Carotenoids, vitamin A, vitamin C, vitamin E, and folate and risk of self-reported hearing loss in women.

BACKGROUND: Higher intake of certain vitamins may protect against cochlear damage from vascular compromise and oxidative stress, thereby reducing risk of acquired hearing loss, but data are limited. OBJECTIVE: We prospectively examined the relation between carotenoids, vitamin A, vitamin C, vitamin E, and folate intake and risk of self-reported hearing loss in women. DESIGN: This prospective cohort study followed 65,521 women in the Nurses' Health Study II from 1991 to 2009. Baseline and updated information obtained from validated biennial questionnaires was used in Cox proportional hazards regression models to examine independent associations between nutrient intake and self-reported hearing loss. RESULTS: After 1,084,598 person-years of follow-up, 12,789 cases of incident hearing loss were reported. After multivariable adjustment, we observed modest but statistically significant inverse associations between higher intake of ß-carotene and ß-cryptoxanthin and risk of hearing loss. In comparison with women in the lowest quintile of intake, the multivariable-adjusted RR of hearing loss among women in the highest quintile was 0.88 (95% CI: 0.81, 0.94; P-trend < 0.001) for ß-carotene and 0.90 (95% CI: 0.84, 0.96; P-trend < 0.001) for ß-cryptoxanthin. In comparison with women with folate intake 200-399 µg/d, very low folate intake (<200 µg/d) was associated with higher risk (RR: 1.19; 95% CI: 1.01, 1.41), and higher intake tended to be associated with lower risk (P-trend = 0.04). No significant associations were observed for intakes of other carotenoids or vitamin A. Higher vitamin C intake was associated with higher risk; in comparison with women with intake <75 mg/d, the RR among women with vitamin C intake ≥1000 mg/d (mainly supplemental) was 1.22 (95% CI: 1.06, 1.42; P-trend = 0.02). There was no significant trend between intake of vitamin E intake and risk. CONCLUSION: Higher intakes of ß-carotene, ß-cryptoxanthin, and folate, whether total or from diet, are associated with lower risk of hearing loss, whereas higher vitamin C intake is associated with higher risk.

Daily intake of ß-cryptoxanthin prevents bone loss by preferential disturbance of osteoclastic activation in ovariectomized mice.

Although ß-cryptoxanthin, a xanthophyll carotenoid, has been shown to exert an anabolic effect on bone calcification, little attention has been paid thus far to the precise mechanism of bone remodeling. Daily oral administration of ß-cryptoxanthin significantly inhibited osteoclastic activation as well as reduction of bone volume in ovariectomized mice. In vitro studies revealed that ß-cryptoxanthin inhibited differentiation and maturation of osteoclasts by repression of the nuclear factor-κB-dependent transcriptional pathway. Our results suggest that supplementation with ß-cryptoxanthin would be beneficial for prophylaxis and for therapy of metabolic bone diseases associated with abnormal osteoclast activation.

Assessment of dietary vitamin A intake (retinol, α-carotene, ß-carotene, ß-cryptoxanthin) and its sources in the National Survey of Dietary Intake in Spain (2009-2010).

The aim of this study is to assess the intake of the individual components of vitamin A and major dietary sources in the Spaniards using data on food consumption from Spanish National Dietary Intake Survey (2009-2010). A 24-h dietary recall, 3-day diet diary and a software application that includes HPLC analytical data were used. Average dietary vitamin A intake is 716.4 µg retinol equivalents (RE), which is supplied as retinol (57.9%RE) and as provitamin-A carotenoids (42.1%RE). ß-Carotene represents 71.9% of provitamin-A carotenoids, ß-cryptoxanthin 15.3%, α-carotene 12.8%. Red- and orange-colored fruits and vegetables are major contributors of provitamin-A (1587 µg/day). Spanish diet covers the dietary reference on the intake for vitamin A, provided mainly by foods of animal origin. The main contributors to the intake of provitamin-A carotenoids are carrots, tomatoes, spinach and oranges. Data on the intake of individual components of vitamin A contribute to improving our understanding of the relationship between diet and health.

Effect of kumquat (Fortunella crassifolia) pericarp on natural killer cell activity in vitro and in vivo.

Natural killer (NK) cells play a key role in innate immune defense against infectious disease and cancer. A reduction of NK activity is likely to be associated with increased risk of these types of disease. In this study, we investigate the activation potential of kumquat pericarp acetone fraction (KP-AF) on NK cells. It is shown to significantly increase IFN-γ production and NK cytotoxic activity in human KHYG-1 NK cells. Moreover, oral administration of KP-AF significantly improves both suppressed plasma IFN-γ levels and NK cytotoxic activity per splenocyte in restraint-stressed mice. These results indicate that raw kumquat pericarp activates NK cells in vitro and in vivo. To identify the active constituents, we also examined IFN-γ production on KHYG-1 cells by the predicted active components. Only ß-cryptoxanthin increased IFN-γ production, suggesting that NK cell activation effects of KP-AF may be caused by carotenoids such as ß-cryptoxanthin.

Dietary intake of carotenoids and risk of type 2 diabetes.

