544
F. Tourniaire et al.
termed provitamin A as they can be cleaved by animals to release retinal, which
can be subsequently converted to retinol (von Lintig 2010).
21.2 Carotenoids and Obesity Relationship in Human
Studies
21.2.1 Observational Studies
Obesity has been associated in many epidemiological and observational studies with
low circulating concentrations of carotenoids (Kimmons et al. 2006; Garcia et al.
2009). A strong inverse correlation between BMI and all measured carotenoids in
plasma, except lycopene, has been highlighted in the CARDIA study (Andersen et al.
2006). In addition, many obesity-associated disorders, such as low-grade inflammation or insulin resistance, are also strongly inversely associated with serum carotenoid
concentrations (Calder et al. 2011; Beydoun et al. 2011, 2019).
21.2.2 Intervention Studies
Several trials have been conducted to study the putative role of carotenoids on
obesity management. Most of these studies used mixtures of carotenoids and vitamins included within natural matrices such as fruit juices or plant extracts (reviewed
by Bonet et al. 2015), making the interpretation related to the specific contribution of carotenoids difficult. To our knowledge, only two randomized clinical trials,
performed in double-blind and placebo-controlled, investigated the effect of pure
carotenoids or xanthophylls supplementation. Indeed Canas et al. (2017) reported a
decrease in BMI z-score, waist to height ratio, and subcutaneous adipose tissue in
children submitted for 6 months to a mixture of carotenoids (β-carotene, α-carotene,
lutein, zeaxanthin, lycopene, astaxanthin, γ -tocopherol). Such beneficial effects were
strongly associated with an increase in plasma β-carotene concentration in children (Canas et al. 2017). Another study, using a mixture of paprika xanthophylls
and carotenoid, administrated for 12 weeks to healthy overweight volunteers. Such
supplementation reduced visceral fat area, subcutaneous fat area, and total fat area,
as well as BMI in treated group compared to placebo group (Kakutani et al. 2018).
These data suggest that carotenoid may have an impact on adipocyte/adipose
tissue biology, that may in turn result in a modification of several parameters linked
to obesity and/or associated comorbidities. This assumption is strongly supported by
the fact that carotenoids are stored, metabolized, and bioactive in adipocytes and in
adipose tissue.
F. Tourniaire et al.
termed provitamin A as they can be cleaved by animals to release retinal, which
can be subsequently converted to retinol (von Lintig 2010).
21.2 Carotenoids and Obesity Relationship in Human
Studies
21.2.1 Observational Studies
Obesity has been associated in many epidemiological and observational studies with
low circulating concentrations of carotenoids (Kimmons et al. 2006; Garcia et al.
2009). A strong inverse correlation between BMI and all measured carotenoids in
plasma, except lycopene, has been highlighted in the CARDIA study (Andersen et al.
2006). In addition, many obesity-associated disorders, such as low-grade inflammation or insulin resistance, are also strongly inversely associated with serum carotenoid
concentrations (Calder et al. 2011; Beydoun et al. 2011, 2019).
21.2.2 Intervention Studies
Several trials have been conducted to study the putative role of carotenoids on
obesity management. Most of these studies used mixtures of carotenoids and vitamins included within natural matrices such as fruit juices or plant extracts (reviewed
by Bonet et al. 2015), making the interpretation related to the specific contribution of carotenoids difficult. To our knowledge, only two randomized clinical trials,
performed in double-blind and placebo-controlled, investigated the effect of pure
carotenoids or xanthophylls supplementation. Indeed Canas et al. (2017) reported a
decrease in BMI z-score, waist to height ratio, and subcutaneous adipose tissue in
children submitted for 6 months to a mixture of carotenoids (β-carotene, α-carotene,
lutein, zeaxanthin, lycopene, astaxanthin, γ -tocopherol). Such beneficial effects were
strongly associated with an increase in plasma β-carotene concentration in children (Canas et al. 2017). Another study, using a mixture of paprika xanthophylls
and carotenoid, administrated for 12 weeks to healthy overweight volunteers. Such
supplementation reduced visceral fat area, subcutaneous fat area, and total fat area,
as well as BMI in treated group compared to placebo group (Kakutani et al. 2018).
These data suggest that carotenoid may have an impact on adipocyte/adipose
tissue biology, that may in turn result in a modification of several parameters linked
to obesity and/or associated comorbidities. This assumption is strongly supported by
the fact that carotenoids are stored, metabolized, and bioactive in adipocytes and in
adipose tissue.