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.

The applicability of a commercial 3DO body scanner in measuring body composition in Chinese adults with overweight and obesity: a secondary analysis based on a weight-loss clinical trial.

BACKGROUND: A commercial three-dimensional optical (3DO) scanning system was reported to be used in body composition assessment. However, the applicability in Chinese adults has yet to be well-studied. METHODS: This secondary analysis was based on a 16-week weight-loss clinical trial with an optional extension to 24 weeks. Waist and hip circumference and body composition were measured by 3DO scanning at each follow-up visit during the study. Bioelectrical impedance analysis (BIA) was also performed to confirm the reliability of 3DO scanning at each visit. We used Lin's concordance correlation coefficients (CCC) to evaluate the correlation between the two methods above-mentioned. Bland-Altman analysis was also performed to evaluate the agreement and potential bias between different methods. RESULTS: A total number of 70 Chinese adults overweight and obese (23 men and 47 women, aged 31.8 ± 5.8 years) were included in the analysis, which resulted in 350 3DO scans and corresponding 350 BIA measurements. The percent body fat, fat mass, and fat-free mass were 33.9 ± 5.4%, 26.7 ± 4.6 kg, and 50.3 ± 8.7 kg before the trial by 3DO scanning. And they were 30.5 ± 5.8%, 22.5 ± 4.7 kg, and 49.4 ± 8.3 kg after 16 weeks of the trial. Compared with BIA, 3DO scanning performed best in the assessment of fat-free mass (CCC = 0.89, 95%CI: 0.86, 0.90), then followed by fat mass (CCC = 0.76, 95%CI: 0.71, 0.80) and percent body fat (CCC = 0.70, 95%CI: 0.64, 0.75). Subgroup analysis showed that 3DO scanning and BIA correlated better in women than that in men, and correlated better in measuring fat-free mass in participants with larger body weight (BMI ≥28.0 kg/m2) than those with smaller body weight (<28.0 kg/m2). CONCLUSIONS: 3DO scanning is an effective technology to monitor changes in body composition in Chinese adults overweight and obese. However its accuracy and reliability in different ethnicities needs further exploration.

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.

Perspective: A Comprehensive Evaluation of Data Quality in Nutrient Databases.

Nutrient databases are a critical component of nutrition science and the basis of exciting new research in precision nutrition (PN). To identify the most critical components needed for improvement of nutrient databases, food composition data were analyzed for quality, with completeness being the most important measure, and for FAIRness, how well the data conformed with the data science criteria of findable, accessible, interoperable, and reusable (FAIR). Databases were judged complete if they provided data for all 15 nutrition fact panel (NFP) nutrient measures and all 40 National Academies of Sciences, Engineering, and Medicine (NASEM) essential nutrient measures for each food listed. Using the gold standard the USDA standard reference (SR) Legacy database as surrogate, it was found that SR Legacy data were not complete for either NFP or NASEM nutrient measures. In addition, phytonutrient measures in the 4 USDA Special Interest Databases were incomplete. To evaluate data FAIRness, a set of 175 food and nutrient data sources were collected from worldwide. Many opportunities were identified for improving data FAIRness, including creating persistent URLs, prioritizing usable data storage formats, providing Globally Unique Identifiers for all foods and nutrients, and implementing citation standards. This review demonstrates that despite important contributions from the USDA and others, food and nutrient databases in their current forms do not yet provide truly comprehensive food composition data. We propose that to enhance the quality and usage of food and nutrient composition data for research scientists and those fashioning various PN tools, the field of nutrition science must step out of its historical comfort zone and improve the foundational nutrient databases used in research by incorporating data science principles, the most central being data quality and data FAIRness.

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.

Pomegranate juice alters the microbiota in breast milk and infant stool: a pilot study.

