Memory and Brain Amyloid and Tau Effects of a Bioavailable Form of Curcumin in Non-Demented Adults: A Double-Blind, Placebo-Controlled 18-Month Trial.

OBJECTIVE: Because curcumin's anti-inflammatory properties may protect the brain from neurodegeneration, we studied its effect on memory in non-demented adults and explored its impact on brain amyloid and tau accumulation using 2-(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile positron emission tomography (FDDNP-PET). METHODS: Forty subjects (age 51-84 years) were randomized to a bioavailable form of curcumin (Theracurmin® containing 90 mg of curcumin twice daily [N = 21]) or placebo (N = 19) for 18 months. Primary outcomes were verbal (Buschke Selective Reminding Test [SRT]) and visual (Brief Visual Memory Test-Revised [BVMT-R]) memory, and attention (Trail Making A) was a secondary outcome. FDDNP-PET signals (15 curcumin, 15 placebo) were determined in amygdala, hypothalamus, medial and lateral temporal, posterior cingulate, parietal, frontal, and motor (reference) regions. Mixed effects general linear models controlling for age and education, and effect sizes (ES; Cohen's d) were estimated. RESULTS: SRT Consistent Long-Term Retrieval improved with curcumin (ES = 0.63, p = 0.002) but not with placebo (ES = 0.06, p = 0.8; between-group: ES = 0.68, p = 0.05). Curcumin also improved SRT Total (ES = 0.53, p = 0.002), visual memory (BVMT-R Recall: ES = 0.50, p = 0.01; BVMT-R Delay: ES = 0.51, p = 0.006), and attention (ES = 0.96, p < 0.0001) compared with placebo (ES = 0.28, p = 0.1; between-group: ES = 0.67, p = 0.04). FDDNP binding decreased significantly in the amygdala with curcumin (ES = -0.41, p = 0.04) compared with placebo (ES = 0.08, p = 0.6; between-group: ES = 0.48, p = 0.07). In the hypothalamus, FDDNP binding did not change with curcumin (ES = -0.30, p = 0.2), but increased with placebo (ES = 0.26, p = 0.05; between-group: ES = 0.55, p = 0.02). CONCLUSIONS: Daily oral Theracurmin may lead to improved memory and attention in non-demented adults. The FDDNP-PET findings suggest that symptom benefits are associated with decreases in amyloid and tau accumulation in brain regions modulating mood and memory.

Decaffeinated green and black tea polyphenols decrease weight gain and alter microbiome populations and function in diet-induced obese mice.

PURPOSE: Decaffeinated green tea (GT) and black tea (BT) polyphenols inhibit weight gain in mice fed an obesogenic diet. Since the intestinal microflora is an important contributor to obesity, it was the objective of this study to determine whether the intestinal microflora plays a role in the anti-obesogenic effect of GT and BT. METHODS: C57BL/6J mice were fed a high-fat/high-sucrose diet (HF/HS, 32% energy from fat; 25% energy from sucrose) or the same diet supplemented with 0.25% GTP or BTP or a low-fat/high-sucrose (LF/HS, 10.6% energy from fat, 25% energy from sucrose) diet for 4 weeks. Bacterial composition was assessed by MiSeq sequencing of the 16S rRNA gene. RESULTS: GTP and BTP diets resulted in a decrease of cecum Firmicutes and increase in Bacteroidetes. The relative proportions of Blautia, Bryantella, Collinsella, Lactobacillus, Marvinbryantia, Turicibacter, Barnesiella, and Parabacteroides were significantly correlated with weight loss induced by tea extracts. BTP increased the relative proportion of Pseudobutyrivibrio and intestinal formation of short-chain fatty acids (SCFA) analyzed by gas chromatography. Cecum propionic acid content was significantly correlated with the relative proportion of Pseudobutyrivibrio. GTP and BTP induced a significant increase in hepatic 5'adenosylmonophosphate-activated protein kinase (AMPK) phosphorylation by 70 and 289%, respectively (P < 0.05) determined by Western blot. CONCLUSION: In summary, both BTP and GTP induced weight loss in association with alteration of the microbiota and increased hepatic AMPK phosphorylation. We hypothesize that BTP increased pAMPK through increased intestinal SCFA production, while GTPs increased hepatic AMPK through GTP present in the liver.

Pomegranate ellagitannins stimulate the growth of Akkermansia muciniphila in vivo.

