Selected nutritional biomarkers predict diet quality

Abstract

Objective: To examine associations of biomarkers of nutrient intake with overall diet quality. Subjects: A convenience sample of 102 healthy postmenopausal women in Seattle, Washington (USA). Design and method: Participants attended a study centre where they provided fasting blood specimens and completed a 122-item validated food-frequency questionnaire (FFQ). Data from the FFQ were used to calculate Diet Quality Index (DQI) scores and categorise women as having diets of excellent, good, fair or poor quality. The blood specimens were analysed for nine phospholipid fatty acids (as percentage of total) and serum concentrations of vitamin C, a-tocopherol, g-tocopherol, vitamin B 12 , folate and six carotenoids. Multivariate linear regression was used to model associations of the nutrient biomarkers with DQI scores. Results: Compared with women with poor-quality diets, women with excellent diets, as measured by the DQI, had higher plasma concentrations of vitamin C (P for trend ¼ 0.01), a-tocopherol (P for trend ¼ 0.02) and b-cryptoxanthin (P for trend ¼ 0.03). Women with excellent diets also had lower proportions of plasma phospholipid fatty acids of two potentially atherogenic fatty acids: stearic acid (P for trend ¼ 0.01) and behenic acid (P for trend ¼ 0.03). A group of six biomarkers explained a moderate proportion of the total variability in DQI scores (36%). Conclusions: These objective measures of dietary intake support the use of the DQI as a useful tool to measure dietary patterns.

Selenium and antioxidant vitamin status of elderly German women

“…Therefore, we hypothesized that even well-educated younger female seniors may exhibit an insufficient antioxidant status. Although a great number of studies on the antioxidant status have been published (Palli et al, 1999;Murphy and Cashman, 2002;Neuhouser et al, 2003), there are only few data available for elderly people. Especially information on the selenium and coenzyme Q10 status of elderly people is scarce.…”

Diet quality of a population sample from coastal north-east Spain evaluated by a Mediterranean adaptation of the Diet Quality Index (DQI)

“…and provide a more objective and complementary measure of dietary intake (27) . However, such biomarkers have not been used to describe dietary patterns until recently (25,(28)(29)(30)(31)(32)(33)(34)(35)(36) . The M-DQI, applied in representative samples of the French (37) and the Croatian population (38) , has not yet been applied to a Spanish Mediterranean population.…”

Relationship between 24 h urinary potassium and diet quality in the adult Spanish population

“…when studying children), recording errors can occur, leading to distorted energy and nutrient intakes when data are calculated (19) . Thus, there is growing interest in the possibility of using biological markers of dietary intake (5) . In the present study, 24 h urinary K excretion was found not to be related to energy intake (r = 0·046; P = 0·411), but to be positively related to self-reported K intake adjusted (r = 0·261; P<0·001) and not adjusted by energy intake (r = 0·233; P<0·001), as reported by other authors (7) .…”

“…However, the need to weigh and record intake over several days can be seen as tedious and time consuming and thus is often associated with poor compliance and/or an alteration of the diet during the recording period (4) . Because of the existence of these limitations and others, such as subject difficulty in completing questionnaires, the need for trained personnel to review the information collected, etc., there is growing interest in the possibility of using biological markers of dietary intake (5) . K is present in many foods such as vegetables, fruits, pulses and dairy products, all of which are necessary in an adequate diet (6) .…”