Table 3 Description of semen parameters in different dietary intake
Characteristic | N | Semen volume(ml) | Progressive motility (%) | Total motility (%) | Sperm concentration(106/ml) | Sperm count (106/ml) | pH value | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Median (25th, 75th) | Effect size | Median (25th, 75th) | Effect size | Median (25th, 75th) | Effect size | Median (25th, 75th) | Effect size | Median (25th, 75th) | Effect size | Median (25th, 75th) | Effect size | ||
Drinking | |||||||||||||
 Yes | 135 | 3.6 (2.5–5.0) | − 0.016 | 40.0 (25.0–54.0) | 0.347 | 56.0 (40.0–71.0) | 0.379 | 61.8 (37.8–98.7) | 0.057 | 209.5 (121.9–389.6) | 0.061 | 7.3 (7.2–7.5) | 0.039 |
 No | 327 | 3.5 (2.6–5.0) | 33.5 (18.3–48.8)* | 64.0 (49.0–79.0)* | 68.0 (41.3–104.8) | 246.0 (119.3–477.4) | 7.3 (7.2–7.5) | ||||||
Frequency of alcohol consumption | |||||||||||||
 Often | 14 | 5.0 (4.2–6.1) | 0.446 | 38.5 (29.8–54.3) | − 0.021 | 66.5 (36.5–77.9) | − 0.131 | 70.2 (40.2–105.5) | − 0.128 | 355.0 (148.1–580.7) | 0.155 | 7.4 (7.2–7.6) | 0.081 |
 Occasionally | 126 | 3.4 (2.6–5.0) | 41.0 (25.0–55.5) | 62.9 (49.0–79.0) | 68.5 (40.7–110.3) | 242.4 (113.9–489.7) | 7.2 (7.2–7.5) | ||||||
 Never | 68 | 3.6 (2.5–6.0) | 33.0 (18.5–47.5) | 60.0 (40.2–74.8) | 65.1 (50.7–105.5) | 261.0 (159.8–472.6) | 7.3 (7.2–7.5) | ||||||
 Less | 8 | 2.2 (1.9–4.5) | 30.0 (17.5–45.3) | 45.4 (35.5–64.1) | 55.4 (27.1–77.5) | 153.3 (46.2–285.4) | 7.2 (7.1–7.5) | ||||||
Types of regular drinking | |||||||||||||
 Beer | 51 | 4.1 (3.2–5.6) | 0.026 | 43.0 (25.8–57.0) | 0.017 | 67.0 (51.0–78.0) | 0.023 | 73.6 (41.3–96.9) | 0.014 | 294.4 (118.6–572.4) | 0.014 | 7.2 (7.2–7.5) | 0.003 |
 Liquor | 27 | 4.2 (3.2–6.0)* | 41.0 (25.0–48.0) | 61.2 (52.0–74.4) | 72.9 (35.9–151.3) | 305.7 (160.8–560.2) | 7.2 (7.2–7.5) | ||||||
 Wine | 31 | 3.1 (2.2–4.0) | 38.0 (21.0–53.0) | 55.0 (37.0–72.0) | 66.6 (42.3–128.0) | 189.6 (96.1–433.1) | 7.2 (7.2–7.5) | ||||||
 Miscellaneous | 34 | 3.1 (2.2–4.7) | 37.0 (23.5–58.3) | 67.5 (48.6–86.1) | 72.6 (42.8–117.1) | 221.7 (128.1–418.5) | 7.3 (7.2–7.5) | ||||||
 Other | 50 | 3.6 (2.5–6.1) | 34.0 (19.0–47.0) | 56.9 (33.8–71.0) | 63.8 (38.6–104.8) | 264.2 (114.4–523.1) | 7.3 (7.2–7.5) | ||||||
The consumption of alcohol everyday | |||||||||||||
 Less than 100 mL per day | 152 | 3.5 (2.5–5.3) | 0.045 | 38.0 (24.0–52.0) | 0.025 | 61.0 (47.8–74.0) | 0.049 | 66.7 (41.5–108.8) | 0.016 | 259.5 (119.3–500.8) | 0.035 | 7.3 (7.2–7.5) | 0.007 |
 100–250 mL per day | 12 | 4.8 (2.6–6.0) | 39.5 (24.5–54.8) | 64.0 (38.8–81.6) | 82.2 (49.6–128.9) | 372.5 (136.5–544.0) | 7.3 (7.2–7.5) | ||||||