Results from our previous human pomegranate extract (POM extract) intervention study demonstrated that about seventy percent of participants were able to form urolithin A from ellagitannins in the intestine (urolithin A producers). Urolithin A formation was associated with a high proportion of Akkermansia muciniphila in fecal bacterial samples as determined by 16S rRNA sequencing. Here we investigated whether A. muciniphila counts increased in stool samples collected after the POM extract intervention compared to baseline stool samples using real-time PCR. In addition, we performed in vitro culture studies to determine the effect of POM extract and ellagic acid on the growth of A. muciniphila and to analyze ellagic acid metabolites formed in the culture broth by high-performance liquid chromatography. Supplementation of culture broth with 10 µM of ellagic acid did not change A. muciniphila growth while the addition of 0.18 mg/ml and 0.28 mg/ml of POM extract to the culture broth inhibited the growth of A. muciniphila significantly. Incubation of A. muciniphila with POM extract resulted in formation of ellagic acid and incubation of A. muciniphila with ellagic acid demonstrated hydrolysis of ellagic acid to metabolites different from urolithin A. The in vitro culture studies with A. muciniphila partially explain our in vivo findings that the presence of A. muciniphila was associated with breakdown of ellagic acid for further metabolism by other members of the microbiota. This is the first report of the role of A. muciniphila in ellagitannin hydrolysis. However, we conclude that enzymes from other bacteria must be involved in the formation of urolithin A in the human intestine.

Dietary pomegranate extract and inulin affect gut microbiome differentially in mice fed an obesogenic diet.

Growing evidence suggests that dysbiosis of gut microbiota is associated with pathogenesis of a variety of human diseases. Using dietary intervention to shape the composition and metabolism of the gut microbiota is increasingly recognized. In the present study, we investigated the effects of polysaccharide inulin and polyphenol-rich pomegranate extract (PomX) alone or in combination on the cecal microbiota composition and function in a diet induced obesity mouse model. Male C57BL/6 mice were randomly divided into four experimental groups and consumed either high-fat/high-sucrose [HF/HS (32% energy from fat, 25% energy from sucrose, 17% energy from protein)] diet, HF/HS diet supplemented with PomX (0.25%), or inulin (9%) or PomX and inulin in combination for 4 weeks. In mice fed the PomX-diet the proportion of Turicibacteraceae and Ruminococcaceae was significantly increased compared to the control HF/HS diet. Supplementation with inulin alone and inulin + PomX combination significantly increased the proportion of Verrucomicrobiaceae (A. muciniphila) and decreased Clostridiaceae. Only mice fed the inulin diet experienced an increase in serum lipopolysaccharide (LPS) and monocyte chemoattractant protein 1 (MCP-1), which was reversed when feeding the inulin + PomX diet. Feeding the inulin + PomX diet was associated with a significant increase in Bifidobacteriaceae and Rikenellaceae, which may have contributed to the reduction of endotoxemia markers. Inulin supplementation showed lower species richness of gut microbiota compared to mice fed with HF/HS or HF/HS/PomX, and the reduction was reversed by the addition of PomX. Inulin alone and in combination with PomX had distinct microbial clusters determined by both weighted and unweighted UniFrac Beta-Diversity principle coordinate analysis. A total of 19 KEGG biological pathways were significantly regulated in the gut microbiota with PomX and inulin alone or combined treatment. Inulin significantly enhanced KEGG infectious disease-related pathway associated with increase of serum LPS and MCP-1. No changes in gene expression of ileal proinflammatory cytokine and tight junction genes were observed in mice treated with PomX and inulin. Our results demonstrated that the gut microbiota and their biological pathways were differentially effected by dietary PomX and inulin fed combined or alone. It is therefore very important to consider the interaction among bioactive components of food when evaluating potential prebiotic effects.

Effect of Dietary Omega-3 Fatty Acids on Tumor-Associated Macrophages and Prostate Cancer Progression.

BACKGROUND: Preclinical and clinical studies suggest that a fish oil-based diet may play a role in delaying the progression of prostate cancer through a number of different mechanisms involving inflammatory pathways. Given the importance of tumor-associated macrophages (TAMs) in carcinogenesis, we hypothesized that a fish oil-based diet will inhibit TAM infiltration and delay the growth of prostate cancer. METHODS: Androgen sensitive mouse prostate cancer (MycCaP) allograft tumors were grown in fully immunocompetent FVB mice fed a high- fat fish oil (omega-3) or corn oil (omega-6) diet. Gene expression of markers for immune cell populations, cytokines, chemokines, and signaling pathways were determined by real-time PCR and western blot in tumor tissue. Cell proliferation and apoptosis in vitro were measured by MTS assay and flow cytometry. RESULTS: Tumor volumes were significantly smaller in mice in ω-3 versus the ω-6 group (P = 0.048). Gene expression of markers for M1 and M2 macrophages (F4/80, iNOS, ARG1), associated cytokines (IL-6, TNF alpha, IL-10), and the chemokine CCL-2 were also lower in the omega-3 group. Correlative in vitro studies were performed in M1 and M2 polarized macrophages and mirrored the in vivo findings. Dietary fish oil and in vitro omega-3 fatty acid administration reduced protein expression of transcription factors in the nuclear factor kappa B pathway leading to a significant decrease in gene expression of downstream targets (Bcl-2, BCL-XL, XIAP, survivin) in MycCap cells. CONCLUSIONS: These findings underscore the potential of fish oil in modulating the clinical course of human prostate cancer through the immune system. Further preclinical and clinical studies are warranted evaluating fish oil-based therapies for inhibiting the recruitment and function of M1 and M2 tumor infiltrating macrophages. Prostate 76:1293-1302, 2016. © 2016 Wiley Periodicals, Inc.

