Prediagnostic circulating carotenoid levels and the risk of non-Hodgkin lymphoma: the Multiethnic Cohort

Carrot intake is consistently negatively associated with cancer incidence: A systematic review and meta-analysis of prospective observational studies

Carrots are main dietary sources of several potential anti-cancer compounds, including polyacetylenes, while β-carotene has shown no benefits in controlled cancer trials. Accordingly, associations between carrot intake and cancer incidence were quantified, where necessary using α-carotene as a non-causal biomarker of carrot consumption, by searching for studies published before June 2022 reporting risk estimates for relationships of cancer incidence with carrot intake or α-carotene intake or α-carotene plasma concentration, supplemented with hand searches of included studies and reviews. Meta-analyses comparing highest and lowest reported intakes in prospective studies using a random-effects model estimated summary relative risks (RRs) with 95% confidence intervals (CIs), separately for carrot intake or α-carotene plasma concentration, and the corresponding dose-responses. Of 198 observational studies, in 50 prospective studies with 52000 cases recording carrot intake, the cancer-risk was substantially reduced (RR 0.90, 95% CI 0.87-0.94, p ˂ 0·00004). In 30 prospective studies with 9331 cases reporting plasma α-carotene levels, summary RR was 0.80 (0.72-0.89, p ˂ 0·00006). For both exposure types, inter-study heterogeneity was moderate, interaction with cancer types insignificant, and the dose-response significant (p ˂ 0·01). In conclusion, carrot consumption is robustly associated with decreased cancer-risk; carrot consumption should be encouraged, and the causal mechanisms further investigated.

Associations between serum carotenoid levels and the risk of non-Hodgkin lymphoma: a case-control study

Limited studies have investigated the effects of serum carotenoids on the risk of non-Hodgkin lymphoma (NHL), and the findings have been inconclusive. This study aims to assess the association between serum total or specific carotenoid levels and NHL risk. This 1:1 matched, hospital-based case-control study enrolled 512 newly diagnosed (within 1 month) NHL patients and 512 healthy controls who were matched by age (±5 years) and sex in Urumqi, China. Serum carotenoid levels were measured by HPLC. Conditional logistic regression showed that higher serum total carotenoid levels and their subtypes (e.g. α-carotene, β-carotene, β-cryptoxanthin and lycopene) were dose-dependently associated with decreased NHL risk. The multivariable-adjusted OR and their 95 % CI for NHL risk for quartile 4 (v. quartile 1) were 0·31 (95 % CI 0·22, 0·48; Pfor trend < 0·001) for total carotenoids, 0·52 (95 % CI 0·33, 0·79; Pfor trend: 0·003) for α-carotene, 0·63 (95 % CI 0·42, 0·94; Pfor trend: 0·031) for β-carotene, 0·73 (95 % CI 0·49, 1·05; Pfor trend: 0·034) for β-cryptoxanthin and 0·51 (95 % CI 0·34, 0·75; Pfor trend: 0·001) for lycopene. A null association was observed between serum lutein + zeaxanthin and NHL risk (OR 0·89, 95 % CI 0·57, 1·38; Pfor trend: 0·556). Significant interactions were observed after stratifying according to smoking status, and inverse associations were more evident among current smokers than past or never smokers for total carotenoids, α-carotene and lycopene (Pfor heterogeneity: 0·047, 0·042 and 0·046). This study indicates that higher serum carotenoid levels might be inversely associated with NHL risk, especially among current smokers.

