SCIENTIFIC UPDATES

India, a country where around 40% of the population is vegetarian, has seen a marked increase in the number of people who have diabetes, heart disease, and stroke. We usually think of these diseases as being less common in vegetarians; instead, India has the second highest prevalence of diabetes in the world. Researchers examined possible reasons for the increased prevalence of diabetes and heart disease in Indians. Although there has been some increase in meat intake in Indians over the past 25 years, the increase is small — less than 3 pounds more meat per person per year now compared to 25 years ago. What may be happening is that traditional whole plant foods are being replaced by processed foods, fried foods, and sweets. This, in combination with the higher risk metabolic profile of many Asian Indians, may explain why chronic diseases are more prevalent.

Rice is one example of a dietary staple in India whose consumption has changed. Traditionally, brown rice and, in some regions, grains such as barley, millet, and amaranth, were central components of the diet. Now, brown rice and other grains have been largely replaced by polished white rice. In some parts of India, about half of the day's calories come from nutritionally deficient white rice. Additionally, lentils, fruits, vegetables, nuts, and seeds are being replaced by refined carbohydrates. These dietary changes may, at least partially, explain the elevated risk of chronic disease seen in many Asian Indians.

Additional evidence for diet's effect on disease risk in Asian Indians was seen in a study of Asian Indian Seventh-day Adventists living in the United States and Canada. In this group, changing from a vegetarian to a non-vegetarian diet was associated with weight gain, stroke, diabetes, and heart disease, and with a decreased life expectancy. This may have been due, in part, to both eating more meat and to eating fewer plant foods. Taken together, these results suggest that a diet based on unprocessed plant foods could have a marked effect on the risk of chronic disease in the Asian Indian population.

The Olympics and other international competitive events include athletes from many countries. Researchers surveyed athletes at the 2010 Commonwealth Games, held in Delhi, India, in order to explore the different diets used by athletes and the motivations for those diets. The Commonwealth Games include thousands of athletes from the 71 Commonwealth nations and dependencies. A total of 351 athletes completed questionnaires. Thirteen percent of athletes reported avoiding red meat; 8% were self-defined vegetarians (7% said they were lacto-ovo or lacto vegetarian and 1% reported being vegan).Non-Western athletes, including those from Africa, India, the Caribbean, and Southeast Asia, were more likely to follow a vegetarian diet. Those athletes who participated in events with weight categories were more likely to follow a vegetarian diet than were athletes participating in other sports. Athletes following a vegetarian diet were more likely to avoid additives and wheat than were non-vegetarians. Five percent of participants followed a low/no lactose diet and 3% reported that they followed a dairy-free diet.

Athletes who followed a vegetarian diet may have done so because of religious beliefs. A number of athletes from Africa reported following vegetarian diets, possibly because meat was not a regular part of their traditional diet. Some athletes may have temporarily become vegetarian because the main meat sources at the Commonwealth Games were buffalo and goat, which are unfamiliar foods to many Westerners. The percentage of athletes reporting that they follow vegetarian diets is somewhat higher than The Vegetarian Resource Group's polls (http://www.vrg.org/nutshell/faq.htm#poll). The difference could be due to the international nature of the athletes surveyed and to the potential difference between people who say they follow a "vegetarian diet" and those who say they "never eat meat, fish, and poultry."

One in 10 Americans will have a kidney stone during his or her lifetime. This painful condition may be affected by dietary choices. A study of more than 50,000 people living in the United Kingdom found that vegetarians had almost a 30% lower risk of having kidney stones compared to "high meat-eaters" who were described as eating more than 3 ounces of meat daily. Both red meat and poultry were associated with higher risk of kidney stones. Higher fresh fruit intakes were associated with lower risk. Although being overweight is associated with an increased risk of having a kidney stone, vegetarians were at lower risk even when their typical lower body mass was accounted for.

You can read more about vegetarians and kidney stones at http://www.vrg.org/journal/vj2006issue3/2006_issue3_hotline.php.

Vitamin B12 plays an important role in human development. It is needed to support nervous system formation. Poor vitamin B12 status during pregnancy has been associated with low birth weight and vitamin B12 deficiency in infants. Results of studies of vitamin B12 status in vegetarians and vegans suggest that not all are aware of or are regularly using reliable sources of vitamin B12.

Vitamin B12 supplements are an effective way to improve the vitamin B12 status of pregnant and breast-feeding women and their infants. This was demonstrated with a study of 366 pregnant women in Bangalore, India. Half of the women were given a vitamin B12 supplement providing 50 micrograms per day of vitamin B12 and half were given a placebo. They took the supplement or placebo throughout pregnancy and for six weeks after giving birth. Indicators of vitamin B12 status were checked several times during the study. The researchers did not say whether or not the women were vegetarian. More than 40% of the women had vitamin B12 intakes which were below recommendations at the start of the study. Women who received vitamin B12 and their infants had higher blood levels of vitamin B12 compared to women who did not receive vitamin B12 and their infants. Breast milk vitamin B12 was also higher in women receiving the supplement. These results support the importance of adequate vitamin B12 in pregnancy and lactation and show that supplements can be an effective way to meet vitamin B12 needs. To learn more about vitamin B12, see our website http://www.vrg.org/nutrition/b12.htm.

Vegetarians tend to have lower blood pressure, lower risk of heart disease and diabetes, and less obesity than do nonvegetarians. Most studies of vegetarians, however, have focused on predominantly white subjects. Diabetes and high blood pressure are especially prevalent in black people. Researchers from Loma Linda University investigated the effect of a vegetarian diet on risk factors for heart disease, diabetes, and high blood pressure in black Seventh-day Adventists (75% African American and 25% West Indian) in the US and Canada. Of the approximately 600 study participants, 25% were vegetarian (includes both lacto-ovo vegetarians and vegans), 13% ate fish, and 62% were not vegetarian. Compared to nonvegetarians, the vegetarians had a lower risk of having high blood pressure and had lower average blood pressure. The vegetarians also had a lower risk of diabetes and had lower average blood glucose. Vegetarians also had a lower body mass index (BMI) than nonvegetarians.

These results suggest that a vegetarian diet is associated with significantly lower risk of common chronic diseases in black Americans. The study authors point out that the differences in risk factors which they observed could lead to a reduced risk of heart attack, stroke and kidney failure.