Biomarkers of Dietary Intake Are Correlated with Corresponding Measures from Repeated Dietary Recalls and Food-Frequency Questionnaires in the Adventist Health Study-2.

BACKGROUND: Accurate assessment of diet in study populations is still a challenge. Some statistical strategies that use biomarkers of dietary intake attempt to compensate for the biasing effects of reporting errors. OBJECTIVE: The objective was to correlate biomarkers of dietary intake with 2 direct measures of dietary intake. METHODS: Subjects provided repeated 24-h dietary recalls and 2 food-frequency questionnaires (FFQs) separated by ∼3 y. Correlations between biomarkers and reported dietary intakes as measured by the recalls and FFQs were de-attenuated for within-person variability. The Adventist Health Study-2 (AHS-2) has a large database of biomarkers of dietary intake (blood, urine, adipose tissue) from a calibration study (909 analytic subjects) representing the cohort. Participants were black and non-black Adventists in the United States and Canada. RESULTS: Dietary items with higher-valued de-attenuated correlations (≥0.50) between biomarkers and recalls included some fatty acids (FAs), the non-fish meats, fruit (non-black subjects), some carotenoids, vitamin B-12 (non-black subjects), and vitamin E. Moderately valued correlations (0.30-0.49) were found for very long chain ω-3 (n-3) FAs, some carotenoids, folate, isoflavones, cruciferous vegetables, fruit (black subjects), and calcium. The highest correlation values in non-black and black subjects were 0.69 (urinary 1-methyl-histidine and meat consumption) and 0.72 (adipose and dietary 18:2 ω-6), respectively. Correlations comparing biomarkers with recalls were generally similar for black and non-black subjects, but correlations between biomarkers and the FFQ were slightly lower than corresponding recall correlations. Correlations between biomarkers and a single FFQ estimate (the usual cohort situation) were generally much lower. CONCLUSIONS: Many biomarkers that have relatively high-valued correlations with dietary intake were identified and were usually of similar value in black and non-black subjects. These may be used to correct effects of dietary measurement errors in the AHS-2 cohort, and in some cases they also provide evidence supporting the validity of the dietary data.

Randomized clinical trial of brewed green and black tea in men with prostate cancer prior to prostatectomy.

BACKGROUND: Preclinical and epidemiologic studies suggest chemopreventive effects of green tea (GT) and black tea (BT) in prostate cancer. In the current study we determined the effect of GT and BT consumption on biomarkers related to prostate cancer development and progression. METHODS: In this exploratory, open label, phase II trial 113 men diagnosed with prostate cancer were randomized to consume six cups daily of brewed GT, BT or water (control) prior to radical prostatectomy (RP). The primary endpoint was prostate tumor markers of cancer development and progression determined by tissue immunostaining of proliferation (Ki67), apoptosis (Bcl-2, Bax, Tunel), inflammation (nuclear and cytoplasmic nuclear factor kappa B [NFκB]) and oxidation (8-hydroxydeoxy-guanosine [8OHdG]). Secondary endpoints of urinary oxidation, tea polyphenol uptake in prostate tissue, and serum prostate specific antigen (PSA) were evaluated by high performance liquid chromatography and ELISA analysis. RESULTS: Ninety three patients completed the intervention. There was no significant difference in markers of proliferation, apoptosis and oxidation in RP tissue comparing GT and BT to water control. Nuclear staining of NFκB was significantly decreased in RP tissue of men consuming GT (P = 0.013) but not BT (P = 0.931) compared to water control. Tea polyphenols were detected in prostate tissue from 32 of 34 men consuming GT but not in the other groups. Evidence of a systemic antioxidant effect was observed (reduced urinary 8OHdG) only with GT consumption (P = 0.03). GT, but not BT or water, also led to a small but statistically significant decrease in serum prostate-specific antigen (PSA) levels (P = 0.04). CONCLUSION: Given the GT-induced changes in NFκB and systemic oxidation, and uptake of GT polyphenols in prostate tissue, future longer-term studies are warranted to further examine the role of GT for prostate cancer prevention and treatment, and possibly for other prostate conditions such as prostatitis.