Serum Retinol and Risk of Overall and Site-Specific Cancer in the ATBC Study

Retinol, the most biologically active form of vitamin A, might influence cancer-related biological pathways. However, results from observational studies of serum retinol and cancer risk have been mixed. We prospectively examined serum retinol and risk of overall and site-specific cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (n = 29,104 men), conducted in 1985-1993, with follow-up through 2012. Serum retinol concentration was measured using reverse-phase high-performance liquid chromatography. Cox proportional hazards models estimated the association between baseline serum retinol quintile and overall and site-specific cancer risk in 10,789 cases. After multivariable adjustment, higher serum retinol was not associated with overall cancer risk (highest vs. lowest quintile: hazard ratio (HR) = 0.97, 95% confidence interval (CI): 0.91, 1.03; P for trend = 0.43). Higher retinol concentrations were, however, associated with increased risk of prostate cancer (highest vs. lowest quintile: HR = 1.28, 95% CI: 1.13, 1.45; P for trend < 0.0001) and lower risk of both liver and lung cancers (highest vs. lowest quintile: for liver, HR = 0.62, 95% CI: 0.42, 0.91; P for trend = 0.004; and for lung, HR = 0.80, 95% CI: 0.72, 0.88; P for trend < 0.0001). No associations with other cancers were observed. Understanding the mechanisms that underlie these associations might provide insight into the role of vitamin A in cancer etiology.

Diet Quality and Biomarker Profiles Related to Chronic Disease Prevention: The Multiethnic Cohort Study

Objective: To understand how diet quality affects chronic disease etiology, the associations of 4 a priori diet quality indices with blood levels of lipid-soluble micronutrients and biomarkers of inflammation, lipid, and glucose metabolism were examined in 5 ethnic groups.Methods: In a cross-sectional design, the Adiposity Phenotype Study, a subset of the Multiethnic Cohort in Hawaii and Los Angeles, recruited participants of white, African American, Native Hawaiian, Japanese American, and Latino ancestry. A total of 896 men and 910 women completed a validated quantitative food frequency questionnaire and anthropometric measurements and donated a fasting blood sample. Using general linear models, covariate-adjusted mean levels of lipid-soluble micronutrients (total carotenes, lycopene, total tocopherols, total lutein, cryptoxanthins), biomarkers of inflammation (C-reactive protein [CRP], tumor necrosis factor-[Formula: see text]), adipokines (adiponectin, leptin), lipids (total cholesterol, high-density lipoprotein cholesterol [HDL-C], triglycerides), and glucose metabolism (glucose, insulin, homeostatic model assessment of insulin resistance [HOMA-IR]) were computed across tertiles of 4 a priori dietary indices Healthy Eating Index (HEI)-2010, Alternative HEI (AHEI)-2010, alternate Mediterranean Diet (aMED), Dietary Approaches to Stop Hypertension (DASH); trends were evaluated in models with diet quality scores as continuous variables.Results: With better diet quality, levels of carotenes, lutein, cryptoxanthin, adiponectin, and HDL-C were significantly higher (p_trend < 0.01), whereas levels of CRP, leptin, total cholesterol, triglycerides, glucose, insulin, and HOMA-IR were inversely associated (p_trend < 0.05) with diet quality. With the exception of cryptoxanthins and triglycerides, the associations were consistent across ethnic groups.Conclusions: These findings confirm the association between diet quality and nutrition-related biomarkers and support the idea that a high-quality diet positively influences biologic pathways involved in chronic disease etiology across different ethnic groups.

Micronutrient Intake and Risk of Hematological Malignancies in Adults: A Systematic Review and Meta-analysis of Cohort Studies

There has been accumulating evidence that several micronutrients may play a protective role in the risk of solid cancers. However, their role in hematological malignancies remains to be elucidated; this meta-analysis aims to evaluate the associations between micronutrient intake as well as supplementation and risk of hematological cancer in adults. Eligible cohort studies (examining intake of vitamin A, vitamin C, vitamin D, vitamin E, lycopene, folate, iron, carotenoids, beta-carotene, selenium, pyridoxine) were sought in PubMed up to July 31, 2016. Random-effects models were used for the calculation of pooled relative risks (RR) with their 95% confidence intervals (CI). Twelve cohort studies were deemed eligible. Null associations were noted regarding supplemented vitamin A (pooled relative risk [RR] = 0.92, 95% confidence interval [CI]: 0.80-1.07), supplemented vitamin C (pooled RR = 1.00, 95%CI: 0.90-1.12), total vitamin D (pooled RR = 1.05, 95%CI: 0.91-1.20), supplemented vitamin E (pooled RR = 0.98, 95%CI: 0.88-1.10), and dietary lycopene intake (pooled RR = 1.00, 95%CI: 0.86-1.16) and the risk of non-Hodgkin lymphoma. No summary estimates are provided for other hematological malignancies due to the limited number of studies. Future prospective trials should be conducted for a better understanding of this field; especially regarding Hodgkin lymphoma, leukemia and plasma cell neoplasms, on which data are scarce.

