Biomarkers for Food Components With Health Benefits: Progress and Issues Carl L. Keen Department of Nutrition University of California, Davis clkeen@ucdavis.edu Food Forum & the ILSI North American Project Committee on Flavonoids Washington, D.C. June 8 th, 2010
Diets rich in plant foods are strongly associated with a decreased risk for cardiovascular disease. Is this a true causative relationship? If yes, what are the factors driving it?
CHD IHD Dauchet et al., J Nutr 136: 2588-93, 2006
Fruits, vegetables and coronary heart disease Evidence that fruit and vegetable consumption reduces the risk of cardiovascular disease remains scarce thus far. Dauchet et al., Nat. Rev. Cardiol. 2009 1) Consumption of fruits and vegetables is weakly associated with the risk of CHD in cohort studies 2) Prevention trials have failed to show clear effects of fruit and vegetable consumption on the occurrence of CHD 3) Consumption of fruits and vegetables is associated with decreases in the risk for high blood pressure, but effects on other CHD risk factors has not been clearly established 4) Prevention trials have failed to confirm the hypothesis that vitamins and other individual nutrients in fruits and vegetables prevent CHD
The inverse association seen between the consumption of plant food-rich diets and the risk for CVD is due to multiple nutritional variables: favourable sodium/potassium profile low in saturated fat high in essential nutrients (Mg, vitamin C, Vitamin E, etc ) high in fibre high in select non-essential phytochemicals
Biomarkers are needed for the assessing an individuals status for the phytochemical(s) in question, as well as for following the acute, and chronic impact of these phytochemicals on select health parameters
Evaluation of Biomarkers 2010- The Biomarker Evaluation Process Recommendations Recommendation 1: The biomarker evaluation process should consist of the following three steps: 1a. Analytical validation: analyses of available evidence on the analytical performance of an assay; 1b. Qualification: assessment of available evidence on associations between the biomarker and disease states, including data showing effects of interventions on both the biomarker and clinical outcomes; and 1c. Utilization: contextual analysis based on the specific use proposed and the applicability of available evidence to this use. This includes a determination of whether the analytical validation and qualification conducted provide sufficient support for the use proposed.
Evaluation of Biomarkers 2010- The Biomarker Evaluation Process Recommendations Recommendation 2: 2a. For biomarkers with regulatory impact, the FDA should convene expert panels to evaluate biomarkers and biomarker tests. 2b. Initial evaluation of analytical validation and qualification should be conducted separately from a particular context of use. 2c. The expert panels should reevaluate analytical validation, qualification, and utilization on a continual and a case-by-case basis. Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease; IOM, 2010
Evaluation of Biomarkers 2010- The Biomarker Evaluation Process Recommendations Recommendation 3: The FDA should use the same degree of scientific rigor for evaluation of biomarkers across regulatory areas, whether they are proposed for use in the arenas of drugs, medical devices, biologics, or foods and dietary supplements. Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease; IOM, 2010
