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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.]

Vegetarian Diets and Pregnancy

Inadequate vitamin B12 during pregnancy is associated with birth defects including neural tube defects and it is known that vegetarians are at risk for developing a B12 deficiency because they do not consume animal products, which are the principle source of this nutrient.  Scientists in Germany compared 70 pregnant women who had been vegetarian or near-vegetarian for at least three years (including 27 lacto-ovo vegetarians and 43 “low meat eaters”) to a control group of 39 pregnant women eating an average Western diet. By testing the women’s blood three times during pregnancy, they concluded that serum B-12 levels of the lacto-ovo vegetarians were lowest, the low meat eaters in the middle and the control group highest. The authors urge that recommended dietary intake levels of B-12 for pregnant women be re-evaluated.
The Journal of Nutrition. December 2004; 134(12):3319-3326. [Koebnick et al.]

Nutrition for Vegetarian Athletes

Scientists at the University of British Columbia  reviewed possible mechanisms by which vegetarian dietary practices could theoretically influence athletic performance.  After considering many different factors, including protein levels, carbohydrates, iron, vitamin B-12, and creatine levels, the researchers concluded that “well-planned, appropriately supplemented vegetarian diets appear to effectively support athletic performance.” 
Nutrition.  July-August 2004; 20:696-703.  [Barr and Rideout]

Nutrition Transition in Mexico and Other Latino Countries

 

In the past, the most common nutritional problem in Latin American countries was undernutrition.  However, these countries have recently undergone a nutritional transition characterized by an increase in energy-dense diets and increase in the prevalence of noncommunicable chronic diseases (NCCD) such as obesity, type 2 diabetes, and high blood pressure.  Researchers reviewed the available literature to determine the characteristics of the nutrition transition with emphasis in data from Mexico, Brazil, and Chile.  They found that some countries in Latin America like Brazil, Mexico and Chile are suffering from increased prevalence of overweight, obesity and NCCD related to dietary changes such as increased consumption of higher energy-dense processed foods and decreased consumption of fruits and vegetables.  
International Life Sciences Institute, July 2004; 62(7)S149-S157 (Rivera J et al.)

Diets of Latin-American and African-American Women

University of Hawaii researchers surveyed 271 African-American women and 234 Latin-American women, and assessed their diets. They found that the African-American women consumed more calories and more fat, while the Latino women consumed more carbohydrates and more fiber. While the Latino women weighed less, they were perceived themselves as heavier and reported “greater body image dissatisfaction.”
Obesity Research. April 2004; 12(4):652-60 (Sánchez-Johnsen et al.)

More Acculturation, Fewer Fruits and Vegetables

Acculturation is the extent to which mainstream customs, beliefs, and practices are adopted by immigrants.  Researchers in Washington State recruited 1,689 adult Hispanic and non-Hispanic participants to investigate whether acculturation is a predictor of fruit, vegetable, and fat intake among Hispanics.  Using the National 5-A Day for Better Health program dietary assessment instruments, researchers determined that highly acculturated Hispanics in Washington State consume significantly fewer fruits and vegetables than less acculturated Hispanics. 
Journal of the American Dietetics Association, January 2004; 104:51-57 (Neuhouser M et al.) 

Type 2 Diabetes and the Vegetarian Diet

While there are currently few data specifically connecting vegetarian diets and diabetes prevention or treatment, it is known that many of the specific foods that make up a vegetarian diet have advantages in the treatment of type 2 diabetes.  These foods include whole grains, legumes, nuts, seeds, soy proteins, and plant sterols.  This summary article from researchers at the University of Toronto details the benefits of different plant foods, and concludes that evidence documented in both cohort studies and intervention studies show that vegetarian diets “can help reduce the risk of developing type 2 diabetes and cardiovascular disease—a major complication of type 2 diabetes.”
American Journal of Clinical Nutrition. September 2003; 78(suppl):610S–6S. [Jenkins D et al.]

Colon Cancer Increases as Mexican Diet Fades

Researchers in Los Angeles examined whether the changing incidence of colorectal cancer in their city’s Mexican-American population was due to changes in dietary practices in this group.  Cancer incidence and dietary intake data were obtained for over 35,000 Latinos of Mexican national origin – the largest sample of Mexican-origin Latinos of any such study in the US.  The incidence of colorectal cancer saw the greatest increase between the first and second generations.  Nearly all dietary changes due to acculturation also occurred between the first and second generations.  These findings suggest an association between colorectal cancer risk and certain dietary components. Higher intakes of alcohol and refined carbohydrates were major risk factors, and lower consumption of vegetables was a protective factor.
Nutrition and Cancer 2003, Volume 45, Issue 2 (Monroe et al.)

Acculturation and Obesity in Hispanic Adolescents

Between first and second generation US immigrants, a striking increase in overweight and obesity occurs.  A study using data from the National Longitudinal Study of Adolescent Health set out to determine the underlying factors that cause this phenomenon.  More than 8,600 adolescents of varying ethnicity were assessed for overweight and several factors including diet.  Researchers concluded that immigrant adolescents are likely to be influenced by the “obesigenic” environment of the US, including sedentary lifestyles, large portion sizes, heavy advertising of high-fat, energy-dense foods, and mass media.  Lifestyle differences between foreign- and US-born Hispanic adolescent immigrants are likely to underlie the striking increase in overweight between first and subsequent generations of US residence.
Social Science & Medicine, April 2003; 57:2023–2034 (Gordon-Larsena P et al.)

Dietary Trends in Latin-American Populations

In an effort to track the rise in chronic disease among people who move away from their traditional diets, scientists at Tufts University synthesized data about diets and health from many sources. They found a close association between dietary change (starting with the rich) and the health impacts of a more processed, energy-dense diet.
Cadernos de Saúde Pública. 2003; 19 suppl 1:S87-99. (Bermudez et al.)

Vegans have lower prevalence of hypertension

Researchers from Oxford University studied a large cohort of British men and women in the context of diet, lifestyle, and disease risk. They found that hypertension (both systolic and diastolic) is significantly less prevalent among vegan men and women (5.8% and 7.7%, respectively) as compared to omnivorous men and women (15.0% and 12.1%, respectively). The researchers suspect that this is related to the vegan participants’ lower average Body Mass Index.
Public Health Nutrition. 2002 Oct 1;5(5):DOI 10.1079/PHN2002332. (Appleby et al.)

Increasing Vegetable Intake May Decrease Risk of Breast Cancer

Researchers from the London School of Hygiene and Tropical Medicine compared the diets of 240 South Asian women who had breast cancer with age-matched South Asian women who did not. They found that there was a slight reduction in the risk of breast cancer among women who identified as lifelong vegetarians compared with those who identified as lifelong meat-eaters. The researchers believe that reduction in the risk of breast cancer among lifelong vegetarians is most likely related to increased consumption of vegetables and pulses (legumes).
International Journal of Cancer. 2002 May 10. 99, 238-244. (dos Santos Silva et al.)

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