Changes in Lutein Status Markers (Serum and Faecal Concentrations, Macular Pigment) in Response to a Lutein-Rich Fruit or Vegetable (Three Pieces/Day) Dietary Intervention in Normolipemic Subjects

Avocado (Persea americana Mill) and its phytoconstituents: potential for cancer prevention and intervention

Dietary compounds, including fruits, vegetables, nuts, and spices, have been shown to exhibit anticancer properties due to their high concentrations of vitamins, minerals, fiber, and secondary metabolites, known as phytochemicals. Although emerging studies suggest that avocado (Persea americana Mill) displays antineoplastic properties in addition to numerous other health benefits, current literature lacks an updated comprehensive systematic review dedicated to the anticancer effects of avocado. This review aims to explore the cancer-preventive effects of avocados and the underlying molecular mechanisms. The in vitro studies suggest the various avocado-derived products and phytochemicals induced cytotoxicity, reduced cell viability, and inhibited cell proliferation. The in vivo studies revealed reduction in tumor number, size, and volume as well. The clinical studies demonstrated that avocado leaf extract increased free oxygen radical formation in larynx carcinoma tissue. Various avocado products and phytochemicals from the avocado fruit, including avocatin-B, persin, and PaDef defensin, may serve as viable cancer prevention and treatment options based on current literature. Despite many favorable outcomes, past research has been limited in scope, and more extensive and mechanism-based in vivo and randomized clinical studies should be performed before avocado-derived bioactive phytochemicals can be developed as cancer preventive agents.

Carotenoid Markers of Dietary Exposure and Nutritional Status

Carotenoids are lipophilic isoprenoid compounds synthesized by photosynthetic organisms and some non-photosynthethic prokaryotes and fungi [...].

Plasma lutein and zeaxanthin concentrations associated with musculoskeletal health and incident frailty in The Irish Longitudinal Study on Ageing (TILDA)

INTRODUCTION

Lutein and zeaxanthin are diet-derived carotenoids that are proposed to help mitigate frailty risk and age-related declines in musculoskeletal health via their anti-oxidant and anti-inflammatory properties. Therefore, this study aimed to investigate the association between lutein and zeaxanthin status and indices of musculoskeletal health and incident frailty among community-dwelling adults aged ≥50 years in the Irish Longitudinal Study on Ageing (TILDA).

METHODS

Cross-sectional analyses (n = 4513) of plasma lutein and zeaxanthin concentrations and grip strength, usual gait speed, timed up-and-go (TUG), probable sarcopenia (defined as grip strength <27 kg in men, <16 kg in women), and bone mass (assessed using calcaneal broadband ultrasound stiffness index) were performed at Wave 1 (2009-2011; baseline). In the longitudinal analyses (n = 1425-3100), changes in usual gait speed (at Wave 3, 2014-2015), grip strength (Wave 4, 2016) and TUG (at Wave 5, 2018), incident probable sarcopenia (at Wave 4) and incident frailty (Fried's phenotype, Frailty Index, FRAIL Scale, Clinical Frailty Scale-classification tree, at Wave 5) were determined. Data were analysed using linear and ordinal logistic regression, adjusted for confounders.

RESULTS

Cross-sectionally, plasma lutein and zeaxanthin concentrations were positively associated with usual gait speed (B [95 % CI] per 100-nmol/L higher concentration: Lutein 0.59 [0.18, 1.00], Zeaxanthin 1.46 [0.37, 2.55] cm/s) and inversely associated with TUG time (Lutein -0.07 [-0.11, -0.03], Zeaxanthin -0.14 [-0.25, -0.04] s; all p < 0.01), but not with grip strength or probable sarcopenia (p > 0.05). Plasma lutein concentration was positively associated with bone stiffness index (0.54 [0.15, 0.93], p < 0.01). Longitudinally, among participants who were non-frail at Wave 1, higher plasma lutein and zeaxanthin concentrations were associated lower odds of progressing to a higher frailty category (e.g. prefrailty or frailty) by Wave 5 (ORs 0.57-0.89, p < 0.05) based on the Fried's phenotype, FRAIL Scale and the Clinical Frailty Scale, and in the case of zeaxanthin, Frailty Index. Neither plasma lutein nor zeaxanthin concentrations were associated with changes in musculoskeletal indices or incident probable sarcopenia (p > 0.05).

CONCLUSION

Higher plasma lutein and zeaxanthin concentrations at baseline were associated with a reduced likelihood of incident frailty after ~8 years of follow up. Baseline plasma lutein and zeaxanthin concentrations were also positively associated with several indices of musculoskeletal health cross-sectionally but were not predictive of longitudinal changes in these outcomes over 4-8 years.

Status and Dietary Intake of Phytoene and Phytofluene in Spanish Adults and the Effect of a Four-Week Dietary Intervention with Lutein-Rich Fruits or Vegetables

Phytoene (PT) and phytofluene (PTF) are colourless carotenoids presents in the human diet and in blood, faeces and tissues and are biologically active. However, there is very little data on these carotenoids. This study aims to assess PT and PTF concentrations in serum from healthy Spanish normolipemic subjects (n = 101, 45-65 years) and the effect of a fruit and vegetable dietary intervention (4 weeks, n = 29) on PT and PTF concentration in serum and faeces and dietary intake. Serum and faecal concentrations were analysed by HPLC and dietary intake by 3 × 24 h recalls. PT showed higher concentrations than PTF in serum, faeces and in the dietary intake. Considering both studies, PT and PTF concentrations in serum were 0.16 ± 0.07 and 0.05 ± 0.04 µmol/L, respectively, in faeces 17.7 ± 20.3 and 6.5 ± 7.9 µg/g, respectively, and in dietary intake the median was 2.4 and 0.6 mg/p/day, respectively. Carrots and tomatoes were the major dietary contributors of these carotenoids. The dietary intervention did not cause significant variations in the PT and PTF intake or serum concentrations, but a lower concentration in faeces was observed for the fruit group (PT: p = 0.024; PTF isomer-3: p = 0.034). These data highlight the need for further research on the activities of these carotenoids in humans.