Table 2.
Amount of phenolic acid in 24 h urine (µmol/day) after low and high-polyphenol diet in younger (n = 8) and older (n = 13) participants
| Group | Younger | Older | p value | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diet | Low-polyphenol diet | High-polyphenol diet | ∆ | Low-polyphenol diet | High-polyphenol diet | ∆ | |||||||||||
| Phenolic Acid# | N | Median | IQR (Q1 to Q3) | N | Median | IQR (Q1 to Q3) | Median | IQR (Q1 to Q3) | N | Median | IQR (Q1 to Q3) | N | Median | IQR (Q1 to Q3) | Median | IQR (Q1 to Q3) | |
| BA [23] | 8/8 | 16.6† | 10.8 to 25.1 | 8/8 | 31.1§ | 13.9 to 46.8 | 13.0 | 4.7 to 24.0 | 13/13 | 1.1† | 0.8 to 2.3 | 13/13 | 1.8§ | 1.1 to 5.4 | 0.5 | 0.0 to 4.0 | 0.03 |
| PAA [23] | 8/8 | 3.2† | 1.7 to 4.0 | 8/8 | 3.2 | 0.0 to 4.8 | 0.6 | − 1.7 to 1.3 | 7/13 | 0.9† | 0.6 to 1.0 | 6/13 | 1.1 | 0.6 to 1.3 | 0.2 | 0.1 to 0.4 | 0.80 |
| MA [23] | 8/8 | 0.7 | 0.4 to 0.9 | 8/8 | 1.1 | 0.5 to 1.7 | 0.6 | 0.0 to 0.8 | 13/13 | 0.3 | 0.3 to 0.8 | 13/13 | 0.5 | 0.5 to 1.0 | 0.2 | 0.0 to 0.2 | 0.14 |
| 3-OHBA [23] | 8/8 | 0.6* | 0.2 to 0.7 | 8/8 | 0.9* | 0.3 to 1.5 | 0.3 | 0.2 to 0.7 | 8/13 | 0.4 | 0.2 to 1.3 | 9/13 | 1.2 | 0.3 to 1.5 | 0.1 | 0.0 to 0.5 | 0.27 |
| 3-OHPAA [22, 24, 57] | 8/8 | 2.3* | 1.9 to 3.2 | 8/8 | 19.2* | 10.7 to 34.0 | 16.6 | 8.8 to 27.2 | 13/13 | 2.3** | 1.6 to 3.1 | 13/13 | 30.2** | 18.7 to 57.8 | 26.3 | 17.1 to 54.7 | 0.40 |
| 4-OHBA [23] | 8/8 | 2.1 | 1.5 to 2.5 | 8/8 | 3.8 | 2.5 to 4.4 | 1.3 | 0.2 to 1.9 | 12/13 | 2.2 | 1.6 to 3.7 | 12/13 | 2.9 | 1.7 to 3.8 | 0.1 | − 0.4 to 0.7 | 0.17 |
| 4-OHPPA [23, 57] | 8/8 | 0.4 | 0.1 to 0.4 | 8/8 | 0.5 | 0.1 to 1.0 | 0.2 | 00 to 0.6 | 8/13 | 0.2 | 0.1 to 0.6 | 8/13 | 0.3 | 0.1 to 0.6 | 1.4 | − 14.1 to 8.8 | 0.08 |
| VA [23, 57] | 8/8 | 0.7* | 0.4 to 0.8 | 8/8 | 2.8* | 1.3 to 4.1 | 2.0 | 0.6 to 3.4 | 9/13 | 0.9 | 0.2 to 1.3 | 12/13 | 1.4 | 1.1 to 2.3 | 0.9 | 0.3 to 2.3 | 0.04 |
| HVA [22, 23, 57] | 8/8 | 10.8* | 7.4 to 11.8 | 8/8 | 19.8* | 10.7 to 23.4 | 9.5 | 4.8 to 15.2 | 13/13 | 7.6** | 6.0 to 7.9 | 4/13 | 12.4** | 11.7 to 17.3 | 6.9 | 4.1 to 9.4 | 0.71 |
| 4-OHMA [57] | 8/8 | 4.9 | 4.5 to 6.0 | 8/8 | 3.9 | 3.1 to 4.7 | − 0.5 | −2.4 to − 0.2 | 13/13 | 3.7** | 3.0 to 4.0 | 13/13 | 2.6** | 2.0 to 3.1 | − 1.1 | − 1.2 to 0.2 | 0.84 |
| 3,4diOHBA [23] | 8/8 | 1.0* | 0.9 to 1.1 | 8/8 | 2.1* | 1.6 to 2.7 | 1.1 | 0.7 to 1.5 | 4/13 | 0.9 | 0.9 to 1.0 | 4/13 | 1.2 | 1.0 to 1.4 | 0.5 | 0.4 to 0.6 | 0.20 |