 More than 250 mL per day | 10 | 4.8 (2.8–6.3) | 45.5 (29.5–58.5) | 67.0 (43.3–84.4) | 50.1 (39.2–95.2) | 172.7 (123.2–616.3) | 7.4 (7.2–7.6) | ||||||
 0 mL per day | 6 | 3.5 (2.3–4.9) | 38.5 (15.0–56.5) | 53.5 (34.7–82.5) | 72.6 (40.2–113.7) | 253.4 (133.4–500.5) | 7.2 (7.2–7.5) | ||||||
 Daily water intake | |||||||||||||
  Below 500 mL | 55 | 3.5 (2.5–4.6) | 0.009 | 44.0 (28.3–56.8) | 0.008 | 66.0 (39.5–79.0) | 0.003 | 71.6 (42.6–129.0) | 0.005 | 245.2 (132.2–522.4) | 0.002 | 7.2 (7.2–7.5) | 0.001 |
  500–2500 mL | 360 | 3.6 (2.5–5.0) | 38.0 (24.0–52.0) | 58.0 (42.9–72.4) | 62.5 (38.0–98.0) | 209.1 (111.9–400.9) | 7.3 (7.2–7.5) | ||||||
  More than 2500 mL | 47 | 4.2 (2.8–6.0) | 35.5 (19.0–52.0) | 55.0 (35.0–68.0) | 62.1 (39.1–96.6) | 211.2 (133.1–484.7) | 7.3 (7.2–7.7) | ||||||
Types of drinking water for outdoor activities | |||||||||||||
 Mineral water | 219 | 3.6 (2.5–5.0) | 0.008 | 42.0 (25.0–53.0) | 0.002 | 59.0 (42.0–72.9) | 0.010 | 70.4 (41.5–98.2) | 0.008 | 219.3 (129.1–414.5) | 0.005 | 7.3 (7.2–7.5) | 0.001 |
 Pure water | 77 | 3.5 (2.8–5.7) | 40.0 (20.0–53.0) | 56.0 (41.5–73.1) | 55.5 (27.3–102.1) | 203.8 (105.6–413.0) | 7.2 (7.2–7.5) | ||||||
 Tap water (boiled water) | 109 | 3.7 (2.5–5.4) | 38.5 (22.8–48.0) | 56.0 (42.1–72.0) | 59.0 (37.5–106.0) | 222.2 (112.3–419.9) | 7.3 (7.2–7.5) | ||||||
 Tea | 20 | 4.0 (2.2–6.0) | 41.0 (23.0–56.0) | 62.5 (41.4–74.5) | 96.9 (40.8–145.0) | 307.9 (142.6–578.6) | 7.3 (7.2–7.5) | ||||||
 Beverage | 37 | 3.6 (2.8–4.8) | 36.0 (20.5–45.0) | 60.0 (40.7–75.0) | 51.8 (38.2–86.1) | 181.7 (130.8–424.5) | 7.3 (7.2–7.5) | ||||||
Beverages that often consumed | |||||||||||||
 Pure juice | 37 | 3.5 (2.3–5.6) | 0.005 | 44.0 (31.0–56.0) | 0.001 | 64.1 (44.0–79.5) | 0.001 | 65.8 (39.2–96.8) | − 0.002 | 202.5 (130.0–517.9) | 0.005 | 7.5 (7.2–7.6) | 0.006 |
 Non-carbonated sugar-sweetened beverages | 37 | 3.8 (3.1–4.3) | 37.0 (26.8–42.3) | 50.0 (35.5–66.7) | 52.4 (36.6–97.6) | 181.7 (135.5–347.5) | 7.3 (7.2–7.5) | ||||||
 Coffee | 18 | 3.4 (2.6–4.2) | 39.5 (29.5–55.8) | 59.1 (46.6–69.7) | 65.6 (27.7–102.9) | 240.7 (96.1–397.5) | 7.3 (7.2–7.7) | ||||||
 Carbonated drinks | 89 | 4.0 (3.0–5.6) | 36.0 (22.0–54.8) | 61.0 (43.5–75.5) | 67.4 (33.4–93.3) | 240.2 (132.7–541.3) | 7.3 (7.2–7.5) | ||||||
 Hardly drink | 281 | 3.5 (2.5–5.0) | 40.0 (24.0–52.0) | 57.9 (41.5–72.3) | 61.8 (39.9–106.7) | 213.9 (115.1–415.7) | 7.2 (7.2–7.5) | ||||||
Number of drinks purchased in a week | |||||||||||||
