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Proanthocyanidin
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<h2 id="distribution-in-plants">Distribution in plants</h2> <p>Proanthocyanidins, including the lesser bioactive and bioavailable polymers (four or more catechins), represent a group of condensed flavan-3-ols, such as <a href="/facts/Procyanidin/slDk1wsV">procyanidins</a>, prodelphinidins and propelargonidins. They can be found in many plants, most notably <a href="/facts/Apple/SF1WND0v">apples</a>, <a href="/facts/Maritime_pine/uso8oCEK">maritime pine</a> bark and that of most other pine species, <a href="/facts/Cinnamon/Aag9baI6">cinnamon</a>,<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> <a href="/facts/Aronia/jYBDQelt">aronia</a> fruit, <a href="/facts/Cocoa_bean/cAdQvQxy">cocoa beans</a>, grape seed, grape skin (procyanidins and <a href="/facts/Prodelphinidin/FKQkzutT">prodelphinidins</a>),<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> and <a href="/facts/Red_wine/Qs8V3v0x">red wines</a> of <i><a href="/facts/Vitis_vinifera/n7u6fzeq">Vitis vinifera</a></i> (the European wine grape). However, <a href="/facts/Bilberry/FWBS920q">bilberry</a>, <a href="/facts/Cranberry/Nj5EuTY1">cranberry</a>, <a href="/facts/Black_currant/dtdfcy2G">black currant</a>, <a href="/facts/Green_tea/IWfzB2Q2">green tea</a>, <a href="/facts/Black_tea/oXG1AP2X">black tea</a>, and other plants also contain these flavonoids. Cocoa beans contain the highest concentrations.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> Proanthocyanidins also may be isolated from <i><a href="/facts/Quercus_petraea/uzAn7by9">Quercus petraea</a></i> and <i><a href="/facts/Quercus_robur/P1fKs5oj">Q. robur</a></i> heartwood (wine barrel <a href="/facts/Oak_(wine)/WvLFtNon">oaks</a>).<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> <a href="/facts/A%25C3%25A7a%25C3%25AD_oil/WUSVdSAJ">Açaí oil</a>, obtained from the fruit of the açaí palm (<i>Euterpe oleracea</i>), is rich in numerous procyanidin oligomers.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> </p><p>Apples contain on average per serving about eight times the amount of proanthocyanidin found in wine, with some of the highest amounts found in the <a href="/facts/Red_Delicious/5xBSAEXe">Red Delicious</a> and <a href="/facts/Granny_Smith/e9ddlsJs">Granny Smith</a> varieties.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> </p><p>An extract of <a href="/facts/Maritime_pine/uso8oCEK">maritime pine</a> bark called <a href="/facts/Pycnogenol/t4sPgWPw">Pycnogenol</a> bears 65–75 percent proanthocyanidins (procyanidins).<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> Thus a 100 mg serving would contain 65 to 75 mg of proanthocyanidins (procyanidins). </p><p>Proanthocyanidin <a href="/facts/Glycoside/z11RwaaB">glycosides</a> can be isolated from <a href="/facts/Cocoa_liquor/eJFxIQtS">cocoa liquor</a>.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> </p><p>The seed <a href="/facts/Testa_(botany)/a4xGSLxJ">testas</a> of field beans (<i><a href="/facts/Vicia_faba/KPxa7j4I">Vicia faba</a></i>) contain proanthocyanidins<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> that affect the <a href="/facts/Digestibility/sjUBmhBS">digestibility</a> in <a href="/facts/Piglet_(animal)/r8rtDBIH">piglets</a><a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> and could have an inhibitory activity on enzymes.<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> <i><a href="/facts/Cistus_salviifolius/MrrvwUxE">Cistus salviifolius</a></i> also contains oligomeric proanthocyanidins.