Skip to main content Accessibility help
×
Home

Contents:

Information:

  • Access

Figures:

Actions:

      • Send article to Kindle

        To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

        Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

        Find out more about the Kindle Personal Document Service.

        Within-person stability and responsiveness to dietary change of C15:0 and C17:0 concentrations in dry blood spots in the Food4Me Study
        Available formats
        ×

        Send article to Dropbox

        To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

        Within-person stability and responsiveness to dietary change of C15:0 and C17:0 concentrations in dry blood spots in the Food4Me Study
        Available formats
        ×

        Send article to Google Drive

        To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

        Within-person stability and responsiveness to dietary change of C15:0 and C17:0 concentrations in dry blood spots in the Food4Me Study
        Available formats
        ×
Export citation

There is increasing evidence that concentrations in blood of the odd-chain length saturated fatty acids pentadecanoic acid (C15:0) and heptadecanoic acid (C17:0) are biomarkers of dairy intake, and their use in epidemiological studies is growing as more cost-effective methods for collecting biological samples become available (1, 2). The aim of this study was to assess the reliability of these biomarkers for estimates of dietary exposure in large epidemiological studies by exploring their stability over time in a population with relatively stable dairy intakes (Control group), and their sensitivity to changes in dairy intake in a population with changing diets (personalised nutrition Intervention group).

Dry blood spot (DBS) samples were collected and dietary intakes from FFQs measured three times over six months (t0, t3 and t6) in both Control and Intervention groups in the Food4Me Study (2). Stability was explored using data from the Control group through Spearman correlation coefficients, ICCs and within person CVs (WCVs) from one-way random effects models of the log-transformed fatty acid concentrations. Sensitivity to changes in diet was explored using differenced regression of log-transformed fatty acid concentrations over daily portions of dairy from the Intervention group.

For the Control group (N = 760), C15:0 concentrations showed high correlation over time (ICC: 0·62, 95 % CI: 0·57,0·68), but the ICC for C17:0 was much lower (ICC: 0·32, 95 % CI: 0·28,0·46). The WCV for C15:0 was 16·6 % (95 % CI: 14·9,18·3) and that for C17:0 was 14·6 % (95 % CI: 13·3,16·0). The highest Spearman correlations were observed for t0-t3 measurements. As with the ICCs, higher values were observed for C15:0 (t0-t3: 0·69, 95 % CI: 0·61, 0·78) than for C17:0 (t0-t3: 0·47, 95 % CI: 0·36, 0·59).

For the Intervention group, there were significant (p < 0·05) changes (measured as percentage change in fatty acid concentrations) for C15:0 in DBS and in intakes of total dairy, high-fat dairy, cheese and butter; and for C17:0 in DBS and change in intakes of high-fat dairy and cream.

% change in DBS fatty acid concentration per 1 portion change in dairy intake. *p < 0·05, **p < 0·01. 95 % confidence intervals in parenthesis. All regressions adjusted for total energy intake, age, BMI, smoking status; and intake of alcohol, meat, oily fish, savoury pastries and sweet pastries. Intervention group only (N = 1247).

Results provide evidence of reliability for C15:0 concentrations as measured by stability over time and sensitivity to change in intake of high-fat dairy products. Results for C17:0 are less definitive and merit further investigation.

1. Abdullah, MMH, Cyr, A, Lépine, M-C, Labonté, M-E, et al. (2015) Br J Nutr 113, 435–44.
2. Celis-Morales, C, Livingstone, KM, Marsaux, CFM, et al. (2014) Genes & Nutrition 10, 113.