Olive oil improves the intestinal absorption and bioavailability of lutein in lutein-deficient mice.

PURPOSE: To investigate the influence of olive (OO), groundnut (GNO), soybean (SBO), sunflower (SFO), rice bran (RBO), corn (CO), palm (PO) oil or mixed micelle (control) on absorption kinetics and bioavailability of lutein in lutein-deficient mice. Additional aim was to correlate the activity of intestinal triacylglycerol lipase with intestinal and plasma lutein levels. METHODS: After induction of lutein deficiency, mice (n = 165) were divided into eight groups (OO, SFO, GNO, RBO, PO, CO, SBO and control; n = 20/group) and the remaining (n = 5) were used as baseline (0 h). Groups were further divided into four subgroups (n = 5/subgroup) and were intubated with lutein (200 µM) dispersed in different vegetable oils. Plasma and tissue (intestine, liver and eyes), lutein, triglycerides, intestinal triacylglycerol lipases and fatty acid profile of plasma and tissues were measured at different time intervals. RESULTS: The percentage area under the curve value for plasma lutein in OO and GNO was higher by 41.8 and 5.1 %, while it was lower in other groups (18.2-53.3 %), when compared to control. Similarly, the percentage area under the curve for eye lutein in OO and GNO groups was higher by 35.2 and 4.8 %, whereas in other groups it was lower (5.4-69 %) than in control. Results show that olive oil facilitates the lutein absorption more compared to other vegetable oils, which may be due to the difference in fatty acid composition and higher activity of intestinal triacylglycerol lipase. CONCLUSIONS: Dietary olive oil rich in oleic acid improves the bioavailability and accumulation of lutein in lutein-deficient mice by modifying the intestinal triacylglycerol lipase activity.

Dietary and lifestyle risk factors associated with age-related macular degeneration: a hospital based study.

AIM: To establish the frequency, associations and risk factors for age-related macular degeneration (AMD) in hospital population of South India. MATERIALS AND METHODS: In this cross-sectional hospital based study, 3549 subjects (2090 men and 1459 women) above 45 years of age were screened randomly for AMD. Participants underwent ocular evaluation and were interviewed for lifestyle variables and dietary intake of carotenoids by structured food frequency questionnaire. AMD was defined according to the international classifications and grading system. RESULTS: Either form of AMD was detected in 77 (2.2%) participants. Of which, early and late AMD was present in 63 (1.8%) and 14 (0.4%) subjects, respectively. Binary logistic analysis showed that the incidence of AMD was significantly higher with increasing age (Odds ratio [OR] 1.17; 95% CI 1.13-1.22) and diabetes (OR 3.97; 95% CI 2.11-7.46). However, AMD was significant among heavy cigarette smokers (OR 5.58; 95% CI 0.88-7.51) and alcoholics (OR 4.85; 95% CI 2.45-12.22). Dietary lutein/zeaxanthin (L/Z) and ß-carotene intake were associated (P < 0.001) with the reduction in risk for AMD, with an OR of 0.38 and 0.65, respectively. CONCLUSIONS: Higher dietary intake of carotenoids, especially L/Z, was associated with lower risk for AMD. Risk of AMD is higher with increasing age and was prevalent among subjects with diabetes. Cessation of smoking and alcohol may reduce the risk of AMD in this population.

Acute and subacute toxicity assessment of lutein in lutein-deficient mice.

Dietary lutein consumption is lower than the actual recommended allowances to prevent macular degeneration; thus dietary lutein supplements have been recommended. This study aimed to investigate potential adverse effect of lutein from Tagetes erecta in lutein-deficient (LD) male mice. Preliminary acute toxicity study revealed that the LD50 exceeded the highest dose of 10000 mg/kg BW. In a subacute study, male mice were gavaged with 0, 100, 1000 mg/kg BW/day for a period of 4 wk. Plasma lutein levels increased dose dependently (P < 0.01) after acute and subacute feeding of lutein in LD mice. Compared to the control (peanut oil without lutein) group, no treatment-related toxicologically significant effects of lutein were prominent in clinical observation, ophthalmic examinations, body, and organ weights. Further, no toxicologically significant findings were eminent in hematological, histopathological, and other clinical chemistry parameters. In the oral subacute toxicity study, the no-observed-adverse-effect level (NOAEL) for lutein in LD mice was determined as 1000 mg/kg/day, the highest dose tested.