Pomegranate juice (PomJ) contains ellagitannins (ETs) that are metabolized to ellagic acid (EA). Intestinal bacteria convert EA further to urolithins that are absorbed into the circulation and may provide health benefits. PomJ consumption by pregnant women was reported to be neuroprotective for their infants. In order to determine whether EA and metabolites are transferred from breast milk of mothers consuming PomJ to nursing infants, we performed an interventional pilot study and enrolled ten healthy women with full-term, exclusively breast-fed infants, consuming 8 oz. of PomJ daily for two weeks. Breast milk, plasma, urine and stool samples were collected from the mothers and the urine and stool samples from the infants before and after two weeks of PomJ consumption. Samples were analyzed using liquid chromatography-mass spectrometry to identify EA metabolites and 16S rRNA sequencing to determine changes in the microbiota. EA metabolite conjugates (dimethyl EA-glucuronide DMEAG and urolithin A-glucuronide UAG) were found in breast milk, plasma and urine from mothers and in urine of infants after 14 days of PomJ consumption. In addition, urolithin B-glucuronide (UBG) was found in breast milk, plasma and urine from two participants and urine from their infants. PomJ consumption was associated with a significant decrease in breast milk of Lactococcus, Subdoligranulum, and Acinetobacter, while the abundance of Firmicutes/Faecalibacterium increased significantly. In breast milk Escherichia/Shigella was inversely correlated to breast milk UAG. In infant stools, the abundance of Lachnoclostridium and Staphylococcus was increased. Infant stool Blautia was positively correlated to breast milk and mother plasma UBG. This pilot study demonstrates that EA and its metabolites are absorbed by the nursing infant from breast milk, excreted in urine and impact the infant gut microbiome. The concentration of EA metabolites in breast milk increased over time. Phenolic compounds in breast milk could be a way to promote neuroprotective, antioxidant and anti-inflammatory health benefits in infants.

Avocado Consumption Increased Skin Elasticity and Firmness in Women - A Pilot Study.

BACKGROUND: Avocados are a rich dietary source of monounsaturated fatty acids, carotenoids, and phenolic compounds. Clinical studies have demonstrated that oral consumption of carotenoids improved skin aging. However, no studies have investigated whether oral intake of avocado will reduce skin aging. OBJECTIVES: We therefore performed this pilot study to assess whether oral consumption of one avocado daily for 8 weeks can reduce skin aging in healthy overweight women assessing skin physical characteristics and resistance to UVB radiation. METHODS: Thirty-nine female participants (age 27-73 years) with Fitzpatrick skin type II-IV were randomly assigned to consume either one avocado daily or continue habitual diet for 8 weeks. Facial skin elasticity, firmness, pigmentation, sebum, and hydration were determined using a cutometer on the forehead and under eye. Minimal erythema dose (MED) was determined by standardized protocol at inner arm. RESULTS: Elasticity and firmness were increased at forehead comparing 8 weeks to baseline in the avocado group. Comparing avocado to control, change in firmness marker from baseline to week 8 indicated a significant increase in forehead skin firmness in the avocado group. We did not observe any change in hydration, pigmentation, sebum, and UVB resistance between the avocado and control group, although changes in melanin and erythema were observed in both groups over time. CONCLUSIONS: Our findings suggest that daily oral avocado consumption may lead to enhanced elasticity and firmness of the facial skin in healthy women. Further studies of other skin locations are required to establish the connection between avocado consumption and skin aging.

Effect of Standardized Grape Powder Consumption on the Gut Microbiome of Healthy Subjects: A Pilot Study.

Grapes provide a rich source of polyphenols and fibers. This study aimed to evaluate the effect of the daily consumption of 46 g of whole grape powder, providing the equivalent of two servings of California table grapes, on the gut microbiome and cholesterol/bile acid metabolism in healthy adults. This study included a 4-week standardization to a low-polyphenol diet, followed by 4 weeks of 46 g of grape powder consumption while continuing the low-polyphenol diet. Compared to the baseline, 4 weeks of grape powder consumption significantly increased the alpha diversity index of the gut microbiome. There was a trend of increasing Verrucomicrobia (p = 0.052) at the phylum level, and a significant increase in Akkermansia was noted. In addition, there was an increase in Flavonifractor and Lachnospiraceae_UCG-010, but a decrease in Bifidobacterium and Dialister at the genus level. Grape powder consumption significantly decreased the total cholesterol by 6.1% and HDL cholesterol by 7.6%. There was also a trend of decreasing LDL cholesterol by 5.9%, and decreasing total bile acid by 40.9%. Blood triglyceride levels and body composition were not changed by grape powder consumption. In conclusion, grape powder consumption significantly modified the gut microbiome and cholesterol/bile acid metabolism.

The Impact of Obesity on SARS-CoV-2 Pandemic Mortality Risk.