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> </p> <table><tbody><tr><th>Dietary source<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a></th><th>Proanthocyanidin<p>(mg/100g)</p></th></tr><tr><td></td><td></td></tr><tr><td>Fruits</td><td></td></tr><tr><td><a href="/facts/Grape/HaCaS4bT">Grape seeds</a></td><td>3532</td></tr><tr><td><a href="/facts/Blueberry/2xtgLU6Y">Blueberries</a></td><td>332</td></tr><tr><td><a href="/facts/Apple/SF1WND0v">Apples</a></td><td>70–141</td></tr><tr><td><a href="/facts/Pear/pRAKLrdK">Pears</a></td><td>32–42</td></tr><tr><td></td><td></td></tr><tr><td>Nuts</td><td></td></tr><tr><td><a href="/facts/Hazelnut/HH8ac3Qm">Hazelnuts</a></td><td>501</td></tr><tr><td></td><td></td></tr><tr><td>Other</td><td></td></tr><tr><td><a href="/facts/Cinnamon/Aag9baI6">Cinnamon bark</a></td><td>8108</td></tr><tr><td><a href="/facts/Sorghum/D1KNhtdT">Sorghum grains</a></td><td>3965</td></tr><tr><td><a href="/facts/Baking_chocolate/HAYndAJo">Baking chocolate</a></td><td>1636</td></tr><tr><td><a href="/facts/Red_wine/Qs8V3v0x">Red wine</a></td><td>313</td></tr></tbody></table> <h2 id="analysis">Analysis</h2> <p><a href="/facts/Condensed_tannins/t4sPgWPw">Condensed tannins</a> may be characterised by a number of techniques including <a href="/facts/Depolymerisation/r7QTPbGU">depolymerisation</a>, <a href="/facts/Asymmetric_flow_field_flow_fractionation/Gg2S2HzL">asymmetric flow field flow fractionation</a> or <a href="/facts/Small-angle_X-ray_scattering/Q4tvaRn7">small-angle X-ray scattering</a>. </p><p><a href="/facts/DMACA_reagent/8IkzvknH">DMACA</a> is a dye that is particularly useful for localization of proanthocyanidin compounds in plant histology. The use of the reagent results in blue staining.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> It can also be used to titrate proanthocyanidins. </p><p>Proanthocyanidins from field beans (<i><a href="/facts/Vicia_faba/KPxa7j4I">Vicia faba</a></i>)<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> or <a href="/facts/Barley/GH7X2qtG">barley</a><a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a> have been estimated using the <a href="/facts/Vanillin-HCl_method/wzNLSARj">vanillin-HCl method</a>, resulting in a red color of the test in the presence of <a href="/facts/Catechins/W2h9843C">catechins</a> or proanthocyanidins. </p><p>Proanthocyanidins can be titrated using the <i>Procyanidolic Index</i> (also called the <i><a href="/facts/Edgar_Charles_Bate-Smith/H0hNGVEH">Bates-Smith</a> Assay</i>). It is a testing method that measures the change in color when the product is mixed with certain chemicals. The greater the color changes, the higher the PCOs content is. However, the Procyanidolic Index is a relative value that can measure well over 100. Unfortunately, a Procyanidolic Index of 95 was erroneously taken to mean 95% PCO by some and began appearing on the labels of finished products. All current methods of analysis suggest that the actual PCO content of these products is much lower than 95%.<a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a>[<i>unreliable medical source?</i>] </p><p><a href="/facts/Gel_permeation_chromatography/HjDQ7av8">Gel permeation chromatography</a> (GPC) analysis allows separation of monomers from larger proanthocyanidin molecules.<a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a> </p><p>Monomers of proanthocyanidins can be characterized by analysis with <a href="/facts/High-pressure_liquid_chromatography/UNT9jPp0">HPLC</a> and <a href="/facts/Mass_spectrometry/RH5WBHJ2">mass spectrometry</a>.