Intestinal absorption of β-carotene, lycopene and lutein in men and women following a standard meal: response curves in the triacylglycerol-rich lipoprotein fraction

O'Neill, M.; Thurnham, David I.

doi:10.1079/bjn19980026

Cited by 125 publications

(98 citation statements)

References 30 publications

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“…Indeed it was shown that the extent of absorption of carotenoids was comprised of between 11% for all-trans ␤-carotene and 2.5% for all-trans lycopene. It is also in agreement with a study that estimated absorption efficiency from chylomicron response (32). With this method, it was estimated that 1.4 mg of 40 mg ␤-carotene (3.5%) and 1 mg of 40 mg lycopene (2.5%) were absorbed in humans, values close to the solubility values measured here, i.e., 4.8 and 2.0%.…”

Section: Discussionsupporting

confidence: 76%

Processing of vegetable-borne carotenoids in the human stomach and duodenum

Tyssandier

Reboul

Dumas

et al. 2003

American Journal of Physiology-Gastrointestinal and Liver Physi

239

186

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Carotenoids are thought to diminish the incidence of certain degenerative diseases, but the mechanisms involved in their intestinal absorption are poorly understood. Our aim was to obtain basic data on the fate of carotenoids in the human stomach and duodenum. Ten healthy men were intragastrically fed three liquid test meals differing only in the vegetable added 3 wk apart and in a random order. They contained 40 g sunflower oil and mashed vegetables as the sole source of carotenoids. Tomato purée provided 10 mg lycopene as the main carotenoid, chopped spinach (10 mg lutein), and carrot purée (10 mg β-carotene). Samples of stomach and duodenal contents and blood samples were collected at regular time intervals after meal intake. all -trans and ciscarotenoids were assayed in stomach and duodenal contents, in the fat and aqueous phases of those contents, and in chylomicrons. The cis-trans β-carotene and lycopene ratios did not significantly vary in the stomach during digestion. Carotenoids were recovered in the fat phase present in the stomach during digestion. The proportion of all -trans carotenoids found in the micellar phase of the duodenum was as follows (means ± SE): lutein (5.6 ± 0.4%), β-carotene (4.7 ± 0.3%), lycopene (2.0 ± 0.2%). The proportion of 13- cis β-carotene in the micellar phase was significantly higher (14.8 ± 1.6%) than that of the all -trans isomer (4.7 ± 0.3%). There was no significant variation in chylomicron lycopene after the tomato meal, whereas there was significant increase in chylomicron β-carotene and lutein after the carrot and the spinach meals, respectively. There is no significant cis-transisomerization of β-carotene and lycopene in the human stomach. The stomach initiates the transfer of carotenoids from the vegetable matrix to the fat phase of the meal. Lycopene is less efficiently transferred to micelles than β-carotene and lutein. The very small transfer of carotenoids from their vegetable matrices to micelles explains the poor bioavailability of these phytomicroconstituents.

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Section: Discussionsupporting

confidence: 76%

Processing of vegetable-borne carotenoids in the human stomach and duodenum

Tyssandier

Reboul

Dumas

et al. 2003

American Journal of Physiology-Gastrointestinal and Liver Physi

239

186

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“…In contrast, lutein increased plasma β-carotene in five subjects but reduced it in three others. Recent work of our own also suggests that both lycopene (53 %) and lutein (38 %) may not be absorbed as efficiently as β-carotene (P < 0·05; Table 5; O'Neill & Thurnham, 1998).…”

Section: Absorption Of B-carotene and Its Conversion To Retinolmentioning

confidence: 99%

“…However, in two recent studies (Van Vliet et al 1995;O'Neill & Thurnham, 1998) in which very different large intakes of β-carotene were given (15 mg and 40 mg respectively) the mean absorption of β-carotene was < 2·0 mg, suggesting that the human intestine possesses only a limited capacity to absorb β-carotene. In both studies more than half the β-carotene absorbed was converted to retinol.…”

Section: Absorption Of B-carotene and Its Conversion To Retinolmentioning

confidence: 99%

“…The dietary intake of β-carotene in the UK is approximately 2 mg/d (Gregory et al 1990). Evidence suggests that absorbed β-carotene from intakes of this order is mostly converted to retinol (Goodman et al 1966) and is reproducible (O'Neill & Thurnham, 1998). High intakes of β-carotene are needed to increase plasma concentrations, and likewise when the intake is low the need to form retinol explains why very little β-carotene appears in the serum (Northrop-Clewes et al 1996;Thurnham et al 1997).…”

Section: Absorption Of B-carotene and Its Conversion To Retinolmentioning

confidence: 99%

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Optimal nutrition: vitamin A and the carotenoids

Thurnham

Northrop-Clewes

1999

Proc. Nutr. Soc.