Antimicrobial Activity of Pomegranate and Green Tea Extract on Propionibacterium Acnes, Propionibacterium Granulosum, Staphylococcus Aureus and Staphylococcus Epidermidis.

We used pomegranate extract (POMx), pomegranate juice (POM juice) and green tea extract (GT) to establish in vitro activities against bacteria implicated in the pathogenesis of acne. Minimum inhibitory concentrations (MIC) of 94 Propionibacterium acnes, Propionibacterium granulosum, Staphylococcus aureus, and Staphylococcus epidermidis strains were determined by Clinical and Laboratory Standards Institute-approved agar dilution technique. Total phenolics content of the phytochemicals was determined using the Folin-Ciocalteu method and the polyphenol composition by HPLC. Bacteria were identified by 16S rRNA sequence analysis. GT MIC of 400 µg/ml or less was obtained for 98% of the strains tested. 64% of P. acnes strains had POMx MICs at 50 µg/ml whereas 36% had MIC >400 µg/ml. POMx, POM juice, and GT showed inhibitory activity against all the P. granulosum strains at ≤100 µg/ml. POMx and GT inhibited all the S. aureus strains at 400 µg/ml or below, and POM juice had an MIC of 200 µg/ml against 17 S. aureus strains. POMx inhibited S. epidermidis strains at 25 µg/ml, whereas POM juice MICs were ≥200 µg/ml. The antibacterial properties of POMx and GT on the most common bacteria associated with the development and progression of acne suggest that these extracts may offer a better preventative/therapeutic regimen with fewer side effects than those currently available.

Pomegranate ellagitannins stimulate growth of gut bacteria in vitro: Implications for prebiotic and metabolic effects.

The present study investigated the effect of pomegranate extract (POMx) and pomegranate juice (POM juice) on the growth of major groups of intestinal bacteria: Enterobacteriaceae, Bacteroides fragilis group, clostridia, bifidobacteria, and lactobacilli, and the utilization of pomegranate polyphenols by Bifidobacterium and Lactobacillus. The total phenolic content of the pomegranate extract and juice was determined using the Folin-Ciocalteau colorimetric method and reported as gallic acid equivalent (GAE). The polyphenol composition was determined by HPLC. Stool specimens were incubated with 400, 100, and 25 µg/ml GAE POMx and POM juice and subjected to selective culture. Bifidobacterium and Lactobacillus strains were incubated with 400 µg/ml GAE POMx and POM juice and metabolites were analyzed. POMx and POM juice increased the mean counts of Bifidobacterium and Lactobacillus and significantly inhibited the growth of B. fragilis group, clostridia, and Enterobacteriaceae in a dose-response manner. Bifidobacterium and Lactobacillus utilized ellagic acid and glycosyl ellagic acid but little or no punicalin was utilized. Neither POMx nor POM juice was converted to urolithins by the test bacteria or the in vitro stool cultures. The effect of pomegranate on the gut bacteria considered to be beneficial (Bifidobacterium and Lactobacillus) suggests that pomegranate may potentially work as a prebiotic. The concept that polyphenols such as those in pomegranate impact gut microbiota populations may establish a new role for polyphenols in human health.

Turmeric and black pepper spices decrease lipid peroxidation in meat patties during cooking.

Spices are rich in natural antioxidants and have been shown to be potent inhibitors of lipid peroxidation during cooking of meat. Turmeric contains unique conjugated curcuminoids with strong antioxidant activity. Piperine, one of the main constituents of black pepper, is known to increase the bioavailability of curcuminoids in mouse and human studies when consumed with turmeric. We investigated whether adding black pepper to turmeric powder may further inhibit lipid peroxidation when added to meat patties prior to cooking. The addition of black pepper to turmeric significantly decreased the lipid peroxidation in hamburger meat. When investigating the antioxidant activity of the main chemical markers, we determined that piperine did not exhibit any antioxidant activity. Therefore, we conclude that other black pepper ingredients are responsible for the increased antioxidant activity of combining black pepper with turmeric powder.

Antiproliferative effects of pomegranate extract in MCF-7 breast cancer cells are associated with reduced DNA repair gene expression and induction of double strand breaks.