<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> Condensed tannins can undergo acid-catalyzed cleavage in the presence of a <a href="/facts/Nucleophile/xYccoaJQ">nucleophile</a> like <a href="/facts/Phloroglucinol/jkQwf8Hw">phloroglucinol</a> (reaction called phloroglucinolysis), <a href="/facts/Thioglycolic_acid/ezyJKnLS">thioglycolic acid</a> (thioglycolysis), <a href="/facts/Benzyl_mercaptan/Ir2627Sa">benzyl mercaptan</a> or <a href="/facts/Cysteamine/sRnV862R">cysteamine</a> (processes called <a href="/facts/Thiolysis/xKL28V0e">thiolysis</a><a class="footnote-ref" id="fnref:23" href="#fn:23"><sup>23</sup></a>) leading to the formation of oligomers that can be further analyzed.<a class="footnote-ref" id="fnref:24" href="#fn:24"><sup>24</sup></a> </p><p><a href="/facts/Tandem_mass_spectrometry/otT5Q9tY">Tandem mass spectrometry</a> can be used to sequence proanthocyanidins.<a class="footnote-ref" id="fnref:25" href="#fn:25"><sup>25</sup></a> </p> <h2 id="oligomeric-proanthocyanidins">Oligomeric proanthocyanidins</h2> <p>Oligomeric proanthocyanidins (OPC) strictly refer to <a href="/facts/Dimer_(chemistry)/mU64PnEq">dimer</a> and <a href="/facts/Trimer_(chemistry)/ws3JkjuQ">trimer</a> <a href="/facts/Polymerization/1hmBz7Ur">polymerizations</a> of catechins. OPCs are found in most plants and thus are common in the human diet. Especially the <a href="/facts/Peel_(fruit)/p9J9Kp35">skin</a>, seeds, and <a href="/facts/Seed_coat/a4xGSLxJ">seed coats</a> of purple or red pigmented plants contain large amounts of OPCs.<a class="footnote-ref" id="fnref:26" href="#fn:26"><sup>26</sup></a> They are dense in grape seeds and skin, and therefore in red wine and grape seed extract, cocoa, nuts and all <i><a href="/facts/Prunus/EcWe5fUK">Prunus</a></i> fruits (most concentrated in the skin), and in the bark of <i><a href="/facts/Cinnamomum/20mFJbvS">Cinnamomum</a></i> (<a href="/facts/Cinnamon/Aag9baI6">cinnamon</a>)<a class="footnote-ref" id="fnref:27" href="#fn:27"><sup>27</sup></a> and <i><a href="/facts/Pinus_pinaster/uso8oCEK">Pinus pinaster</a></i> (pine bark; formerly known as <i>Pinus maritima</i>), along with many other pine species. OPCs also can be found in <a href="/facts/Blueberries/2xtgLU6Y">blueberries</a>, <a href="/facts/Cranberry/Nj5EuTY1">cranberries</a> (notably <a href="/facts/Procyanidin_A2/2rd0xcVw">procyanidin A2</a>),<a class="footnote-ref" id="fnref:28" href="#fn:28"><sup>28</sup></a> <a href="/facts/Aronia/jYBDQelt">aronia</a>,<a class="footnote-ref" id="fnref:29" href="#fn:29"><sup>29</sup></a> <a href="/facts/Crataegus/SI3RcAJS">hawthorn</a>, <a href="/facts/Rosehip/8lkREeKN">rosehip</a>, and <a href="/facts/Sea_buckthorn/sEqKuzVM">sea buckthorn</a>.<a class="footnote-ref" id="fnref:30" href="#fn:30"><sup>30</sup></a> </p><p>Oligomeric proanthocyanidins can be extracted via <i><a href="/facts/Vaccinium_pahalae/NCxszN25">Vaccinium pahalae</a></i> from <i>in vitro</i> cell culture.<a class="footnote-ref" id="fnref:31" href="#fn:31"><sup>31</sup></a> The <a href="/facts/US_Department_of_Agriculture/3PK2rx7C">US Department of Agriculture</a> maintains a database of botanical and food sources of proanthocyanidins.<a class="footnote-ref" id="fnref:32" href="#fn:32"><sup>32</sup></a> </p> <h3>Plant defense</h3> <p>In nature, proanthocyanidins serve among other chemical and induced defense mechanisms against <a href="/facts/Plant_pathogens/h6DTufWF">plant pathogens</a> and <a href="/facts/Predation/JEGdrX3f">predators</a>, such as occurs in <a href="/facts/Strawberries/M4oa6zJ9">strawberries</a>.