Evaluation of Biomarkers 2010- The Biomarker Evaluation Process Recommendations Recommendation 4: The FDA should take into account a nutrient s or food s source as well as any modifying effects of the food or supplement that serves as the delivery vehicle and the dietary patterns associated with consumption of the nutrient or food when reviewing health related label claims and the safety of food and supplements. Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease; IOM, 2010
Evaluation of Biomarkers 2010- Strengthening Evidence-Based Regulation Recommendations Recommendation 5: 5-a. Congress should strengthen the FDA s authority to request and enforce post market surveillance across drugs, devices, and biologics when approvals are initially based on putative surrogate endpoint data. 5-b. Congress should grant the FDA authority to request studies and sufficient authority to act on the results of studies on consumer understanding of claims on foods and supplements. Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease; IOM, 2010
Evaluation of Biomarkers 2010- Strengthening Evidence-Based Regulation Recommendations Recommendation 6: 6-a. The U.S. Department of Health and Human Services should facilitate a coordinated, department-wide effort to encourage the collection and sharing of data about biomarkers for all uses, including drugs, biologics, devices, and foods. 6-b. The FDA in coordination with other federal agencies should build needed data infrastructure and surveillance systems to handle the information necessary to gain sufficient understanding of the effects of biomarker use. Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease; IOM, 2010
Evaluation of Biomarkers 2010- Case Studies Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease; IOM, 2010
Evaluation of Biomarkers 2010- Case Studies Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease; IOM, 2010
But, prior to defining appropriate biomarkers for these non-essential phytochemicals; we need a list of likely candidates. An analysis of 16 year follow-up dietary data from 34,489 women enrolled in the Iowa s s Women Heath Study Mink et al. Am J Clin Nutr 2007; 85: 895-909
DIVERSITY IS THE RULE Class Flavanols Structure Flavanol Flavonoid Examples Catechin Food Cocoa, Wine, Tea, Dill Weed, Chinese Cabbage Flavonols Flavonol Quercetin Onion, Apple, Kale, Arugula, Asparagus Flavones Flavone Apigenin Celery Hearts, Parsley, Seed-herb, spice Flavanones Flavanone Naringenin Citrus fruits Isoflavones Genistein Soy products Anthocyanidins Anthocyanidin Delphinidin Radishes, Red Cabbage, Purple Carrots
Rate Ratios of CVD Mortality of Flavonoid Intake for CVD-Free Postmenopausal Women Class Total Flavonoids Q1 Q2 Q3 Q4 Q5 P for Trend Intake (mg/day) 0.6-133 133-202 202-282 282-425 425-3524 RR 1.00 0.85 0.78 0.74 0.790 0.005 Flavan-3-ols or monomers Intake (mg/day) 0-7 7-15 15-29 29-136 136-1050 RR 1.00 0.75 0.76 0.77 0.850 0.885 Proanthocyanidins Intake (mg/day) 0.0-90 90-144 144-212 212-343 343-3226 RR 1.00 0.92 0.81 0.81 0.79 0.002 Mink et al. Am J Clin Nutr 2007; 85: 895-909
Lowest Range of Flavonoid Intake for Reduced Risk in CVD Free Postmenopausal Women Total Flavonoids Total Mortality CHD CVD Intake (mg/day) 133.2-201.8 133.2-201.8 133.2-201.8 RR (95% CI) 0.85 (0.79, 0.92) 0.81 (0.69, 0.96) 0.85 (0.75, 0.97) Proanthocyanidins (includes monomers of: apples, chocolate, seeded grapes) Intake (mg/day) 89.5-143.9 143.9-212.3 143.9-212.3 RR (95% CI) 0.89 (0.83, 0.96) 0.79 (0.67, 0.94) 0.81 (0.71, 0.92) Flavan-3-ols (apples, red wine, green tea, black tea) No significant associations Mink et al. Am J Clin Nutr 2007; 85: 895-909
