated with a lower BMD; however, the magnitude of the association is clinically insignificant.
American Journal of Clinical Nutrition. 2009 Oct 1;90:943-50. (Ho-Pham et al.)

Vegetarian, Pescatarian Diets Linked with Decreased Cancer

Combining data from the Oxford Vegetarian Study and the EPIC-Oxford cohort, researchers at the University of Oxford found that the incidence of all cancers combined was lowest among the vegetarians and pescatarians. Specifically, vegetarians were at lower risk for stomach and bladder cancer, as well as cancers of the lymphatic and blood tissues. Pescatarians had the lowest risk of ovarian and prostate cancers. However, the authors note the need for further study, as findings from various studies regarding diet type and cancer incidence have been inconsistent.
British Journal of Cancer. 2009 Jul 7;101:192-197. (Key et al.)

Low-Fat Vegan Diet May Be Most Effective in Controlling Type 2 Diabetes

Researchers from the George Washington University conducted a randomized, controlled trial on 99 participants with type 2 diabetes. 49 participants were randomly selected to follow a low-fat vegan diet, while the remaining 50 were to adopt a diet following the 2003 American Diabetes Association guidelines (“conventional diet”). The groups followed their assigned diets for 74 weeks. By the end of the trial, the researchers found that both diets had resulted in weight loss, improved glycemic control as measured by HbA1C, and a reduction in blood triglycerides. Once the results were controlled for medication adjustments, however, the low-fat vegan diet appeared to improve glycemic control and blood triglycerides more than the conventional diet. This study illustrates the physiological benefits of adopting a plant-based diet.
American Journal of Clinical Nutrition. 2009 May 1;89(suppl):1588S-96S. (Barnard et al.)

Prevalence and Risk of Type 2 Diabetes Lowest Among Vegans

Loma Linda University scientists studied the relationship between various diet types (vegans, lacto-ovo vegetarians, pescatarians, and nonvegetarians) and prevalence of type 2 diabetes in a large cohort of Seventh-Day Adventists in North America. They found that vegans had the lowest prevalence (2.9%) of the disease, while nonvegetarians had the highest (7.6%). Additionally, the vegan diet was associated with a nearly one-half reduction in risk of type 2 diabetes compared with the risk associated with nonvegetarian diets.
Diabetes Care. 2009 May 1;32(5):791-796. (Tonstad et al.)

Health Effects of Vegan Diets

A nationwide poll conducted in 2006 determined that 1.4% of the American population is vegan—they eat no meat, fish, dairy, or eggs.  Scientists at Andrews University in Michigan reviewed existing studies about veganism to assess the pros and cons of adopting such a diet.  Overall, vegans tend to have lower BMI, lower serum cholesterol, and lower blood pressure, decreasing their risk of developing cardiovascular disease.  However, because of the elimination of all animal products, vegans are at greater risk of certain nutritional deficiencies such as vitamins B12 and D, calcium, and omega-3 fatty acids.  It is suggested that vegans consume foods that are fortified with these nutrients or that they take appropriate supplements to prevent deficiencies.
American Journal of Clinical Nutrition.  May 2009; 89:1627s-33s [Craig WJ]

Nutrition Concerns for Vegetarian Athletes

Researchers from the University of Rome conducted a review of the recent literature surrounding the nutritional adequacy of vegetarian diets among athletes.  Although it remains unclear whether vegetarian diets are preferable to omnivorous diets for athletic performance, the data show that it is possible for vegetarian athletes to maintain good nutritional profiles. However, vegetarian athletes may have to be more vigilant about ensuring adequate calorie, Iron, Zinc, Vitamin D, and Vitamins B12 (cyanocobalamin) and B2 (riboflavin) intake, through supplementation if necessary. Additionally, creatine supplementation may benefit vegetarian athletes who engage in repeated bouts of short-term high-intensity exercise.
Sport- Und Präventivmedizin. 2009 Jan;39(1):20-24. (Borrione et al.)
 

Vegetarians May Have Increased Risk of Bone Fracture

Researchers at Loma Linda University investigated a cohort of peri- and post-menopausal women over a period of 25 years to compare incidences of wrist fracture with diet type. They found that vegetarians who consumed low amounts of protein suffered the most wrist fractures. However, increasing levels of plant-based protein foods decreased risk by 68% and increasing meat intake decreased risk by 80%. These findings suggest that dietary protein plays a significant role in bone health among middle-aged and elderly females.
Public Health Nutrition. 2008 June 1;11(6):564-572. (Thorpe et al.)

Low Omega-3 Fatty Acid Status in Vegans

Researchers at the University of Vienna compared the ratio of omega-6:omega-3 polyunsaturated fatty acids (PUFAs) in omnivores, vegetarians, vegans, and semi-omnivores to assess essential fatty acid status as it relates to diet. They found that vegans had the highest average ratio of omega-6:omega3 PUFAs. High ratios are believed to be pro-inflammatory and may also contribute to tissue decline and neurological dysfunction. While the authors emphasize the need for further research on this topic, they also urge vegetarians and especially vegans to increase their intakes of omega-3 fatty acids from non-animal sources such as algae.
Annals of Nutrition & Metabolism. 2008 Apr;52:37-47. (Kornsteiner et al.)

Vegetarian Diet Does Not Affect Growth & Development in Children

Data from the European Prospective Investigation into Cancer and Nutrition (the EPIC-Oxford study) shows no difference between age at first menstruation or adult height  (measures of growth and development) between lifelong lacto-ovo vegetarian and non-vegetarian women. While the researchers point out that adult vegetarians generally have a lower average BMI, growth and development does not seem to be affected.
Public Health Nutrition. 2005 Aug 1;8(7), DOI 10.1079/PHN2005730. (Rosell et al.)
 

Blood Pressure and Vegetarian Diets

Lifestyle factors, particularly diet, play a major role in blood pressure regulation.  Randomized, controlled studies indicate that plant-based diets are associated with BP reductions in both normal and hypertensive individuals.  According to this literature review by the Physicians’ Committee for Responsible Medicine, observational studies show that BP levels tend to be lower in individuals following self-selected vegetarian diets.  These findings strongly suggest that individuals with high blood pressure or at risk for developing high blood pressure may benefit from following plant-based vegetarian diets.  
Nutrition Reviews.  January 2005; 63(1):1-8. [Berkow S et al.]

Pages