 ≤ 3 bottles | 407 | 3.5 (2.5–5.0) | 0.011 | 39.5 (23.8–52.3) | 0.012 | 58.0 (42.0–73.0) | 0.012 | 63.7 (38.3–99.9) | 0.003 | 213.9 (120.4–416.9) | 0.005 | 7.3 (7.2–7.5) | 0.009 |
 4–6 bottles | 43 | 4.0 (3.2–5.0) | 40.0 (24.8–54.0) | 58.0 (44.0–75.0) | 64.2 (39.8–114.0) | 233.6 (143.5–569.9) | 7.3 (7.2–7.5) | ||||||
 7–9 bottles | 6 | 3.8 (1.4–4.7) | 29.5 (22.0-) | 61.0 (33.4–70.5) | 49.1 (25.0–79.7) | 120.2 (72.0–318.7) | 7.5 (7.2–7.5) | ||||||
 ≥ 10 bottles | 6 | 3.3 (2.6–4.7) | 32.0 (24.5–48.0) | 45.0 (29.5–67.2) | 56.0 (37.9–140.5) | 209.1 (122.4–418.1) | 7.4 (7.2–7.7) | ||||||
Use plastic beverage bottles for cooking oil, condiments, etc | |||||||||||||
 Never | 301 | 3.5 (2.5–5.0) | 0.004 | 40.0 (25.0–53.0) | 0.004 | 59.0 (43.5–72.3) | 0.007 | 65.5 (41.4–104.7)* | 0.010 | 222.2 (129.6–421.2) | 0.004 | 7.2 (7.2–7.5) | 0.001 |
 Occasionally | 149 | 3.8 (2.5–5.3) | 38.5 (21.5–52.3) | 56.0 (42.0–74.1) | 59.0 (33.4–96.1) | 203.8 (106.8–430.3) | 7.3 (7.2–7.5) | ||||||
 Often | 12 | 3.2 (2.1–6.1) | 34.5 (10.3–42.3) | 38.7 (34.4–56.3) | 40.4 (21.9–73.2) | 130.7 (50.8–403.8) | 7.4 (7.2–7.7) | ||||||
Dietary preference | |||||||||||||
 Light | 270 | 3.8 (2.5–5.0) | 0.008 | 37.0 (24.0–52.3) | 0.012 | 55.0 (39.0–71.0) | 0.021 | 61.6 (36.6–102.0) | 0.004 | 224.6 (116.3–403.0) | 0.002 | 7.3 (7.2–7.5) | 0.007 |
 Partial sweet | 38 | 3.8 (2.5–5.5) | 33.0 (22.3–51.3) | 63.2 (42.0–72.4)* | 63.2 (37.0–135.3) | 280.9 (130.8–591.0) | 7.2 (7.2–7.5) | ||||||
 Partial salty | 107 | 3.6 (2.7–5.0) | 44.0 (26.0–54.0) | 62.0 (47.8–77.0) | 66.1 (42.6–96.6) | 211.7 (129.5–429.4) | 7.2 (7.2–7.5) | ||||||
 Partial greasy | 47 | 3.2 (2.4–4.6) | 40.5 (28.3–53.0) | 60.0 (51.0–79.0) | 57.5 (35.9–88.1) | 179.3 (97.9–442.4) | 7.3 (7.2–7.7) | ||||||
Eat pickled foods | |||||||||||||
 Never | 25 | 4.0 (2.4–6.2) | 0.060 | 36.0 (20.3–53.0) | 0.001 | 61.0 (42.6–74.0) | 0.001 | 65.1 (46.1–87.8) | 0.000 | 249.2 (149.8–386.1) | 0.006 | 7.2 (7.2–7.5) | 0.004 |
 Occasionally | 421 | 3.6 (2.5–5.0) | 39.0 (24.0–52.0) | 58.0 (42.0–72.3) | 63.7 (38.6–99.9) | 218.4 (120.5–425.1) | 7.3 (7.2–7.5) | ||||||
 Often | 15 | 3.0 (2.0–4.0) | 32.0 (20.0–67.0) | 50.0 (21.0–87.1) | 58.2 (27.2–104.0) | 163.0 (90.3–332.8) | 7.2 (7.2–7.5) | ||||||
 Almost every day | 1 | – | – | – | – | – | – | ||||||
Eat fried food | |||||||||||||
 Never | 18 | 4.7 (2.8–6.4) | 0.009 | 51.0 (21.3–56.8) | 0.000 | 67.5 (38.5–79.7) | 0.001 | 74.1 (50.3–130.4) | 0.001 | 328.6 (181.7–432.1) | 0.003 | 7.2 (7.2–7.3) | 0.012 |
 Occasionally | 430 | 3.5 (2.5–5.0) | 39.0 (24.0–52.0) | 58.0 (42.0–72.2) | 62.3 (37.8–99.7) | 205.5 (119.3–417.5) | 7.3 (7.2–7.5) | ||||||