<a class="footnote-ref" id="fnref:33" href="#fn:33"><sup>33</sup></a> </p> <h3>Bioavailability</h3> <p>Proanthocyanidin has low bioavailability, with 90% remaining unabsorbed from the intestines until metabolized by <a href="/facts/Gut_flora/Xy1IWzSP">gut flora</a> to the more bioavailable metabolites.<a class="footnote-ref" id="fnref:34" href="#fn:34"><sup>34</sup></a> </p> <h3>Non-oxidative chemical depolymerisation</h3> <p>Condensed tannins can undergo acid-catalyzed cleavage in the presence of (or an excess of) a <a href="/facts/Nucleophile/xYccoaJQ">nucleophile</a><a class="footnote-ref" id="fnref:35" href="#fn:35"><sup>35</sup></a> like <a href="/facts/Phloroglucinol/jkQwf8Hw">phloroglucinol</a> (reaction called phloroglucinolysis), <a href="/facts/Benzyl_mercaptan/Ir2627Sa">benzyl mercaptan</a> (reaction called <a href="/facts/Thiolysis/xKL28V0e">thiolysis</a>), <a href="/facts/Thioglycolic_acid/ezyJKnLS">thioglycolic acid</a> (reaction called thioglycolysis) or <a href="/facts/Cysteamine/sRnV862R">cysteamine</a>. <a href="/facts/Flavan-3-ol/W2h9843C">Flavan-3-ol</a> compounds used with <a href="/facts/Methanol/EIfpoNCg">methanol</a> produce short-chain procyanidin <a href="/facts/Dimer_(chemistry)/mU64PnEq">dimers</a>, <a href="/facts/Trimer_(chemistry)/ws3JkjuQ">trimers</a>, or <a href="/facts/Tetramers/qeUFnwC4">tetramers</a> which are more absorbable.<a class="footnote-ref" id="fnref:36" href="#fn:36"><sup>36</sup></a> </p><p>These techniques are generally called <a href="/facts/Depolymerisation/r7QTPbGU">depolymerisation</a> and give information such as <a href="/facts/Average_degree_of_polymerisation/1WYmrcNk">average degree of polymerisation</a> or percentage of galloylation. These are <a href="/facts/SN1_reaction/2myaFQEv">SN1 reactions</a>, a type of substitution reaction in <a href="/facts/Organic_chemistry/djxhxaNg">organic chemistry</a>, involving a <a href="/facts/Carbocation/vIggUxTh">carbocation</a> intermediate under strongly acidic conditions in polar <a href="/facts/Protic_solvent/oSApp96e">protic solvents</a> like methanol. The reaction leads to the formation of free and derived monomers that can be further analyzed or used to enhance procyanidin <a href="/facts/Absorption_(pharmacokinetics)/LCezQPJK">absorption</a> and <a href="/facts/Bioavailability/9l6na9MV">bioavailability</a>.<a class="footnote-ref" id="fnref:37" href="#fn:37"><sup>37</sup></a> The free monomers correspond to the terminal units of the condensed tannins chains. </p><p>In general, reactions are made in methanol, especially thiolysis, as benzyl mercaptan has a low solubility in water. They involve a moderate (50 to 90 °C) heating for a few minutes. <a href="/facts/Epimerisation/613YtVHR">Epimerisation</a> may happen. </p><p>Phloroglucinolysis can be used for instance for proanthocyanidins characterisation in wine or in grape seeds and skin.<a class="footnote-ref" id="fnref:38" href="#fn:38"><sup>38</sup></a> </p><p>Thioglycolysis can be used to study proanthocyanidins<a class="footnote-ref" id="fnref:39" href="#fn:39"><sup>39</sup></a> or the oxidation of condensed tannins.<a class="footnote-ref" id="fnref:40" href="#fn:40"><sup>40</sup></a> It is also used for <a href="/facts/Lignin/CdaxpB3b">lignin</a> <a href="/facts/Quantitation/5YoKbeTW">quantitation</a>.<a class="footnote-ref" id="fnref:41" href="#fn:41"><sup>41</sup></a> Reaction on condensed tannins from <a href="/facts/Douglas_fir/AhxXILF4">Douglas fir</a> bark produces <a href="/facts/Epicatechin/EaYR3n8G">epicatechin</a> and <a href="/facts/Catechin/EaYR3n8G">catechin</a> <a href="/facts/Thioglycolate/ezyJKnLS">thioglycolates</a>.