Purdue research shows added calcium benefits women on the pill

Women who take oral contraceptives can counteract bone loss by making sure they have enough calcium in their daily diet, especially early in life, according to Purdue University research.

Earlier research has indicated that optimizing bone mass in adolescence and young adulthood prevents low bone density and osteoporosis later in life. On the other hand, oral contraceptives appear to decrease bone density.

"It's estimated that eight out of 10 women in the United States use oral contraceptives at some time during the years in which peak bone mass is developing," said Dorothy Teegarden, assistant professor in Purdue's Department of Foods and Nutrition. "The results of our study suggest that the loss for this group can be prevented by increasing calcium intake."

According to the National Academy of Sciences, the recommended dietary allowance of calcium for adolescents age 9 to 18 is 1,300 milligrams a day.

The 12-month study, funded by the American Dairy Association/National Dairy Council, was published in the July issue of Journal of Clinical Endocrinology and Metabolism.

The study compared 135 oral contraceptive users to non-users between the ages of 18 and 30. Three groups were randomized to receive one of three diets: control (less than 800 mg calcium a day), medium dairy, (1,000-1,100 mg calcium a day) and high dairy (1,200-1,300 mg calcium a day.)

At the end of the year, women using oral contraceptives and consuming the medium or high dairy diet gained significantly more bone mineral density in their hips and spines compared to the low-dairy group.

"These results suggest that many women who are using oral contraceptives in their peak bone development years could reduce their risk of osteoporosis by approximately 3-10 percent over one year by making sure they get enough calcium in their diet," Teegarden said. "This demonstrates the importance of calcium intake, either by getting enough dairy or with supplements."

Teegarden's laboratory currently is involved in a number of clinical trials to investigate the effect of calcium consumption on body fat. Her studies have shown that a high consumption of calcium slows weight gain for young women, but her more recent studies show that it may take years to make a noticeable difference.

Writer: Maggie Morris, (765) 494-2432, mailto:maggiemorris@purdue.edu

Source: Dorothy Teegarden, (765) 494-8246, mailto:teegarden@purdue.edu

With the measurements at all six universities now completed and much of the data already being analyzed at Purdue, the ACT Project is well on its way to helping unravel the relationships between developmental growth patterns, bone accretion rates and calcium intake habits of adolescent girls.  The acronym “ACT” stands for Adequate Calcium Today, and that is the overriding nutritional goal of this many-faceted project.

ACT Project subjects were recruited from 11-12 year old girls in Indiana, Ohio, California, Hawaii, Arizona and Nevada.  In order to be eligible for the study, the girls had to be 75% of either Asian, Hispanic, or non-Hispanic white heritage.  Of the 851 girls that volunteered, 745 of them fit the above race/ethnicity criterion.  In addition to the regular lab component of the study, almost 300 of these girls also participated in lactose maldigestion testing; the results were compared to their perceived level of lactose intolerance and any subsequent influence on bone status.

 The vast majority of ACT subjects stayed in the study until the completion of all three regular lab visits, spanning a period of about 18 months.  Each girl’s lab visit included various anthropometric measurements and DXA scans to determine her developing body’s rates of bone, fat and muscle tissue growth.  Besides completing a computerized food frequency questionnaire, she also filled out paper and pencil assessments of her family’s eating habits, her cultural background, her growth and development, and her physical and sedentary activities for the preceding year.   The results of such substantial data collecting have only begun to yield the publishing dividends for many journal articles to come. 

The primary objective of the ACT Project was to pilot test a bone health classroom curriculum in as many as 40 schools across six states per year.  The purpose of the educational component was to motivate young students and encourage them to start now to prevent osteoporosis from disabling them later on in life.  Presented primarily through a serialized story on a DVD, the curriculum engaged the students’ interest by using adolescent actors who came across as real peers, mainly because they were of mixed racial/ethnic heritage and behaved in a manner consistent with the target students’ age group.  The DVD story centered around three children whose foster grandmother had broken her hip, and it required that the students respond creatively to the story, including designing their own “action plans” for building strong bones. The majority of the students indicated they would start an action plan in the near future.  Compared to students in control schools, the students in the intervention schools scored significantly higher on a test addressing knowledge and behaviors related to bone health and consumption of calcium rich foods.

Although the far-reaching ramifications of the ACT Project remain to be seen, the research has already begun to show immense promise towards the understanding of bone growth in adolescent girls.  A proposed continuation of the ACT Project would involve measuring the same lab subjects who this fall will be in the 8th grade.  When asked if they would like to come back into the lab and participate in the project again, many of the Purdue ACT subjects have already responded enthusiastically.  With willing subjects and a proven research proposal, the ACT Project has not yet begun to peak in its impact upon the growing body of nutritional knowledge of adolescent girls.

Purdue Extension Promotes Fruits and Vegetables at the Indiana State Fair

The Expanded Foods and Nutrition Education Program (EFNEP) and the Family Nutrition Program (FNP) encourage Hoosiers to consume a variety of colorful fruits and vegetables on a daily basis in an effort to help limited resource audiences stretch their food dollars while maintaining optimal health.

The new Dietary Guidelines for Americans 2005 recommend eating more fruits and vegetables – five cups a day for most adults.  One excellent way to boost the nutritive value, taste, and eye appeal of any meal or snack is to serve more fruits and vegetables in a variety of creative and appetizing ways.  EFNEP and FNP staff offered Indiana State Fair visitors an opportunity to create and taste recipes that provide a dazzling array of colorful and tasty fruits.  Participants were given the opportunity to make their own fruit salads at the kitchen in Centennial Hall on the State Fair grounds.  In addition to doing food demonstration and taste tests for five days at the fair , EFNEP and FNP staff offered tips and recipes for increasing fruit and vegetable consumption at home and on the go.

For more information about the EFNEP program visit their web site at www.ces.purdue.edu/cfs/topics/EFNEP or contact Donna Vandergraff, EFNEP Coordinator vandergraff@purdue.edu.

For more information about FNP visit their web site at www.ces.purdue.edu/cfs/topics/FNP or contact Angie Abbott, FNP Director abbottar@purdue.edu.