Carotenoid consumption boosted by multivitamins
intentional usage having reached a plateau in recent years, due to
the addition of ingredients such as lutein and lycopene in
multivitamins, say researchers.
A study led by Judith Kelly of Boston University School of Public Health set out to determine which dietary supplements American adults use, whether the prevalence has continued to increase in recent years and whether the popularity of certain supplements has changed.
It was carried out between 1998 and 2002 through telephone interviews with 8,470 participants, who were asked about their use of medicines and dietary supplements over the preceding seven days. The results were published in yesterday's issue of Archives of Internal Medicine (2005; 165: 281 - 286).
They show that the annual prevalence of dietary supplements increased from 14.2 percent in 1998-9 to 18.8 percent in 2002, with a dip to 12.3 percent in 2000. Usage peaked in 2001, when it reached 19.8 percent.
While this overall increase was in line with expectations, the authors were surprised to see a dramatic rise in lutein consumption in both men and women, from prevalence of 0.3 percent in 1998-9 to 8.4 percent in 2002.
This increase is less startling, however, when one factors in the addition of the carotenoid antioxidant to many multivitamin products since 1999. Lycopene, an antioxidant thought to have a role in reducing the risk of some types of cancer, has also been added to major supplements since 2003.
However the researchers say that the decision by manufacturers to include these ingredients are symptomatic of two important changes that have taken place in the industry since the start of the study.
"First, the acceptance of herbal supplements and other dietary supplements as part of the mainstream health milieu has apparently increased," they said.
"Second, the marketing strategy for multivitamin products appears to have broadened from supplying recommended daily allowances of vitamins and minerals that may be lacking in the diet to preventing chronic disease, such as macular degeneration and cancer."
The results also signaled a decline in use of ginko biloba and panax over the study period.
The fastest growing group of supplement users was baby boomers, with the percentage of 45- to 64-year-olds taking supplements having increased by half between 1998-9 and 2002.
Overall, supplement users were more likely to be older, with 59.9 percent of women taking supplements compared to 55.5 percent of men and 80.7 percent of white people compared with 75.6 percent of non-whites.
