Calcium consumption is associated with serum high-sensitivity C-reactive protein (hs-CRP) levels, a risk factor in heart disease.
However, the impact of dietary calcium intake on hs-CRP levels has not been completely investigated or understood.
Researchers at the Tokushima University Graduate School and National Institutes of Biomedical Innovation decided to explore the link between dietary calcium intake and serum hs-CRP levels in the general Japanese population.
Calcium intake versus cardiovascular disease
Taking their data from the Japan Multi-Institutional Collaborative Cohort Study, they analysed 2019 participants (1,194 male and 825 female) between the ages of 35 and 69 using a cross-sectional study design.
They then assessed the participants' nutrient consumption (including calcium intake) via a questionnaire on food frequency, and subsequently found that their dietary calcium intake was inversely associated with serum hs-CRP levels.
This observation was made after the was after the results had been adjusted for factors such as sex, age, research group, smoking and drinking status, menopausal status, physical activity in leisure time, and dietary intakes of dietary fibre, saturated fatty acids, vitamin D and energy.
The researchers then wrote that although the inverse relationship between dietary calcium intake and serum hs-CRP levels were "slightly attenuated after additional adjustment for body mass index (BMI)" it remained significant.
They added that when it came to serum hs-CRP levels, there were "no significant interactions" between dietary calcium intake and factors like BMI, sex or vitamin D consumption.
Additional factors and limitations
They elaborated on the limitations of their study, saying its subjects were unaware of their own hs-CRP status as routine medical examinations often do not measure it.
The researchers also did not measure inflammatory biomarkers, circulating vitamin D concentrations or magnesium intake; the latter can influence calcium absorption, and is inversely associated with systemic inflammation.
In addition, they stated that "further studies in different ethnic groups are necessary because this study included only Japanese populations".
They maintained, however, that the study had sufficiently demonstrated dietary calcium intake's inverse relationship with serum hs-CRP levels in the general population.
They then concluded: "The present study showed a significant inverse relationship between dietary calcium intake and serum hs-CRP concentrations in the general population, an association that was not confounded or totally mediated by BMI.
"Further studies are needed to confirm the relationship between dietary calcium and inflammation."
Source: Journal of Clinical Biochemistry and Nutrition
"Dietary calcium intake is associated with serum high-sensitivity C-reactive protein level in the general Japanese population"
Authors: Sakurako Katsuura Kamano, et al.