Pomegranate extract (PE) inhibits the proliferation of breast cancer cells and stimulates apoptosis in MCF-7 breast cancer cells. While PE is a potent antioxidant, the present studies were conducted to examine the mechanisms of action of PE beyond antioxidation by studying cellular and molecular mechanisms underlying breast tumorigenesis. PE inhibited cell growth by inducing cell cycle arrest in G2 /M followed by the induction of apoptosis. In contrast, antioxidants N-acetylcysteine and Trolox did not affect cell growth at doses containing equivalent antioxidant capacity as PE, suggesting that growth inhibition by PE cannot solely be attributed to its high antioxidant potential. DNA microarray analysis revealed that PE downregulated genes associated with mitosis, chromosome organization, RNA processing, DNA replication and DNA repair, and upregulated genes involved in regulation of apoptosis and cell proliferation. Both microarray and quantitative RT-PCR indicated that PE downregulated important genes involved in DNA double strand break (DSB) repair by homologous recombination (HR), such as MRE11, RAD50, NBS1, RAD51, BRCA1, BRCA2, and BRCC3. Downregulation of HR genes correlated with increased levels of their predicted microRNAs (miRNAs), miR-183 (predicted target RAD50) and miR-24 (predicted target BRCA1), suggesting that PE may regulate miRNAs involved in DNA repair processes. Further, PE treatment increased the frequency of DSBs. These data suggest that PE downregulates HR which sensitizes cells to DSBs, growth inhibition and apoptosis. Because HR represents a novel target for cancer therapy, downregulation of HR by PE may be exploited for sensitization of tumors to anticancer drugs.

Green tea, black tea, and oolong tea polyphenols reduce visceral fat and inflammation in mice fed high-fat, high-sucrose obesogenic diets.

Green tea (GT) and caffeine in combination were shown to increase energy expenditure and fat oxidation, but less is known about the effects of black tea (BT) and oolong tea (OT). This study investigated whether decaffeinated polyphenol extracts from GT, BT, and OT decrease body fat and inflammation in male C57BL/6J mice fed high-fat/high-sucrose [HF/HS (32% energy from fat, 25% energy from sucrose)] diets. Mice were fed either an HF/HS diet with 0.25% of polyphenol from GT, OT, or BT or a low-fat/high-sucrose [LF/HS (10.6% energy from fat, 25% energy from sucrose)] diet for 20 wk. Monomeric tea polyphenols were found in the liver and adipose tissue of mice fed the HF/HS diet with GT polyphenols (GTPs) and OT polyphenols (OTPs) but not BT polyphenols (BTPs). Treatment with GTPs, OTPs, BTPs, and an LF/HS diet led to significantly lower body weight, total visceral fat volume by MRI, and liver lipid weight compared with mice in the HF/HS control group. Only GTPs reduced food intake significantly by ∼10%. GTP, BTP, and LF/HS-diet treatments significantly reduced serum monocyte chemotactic protein-1 (MCP-1) compared with HF/HS controls. In mesenteric fat, monocyte chemotactic protein-1 (Mcp1) gene expression was significantly decreased by treatment with GTPs, BTPs, OTPs, and an LF/HS diet and in liver tissue by GTP and BTP treatments. Mcp1 gene expression in epididymal fat was significantly decreased by the BTP and LF/HS diet interventions. In epididymal fat, consistent with an anti-inflammatory effect, adiponectin gene expression was significantly increased by GTPs and OTPs. Angiogenesis during adipose tissue expansion is anti-inflammatory by maintaining adipocyte perfusion. We observed significantly increased gene expression of vascular endothelial growth factor A by GTPs and vascular endothelial growth factor receptor 2 by BTPs and the LF/HS diet and a decrease in pigment epithelium-derived factor gene expression by OTPs and BTPs. In summary, all 3 tea polyphenol extracts induced weight loss and anti-inflammatory and angiogenic effects, although the tissue content of polyphenols differed significantly.

Enhanced Chemoprevention of Prostate Cancer by Combining Arctigenin with Green Tea and Quercetin in Prostate-Specific Phosphatase and Tensin Homolog Knockout Mice.