The COVID-19 pandemic has uncovered the increased susceptibility of individuals with obesity to infection and severe disease leading to hospitalization and death. Studies in New York City demonstrated that after advanced age, obesity was the most common risk factor leading to severe disease and death from COVID-19. While the connection has been recognized, there has not been a general recognition of the potential mechanisms for this link between excess body fat and mortality from this viral pandemic including respiratory complications and sequelae of increased activation of the immune system. Despite plans for vaccination of the global population, the risk community spread of COVID-19 and future pandemics will be linked in part to obesity and immunity. This review will detail a number of potential mechanisms through which obesity may contribute to the lethality of this viral infection. These insights will hopefully lead to a greater emphasis on obesity prevention and treatment as part of the global response to this and future pandemic threats.

Association of a Self-Paid Medically Supervised Weight Management Program with Reversal of Obesity-Associated Impaired Fasting Glucose.

AIMS: The progression of prediabetes to T2DM can be delayed through diet modification and weight management. However, the intensive lifestyle program is often not covered by medical insurance. This retrospective analysis evaluates the association of a patient self-paid weight management program on an improvement of blood sugar in overweight and obese patients with impaired fasting glucose (IFG). METHODS: The medical records of 4634 patients who participated in the self-pay UCLA Weight Management Program were reviewed and 2572 patients met the criteria for this retrospective analysis to examine whether this program was associated with the reversal of IFG over 3 months among 1396 patients with normal fasting glucose (NFG) and 1176 with IFG. RESULTS: The patients with IFG lost comparable amounts of weight (10.5 ± 1.3 kg) at three months, as did the subjects with NFG (10.1 ± 1.3 kg). Fasting blood glucose in the IFG group decreased from 108.49 ± 6.4 to 101.8 ± 9.41 mg/dL (p < 0.0001) after three months. There were also significant reductions in triglycerides, and both systolic and diastolic blood pressure in both groups in association with weight loss. CONCLUSION: Our medically supervised self-pay multidisciplinary weight management program was associated with reduced fasting blood glucose levels in patients with IFG over three months with comparable weight loss to patients with NFG.

Mixed Tree Nut Snacks Compared to Refined Carbohydrate Snacks Resulted in Weight Loss and Increased Satiety during Both Weight Loss and Weight Maintenance: A 24-Week Randomized Controlled Trial.

Mixed tree nuts (MTNs) are an excellent source of protein and healthy fat contributing to satiety. However, their relatively high caloric content might not be beneficial in a weight loss diet. The present study was designed to test whether including MTNs in a weight loss and maintenance program interferes with weight management compared to a refined carbohydrate pretzel snack (PS). We performed a randomized, controlled, two-arm study in 95 overweight individuals consuming 1.5 oz of MTNs or PS daily as part of a hypocaloric weight loss diet (-500 kcal) over 12 weeks followed by an isocaloric weight maintenance program for 12 weeks. Participants in both groups experienced significant weight loss (12 weeks: -1.6 and -1.9 and 24 weeks: -1.5 and -1.4 kg) compared to baseline in the MTN and PS groups, respectively. However, there was no difference in weight loss and other outcome parameters between the MTN and PS groups. The MTN group showed a significant increase in satiety at 24 weeks. Both groups had a decrease in diastolic blood pressure at 12 weeks. Participants in the MTN group showed significant decreases in heart rate at 4, 12, and 24 weeks. Plasma oleic acid was significantly increased at 12 and 24 weeks in the MTN group but only at 12 weeks in the PS group. Plasma MCP-1 was decreased significantly in the MTN group at 4 weeks. In summary, participants in both groups lost weight, but only the MTN intervention increased satiety at 24 weeks, enhanced retention, decreased heart rate, and increased serum oleic acid at 24 weeks.

The Effect of Broccoli Sprout Extract on Seasonal Grass Pollen-Induced Allergic Rhinitis.

Patients exposed to pollutants are more likely to suffer from allergic rhinitis and may benefit from antioxidant treatment. Our study determined if patients diagnosed with grass-induced allergic rhinitis could benefit from broccoli sprout extract (BSE) supplementation. In total, 47 patients were confirmed with grass-induced allergic rhinitis and randomized to one of four groups: group 1 (nasal steroid spray + BSE), group 2 (nasal steroid spray + placebo tablet), group 3 (saline nasal spray + BSE) and group 4 (saline nasal spray + placebo tablet). Peak Nasal Inspiratory Flow (PNIF), Total Nasal Symptoms Scores (TNSS) and nasal mucus cytokine levels were analyzed in samples collected before and after the 3-week intervention. Comparing before and after the intervention, PNIF improved significantly when comparing Groups 1 and 2, vs. placebo, at various time points (p ≤ 0.05 at 5, 15, 60 and 240 min) following nasal challenge, while TNSS was only statistically significant at 5 (p = 0.03), 15 (p = 0.057) and 30 (p = 0.05) minutes. There were no statistically significant differences in various cytokine markers before and after the intervention. Combining nasal corticosteroid with BSE led to the most significant improvement in objective measures.

