Chapter 27
Intervention Studies in Humans
Begon ˜ a Olmedilla-Alonso
Abstract
Intervention studies in humans provide the highest level of evidence in the assessment of the effect of
nutrients or bioactive food components on human health /disease. There are different intervention study
designs, and their selection depends on the objectives of the study. Here we present the main designs and
the factors that should be considered when selecting and developing them.
Key words Human intervention studies, Carotenoids, Provitamin A, Biomarkers
1 Introduction
When evaluating the relationship between the diet, the intake of
nutrients or bioactive food components, and human health/disease, intervention studies—those experimental studies where the
researcher intervenes at some point throughout the study—are
essential tests that provide a direct and high level of evidence
needed prior to making decisions in areas such as public health
recommendations and effective nutritional intervention programs
(see Note 1) and confirming claims of alleged health-promoting
properties of a food or a component [1–4]. Intervention studies on
humans provide information that complements that obtained
through in vitro digestion assays which, in general, do not fully
explain the impact of carotenoid intake in humans but do explain
the effect that different food-related factors have [5–7].
Traditionally, intervention studies involving carotenoids have
focused on assessing the effect of the intake, at dietary or pharmacological level, of b-carotene on vitamin A status and on reducing
the risk of several chronic diseases including some types of cancer.
However, in the last decades, there has been growing interest in the
diverse biological activities of the major dietary carotenoids and
hence in intervention studies on subjects with different chronic
diseases or with related risk factors (i.e., cancer, cardiovascular
Manuel Rodrı ´guez-Concepcio ´ n and Ralf Welsch (eds.), Plant and Food Carotenoids: Methods and Protocols,
Methods in Molecular Biology, vol. 2083, https://doi.org/10.1007/978-1-4939-9952-1_27,
© Springer Science+Business Media, LLC, part of Springer Nature 2020
363
Intervention Studies in Humans
Begon ˜ a Olmedilla-Alonso
Abstract
Intervention studies in humans provide the highest level of evidence in the assessment of the effect of
nutrients or bioactive food components on human health /disease. There are different intervention study
designs, and their selection depends on the objectives of the study. Here we present the main designs and
the factors that should be considered when selecting and developing them.
Key words Human intervention studies, Carotenoids, Provitamin A, Biomarkers
1 Introduction
When evaluating the relationship between the diet, the intake of
nutrients or bioactive food components, and human health/disease, intervention studies—those experimental studies where the
researcher intervenes at some point throughout the study—are
essential tests that provide a direct and high level of evidence
needed prior to making decisions in areas such as public health
recommendations and effective nutritional intervention programs
(see Note 1) and confirming claims of alleged health-promoting
properties of a food or a component [1–4]. Intervention studies on
humans provide information that complements that obtained
through in vitro digestion assays which, in general, do not fully
explain the impact of carotenoid intake in humans but do explain
the effect that different food-related factors have [5–7].
Traditionally, intervention studies involving carotenoids have
focused on assessing the effect of the intake, at dietary or pharmacological level, of b-carotene on vitamin A status and on reducing
the risk of several chronic diseases including some types of cancer.
However, in the last decades, there has been growing interest in the
diverse biological activities of the major dietary carotenoids and
hence in intervention studies on subjects with different chronic
diseases or with related risk factors (i.e., cancer, cardiovascular
Manuel Rodrı ´guez-Concepcio ´ n and Ralf Welsch (eds.), Plant and Food Carotenoids: Methods and Protocols,
Methods in Molecular Biology, vol. 2083, https://doi.org/10.1007/978-1-4939-9952-1_27,
© Springer Science+Business Media, LLC, part of Springer Nature 2020
363