The low bioavailability of most phytochemicals limits their anticancer effects in humans. The present study was designed to test whether combining arctigenin (Arc), a lignan mainly from the seed of Arctium lappa, with green tea (GT) and quercetin (Q) enhances the chemopreventive effect on prostate cancer. We performed in vitro proliferation studies on different cell lines. We observed a strong synergistic anti-proliferative effect of GT+Q+Arc in exposing androgen-sensitive human prostate cancer LNCaP cells. The pre-malignant WPE1-NA22 cell line was more sensitive to this combination. No cytotoxicity was observed in normal prostate epithelial PrEC cells. For an in vivo study, 3-week-old, prostate-specific PTEN (phosphatase and tensin homolog) knockout mice were treated with GT+Q, Arc, GT+Q+Arc, or the control daily until 16 weeks of age. In vivo imaging using prostate-specific membrane antigen (PSMA) probes demonstrated that the prostate tumorigenesis was significantly inhibited by 40% (GT+Q), 60% (Arc at 30 mg/kg bw), and 90% (GT+Q+Arc) compared to the control. A pathological examination showed that all control mice developed invasive prostate adenocarcinoma. In contrast, the primary lesion in the GT+Q and Arc alone groups was high-grade prostatic intraepithelial neoplasia (PIN), with low-grade PIN in the GT+Q+Arc group. The combined effect of GT+Q+Arc was associated with an increased inhibition of the androgen receptor, the PI3K/Akt pathway, Ki67 expression, and angiogenesis. This study demonstrates that combining Arc with GT and Q was highly effective in prostate cancer chemoprevention. These results warrant clinical trials to confirm the efficacy of this combination in humans.

Effect of cinnamon spice on continuously monitored glycemic response in adults with prediabetes: a 4-week randomized controlled crossover trial.

BACKGROUND: Previous clinical studies showing that cinnamon spice lowers blood glucose concentrations had inconsistent results. OBJECTIVES: To determine the effect of daily cinnamon spice supplementation in an amount commonly used for seasoning on glucose concentrations in adults with obesity and prediabetes. METHODS: Following a 2-wk run-in period of maintaining a low polyphenol/fiber diet, 18 participants with obesity and prediabetes underwent a 10-wk randomized, controlled, double-blind, crossover trial (mean age 51.1 y; mean fasting plasma glucose 102.9 mg/dL). The participants were randomly assigned to take cinnamon (4 g/d) or placebo for 4-wk, followed by a 2-wk washout period, and then crossed over to the other intervention for an additional 4-wk. Glucose changes were measured with continuous glucose monitoring. Oral glucose tolerance testing immediately following ingestion of cinnamon or placebo was performed at 4-time points to assess their acute effects both at the baseline and end of each intervention phase. Digestive symptom logs were obtained daily. RESULTS: There were 694 follow-up days with 66,624 glucose observations. When compared with placebo, 24-h glucose concentrations were significantly lower when cinnamon was administered [mixed-models; effect size (ES) = 0.96; 95 % confidence interval (CI): -2.9, -1.5; P < 0.001]. Similarly, the mean net-area-under-the-curve (netAUC) for glucose was significantly lower than for placebo when cinnamon was given (over 24 h; ES = -0.66; 95 % CI: 2501.7, 5412.1, P = 0.01). Cinnamon supplementation resulted in lower glucose peaks compared with placebo (Δpeak 9.56 ± 9.1 mg/dL compared with 11.73 ± 8.0 mg/dL; ES = -0.57; 95 % CI: 0.8, 3.7, P = 0.027). Glucose-dependent-insulinotropic-polypeptide concentrations increased during oral glucose tolerance testing + cinnamon testing (mixed-models; ES = 0.51; 95 % CI: 1.56, 100.1, P = 0.04), whereas triglyceride concentrations decreased (mixed-models; ES = 0.55; 95 % CI: -16.0, -1.6, P = 0.02). Treatment adherence was excellent in both groups (cinnamon: 97.6 ± 3.4 % compared with placebo: 97.9 ± 3.7 %; ES = -0.15; 95 % CI: -1.8, 0.2, P = 0.5). No differences were found in digestive symptoms (abdominal pain, borborygmi, bloating, excess flatus, and stools/day) between cinnamon and placebo groups. CONCLUSIONS: Cinnamon, a widely available and low-cost supplement, may contribute to better glucose control when added to the diet in people who have obesity-related prediabetes. This trial was registered at clinicaltrials.gov as NCT04342624.

Effect of omega-3 fatty acid diet on prostate cancer progression and cholesterol efflux in tumor-associated macrophages-dependence on GPR120.