Consumption of Flavanol-containing Beverage Products - Uptake of Flavanols into the Circulation- 300 6 hours 2 hours 1 hours 0 hours Epicatechin Response (na) 200 100 Catechin 0
Flavanol Stereoisomers
Blood Plasma Flavanols/Metabolites after eating a high-flavanol cocoa product Circulating Flavanols/Metabolites [nm] 3000 2500 2000 1500 1000 500 250 epicatechin catechin 4'MEC EC-7Gluc 4'MEC-Gluc Sum 0-1 0 1 2 3 4 5 6 7 time [h] Schroeter et al. PNAS 103:1024-29,2006 29,2006
FMD Nitric Oxide Flavanol/Metabolites a 12 Flavanol-mediated increases in FMD are inhibited by L-NMMA infusion and NOS inhibition b 4 c 3,500 hfcd lfcd Flow-mediated dilation (%) 10 8 6 4 2 0 *# *# *# *# Increase RXNO (nm) 3 2 1 0-1 -2 *# *# * # * * Sum of plasma flavanols (nm) 3,000 2,500 2,000 1,500 1,000 500 0 *# *# * * *# * *# *# 0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 Time after cocoa drink (h) Schroeter et al. PNAS 2006
Epicatechin - FMD d PAT index 4 3 2 1 *# *# * * * Flow-mediated dilation (%) b 10 8 6 4 2 *# *# Water 1 mg/kg Epicatechin 0 Water 1 mg/kg Epicatechin 0 1 2 3 4 Time after Ingestion (h) 0 0 1 2 3 4 Time after Ingestion (h) Schroeter et al. PNAS 103:1024-29,2006 29,2006
How Does FMD/PAT Compare to Blood Pressure as An Accepted Marker? Predictive value of noninvasively determined endothelial dysfunction for long-term cardiovascular events and restenosis in patients undergoing coronary stent implantation: a prospective study. Akcakoyun M, et. al. Coron Artery Dis, 2008; 19:337-343 Persistent impairment of endothelial vasomotor function has a negative impact on outcome in patients with coronary artery disease. Kitta Y, et. al., J Am Coll Cardiol 2009;53:323-30
Assessment of Peripheral Vascular Endothelial Function in the Ambulatory Setting CAD+ n = 31 CAD- n = 29 Kuvin, JT et al. Vasc Med 12:13-16, 16, 2007
Rubinshtein, R et al. Eur Heart J 31:1142-8, 2010
Cardiovascular Adverse Events in Patients with or without Low L-RHI L (natural log of PAT ratio) Rubinshtein, R et al. Eur Heart J 31:1142-8, 2010
PAT Gender Differences Hamburg, NM et al. Circulation 117:2467-74, 74, 2008
Flavanol Steroisomers
Stereospecific Effects of Flavanols on Arterial Dilation in a Rodent Model (Momma et al., unpublished) A C FA diameter (Δ%) 15 10 5 * B B FA diameter (Δ%) 15 10 5 0 * 0 (-) (+) (+) (-) Catechin Epicatechin -5 Saline + - - - (-)Epicatechin - + - + L-NMMA - - + + Is there evidence of a similar specificity in humans?
Influence of stereochemistry on plasma flavanol levels in humans Sum of flavanol metabolites ± SD (nm) 1400 1200 1000 800 600 400 200 0 Control (-)-Epicatechin (+)-Epicatechin (+)-Catechin (-)-Catechin n.d. a b 0 2 4 Time post-consumption (h) b c n.d. (Ottaviani et al unpublished) d e e,c c
Influence of stereochemistry on flavanol metabolism in humans 1200 p<0.05 Plasma flavanol metabolites 2 h post-consumption (nm) 1000 800 600 400 200 non-methylated metabolites 3'-O-methylated metabolites 4'-O-methylated metabolites 0 (-)-epicatechin (+)-epicatechin (-)-catechin (+)-catechin Catechin enantiomers did not yield 4 -O-methylated metabolites Epicatechin enantiomers differed in the levels of non-methylated metabolites n.d. n.d.