BACKGROUND AND AIMS: Carotenoids may reduce diabetes risk, due to their antioxidant properties. However, the association between dietary carotenoids intake and type 2 diabetes risk is still unclear. Therefore, the objective of this study was to examine whether higher dietary carotenoid intakes associate with reduced type 2 diabetes risk. METHODS AND RESULTS: Data from 37,846 participants of the European Prospective Investigation into Cancer and Nutrition- Netherlands study were analyzed. Dietary intakes of ß-carotene, α-carotene, ß-cryptoxanthin, lycopene, lutein & zeaxanthin and the sum of these carotenoids were assessed using a validated food frequency questionnaire. Incident type 2 diabetes was mainly self-reported, and verified against general practitioner information. Mean ±SD total carotenoid intake was 10 ± 4 mg/day. During a mean ±SD follow-up of 10 ± 2 years, 915 incident cases of type 2 diabetes were ascertained. After adjustment for age, sex, diabetes risk factors, dietary intake, waist circumference and BMI, higher ß-carotene intakes associated inversely with diabetes risk [Hazard Ratio quartile 4 versus quartile 1 (HR(Q4)): 0.78 (95%CI:0.64,0.95), P-linear trend 0.01]. For α-carotene, a borderline significant reduced risk was observed, with a HR(Q4) of 0.85 (95%CI:0.70,1.03), and P-linear trend 0.05. ß-cryptoxanthin, lycopene, lutein & zeaxanthin, and the sum of all carotenoids did not associate with diabetes risk. CONCLUSIONS: This study shows that diets high in ß-carotene and α-carotene are associated with reduced type 2 diabetes in generally healthy men and women.

Higher intake of carotenoid is associated with a lower risk of colorectal cancer in Chinese adults: a case-control study.

PURPOSE: The associations between specific carotenoid intake and colorectal cancer risk remain inconsistent. The aim of this study was to examine the association between specific dietary carotenoid intake with colorectal cancer risk in Chinese adults. METHOD: From July 2010 to October 2013, 845 eligible colorectal cancer cases and 845 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate logistical regression models were used to calculate the odds ratio (OR) and 95% confidence intervals (95% CIs) of colorectal cancer risk after adjusting for various confounders. RESULTS: A strong inverse association was found between ß-cryptoxanthin intake and colorectal cancer risk. Compared with the lowest quartile, the highest quartile intake showed a risk reduction of 77% (OR 0.23, 95% CI 0.17-0.33, P trend < 0.01) after adjustment for various confounding variables. The inverse associations were also observed for α-carotene (OR 0.50, 95% CI 0.37-0.68, P trend < 0.01), ß-carotene (OR 0.67, 95% CI 0.49-0.91, P trend < 0.01), and lycopene (OR 0.51, 95% CI 0.37-0.70, P trend < 0.01). There was no statistically significant association between lutein/zeaxanthin intake and colorectal cancer risk. These findings were consistent across cancer site, sources of controls, and smoking status. The inverse associations between dietary α-carotene, ß-cryptoxanthin, and lycopene intake and colorectal cancer risk were found in both males and females, while inverse associations between ß-carotene intake and colorectal cancer risk were only observed in males. CONCLUSIONS: Consumption of α-carotene, ß-carotene, ß-cryptoxanthin, and lycopene was inversely associated with colorectal cancer risk. No significant association was found between lutein/zeaxanthin intake and colorectal cancer risk.

Antioxidant micronutrients and the risk of renal cell carcinoma in the Women's Health Initiative cohort.

BACKGROUND: Renal cell carcinoma (RCC) is the eighth leading cancer among women in incidence and commonly is diagnosed at a more advanced stage. Oxidative stress has been considered to play an important role in the pathogenesis of RCC. Various dietary micronutrients have antioxidant properties, including carotenoids and vitamins C and E; thus, diets rich in these nutrients have been evaluated in relation to RCC prevention. The objective of this study was to explore the correlation between antioxidant micronutrients and the risk of RCC. METHODS: In total, 96,196 postmenopausal women who enrolled in the Women's Health Initiative (WHI) between 1993 and 1998 and were followed through July 2013 were included in this analysis. Dietary micronutrient intake was estimated from the baseline WHI food frequency questionnaire, and data on supplement use were collected using an interview-based inventory procedure. RCC cases were ascertained from follow-up surveys and were centrally adjudicated. The risks for RCC associated with intake of α-carotene, ß-carotene, ß-cryptoxanthin, lutein plus zeaxanthin, lycopene, vitamin C, and vitamin E were analyzed using Cox proportional hazards regression adjusted for confounders. RESULTS: Two hundred forty women with RCC were identified during follow-up. Lycopene intake was inversely associated with RCC risk (P = .015); compared with the lowest quartile of lycopene intake, the highest quartile of intake was associated with a 39% lower risk of RCC (hazard ratio, 0.61; 95% confidence interval, 0.39-0.97). No other micronutrient was significantly associated with RCC risk. CONCLUSIONS: The current results suggest that further investigation into the correlation between lycopene intake and the risk of RCC is warranted.