Dietary biomarkers to measure whole grain intake and health effects - three new studies
A high intake of whole grain foods has been associated with lowered risk of developing chronic life-style related diseases, such as obesity, type 2 diabetes, cardiovascular disease and colorectal cancer. However, studies evaluating diet-health relationships generally suffer from limited accuracy of self-reported dietary intakes in observational studies, or lack of compliance, to the study diet in intervention studies. This makes it difficult to capture the whole grain intake properly. In turn, the evaluation of the relationship between whole grain foods and health may suffer from lack of accuracy or bias, which may mask true relationships between whole grain and health outcomes.
Alkylresorcinols as a biomarker of whole grain intake
Biomarkers may be used to overcome the problems and provide a more accurate ranking tool. Alkylresorcinols is a group of compounds mainly present in the bran of wheat and rye, and may therefore be used to objectively estimate the whole grain intake. Total plasma concentrations of alkylresorcinols have previously been shown to correlate in a dose dependent manner with total whole grain wheat and rye intake. In addition, the ratio of two specific alkylresorcinols reflects the relative intake of whole grain wheat to whole grain rye.
Plasma alkylresorcinols and type 2 diabetes
The association between alkylresorcinol concentrations in plasma and the risk of type 2 diabetes was recently evaluated in a Chinese study. The findings suggested that higher concentrations were related to lower odds of developing diabetes. Read more here.
Alkylresorcinols in urine as a biomarker?
As an alternative to alkylresorcinol concentrations in plasma as a biomarker for whole grain intake, the concentrations of their two main metabolites in urine samples collected during 24 hours have previously been suggested. To evaluate if also single urine samples along with determination of some new alkylresorcinol metabolites may be used, Landberg and coworkers performed a study among 40 Swedish subjects. The results showed about the same performance as for intact alkylresorcinols in plasma Read more here.
Alkylresorcinols in adipose tissue as a long-term biomarker?
To find out if alkylresorcinols may act as long-term biomarkers of whole grain rye and wheat intake, adipose tissue concentrations were analyzed in 258 Swedish men and women. The results were promising for whole grain rye; although less so for wheat, probably due to poor precision in estimating the whole grain intake. Read more here.