 Often | 14 | 4.5 (2.2–6.7) | 39.5 (34.0–48.3) | 55.2 (50.3–70.1) | 73.7 (44.2–96.9) | 314.7 (121.8–487.9) | 7.5 (7.2–7.7) | ||||||
Daily meal plan | |||||||||||||
 Mainly meat | 48 | 3.5 (2.7–5.9) | 0.000 | 51.0 (21.3–56.8) | 0.007 | 61.5 (46.9–80.9) | 0.011 | 71.7 (44.6–118.4) | 0.005 | 295.9 (126.0–610.3) | 0.006 | 7.2 (7.2–7.5) | 0.022 |
 Half meat and half vegetable | 378 | 3.6 (2.5–5.0) | 39.0 (24.0–52.0) | 58.0 (42.0–72.0) | 62.4 (37.9–99.0) | 211.5 (120.1–397.2) | 7.3 (7.2–7.5) | ||||||
 Mainly vegetarian | 36 | 4.3 (2.5–5.3) | 39.5 (34.0–48.3) | 54.7 (38.1–69.3) | 61.0 (41.6–91.2) | 221.5 (128.3–399.0) | 7.2 (7.2–7.3) | ||||||
Frequency of eating whole grains | |||||||||||||
 Occasionally | 421 | 3.6 (2.5–5.0) | 0.247 | 39.5 (23.3–52.8) | 0.019 | 58.0 (42.0–73.0) | 0.003 | 65.0 (39.1–101.0) | 0.203 | 224.6 (125.9–425.1) | 0.176 | 7.3 (7.2–7.5) | 0.061 |
 Basically don’t | 41 | 3.4 (2.6–5.0) | 39.0 (25.0–50.0) | 55.0 (40.1–73.1) | 50.3 (33.3–90.1) | 160.8 (97.9–361.1) | 7.2 (7.2–7.5) | ||||||
Frequency of eating soy products | |||||||||||||
 Every day | 16 | 3.5 (2.2–5.0) | 0.002 | 38.5 (17.5–56.3) | 0.000 | 51.1 (42.2–80.7) | 0.000 | 51.6 (23.3–103.4) | 0.003 | 170.6 (97.6–263.9) | 0.003 | 7.3 (7.2–7.7) | 0.000 |
 Occasionally | 430 | 3.6 (2.5–5.0) | 39.5 (24.0–52.0) | 58.6 (42.0–73.0) | 62.8 (38.3–98.6) | 214.4 (123.8–423.0) | 7.3 (7.2–7.5) | ||||||
 Basically don't | 16 | 3.2 (2.1–5.0) | 25.0 (24.0-) | 52.4 (42.7–71.0) | 104.2 (61.5–127.3) | 366.1 (119.2–525.3) | 7.2 (7.2–7.7) | ||||||
Consumption of milk and dairy products | |||||||||||||
 Every day | 89 | 3.4 (2.5–5.0) | 0.003 | 41.0 (21.3–55.3) | 0.005 | 63.0 (48.9–78.0)* | 0.017 | 66.1 (45.7–103.2)* | 0.009 | 218.4 (145.9–378.2) | 0.009 | 7.2 (7.2–7.5) | 0.008 |
 Occasionally | 351 | 3.8 (2.5–5.0) | 38.0 (24.0–50.3) | 56.0 (41.0–71.0) | 63.7 (37.9–100.8) | 224.5 (119.3–433.1) | 7.3 (7.2–7.5) | ||||||
 Basically don’t | 22 | 4.0 (2.1–5.1) | 44.0 (20.0–59.5) | 54.5 (31.8–81.5) | 41.6 (27.9–67.0) | 126.3 (78.5–316.0) | 7.3 (7.2–7.5) | ||||||
Frequency of eating eggs | |||||||||||||
 Every day | 86 | 4.0 (3.1–5.0)* | 0.014 | 42.0 (24.0–56.0) | 0.010 | 56.5 (42.5–74.4) | 0.007 | 61.5 (40.7–108.9) | 0.002 | 189.3 (100.8–342.4) | 0.005 | 7.2 (7.2–7.5) | 0.005 |
 Occasionally | 369 | 3.8 (2.7–5.0) | 39.0 (24.3–52.0) | 58.9 (42.0–73.0) | 64.0 (38.3–99.2) | 228.9 (126.2–432.1) | 7.3 (7.2–7.5) | ||||||
 Basically don't | 7 | 3.1 (2.1–5.0) | 20.0 (7.0–41.3) | 39.0 (36.0–55.6) | 42.2 (24.3–97.2) | 211.2 (61.9–388.9) | 7.3 (7.2–7.5) | ||||||
