Antioxidant intake in relation to serum C-reactive protein in mid-life and older African Americans

ABSTRACT

Objective: African Americans (AAs) experience greater prevalence of cardiovascular disease (CVD) compared to other ethnic/racial groups. Low-grade chronic inflammation (often quantified by serum C-reactive protein CRP) is a well-documented risk factor for CVD. A healthy diet is plentiful in antioxidant nutrients and is associated with a lower inflammatory status and CVD risk. Our objective was to examine the relationship between dietary intake of antioxidants (carotenoids, vitamins A, C, E, and selenium) and serum CRP concentrations in mid-life and older AAs, while controlling for confounders.

Methods: Data were from the baseline phase of a longitudinal church-based intervention study to reduce CVD risk in AAs. Anthropometrics were measured in a standard manner. Fasting serum samples were analyzed with ELISA for CRP. Multiple-pass 24-hour dietary recalls were used to assess intake; self-reported questionnaires were used to collect demographics. Statistical analyses were performed using SPSS Statistics 21 with the level of significance set at p < 0.05.

Results: A total of n = 73 participants (n = 51 females) were included in the analyses. The females and males, respectively were 58.9 ± 10.3 and 59.4 ± 9.7 years old, with BMI of 34.6 ± 8.3 and 35.6 ± 9.3 kg/m² (Mean ± SD). The mean serum CRP was above 0.6 mg/dL, although slightly lower in males. Males consumed more energy (kcal) and met RDA for selenium, whereas females met RDA for vitamin C. Both groups met RDA for vitamin A. All other dietary variables fell below the RDA or had no RDA established. Results from the binary logistic regression did not show significant association between dietary antioxidants and serum CRP in males or females. However, among females, for every unit increase in BMI, there was a 15% increase in serum CRP (OR = 1.15, p = 0.04).

Conclusions: Our study does not support the inverse relationship between antioxidants intake and CRP, but does support the evidence for obesity-induced inflammation and suggests the association can be applied to AA women.

KEYWORDS:

• African Americans
• antioxidants
• cardiovascular disease
• C-reactive protein

Acknowledgments

The authors are in debt to all the participants of the study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Key messages

• Diet rich in fruits, vegetables, grains and nuts, containing antioxidant nutrients should be practiced for better overall health, management of weight and possibly lower serum CRP in African Americans.

• Maintaining the healthy weight might lead to reduced low-grade chronic inflammation in African Americans and subsequent reduction in CRP.

Additional information

Funding

This study was supported by the National Institute on Minority Health and Health Disparities, National Institutes of Health Award Number 1R24MD002807 (P.I. Penny A. Ralston). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute on Minority Health and Health Disparities or the National Institutes of Health.