Even more concerning: the rate of decline has shown no signs of levelling off in recent years.
The cause of this fall is still unknown, although pesticides, hormone-disrupting chemicals, diet, stress, smoking and obesity have all been “plausibly associated” with the problem, according to the study authors.
One expert commenting on the study described the figures as “shocking” and a “wake-up call” for urgent research into the reasons driving the fall.
Want to protect your swimmers?
Here are some sensible steps you can take...
Eat organic produce three times a day
Studies have found that hitting pesticide-free produce this often can bump your sperm count up by 169 per cent.
Eat oily fish at least once a week
Salmon, tuna and other fish rich in omega-3 fats have been shown to boost sperm count by 51 per cent.
Even low-level smoking (less than 5 cigarettes a day) causes your sperm count to dive by as much as 21 per cent.
Leave the office early
Men who are stressed and anxious showed sperm counts up to 60 per cent lower than their more relaxed peers.
Can’t just down tools and leave the office? Exercise and mindful breathing are two excellent ways to slash stress.