The potential of chiroptical and vibrational spectroscopy of blood plasma for the discrimination between colon cancer patients and the control group

Colorectal cancer is one of the most abundant causes of cancer deaths in the world. At an early stage, the established clinical procedures have low reliability and sensitivity. Therefore, we tested a novel approach based on chiroptical methods such as electronic circular dichroism (ECD) and Raman optical activity (ROA). These methods are suitable for detecting slight changes in the 3D structure of chiral biomolecules, some of which may be caused by pathological processes occurring during cancer growth. Fifty-five blood plasma samples were analyzed using the combination of ECD and ROA supplemented by conventional Raman and FT-IR spectroscopy. All obtained spectra were evaluated together by linear discriminant analysis. The accuracy of sample discrimination reached 100% and the subsequent leave-one-out cross-validation resulted in 93% sensitivity and 81% specificity. The achieved results indicate that chiroptical methods supplemented by Raman and FT-IR spectroscopy might be new supporting and minimally invasive tools in the clinical diagnosis of colon cancer.

β-Cryptoxanthin Synergistically Enhances the Antitumoral Activity of Oxaliplatin through ΔNP73 Negative Regulation in Colon Cancer

BACKGROUND

The acquired resistance to chemotherapy represents the major limitation in the treatment of cancer. New strategies to solve this failure and improve patients' outcomes are necessary. The cancer preventive effect of β-cryptoxanthin has been widely described in population studies. Few reports support its putative use as an antitumoral compound. Here we focus on the therapeutic potential of β-cryptoxanthin individually or in combination with oxaliplatin in colon cancer and try to decipher the molecular basis underlying its effect.

METHODS

Apoptosis, viability and proliferation assays, mouse models, and an intervention study in 20 healthy subjects were performed. A PCR array was carried out to unravel the molecular putative basis of the β-cryptoxanthin effect, and further signaling experiments were conducted. Comet Assay was completed to evaluate the genotoxicity of the treatments.

RESULTS

β-Cryptoxanthin differentially regulates the expression of the P73 variants in vitro, in vivo, and in a human intervention study. This carotenoid decreases the proliferation of cancer cells and cooperates with oxaliplatin to induce apoptosis through the negative regulation of ΔNP73. The antitumoral concentrations of oxaliplatin decrease in the presence of β-cryptoxanthin to achieve same percentage of growth inhibition. The genotoxicity in peripheral blood mononuclear cells of mice decreased in the combined treatment.

CONCLUSIONS

We propose a putative novel therapeutic strategy for the treatment of colon cancer based on the combination of β-cryptoxanthin and oxaliplatin. The combined regimen produced more benefit than either individual modality without increasing side effects. In addition, the concentration-limiting toxicity of oxaliplatin is reduced in the presence of the carotenoid.

Genetic variation predicts serum lycopene concentrations in a multiethnic population of postmenopausal women

BACKGROUND

The consumption and blood concentrations of lycopene are both positively and inversely associated with the risk of several chronic diseases. The inconsistences in lycopene disease association studies may stem from a lack of knowledge about the genetic variation in the synthesis, metabolism, and deposition of transport and binding proteins, which potentially influence serum lycopene concentrations.

OBJECTIVE

We examined the association between variation across the genome and serum concentrations of lycopene in a multiethnic population.

METHODS

Participants included African (n = 914), Hispanic (n = 464), and European (n = 1203) American postmenopausal women from the Women's Health Initiative. We analyzed ∼7 million single nucleotide polymorphisms (SNPs). Linear regression models were used to assess associations between each SNP and serum concentrations (log transformed, continuous) of lycopene; we adjusted for age, body mass index, and population substructure. Models were run separately by ethnicity, and results were combined in a transethnic fixed-effects meta-analysis.

