SCIENTIFIC UPDATES

People differ in how they metabolize soy products. Between 20 and 35 percent of Western adults are able to produce a substance called equol when they consume soyfoods. Bacteria in the intestines produce equol. Equol production is higher in those living in Asian countries, where 50 to 55 percent of adults are equol producers. There may be health advantages to producing equol, although research in this area is preliminary. Equol may play a role in preventing some cancers and may function as an antioxidant.

Do vegetarians have an edge when it comes to equol production? Apparently, they do. A group of 41 adults, 29 of whom said they were vegetarian, was given a soymilk drink twice daily for three days. Equol production was measured. Vegetarians were more than four times as likely to produce equol compared to non-vegetarians. Close to 60 percent of vegetarians produced equol. Diets of study participants were not assessed, so we cannot know if dietary differences in carbohydrate, protein, or fat were associated with the results. Although the vegetarians were more likely to have used soy products before this study, other studies have found no link between long-term soy food use and the ability to produce equol.

Type 2 diabetes, formerly called adult-onset diabetes, is the most common form of diabetes, affecting at least 8 percent of adults. Researchers at George Washington University recently investigated the use of a lowfat vegan diet as a way of treating adults with type 2 diabetes. Subjects were randomly assigned to one of two groups. One group, with 50 participants, was instructed about a standard diet for diabetics, the kind most doctors and dietitians recommend. This diet was low in saturated fat and promoted weight loss by reducing calories. The other group, with 49 participants, was instructed on a lowfat (10 percent calories) vegan diet. The vegan diet did not limit portion sizes or calories. Both groups reduced their intake of calories, fat, saturated fat, and cholesterol, but greater reductions in saturated fat and cholesterol were seen in those following the vegan diet. Participants on the vegan diet increased their carbohydrate intake. Both groups lost weight and had lower blood total and LDL cholesterol levels. Those following a vegan diet had a greater reduction in blood total and LDL cholesterol levels, possibly because of the lower saturated fat in their diet.

During the study period, 43 percent of vegan diet participants and 26 percent of the other participants reduced the amount of diabetes medication they used. This adjustment was done under a doctor's supervision. This study suggests that a lowfat vegan diet can be used to treat type 2 diabetes. However, people with diabetes should not attempt dietary or medication changes without medical supervision.

One of the consequences of poor oral hygiene is gum disease that can lead to tooth loss. Some people may know that severe gum disease can also increase the risk of heart attacks, stroke, and having a premature baby. What they may not know is that their diet can play a role in reducing risk of gum disease. A recent study of more than 34,000 men found that those who ate the most whole grains (at least 3 servings a day) were 23 percent less likely to develop gum disease compared to men eating less than half a serving of whole grains daily. So keep brushing and flossing and be sure to eat plenty of whole grains, including whole wheat breads, whole grain cereals and pasta, and brown rice.

Dioxins and furans are among the most toxic substances known. They increase risk of cancer and other health problems. A major source of these toxic substances is waste-burning incinerators that release dioxins and furans into the atmosphere. They then accumulate in foods, especially in animal fats and fish. Vegetarians who do not eat animal fats or fish would be expected to have lower blood levels of dioxins and furans. A study of adults in Taiwan who lived near municipal waste incinerators for at least five years compared blood levels of dioxins and furans in 33 vegetarians and 1,675 non-vegetarians. Vegetarians had significantly lower levels of dioxins and furans. Results of this study are similar to other reports that found that fish, seafood, dairy products, pork, poultry, and beef were all significant sources of dioxins and furans.

Non-Hodgkins lymphomas are cancers of the lymph nodes, spleen, and other components of the immune system. The incidence of non-Hodgkins lymphomas has increased over the past 25 years for unknown reasons. This type of cancer accounts for about 4 percent of all new cancer diagnoses and 3 percent of all cancer deaths in the United States. Dietary factors may be related to risk for non-Hodgkins lymphomas. A recent study matched 466 people who had non-Hodgkins lymphomas with 391 control subjects. Both groups were asked about their usual diet. Those who ate the most vegetables (more than 20 servings a week) had a markedly lower risk of non-Hodgkins lymphomas. This was especially true for those eating more green leafy vegetables and more cruciferous vegetables, such as cabbage, broccoli, and kale. The most active and the most lean people were also less likely to develop non-Hodgkins lymphomas. This study adds to already strong evidence for eating generous amounts of vegetables.

Vegetarian Journal readers know that there's much more to bone health than just calcium. An intriguing new study suggests that fruit and vegetable intakes, especially during adolescence, may be important for healthy bones. Researchers examined boys and girls aged 16 to 18 years and living in the United Kingdom. They also studied young women (aged 23 to 37 years) and older adults (aged 60 to 83 years). They asked subjects about their intake of fruits and vegetables and evaluated their bones. In adolescents, stronger and larger bones were found in those eating the largest amounts of fruits and vegetables. The amount of fruit eaten seemed to be more important for bone health than the amount of vegetables consumed. Similar results were seen in older women. There was little effect of fruit or vegetable consumption on bone health in young women or older men. Calcium intake did not determine bone health in any of the groups studied. The effects of fruits and vegetables on bone health may be due to the alkaline nature of these foods or to their vitamin C, beta-carotene, or vitamin K content. In the United States, costs associated with osteoporosis are close to 18 billion dollars each year. Simple measures like encouraging people, especially teens, to eat more fruits and vegetables may be important in reducing both the financial and human cost of osteoporosis.