Insights Into the Interplay Among Zinc, Biological Aging, Fasting, Energy Intake, and Inflammation: A Cross-Sectional Analysis Using 2015–2018 NHANES Participants

OBJECTIVES: Although it is documented that zinc plays an essential role in immune function, little is known about its relationship to factors that influence biological aging. Therefore, the primary objective of this study is to investigate how fasting status, total energy intake, and carbohydrate intake interfaces with dietary zinc (Zn) intake and acute inflammation status via HS-CRP in different age groups. METHODS: 4,415 adult participants from the 2015–2018 NHANES cycles with a BMI of 17–34.9 were included in the analysis. The data derived from the first and secondary dietary recall, fasting questionnaire, physical examination, and bloodwork collected at the MEC. Participants were stratified into the following four age groups: “Young Adult” (19–35; n = 1211), “Adult” (36–50; n = 1032), “Middle-Aged Adult” (51–65; n = 1177), and “Older Adult”(66–80; n = 995). Per age group, circulating levels of HS-CRP were associated with dietary Zn intake and either fasting status, energy intake and or carbohydrate intake while adjusting for WBC count, choline intake, folate intake, BMI, and gender. Survey weighted generalized linear models were constructed and the Rao-Scott likelihood ratio test was implemented via the survey package in R. RESULTS: 35.9% of the Young Adult group had an inadequate intake of zinc, which was defined as consuming less than 8 mg of Zn per day, 48.8% fasted for 9 or more hours, and the mean HS-CRP was 3.2 (SD = 6.0). For the group Young Adult, a two-way interaction effect was identified between the variables Adequate Zn Intake, defined as consuming at least 8 mg of Zn per day and Fasting, defined as fasting for 9 or more hours, which was associated with a reduction in circulating HS-CRP (OR = 0.56, 95% CI: 0.33–0.96, P = 0.038). Fasting was also associated with higher levels of HS-CRP (OR = 1.76, 95% CI: 1.12–2.76, P = 0.016). No other models were significant. CONCLUSIONS: Short-term fasting in the 19–35-year-old participants is associated with an increase in HS-CRP; however, having adequate Zn intake when fasting may lower circulating levels of HS-CRP. Neither energy intake nor carbohydrate consumption had any significant associations in any of the age groups. FUNDING SOURCES: None.