California strawberry consumption increased the abundance of gut microorganisms related to lean body weight, health and longevity in healthy subjects.

It was our hypothesis that foods high in polyphenols and fiber have prebiotic activity. This human intervention study aimed to determine if daily consumption of freeze-dried California strawberry powder (SBP) leads to changes in the intestinal microbiota, fecal cholesterol and bile acid (BA) microbial metabolites. Fifteen healthy adults consumed a beige diet+26 g of SBP for 4 weeks, followed by 2 weeks of beige diet only. Stool samples were collected at 0, 4, and 6 weeks. Fecal microbiota was analyzed by 16S rRNA sequencing; fecal cholesterol, BA, and microbial metabolites by gas chromatography. Confirming compliance, urine concentration of pelargonidin, urolithin A glucuronide and dimethylellagic acid glucuronide were present after 4 weeks of SBP consumption. Daily SBP altered the abundance of 24 operational taxonomic units (OTUs). Comparing week 4 to baseline the most significant increases were observed for one OTU from Firmicutes\Clostridia\ Christensenellaceae\NA, one OTU from Firmicutes\ Clostridia\Mogibacteriacea\NA, one OTU from Verrucomicrobia\ Verrucomicrobiaceae\Akkermansia\Muciniphila, one OTU from Actinobacteria\ Bifidobacteriaceae\Bifidobacterium\NA, and one OTU from Bacteroidetes\Bacteroidia\ Bacteroidaceae\Bacteroides and decrease of one OTU from Proteobacteria\ Betaproteobacteria\Alcaligenaceae\Sutterella. Comparing week 4 to 6, we observed a reversal of the same OTUs from C Christensenellaceae, V muciniphilia and C Mogibacteriaceae. Fecal short chain fatty acids and most of the fecal markers including cholesterol, coprostanol, primary and secondary BAs were not changed significantly except for lithocholic acid, which was increased significantly at week 6 compared to baseline. In summary, SBP consumption increased the abundance of gut microorganisms related to lean body weight, health and longevity, and increased fecal lithocholic acid at week 6 in healthy study participants.

Almond consumption increased UVB resistance in healthy Asian women.

BACKGROUND: Almonds are a rich source of phenolic and polyphenolic compounds, which have antioxidant activity. In vitro and in vivo studies have demonstrated that topical application of almond oil and almond skin extract reduces UVB-induced photoaging. Ultraviolet-B (UVB) protection by oral almond consumption has not been previously studied in humans. OBJECTIVES: To investigate whether oral almond consumption can increase resistance to UVB radiation and reduce skin aging in healthy Asian women. METHODS: Thirty-nine female participants (18-45 years) with Fitzpatrick skin type II-IV were randomly assigned to consume either 1.5 oz of almonds or 1.8 oz of pretzels daily for 12 weeks. Minimal erythema dose (MED) was determined using a standardized protocol, which determined the minimal radiation needed to induce erythema on the inner arm following UVB exposure. Facial skin texture was evaluated by two dermatologists using the Clinician's Erythema Assessment scale and Allergan Roughness scale. Facial melanin index, hydration, sebum, and erythema were determined using a cutometer. RESULTS: The MED was increased in the subjects consuming almonds compared to the control group consuming pretzels. There were no differences noted between the groups consuming almonds versus pretzels in Allergan roughness, melanin, hydration, or sebum on facial skin. CONCLUSIONS: Our findings suggest that daily oral almond consumption may lead to enhanced protection from UV photodamage by increasing the MED.

Pomegranate Metabolites Impact Tryptophan Metabolism in Humans and Mice.