Which part of the egg do you eat | |||||||||||||
 Whole egg | 408 | 3.5 (2.5–5.0) | 0.004 | 38.5 (23.8–52.0) | 0.008 | 57.9 (42.0–72.4) | 0.012 | 61.5 (38.2–98.4) | 0.008 | 205.5 (119.9–402.9) | 0.012 | 7.3 (7.2–7.5) | 0.003 |
 Remove the yolks | 52 | 4.1 (3.3–5.9) | 40.0 (27.0–52.0) | 64.2 (43.0–73.4) | 81.9 (40.7–112.5) | 296.8 (127.9–527.1) | 7.3 (7.2–7.5) | ||||||
 Basically don’t | 2 | 4.1 (4.0-.) | 57.5 (57.0-) | 90.5 (88.0-.) | 107.6 (84.6-.) | 434.7 (346.9-.) |  |  | |||||
Frequency of eating animal food (pork, beef, lamb) | |||||||||||||
 Every day | 278 | 3.5 (2.5–5.0) | 0.006 | 40.0 (24.0–53.0) | 0.002 | 58.0 (42.0–73.9) | 0.001 | 59.9 (35.0–99.0) | 0.005 | 201.9 (106.3–388.1) | 0.009 | 7.2 (7.2–7.5) | 0.005 |
 Occasionally | 180 | 3.8 (2.5–5.3) | 38.0 (22.3–52.0) | 59.0 (42.5–72.0) | 66.8 (41.4–106.8) | 240.0 (131.6–452.5) | 7.3 (7.2–7.5) | ||||||
 Basically don’t | 4 | 5.1 (2.8–8.8) | 40.3 (22.4–52.0) | 51.5 (46.3–56.8) | 48.9 (42.5–58.2) | 229.8 (142.2–420.1) | 7.3 (7.2–7.5) | ||||||
Vegetarian | |||||||||||||
 Yes, but there is a corresponding daily intake of egg and milk | 200 | 3.8 (2.6–5.1) | 0.003 | 41.0 (22.3–52.0) | 0.001 | 56.9 (44.0–72.0) | 0.007 | 64.1 (39.0–102.1) | 0.006 | 217.1 (123.2–392.8) | 0.004 | 7.3 (7.2–7.5) | 0.008 |
 No, I like to eat meat, especially fatty meat | 248 | 3.5 (2.5–5.0) | 38.0 (25.0–54.0) | 59.0 (42.0–74.8) | 61.1 (38.0–97.1) | 210.4 (115.3–454.7) | 7.3 (7.2–7.5) | ||||||
 Yes, completely vegetarian | 14 | 3.7 (2.3–5.6) | 39.5 (23.0–54.3) | 54.5 (34.8–62.0) | 102.9 (63.6–129.7) | 375.7 (180.2–536.2) | 7.2 (7.2–7.3) | ||||||
Frequency of eating animal viscera (liver, kidney, stomach, intestine) | |||||||||||||
 Basically don’t | 64 | 3.6 (2.4–5.5) | 0.113 | 38.0 (28.5–51.0) | − 0.001 | 57.8 (42.9–73.9) | − 0.143 | 63.2 (43.2–100.9) | 0.013 | 218.5 (131.1–418.1) | 0.096 | 7.3 (7.2–7.6) | 0.042 |
 Occasionally | 398 | 3.6 (2.5–5.0) | 40.0 (23.0–53.0) | 58.0 (42.0–72.9) | 63.6 (37.9–99.8) | 212.8 (120.1–423.3) | 7.3 (7.2–7.5) | ||||||
Frequency of eating dark colored vegetables such as yellow, red and purple | |||||||||||||
 Often | 184 | 4.0 (2.5–5.0) | 0.003 | 40.0 (23.0–53.0) | 0.001 | 58.0 (43.7–73.0) | 0.002 | 66.8 (40.9–107.7) | 0.012 | 245.6 (133.1–459.5)* | 0.016 | 7.3 (7.2–7.5) | 0.002 |
 Occasionally | 274 | 3.5 (2.5–5.0) | 39.0 (24.0–52.0) | 58.3 (40.4–72.9) | 57.8 (36.5–92.9) | 186.3 (101.0–367.6) | 7.3 (7.2–7.5) | ||||||
 Basically don’t | 4 | 2.6 (2.2–8.2) | 39.0 (22.1–52.0) | 46.0 (34.5–70.3) | 105.7 (38.5–184.1) | 243.8 (98.6–1546.4) | 7.1 (6.9–7.8) | ||||||