Cocoa Processing Effects on Flavanol Epimerization Non-alkalized Alkalized Ritter C et al. Anal Bioanal Chem 397:723-30, 30, 2010
Time Course of (-)( ) Catechin Formation When Tea is Heated (-) Epicatechin degradation (-)) Catechin formation 100 70 o C 80 o C 90 o C 50 40 Concentration % 50 Concentration % 30 20 70 o C 10 80 o C 90 o C 10 0 20 40 60 80 100 120 Time, min 0 0 20 40 60 80 100 120 Time, min Gotti et al, Electrophoresis, 2009
Effects of Flavanols and Flavanol-Rich Food Consumption on Vascular Function Reference Type Dose Duration Subjects n Vascular Reactivity Engler 04 Chocolate 213 mg / dy 2 wks Healthy adults 21 Increase FMD Vlachopoulos 05 Chocolate 100g chocolate 1 dose Healthy adults 17 Increase FMD, PWV Heiss 05 Cocoa beverage 180 mg 1 dose Smokers 11 Increase FMD Grassi 05 Chocolate 88 mg 2 wks Hypertensive & Healthy Controls 20 Increase FMD both groups Schroeter 06 Epicatechin 1-22 mg/kg 1 dose Healthy adults 3 Increase FMD, PAT Fisher 06 Cocoa Beverage 821 mg 4 days Healthy adults 27 Increase PAT Heiss 07 Cocoa Beverage 918 1 week Smokers 6 Increase FMD Flammer 08 Chocolate 36 mg 1 dose Heart transplant 44 Increase Coronary Reactivity Balzer 08 Cocoa Up to 960 mg 30 days Diabetics 41 Increase FMD Muniyappa 08 Shiina 09 Cocoa Chocolate ~ 900 mg 550 mg 2 wks 2 wks Hypertensive Healthy Adults 20 39 Increase Insulin stimulated FMD Increase Coronary Flow Velocity
Can changes in FMD be associated with changes in well accepted vascular health biomarkers? (750 mg flavanols/procyanidins for 30 days) Heiss et al. JACC In Press
Epidemiology evidence that high flavanol diets are associated with a reduced risk for hypertension. Hollenberg, NK J Cardiovasc Phamacol 2006
Urine can reflect epicatechin intake a Urinary nitrate/nitrite (μmol/mmol creatinine) Urinary epicatechin equivalents (nμ) 70 700 60 600 50 500 40 30 * * 400 300 20 200 10 100 0 Ailigandi Kuna Nega 0 Schroeter et al., PNAS 103: 1024-29, 29, 2006
Urinary Flavanol Metabolite Concentrations 24 h After Cocoa Consumption Urpi-Sada et al., J Chromatogr A, 2009
Effects of Flavanols and Flavanol-Rich Food Consumption on Blood Pressure Reference Type Dose Duration Subjects n Blood Pressure Engler 2004 Chocolate 213 mg / dy 2 wks Healthy adults 21 No Change Grassi 2005 Chocolate ~ 500 mg polyphenols 2 wks Healthy adults 15 Decreased Systolic Grassi 2005 Cocoa beverage 88 mg 2 wks Hypertensive 20 Decreased Taubert 2007 Chocolate 30 mg /day 18 weeks Pre Stage 1 hypertensive 44 Decreased Davison 2008 Grassi 2008 Cocoa Beverage Chocolate 902 mg 150 mg 12 wks 2 wks Overweight/ Obese Hypertensive 49 19 Decreased Diastolic, MAP Decreased 24 hr ambulatory BP Balzer 2008 Cocoa 960 mg 30 dys Medicated Diabetics 41 No Change Faridi 2008 Chocolate 821 mg 1 dose Healthy 45 Decreased Manuiyappa 08 Cocoa ~ 900 mg 2 wk Hypertensive 20 No Change Shiina 2009 Chocolate 550 mg 2 wks Healthy Adults 39 No Change
On an acute basis, dose dependent effects can be shown Acute Effects from the Feasibility Trial ( 75, 371, 963 mg) Balzer et al., J Am Coll Cardio, 51: 2141-9, 2008
What are the dose dependent effects over time? Efficacy Trial: 321 mg flavanols per day - 3 times per day versus 25 mg - 3 times per day Thus, the total daily dose was 963 mg versus 75 mg Balzer et al., J Am Coll Cardio, 51: 2141-9, 2008
(What are appropriate controls/placebos?) Taubert D et al., JAMA 298: 49-60, 2007
Flavonoids & Vascular Health Speculation: The inverse association seen between the consumption of plant food-rich diets and the risk for CVD is due to numerous factors including flavonoid-induced induced changes in: oxidant production and defence; membrane structure/function; the immune system; platelet reactivity, blood pressure, tissue repair and vascular reactivity.