BACKGROUND: We showed that pomegranate juice (PomJ) can help to maintain memory in adults aged >50 y. The mechanism for this effect is unknown, but might involve Trp and its metabolites, which are important in brain function. OBJECTIVES: We aimed to test the hypothesis that PomJ and its metabolites ellagic acid (EA) and urolithin A (UA) affect Trp metabolism. METHODS: Stool and plasma from a cohort [11 PomJ, 9 placebo drink (PL)] of subjects enrolled in our double-blind, placebo-controlled trial (NCT02093130) were collected at baseline and after 1 y of PomJ or PL consumption. In a mouse study, cecum and serum were collected from DBA/2J mice receiving 8 wk of dietary 0.1% EA or UA supplementation. Trp metabolites and intestinal microbiota were analyzed by LC-MS and 16S rRNA gene sequencing, respectively. RESULTS: In the human study, the change in the plasma Trp metabolite indole propionate (IPA) over 1 y was significantly different between PomJ and PL groups (P = 0.03). In serum of experimental mice, we observed a 230% increase of IPA by EA but not UA, a 54% increase of indole sulfate by UA but not EA, and 43% and 34% decreases of kynurenine (KYN) by EA and UA, respectively. In cecum, there was a 32% decrease of Trp by UA but not EA, and an 86% decrease of KYN by EA but not UA (P < 0.05). The abundance of 2 genera, Shigella and Catenibacterium, was reduced by PomJ in humans as well as by UA in mice, and their abundance was negatively associated with blood IPA in humans and mice (P < 0.05). CONCLUSIONS: These results suggest a novel mechanism involving the regulation of host and microbial Trp metabolism that might contribute to the health benefits of ellagitannins and EA-enriched food, such as PomJ.

Ellagic Acid and Its Microbial Metabolite Urolithin A Alleviate Diet-Induced Insulin Resistance in Mice.

SCOPE: This work aims at evaluating the effect of dietary ellagic acid (EA) and its microbial metabolite urolithin A (UA) on glucose metabolism and insulin resistance (IR) in mice with diet-induced IR. METHODS AND RESULTS: DBA2J mice are fed a high fat/high sucrose diet (HF/HS) for 8 weeks to induce IR and then 0.1% EA, UA, or EA and UA (EA+UA) are added to the HF/HS-diet for another 8 weeks. UA significantly decreases fasting glucose and increases adiponectin compared with HF/HS-controls. During intraperitoneal insulin tolerance test, EA+UA significantly improve insulin-mediated glucose lowering effects at 15 and 120 min and reduce blood triglycerides compared with HF/HS-controls. Serum free fatty acids are significantly decreased by EA, UA, and EA+UA. Differential expression of genes related to mitochondrial function by EA, UA, and EA+UA in liver and skeletal muscle is observed. Primary hepatocytes from IR-mice have higher proton leak, basal and ATP-linked oxygen consumption rates compared with healthy controls. EA and EA+UA but not UA reduce the proton leak in hepatocytes from IR-mice. CONCLUSION: EA and UA induce different metabolic benefits in IR mice. The effects of EA and UA on mitochondrial function suggest a potentially novel mechanism modulating metabolism.

Prospective randomized trial evaluating blood and prostate tissue concentrations of green tea polyphenols and quercetin in men with prostate cancer.

We evaluated if chronic consumption of quercetin (Q) with green tea extract (GTE) enhances the bioavailability of GT polyphenols (GTPs) and reduces methylation activity as previously observed in mouse xenograft tumors. In this prospective, randomized, parallel design, placebo controlled study, thirty-one men with prostate cancer consumed daily 1 gram of GTE (830 mg of GTP) with 800 mg of Q (GT + Q) or placebo (GT + PL) for four weeks before prostatectomy. First morning voided urine was collected at baseline, 3 weeks and the day of surgery, and prostate tissue on the day of surgery. In week 3, plasma concentration of GTPs and Q was measured in blood collected before and 2 hours after the morning dose. Prostate tissue epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) were detected in 67 and 93% of participants in the GT + Q group and 75 and 94% of participants in the GT + PL group. Q was increased 14-fold, 12-fold and 4.5-fold in plasma, urine, and prostate tissue, respectively, in the GT + Q compared to the GT + PL-group. There was a trend for decreased EGC levels in urine collected prior to prostatectomy in the GT + Q compared to GT + PL-group (p = 0.053). Plasma epigallocatechin (EGC) showed a trend to increase (p = 0.066) two hours after capsule intake in the GT + Q vs. the GT + PL-group. There was no significant difference between the groups in GTP content or methylation activity in prostate tissue or RBCs. No liver toxicity was observed. Although our findings are suggestive, further studies are warranted evaluating if Q alters GTP metabolism.