<a class="footnote-ref" id="fnref:42" href="#fn:42"><sup>42</sup></a> </p><p>Condensed tannins from <i><a href="/facts/Lithocarpus_glaber/XRcrWrXv">Lithocarpus glaber</a></i> leaves have been analysed through acid-catalyzed degradation in the presence of <a href="/facts/Cysteamine/sRnV862R">cysteamine</a>.<a class="footnote-ref" id="fnref:43" href="#fn:43"><sup>43</sup></a> </p> <h2 id="research">Research</h2> <h3>Urinary tract infections</h3> <p><a href="/facts/Cranberry/Nj5EuTY1">Cranberries</a> have A2-type proanthocyanidins (PACs) which may be important for the ability of PACs to bind to proteins, such as the <a href="/facts/Bacterial_adhesin/GXFLgd56">adhesins</a> present on <i>E. coli</i> <a href="/facts/Fimbria_(bacteriology)/8sjcDFtU">fimbriae</a> and were thought to inhibit bacterial infections, such as <a href="/facts/Urinary_tract_infections/4NwY9tL0">urinary tract infections</a> (UTIs).<a class="footnote-ref" id="fnref:44" href="#fn:44"><sup>44</sup></a> <a href="/facts/Clinical_trial/q8LMr832">Clinical trials</a> have produced mixed results when asking the question to confirm that PACs, particularly from cranberries, were an alternative to antibiotic prophylaxis for UTIs: 1) a 2014 scientific opinion by the <a href="/facts/European_Food_Safety_Authority/wooppnvX">European Food Safety Authority</a> rejected <a href="/facts/Physiological/fh25y2pQ">physiological</a> evidence that cranberry PACs have a role in inhibiting bacterial pathogens involved in UTIs;<a class="footnote-ref" id="fnref:45" href="#fn:45"><sup>45</sup></a> 2) an updated 2023 <a href="/facts/Cochrane_Collaboration/UlmdJ1H8">Cochrane Collaboration</a> review supported the use of cranberry products for the prevention of UTIs for certain groups.<a class="footnote-ref" id="fnref:46" href="#fn:46"><sup>46</sup></a> </p><p>A 2017 <a href="/facts/Systematic_review/dGvq3BGx">systematic review</a> concluded that cranberry products significantly reduced the incidence of UTIs, indicating that cranberry products may be effective particularly for individuals with recurrent infections.<a class="footnote-ref" id="fnref:47" href="#fn:47"><sup>47</sup></a> In 2019, the <a href="/facts/American_Urological_Association/X7MBCFqM">American Urological Association</a> released guidelines stating that a moderate level of evidence supports the use of cranberry products containing PACs for possible prevention from recurrent UTIs.<a class="footnote-ref" id="fnref:48" href="#fn:48"><sup>48</sup></a> </p> <h3>Wine consumption</h3> <p>Proanthocyanidins are the principal polyphenols in red wine that are under research to assess risk of <a href="/facts/Coronary_heart_disease/szCt0nVx">coronary heart disease</a> and lower overall mortality.<a class="footnote-ref" id="fnref:49" href="#fn:49"><sup>49</sup></a> With <a href="/facts/Tannins/vKIvHoTX">tannins</a>, they also influence the aroma, flavor, <a href="/facts/Mouth-feel/rBy2P0Sg">mouth-feel</a> and <a href="/facts/Astringency/Na9nEIr7">astringency</a> of red wines.<a class="footnote-ref" id="fnref:50" href="#fn:50"><sup>50</sup></a><a class="footnote-ref" id="fnref:51" href="#fn:51"><sup>51</sup></a> </p><p>In red wines, total OPC content, including <a href="/facts/Flavan-3-ol/W2h9843C">flavan-3-ols</a> (<i>catechins</i>), was substantially higher (177 mg/L) than that in white wines (9 mg/L).<a class="footnote-ref" id="fnref:52" href="#fn:52"><sup>52</sup></a> </p> <h3>Other</h3> <p>Proanthocyanidins found in the proprietary extract of <a href="/facts/Maritime_pine/uso8oCEK">maritime pine</a> bark called <i><a href="/facts/Pycnogenol/t4sPgWPw">Pycnogenol</a></i> were not found (in 2012) to be effective as a treatment for any disease: </p> "Current evidence is insufficient to support Pycnogenol(®) use for the treatment of any chronic disorder. Well-designed, adequately powered trials are needed to establish the value of this treatment."