| 3,4diOHPAA [22, 23] | 8/8 | 1.5* | 1.3 to 1.7 | 8/8 | 2.9* | 2.1 to 7.4 | 2.0 | 0.6 to 5.5 | 13/13 | 1.2** | 0.9 to 1.3 | 13/13 | 3.2** | 2.2 to 6.0 | 2.0 | 1.4 to 5.1 | 0.91 |
| HA [23, 57] | 8/8 | 155.7* | 104.8 to 200.5 | 8/8 | 969.8*§ | 633.9 to 1174.1 | 856.7 | 502.0 to 987.4 | 13/13 | 301.5** | 153.7 to 431.4 | 13/13 | 1734.5**§ | 937.4 to 2641.9 | 1507.8 | 653.2 to 2500.9 | 0.06 |
| Dihydrocaffeic acid [23] | 8/8 | 1.3* | 0.8 to 1.7 | 8/8 | 2.3* | 1.3 to 3.4 | 1.0 | 0.5 to 1.4 | 6/13 | 1.3 | 1.0 to 1.4 | 9/13 | 1.5 | 1.2 to 2.3 | 0.8 | 0.3 to 1.0 | 0.54 |
| 3,4diOHPPA [23] | 8/8 | 0.5* | 0.2 to 0.6 | 8/8 | 1.6* | 0.7 to 1.8 | 0.9 | 0.6 to 1.4 | 8/13 | 0.3** | 0.1 to 0.7 | 9/13 | 0.8** | 1.7 to 1.1 | 0.4 | 0.2 to 0.8 | 0.07 |
| GA [23] | 8/8 | 0.6 | 0.2 to 0.9 | 8/8 | 0.8 | 0.3 to 1.7 | 0.5 | 0.2 to 0.8 | 4/13 | 0.8 | 0.6 to 1.1 | 5/13 | 0.7 | 0.5 to 1.0 | 0.3 | − 0.2 to 0.4 | 0.25 |
| 3-OHhippA [22, 57] | 8/8 | 21.0* | 17.6 to 27.8 | 8/8 | 68.6* | 41.7 to 83.1 | 40.9 | 19.0 to 55.2 | 13/13 | 15.1** | 10.8 to 21.6 | 13/13 | 28.4** | 24.3 to 44.3 | 15.1 | 7.2 to 20.8 | 0.76 |
| Total | 205.2 | 158.1 to 251.8 | 1196.7 | 729.7 to 1344.7 | 911.3 | 517.3 to 1074.5 | 336.2 | 190.2 to 468.5 | 1819.1 | 986.1 to 2831.1 | 1562.5 | 696.6 to 2641.7 | 0.06 | ||||
N number of participants; BA benzoic acid; PAA phenylacetic acid; MA mandelic acid; 3-OHBA 3-hydroxybenzoic acid; 3-OHPAA 3-hydroxyphenylacetic acid; 4-OHBA 4-hydroxybenzoic acid; 4-OHPAA 4-hydroxyphenylacetic acid; 4-OHPPA 4-hydroxyphenylpropionic acid; VA vanillic acid; HVA homovanillic acid; 4-OHMA 4-hydroxymandelic acid; 3,4diOHBA 3,4-dihydroxybenzoic acid; 3,4diOHPAA 3,4-dihydroxyphenylacetic acid; HA hippuric acid; Dihydrocaffeic acid 3-(3,4-dihydroxyphenyl) propionic acid; 3,4diOHPPA 4-hydroxy-3-methoxy-phenylpropionic acid; GA gallic acid; 3-OHhippA 3-hydroxyhippuric acid
#Phenolic acids previously described in the literature. ∆ Difference in urinary excretion (high diet minus low diet). p value is the difference in urinary phenolic acid excretion (∆high–low diet) between groups. *Significant increase in younger group after the high-polyphenol diet p ≤ 0.01. ** Significant increase in older group after the high-polyphenol diet p ≤ 0.01. §Significant difference between groups after the low-polyphenol diet p ≤ 0.05. † Significant difference between groups after the high-polyphenol diet p ≤ 0.05