BACKGROUND: Preclinical and clinical translational research supports the role of an ω-3 fatty acid diet for prostate cancer prevention and treatment. The anti-prostate cancer effects of an ω-3 diet require a functional host g-protein coupled receptor 120 (GPR120) but the underlying effects on the tumor microenvironment and host immune system are yet to be elucidated. METHODS: Friend leukemia virus B (FVB) mice received bone marrow from green fluorescent protein (GFP) labeled GPR120 wild-type (WT) or knockout (KO) mice followed by implanting Myc-driven mouse prostate cancer (MycCap) allografts and feeding an ω-3 or ω-6 diet. Tumor associated immune cells were characterized by flow cytometry, and CD206+ tumor infiltrating M2-like macrophages were isolated for gene expression studies. MycCap prostate cancer cell conditioned medium (CM) was used to stimulate murine macrophage cells (RAW264.7) and bone marrow-derived (BMD) macrophages to study the effects of docosahexanoic acid (DHA, fish-derived ω-3 fatty acid) on M2 macrophage function and cholesterol metabolism. RESULTS: The bone marrow transplantation study showed that an ω-3 as compared to an ω-6 diet inhibited MycCaP allograft tumor growth only in mice receiving GPR120 WT but not GPR120 KO bone marrow. In the ω-3 group, GPR120 WT BMD M2-like macrophages infiltrating the tumor were significantly reduced in number and gene expression of cholesterol transporters Abca1, Abca6, and Abcg1. RAW264.7 murine macrophages and BMDMs exposed to MycCaP cell CM had increased gene expression of cholesterol transporters, depleted cholesterol levels, and were converted to the M2 phenotype. These effects were inhibited by DHA through the GPR120 receptor. CONCLUSION: Host bone marrow cells with functional GPR120 are essential for the anticancer effects of dietary ω-3 fatty acids, and a key target of the ω-3 diet are the M2-like CD206+ macrophages. Our preclinical findings provide rationale for clinical trials evaluating ω-3 fatty acids as a potential therapy for prostate cancer through inhibition of GPR120 functional M2-like macrophages.

Mixed Nuts as Healthy Snacks: Effect on Tryptophan Metabolism and Cardiovascular Risk Factors.

We recently demonstrated that the consumption of mixed tree nuts (MTNs) during caloric restriction decreased cardiovascular risk factors and increased satiety. Tryptophan (Trp) metabolism has been indicated as a factor in cardiovascular disease. Here, we investigated the effect of MTNs on Trp metabolism and the link to cardiovascular risk markers. Plasma and stool were collected from 95 overweight individuals who consumed either MTNs (or pretzels) daily as part of a hypocaloric weight loss diet for 12 weeks followed by an isocaloric weight maintenance program for an additional 12 weeks. Plasma and fecal samples were evaluated for Trp metabolites by LC-MS and for gut microbiota by 16S rRNA sequencing. Trp-kynurenine metabolism was reduced only in the MTNs group during weight loss (baseline vs. week 12). Changes in Trp-serotonin (week 24) and Trp-indole (week 12) metabolism from baseline were increased in the MTNs group compared to the pretzel group. Intergroup analysis between MTN and pretzel groups does not identify significant microbial changes as indicated by alpha diversity and beta diversity. Changes in the relative abundance of genus Paludicola during intervention are statistically different between the MTNs and pretzel group with p < 0.001 (q = 0.07). Our findings suggest that consumption of MTNs affects Trp host and microbial metabolism in overweight and obese subjects.

Concentrated Grape Powder Consumption Modulates Cholesterol Metabolism and Homeostasis in Healthy Subjects.

SCOPE: Four weeks' of concentrated grape powder (GP) consumption reduces circulating cholesterol in healthy free-living subjects consuming a low-fiber/low-polyphenol diet. Here, the study aims to investigate the underlying mechanisms for cholesterol reduction by evaluating biomarkers of cholesterol de novo biosynthesis, intestinal absorption, miRNA involved in transcriptional regulation of cholesterol metabolism, as well as cholesterol oxidation. METHODS AND RESULTS: Fasting plasma samples collected from 19 healthy free-living subjects at baseline and week 4 of GP consumption are used in this study. Gas chromatography-mass (GC-MS) analysis of plasma samples shows that lathosterol, a precursor of cholesterol synthesis, is significantly decreased after GP consumption indicating reduced cholesterol de novo biosynthesis. Markers of intestinal absorption, campesterol, and ß-sitosterol are not changed. Realtime PCR shows that plasma exosomal miRNA-1 is increased after GP consumption. GC-MS also shows that GP consumption reduces the plasma cholesterol oxidation product 27-hydroxycholesterol (27-HC). CONCLUSIONS: This study enhances the understanding of the mechanisms of the cholesterol lowering effects of GP, and provides new insights into the potential health benefits of grape consumption.

Walnuts improve semen quality in men consuming a Western-style diet: randomized control dietary intervention trial.