<a class="footnote-ref" id="fnref:53" href="#fn:53"><sup>53</sup></a> <h2 id="sources">Sources</h2> <p>Proanthocyanidins are present in fresh grapes, juice, <a href="/facts/Red_wine/Qs8V3v0x">red wine</a>, and other darkly pigmented fruits such as <a href="/facts/Cranberry/Nj5EuTY1">cranberry</a>, <a href="/facts/Blackcurrant/dtdfcy2G">blackcurrant</a>, <a href="/facts/Elderberry/ABVfL9zn">elderberry</a>, and <a href="/facts/Aronia/jYBDQelt">aronia</a>.<a class="footnote-ref" id="fnref:54" href="#fn:54"><sup>54</sup></a> Although red wine may contain more proanthocyanidins by mass per unit of volume than does red grape juice, red grape juice contains more proanthocyanidins per average serving size. An eight US fluid ounces (240 ml) serving of grape juice averages 124 milligrams proanthocyanidins, whereas a five US fluid ounces (150 ml) serving of red wine averages 91 milligrams (<i>i.e.</i>, 145.6 milligrams per 8 fl. oz. or 240 mL).<a class="footnote-ref" id="fnref:55" href="#fn:55"><sup>55</sup></a> Many other foods and beverages may also contain proanthocyanidins, but few attain the levels found in red grape seeds and skins,<a class="footnote-ref" id="fnref:56" href="#fn:56"><sup>56</sup></a> with a notable exception being <a href="/facts/Aronia/jYBDQelt">aronia</a>, which has the highest recorded level of proanthocyanidins among fruits assessed to date (664 milligrams per 100 g).<a class="footnote-ref" id="fnref:57" href="#fn:57"><sup>57</sup></a> </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/A_type_proanthocyanidin/4WSGl1lF">A type proanthocyanidin</a></li> <li><a href="/facts/B_type_proanthocyanidin/ym8hjotf">B type proanthocyanidin</a></li> <li><a href="/facts/Tannin/vKIvHoTX">Tannin</a></li> <li><a href="/facts/Polyphenol/H6Q7QIQH">Polyphenol</a></li> <li><a href="/facts/Phenolic_compounds_in_wine/aAnro4Va">Phenolic compounds in wine</a></li></ul> <h2 id="external-links">External links</h2> Wikimedia Commons has media related to Proanthocyanidins. <ul><li><a href="http://nccam.nih.gov/health/grapeseed/ataglance.htm">Grape seed extract, US National Institutes of Health, Office of Dietary Supplements, The National Center for Complementary and Alternative Medicine, 2014</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Schwitters, Bert (1995). OPC in Practice. Publishing rights search incomplete. p. 15. ISBN 978-8886035132. <a href="978-8886035132" target="_blank">978-8886035132</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"Scientific Opinion on the substantiation of a health claim related to CranMax® and reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract pursuant to Article 14 of Regulation (EC) No 1924/2006". EFSA Journal. 12 (5): 3657 (11 pgs). 2014. doi:10.2903/j.efsa.2014.3657. A cause and effect relationship has not been established between the consumption of CranMax® and reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract <a href="https://doi.org/10.2903%2Fj.efsa.2014.3657" target="_blank">https://doi.org/10.2903%2Fj.efsa.2014.3657</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Williams, Gabrielle; Stothart, Christopher I.; Hahn, Deirdre; Stephens, Jacqueline H.; Craig, Jonathan C.; Hodson, Elisabeth M. (2023-11-10). "Cranberries for preventing urinary tract infections". The Cochrane Database of Systematic Reviews. 2023 (11): CD001321. doi:10.1002/14651858.CD001321.pub7. ISSN 1469-493X. PMC 10636779. 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