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There are two major dietary sources of vitamin A: easily absorbed retinyl palmitate in foods of animal origin, and poorly bioavailable carotenoids from plant foods. Plasma retinol is tightly controlled, probably by regulation of retinol-binding protein (RBP) formation in the liver, and only hormonal factors (e.g. oral contraceptives) and infection will alter the homeostasis. Delivery of retinol to the tissues is facilitated by the RBP-retinol complex; however, there is evidence that this mechanism can be bypassed when very high doses of vitamin A are given. Some retinyl ester may be released to tissues from chylomicrons when the latter bind to tissue lipoprotein receptors during their passage from the gut to the liver following a meal. High-dose vitamin A therapy is a means of rapidly improving vitamin A status in persons with sub-optimal vitamin A nutrition but there are dangers of toxic symptoms (e.g. teratogenicity) from excess vitamin A usage. Evidence is presented to suggest that the plasma retinol : RBP may be a guide to optimal vitamin A status, since values less than one frequently occur in less-developed countries and during infection. In contrast to plasma retinol, plasma carotenoids reflect the dietary intake of plant foods. However, absorption is limited by poor bioavailability and a saturable uptake mechanism in competition with other phytochemicals. Recent work on bioavailability suggests that the calculation of plant food vitamin A activity should be re-examined. Illness has little influence on plasma levels except by suppressing appetite. Carotenoids are generally regarded as non-toxic yet intervention studies with β-carotene in smokers have been associated with increased lung cancer and heart disease. Some carotenoids are important as vitamin A precursors, but the physiological importance of their antioxidant properties is not known and consequently the amount needed for optimal nutrition is uncertain.

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“…Studies have found that lutein and b-carotene compete for absorption (Micozzi et al, 1992;Kostic et al, 1995;Albanes et al, 1997); however, the same is not necessarily true for lycopene and b-carotene. While some have shown enhanced b-carotene absorption with lycopene administration (High & Day, 1951), others have shown either no effect or inhibition on b-carotene absorption (White et al, 1993;Johnson et al, 1997;O'Neill & Thurnham, 1998). Therefore, the larger lycopene to b-carotene ratio present in the tomato paste may inhibit absorption of b-carotene.…”

Section: Discussionmentioning

confidence: 99%

Lycopene and β-carotene are bioavailable from lycopene ‘red’ carrots in humans

2004

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Objective: The purpose of this study was to determine if lycopene and b-carotene are bioavailable from lycopene red carrots and if lycopene absorption is affected by carrot fiber. Design: Two crossover studies in humans attempted to compare the relative bioavailability of lycopene and b-carotene from tomato paste to a genetically selected lycopene red carrot during chronic feeding. Each study contained three treatment groups. The vehicle of administration was muffins. Intervention and methods: Study 1 (n¼9) used white carrots (0 mg lycopene/day), red carrots (5 mg/day), and tomato paste (20 mg/day). Study 2 (n¼10) used red carrots (2.6 mg/day), tomato paste (5 mg/day), and tomato paste plus white carrots (5 mg/day). Each intervention lasted 11 days with a 10-day washout period between treatments. Serum lycopene and bcarotene were measured by HPLC. Results: Statistical analysis indicated a significant effect of muffin type in study 1 (Po0.001), and a significant treatment by sequence interaction in study 2 (P¼0.04). The response to increasing amounts of lycopene is linear at the levels fed in these studies (r¼0.94). The data suggest that maintenance of serum lycopene concentrations at 0.3 mmol/l occurs at about 2 mg/day of lycopene from mixed dietary sources and a serum plateau occurs at Z20 mg/day. Conclusions: These results show that lycopene and b-carotene are bioavailable from red carrots and lycopene absorption seems to be affected by carrot fiber. Making inferences from both studies, the lycopene in the red carrot is about 44% as bioavailable as that from tomato paste. Red carrots provide an alternative to tomato paste as a good dietary source of lycopene and also provide bioavailable b-carotene.

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Intestinal absorption of β-carotene, lycopene and lutein in men and women following a standard meal: response curves in the triacylglycerol-rich lipoprotein fraction

Cited by 125 publications

References 30 publications

Processing of vegetable-borne carotenoids in the human stomach and duodenum

Processing of vegetable-borne carotenoids in the human stomach and duodenum

Optimal nutrition: vitamin A and the carotenoids

Lycopene and β-carotene are bioavailable from lycopene ‘red’ carrots in humans

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