We tested the hypothesis that 75 g of whole-shelled walnuts/day added to the Western-style diet of healthy young men would beneficially affect semen quality. A randomized, parallel two-group dietary intervention trial with single-blind masking of outcome assessors was conducted with 117 healthy men, age 21-35 yr old, who routinely consumed a Western-style diet. The primary outcome was improvement in conventional semen parameters and sperm aneuploidy from baseline to 12 wk. Secondary endpoints included blood serum and sperm fatty acid (FA) profiles, sex hormones, and serum folate. The group consuming walnuts (n = 59) experienced improvement in sperm vitality, motility, and morphology, but no change was seen in the group continuing their usual diet but avoiding tree nuts (n = 58). Comparing differences between the groups from baseline, significance was found for vitality (P = 0.003), motility (P = 0.009), and morphology (normal forms; P = 0.04). Serum FA profiles improved in the walnut group with increases in omega-6 (P = 0.0004) and omega-3 (P = 0.0007) but not in the control group. The plant source of omega-3, alpha-linolenic acid (ALA) increased (P = 0.0001). Sperm aneuploidy was inversely correlated with sperm ALA, particularly sex chromosome nullisomy (Spearman correlation, -0.41, P = 0.002). Findings demonstrated that walnuts added to a Western-style diet improved sperm vitality, motility, and morphology.

Erythrocyte membrane fatty acid composition, serum lipids, and non-Hodgkin's lymphoma risk in a nested case-control study: the multiethnic cohort.

PURPOSE: Composition of dietary fatty acid intake, which influences cytokine production, may contribute to the development of non-Hodgkin's lymphoma (NHL). Serum lipid levels may serve as biomarkers of inflammation associated with NHL risk. METHODS: We conducted a case-control analysis (275 cases and 549 controls) nested within the Multiethnic Cohort Study (whites, Japanese Americans, Latinos, African Americans, and Native Hawaiians) to examine the association of prediagnostic, erythrocyte membrane phospholipid fatty acid composition, and serum cholesterol and triglyceride (TG) concentrations with the risk of NHL. Conditional logistic regression was used to calculate odds ratios (OR) and 95 % confidence intervals (CI) by tertiles of biomarker concentrations. RESULTS: Higher total saturated fatty acids (SFA) were associated with an increase in NHL risk (OR(T3 vs. T1) = 1.57 [95 % CI: 1.03-2.39]; p(trend) = 0.01), whereas no associations were detected for total n-3 or n-6 polyunsaturated fatty acids. Inverse associations were observed for total cholesterol (TC; OR (T3 vs. T1) = 0.51 [95 % CI: 0.35-0.74]; p(trend) < 0.0001) and high-density lipoprotein cholesterol (HDL-C; OR (T3 vs. T1) = 0.47 [95 % CI: 0.31-0.71]; p(trend) = 0.0001) but not for low-density lipoprotein cholesterol or TG. Adjustment for the use of lipid-lowering medication did not modify the results substantially. CONCLUSIONS: This prospective biomarker investigation offers supportive evidence for an adverse effect of higher erythrocyte membrane SFA levels on NHL risk, but preclinical effects cannot be excluded. Inverse relations between prediagnostic, circulating TC and HDL-C and NHL risk may be due to reverse causation or a result of protective actions of these lipids and lipoproteins.

Quercetin increased the antiproliferative activity of green tea polyphenol (-)-epigallocatechin gallate in prostate cancer cells.

We previously demonstrated that 50% of (-)-epigallocatechin gallate (EGCG) was present in methylated form (4″-MeEGCG) in human prostate tissue, which is less bioactive. We therefore investigated whether quercetin, a natural inhibitor of catechol-O-methyl transferase (COMT), will inhibit EGCG methylation leading to enhanced antiproliferative activity of EGCG in prostate cancer cells. Incubation with both quercetin and EGCG for 2 h increased the cellular concentrations of EGCG by 4- to 8-fold and 6- to 10-fold in androgen-independent PC-3 cells and androgen-dependent LNCaP cells, respectively. Concurrently, the percent of 4″-MeEGCG in the total EGCG was decreased from 39% to 15% in PC-3 cells and from 61% to 38% in LNCaP cells. Quercetin and EGCG in combination synergistically inhibited cell proliferation, caused cell cycle arrest, and induced apoptosis in PC-3 cells. In LNCaP cells, EGCG and quercetin exhibited a stronger antiproliferative activity leading to an additive effect. The synergistic effect of these 2 agents in PC-3 cells could be based on the fact that EGCG primarily inhibited COMT activity, whereas quercetin reduced the amount of COMT protein. In summary, quercetin combined with EGCG in vitro demonstrated enhanced inhibition of cell proliferation by increasing the intracellular concentration of EGCG and decreasing EGCG methylation.