An inadequate dietary intake of calcium has been postulated to be factor in the development of essential hypertension, and has long been considered important in the development of osteoporosis among women. Furthermore, animal experiments and limited studies in humans suggest that an increase in the intake of calcium any also have a beneficial effect on blood cholesterol levels. Despite limitations in the research data supporting its benefits, increased calcium intake is being widely advocated to the public and calcium- enriched products are being increasingly purchased and consumed by Americans. The proposed study is designed to measure the effects of a modest increase in calcium intake, such as that currently being advocated to the general public among free-living, healthy young people. The composition of a selected number of food products would be modified to increase the dietary intake of calcium of college students by an average of 500 mg/day. The effects of such a dietary change on blood pressure, blood cholesterol, and bone density would be assessed. The cross-over trial would involve alternately serving calcium-enriched foods (including orange juice and other fruit juices, a variety of soft drinks, and selected cereals) for one school year each at two colleges; similar products without added calcium would be served during the alternate year. It is postulated that, at the end of the school year, students at the intervention school (receiving the calcium-enriched products) would have lower systolic blood pressure (2.5 mmHg), lower blood cholesterol (7 mg/dl), and increased bone density among females (5%) than students at the control school. The proposed project will utilize skills developed by the research team in two pervious studies of dietary intervention in a school setting in which they decreased sodium intake and used fat-modified products to decrease saturated fat intake. The automatic blood pressure devices and other specialized equipment developed by the investigators in these studies will greatly facilitate their carrying out the proposed new project. The demonstration that the consumption of a limited number of food products that have been enriched with calcium has a beneficial effects on cardiovascular risk factors and on bone density could have import implications for the health of the U.S. population.
| Witschi, J C; Capper, A L; Ellison, R C (1990) Sources of fat, fatty acids, and cholesterol in the diets of adolescents. J Am Diet Assoc 90:1429-31 |
| Ellison, R C; Goldberg, R J; Witschi, J C et al. (1990) Use of fat-modified food products to change dietary fat intake of young people. Am J Public Health 80:1374-6 |
| Ellison, R C; Capper, A L; Goldberg, R J et al. (1989) The environmental component: changing school food service to promote cardiovascular health. Health Educ Q 16:285-97 |
| Witschi, J C; Capper, A L; Hosmer Jr, D W et al. (1987) Sources of sodium, potassium, and energy in the diets of adolescents. J Am Diet Assoc 87:1651-5 |