Effects of Flavonoids and Flavonoid-Rich Food Consumption on Platelet Function Reference Type Dose Duration Subjects n Platelet aggregation Pace-Asciak 96 Red wine White wine Purple grape juice 375 ml/day 375 ml/day 500 ml/day 4 wks Healthy adults 24 -- Freedman 01 Purple grape juice Rein 00 Cocoa beverage Hubbard 04 Quercetin-4 -B-O- glucoside 7 ml/kg/day 2 wks Healthy adults 20 300 ml 1 dose Healthy adults 10 Platelet Reactivity 150 mg 1 dose Healthy adults 6 Collagen stimulated platelet aggregation Heptinstall 06 Cocoa Beverage 600-900 mg 1 dose Healthy adults 12 Collagen stimulated Platelet Aggregation Polagruto 07 Grapeseed Extract 400 mg 1 dose Smokers 13 Platelet Reactivity Flammmer 07 Chocolate 40 g 1 dose Heart transplant 28 Platelet adhesion Hamed 08 Chocolate 100 g / day 1 week Healthy adults Platelet Reactivity Erlund 08 Berries 100 g 8 wks Health Adults 72 Platelet Reactivity
Reported *Flavanol-Rich Cocoa/Chocolate Intakes for Select Cardiovascular Effects Outcome Measure Time period Dose (mg)* Platelet Reactivity 1 day 4 weeks **undefined 900 Blood Pressure 1 day 18 weeks 30-900 Vascular Function 1 day 4 weeks 88-960 * flavanol + procyanidins ** chocolate with an undefined flavanol content * f **
Mechanisms? The effect of 220 mg of flavonoids on the ratio of prostacyclin (PGI 2 ) to leukotriene (LT). 8.0 * * PGI2/LT Ratio 6.0 4.0 2.0 * P < 0.05 0.0 0 h 2 h 6 h Schramm et al, AJCN, 2001:73:36 & Holt et al, JAMA, 2002;287:2212 5-lipoxygenase inhibition? Schewe et al, AJCN, 2005;81:304-12S 12S NADPH oxidase inhibition? Schewe et al, Arch Biochem Biophys, 2008;15:102-6
Flavanol Intervention Mobilizes Functional CACs
Circulating Endothelial Progenitor Cells, Vascular Function, and Cardiovascular Risk Hill, JM et al. NEJM 348:593-600, 2003
Do high flavonoid diets influence the immune system? Four Weeks of Cocoa Consumption (~ 500 mg flavonoids/day) Reduces Circulating Inflammatory Markers Compared to Baseline and Milk only sp-selectin p 0.31 sicam-1 p 0.34 Monocyte- VLA-4 p 0.39 CD40 p 0.31 Monagas et al, Am J Clin Nutr, 2009;90:1144-50
Contribution of 30 Biomarkers to 10-Year Cardiovascular Risk Estimation in 2 Population Cohorts: The MONICA, Risk, Genetics, Archiving, and Monograph (MORGAM) Biomarker Project Blackenberg, S et al. Circulation 121:2388-97, 2010
Summary: Collectively, the results obtained from numerous trials support port the concept that the consumption of select plant food products can result in acute (1 30 days) improvements in vascular health parameters that are suggestive of a decreased risk for select chronic diseases. The results obtained to date from numerous epidemiological studies are consistent with the above concept. Accumulating evidence supports the idea that in certain cases, specific non-essential nutrients are driving the positive health effects associated with some plant foods. Established, and validated, biomarkers for an individuals status s of the above non-essential nutrients are largely lacking.
Summary: When considering the development of biomarkers for following the effects of a food or a non-essential nutrient on the risk for select diseases, consideration should be given to using a multiple component model that takes into consideration the potential effects of the food/nutrient on multiple factors.