SCIENTIFIC UPDATE
By Reed Mangels, PhD, RD
Hip Fracture-Part 1
When an older person fractures a hip, it’s serious. According to the Centers for Disease Control and Prevention, one in three adults who lived independently before their hip fracture remains in a nursing home for at least a year after their injury. About one in five adults will die within a year of fracturing a hip. Researchers want to know if dietary factors could reduce the likelihood of hip fractures in older people.
Recent results from the Adventist Health Study-2 suggest that somewhat higher protein intakes may reduce the risk of hip fracture. This makes sense because protein plays a key role in bone strength and strong bones are less likely to fracture, even in a hard fall. This study involved more than 30,000 men and women. About 50% were categorized as “vegetarian” (meat or fish less than 4 times per month). Roughly 20% of the “vegetarian” group was categorized as “vegan” (eating any animal products less than once a month). The risk of hip fracture was more than 50% lower in vegetarians who ate legumes at least once a day as compared to vegetarians who ate legumes less than once a week. Vegetarians who ate meat analogues at least once a day had about a 60% lower risk of hip fracture than did vegetarians who ate meat analogues less than once a week. Dairy products, nuts, soymilk, and tofu did not affect the risk of hip fracture. Among nonvegetarians, subjects eating higher amounts of meat or legumes had the lowest risk of hip fracture. These results suggest that higher-protein foods reduce the risk of hip fracture.
Lousuebsakul-Matthews V, Thorpe DL, Knutsen R, Beeson WL, Fraser GE, Knutsen SF. 2013 Oct 8. Legumes and meat analogues consumption are associated with hip fracture risk independently of meat intake among Caucasian men and women: the Adventist Health Study-2. Public Health Nutr.1-11. [Epub ahead of print]
Hip Fracture-Part 2
Bones are made up of calcium. Stronger bones have a higher calcium content. This calcium comes from food (and supplements, if used). Most bone formation occurs during the teen years. With these facts in mind, the results of a new study are surprising. Researchers at Harvard asked almost 100,000 white men and women, age 50 or older, how much cow’s milk they drank as teens. Other studies have shown that people are reasonably good at remembering how much milk they drank as teens, even if they don’t know how many apples they ate 2 years ago. The researchers studied their subjects for more than 20 years to see who would fracture a hip. The researchers theorized that subjects who drank the most milk as teenagers would have the highest calcium intakes, strongest bones, and be least likely to have fractures as they aged. That’s not what happened. In men, those who drank the least amount of milk as teens had the lowest risk of hip fracture, and those who drank the most milk had the highest risk of fracturing a hip. Women’s risk of hip fracture was not affected by their cow’s milk consumption – both women who drank a lot of milk as teenagers and those who drank milk rarely had about the same risk of breaking a hip as they got older. Of course, adequate calcium, protein, vitamin D and other nutrients are needed for strong bones. The results of this study should not be used to say that getting enough of these nutrients is not important.
Feskanich D, Bischoff-Ferrari HA, Frazier AL, Willett WC. 2013 Nov 18. Milk consumption during teenage years and risk of hip fractures in older adults. JAMA Pediatr. doi: 10.1001/ jamapediatrics.2013.3821. [Epub ahead of print]
Choices at Midlife Affect Health in Aging
A recent study examined the health impact of dietary choices made by women in their 50s and early 60s. More than 10,000 women were studied. They provided dietary records and were followed for about 15 years. Now in their 70s and early 80s, they were categorized as healthy agers or usual agers. Approximately 10% were categorized as healthy agers because they did not have physical or mental disabilities, any sort of dementia, or chronic diseases. The remaining 90% were called usual agers, and had one or more disabilities or diseases. Healthy agers were more likely to have had good diets in midlife – diets high in fruits, vegetables, whole grains, nuts, and dried beans, and low in red or processed meat. While the healthy agers were not vegetarian, their diets were more plant-based. The researchers concluded, “Better diet quality at midlife seems to be strongly linked to greater health and well-being in persons surviving to older ages.” We can only wonder what the results would have been had the women been following vegetarian diets.
Tonstad S, Nathan E, Oda K, Fraser G. Vegan diets and hypothyroidism. 2013 Nov 20. Nutrients. 5(11):4642-52.
Thyroid Disease in Vegetarians Compared to Nonvegetarians
Some researchers have speculated that vegetarians may have a higher risk of developing thyroid disease because some studies show that vegetarians have lower iodine intakes. As a part of the Adventist Health Study-2, participants were asked if they had hypothyroidism that had been diagnosed by a physician. Hypothyroidism is when the thyroid gland is not active enough. Those categorized as “vegan” (eating any animal product less than once a month) had the lowest risk of having hypothyroidism, although this was not statistically significant. The “lacto-ovo vegetarian” (ate fish or meat less than once a month) group had a slightly higher risk of having hypothyroidism, although this also was not statistically significant. The authors theorized that a diet free of animal products may be protective of thyroid gland function. Additional research is needed in this area.
Tonstad S, Nathan E, Oda K, Fraser G. Vegan diets and hypothyroidism. 2013 Nov 20. Nutrients. 5(11):4642-52.
Nutrient Intakes in Adventist Vegetarians & Nonvegetarians
Adventist Health Study-2 continues to provide insights into vegetarian health. This large observational study includes more than 70,000 adult participants whose diets range from vegan to nonvegetarian. A recent article from this study examined nutrient intakes of different dietary groups. “Nonvegetarians” (eating meat or fish at least weekly) had the highest intake of saturated fat and the lowest intake of fiber. One-third of non-vegetarians were categorized as obese. In contrast, less than 10% of “strict vegetarians” were considered obese. “Strict vegetarians” (consumed any animal product less than once a month) had the lowest intake of saturated fat and the highest intake of fiber. Average intakes of nutrients that are often low in vegan diets, such as vitamin D, calcium, iron, and zinc, were above minimum requirements in strict vegetarians in this study. This was partly due to use of supplements and fortified foods. This adequacy was true for average intakes; some strict vegetarians had very low intakes of some of these nutrients.
Rizzo NS, Jaceldo-Siegl K, Sabate J, Fraser GE. 2013. Nutrient profiles of vegetarian and nonvegetarian dietary patterns. J Acad Nutr Diet. 113(12):1610-9.
Benefits of Vegetarian Meals in Preschools
The recently-implemented Healthy, Hungry-Free Kids Act includes changes to preschool menus so that more fruits, vegetables, and whole grains are served to children. A recent study compared vegetarian and nonvegetarian meals that were served at a large preschool in South Carolina. Meals that were served before and after the Healthy, Hungry-Free Kids Act was in place were also compared. On average, vegetarian meals were served about three times a month and were usually based on cooked dried beans. Vegetarian meals were significantly higher in fiber and lower in sodium than nonvegetarian meals. In addition, vegetarian menus had half the cholesterol of nonvegetarian menus. Both vegetarian and nonvegetarian menus met the requirements for iron, zinc, and vitamin B12. A survey of parents found support for adding more meatless items to the menu, including veggie pizza, bean burritos, pinto beans and rice, and spaghetti with tomato sauce and lentils. The changes have the potential to improve the children’s intakes of fiber, sodium, fat, and saturated fat, and could be less costly than meat- based items.
Turner-McGrievy GM, Hales SB, Baum AC. 2013 Oct 19. Transitioning to new child-care nutrition policies: nutrient content of preschool menus differs by presence of vegetarian main entrée. J Acad Nutr pii: S2212-2672(13)01250-1. doi: 10.1016/j. jand.2013.07.036. [Epub ahead of print]