RESULTS

In the meta-analysis, the scavenger receptor class B, member 1 (SCARB1) gene, which encodes for a cholesterol membrane transporter, was significantly associated with lycopene concentrations (rs1672879; P < 2.68 × 10(-9)). Each additional G allele resulted in a 12% decrease in lycopene concentrations for African Americans, 20% decrease for Hispanic Americans, and 9% decrease for European Americans. In addition, 2 regions were significantly associated with serum lycopene concentrations in African Americans: the slit homolog 3 gene (SLIT3), which serves as a molecular guidance cue in cellular migration, and the dehydrogenase/reductase (SDR family) member 2 (DHRS2) gene, which codes for an oxidoreductase that mitigates the breakdown of steroids.

CONCLUSIONS

We found 3 novel loci associated with serum lycopene concentrations, 2 of which were specific to African Americans. Future functional studies looking at these specific genes may provide insight into the metabolism and underlying function of lycopene in humans, which may further elucidate lycopene's influence on disease risk and health. This trial was registered at clinicaltrials.gov as NCT00000611.

Epidemiology and etiology of non-hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) consists of many histologically and biologically distinct lymphoid malignancies with poorly understood, but possibly distinct, etiologies. The patterns of incidence and time trend vary not only by age, sex, and race/ethnicity in the USA, but also show significant geographic differences, suggesting the potential role of infectious agents, environmental factors, and lifestyle factors in addition to host genetic status in the development of NHL. Important pathogenetic mechanisms include immune modulation and chronic antigen stimulation. Epidemiologic studies in the past two decades have provided intriguing new insights on the possible causes of lymphoma and support the idea that there is some mechanistic commonality of lymphomagenesis, but significant etiologic heterogeneity clearly exists. This review presents a summary of the current understanding of the descriptive epidemiology and etiology of NHL and suggests areas of focus for future epidemiologic research.

Race differences in the relation of vitamins A, C, E, and β-carotene to metabolic and inflammatory biomarkers

Using archival data, we conducted a secondary analysis to examine race differences in the relation of serum vitamins A, C, E and β-carotene to insulin resistance (IR), fasting insulin and glucose, high sensitivity C-reactive protein (hs-CRP), and leukocyte count in 176 non-smoking, healthy, white, and African American (AA) adults aged 18 to 65 years (48% women, 33% AA). We hypothesized that micronutrient concentrations would be associated with early risk markers of cardiometabolic diseases in a race-dependent manner. Fasting blood samples were analyzed for micronutrients, insulin, glucose, hs-CRP, and leukocyte count. Insulin resistance was estimated using the homeostatic model assessment. After adjusting for age, body mass index, gender, educational level, use of vitamin supplements, alcohol intake, leisure time physical activity, menopausal status, and total cholesterol, we observed that β-carotene was significantly associated with insulin resistance and fasting insulin in a race-dependent manner. Among AA, lower β-carotene levels were associated with higher estimates of insulin resistance and fasting insulin; whereas, these same associations were not significant for whites. Race also significantly moderated the relation of vitamin C to leukocyte count, with lower vitamin C being associated with higher leukocyte count only in AA but not whites. For all subjects, lower β-carotene was associated with higher hs-CRP. In AA, but not whites, lower levels of β-carotene and vitamin C were significantly associated with early risk markers implicated in cardiometabolic conditions and cancer. Whether or not lower levels of micronutrients contribute uniquely to racial health disparities is a worthwhile aim for future research.

Analysis of circulating lipid-phase micronutrients in humans by HPLC: review and overview of new developments

Retinol, tocopherols, coenzyme Q10, carotenoids, and vitamin D are lipophilic compounds shown to function as important health-protective agents by mitigating the damaging effects of oxidative and other injury. Scientific interest in evaluating these compounds has resurfaced in recent years, particularly in the nutritional, clinical and epidemiologic fields, and has precipitated the development of a multitude of new analytical techniques. This review considers recent developments in HPLC-based assays since 2007 for the simultaneous determination of these lipid-phase compounds utilizing exclusively serum or plasma as these matrices are mostly used in clinical and epidemiological investigations. We also provide an overview of blood measurements for selected carotenoids, tocopherols, coenzyme Q10 and retinol from the last 15years of healthy umbilical cord blood, children, and adults.