It is the mid – piece of the sperm, with its energy source, which is responsible for the tail’s ability to move and transport the sperm independently. Without a properly functioning tail, sperm may swim around in circles rather than forward in a straight line, or may not swim at all.
From the seminiferous tubules, the maturing sperm move into the epididymis, which is a long tube, around 18 feet in length but only a three – hundredth of an inch in diameter, which is coiled and situated at the back of the testicle.
Once produced, sperm then move up into the vas deferens, the tubes that eventually feed into the urethra and on through the penis, via the ejaculatory duct. Here, the sperm mix with secretions from the seminal vesicles and the prostate gland to form the seminal fluid. Once combined, the sperm and seminal fluid are referred to as semen. The secretions of the prostate gland are alkaline, which helps to neutralize the acidity of the woman’s vagina, and protect the sperm. The vas deferens travel from the testes out of the scrotum and through the lower abdomen via the groin, then around to a point underneath the bladder where they join the urethra. They hold an astonishing amount of sperm: it would take around 30 ejaculations to empty the vas deferens of their full load!
Only around 20 per cent of semen is sperm. The seminal fluid that combines with sperm to form semen is composed of more than 22 different chemicals, including sugar, vitamins C, E and B12, prostaglandins (which help stimulate muscle contractions and the dilatation of blood vessels), the minerals zinc, potassium and sulphur, and essential fatty acids (namely DHA). Altogether, ejaculate consists of around 2 to 4 ml of semen, which is quite viscous at first but then liquefies after about 10 minutes. Sperm need to be nourished by this liquid on their journey, and protected from the acidic environment of the woman’s vagina, before any of them can reach an egg. Around 250 million sperm are ejaculated each time, but it takes only one to fertilize an egg.
Why this enormous quantity of sperm? Only a certain proportion – and this varies from man to man – will be normal, active enough and capable of fertilizing an egg in the first place. Then, because the woman’s vagina is acidic, and hostile to sperm, treating it as it would any other ‘foreign body’ and attempting to get rid of it, as it would an infection, this also reduces the available sperm. From here, only around a million sperm will actually get as far as the woman’s cervix, and only around 200 of these, at most, will reach the woman’s Fallopian tube, to fertilize an egg.
If you then consider how many of the remaining sperm are actually of a good enough quality to fertilize an egg – and in sperm analysis only a maximum of 20 per cent pass this test – it’s no wonder that fertilization can be a tricky business. And even if fertilization does occur, if the sperm responsible is faulty in some way then development of the fertilized egg can’t continue, and miscarriage may be the outcome.
A Good Diet
When you consider what sperm need to develop, and the journey they have to undertake in order to stand a chance of fertilizing an egg, it’s easier to understand why good health in a man is just as important as in a woman when it comes to making babies.
The good news is that, because of the continuous 100-day cycle of sperm production, it is possible to improve sperm’s quality relatively easily, by making the necessary health and lifestyle changes.
While the Nutrition chapter (see page 89) offers general guidelines, it is worth mentioning here, too, that when it comes to the sort of adequate nutrition that makes a difference, there is no point grabbing a general multi – vitamin, or an expensive supplement, unless you know what you’re getting and what you need. Before that, it’s worth looking at your general diet and how to improve it.
Generally speaking, the fresher and less processed the food you eat, the better. Many people advocate organic foods, and there is a good argument for this. In one Danish study, an unexpectedly high sperm count was found among organic farmers. Their sperm count was twice as high as that of a control group of blue – collar workers. But it’s tricky, because if it’s a choice between organic beans flown in from Kenya that have taken five days to get to your supermarket shelf and have then sat in your fridge for two days, and some locally – produced beans that are not organic but were picked yesterday, you might want to choose the latter, as the vitamin and mineral content of the fresher food will be higher, and washing it carefully will help remove chemical and pesticide residues.
Now is not the time to go on some extreme weight – loss diet, either. Some men opt for high – protein diets to lose weight, but we have noticed anecdotally that men following this type of diet have poor sperm. There’s evidence to show that extreme diets, like the low – carb ones in such favour these days, increase the body’s acidity if not actually leaving you malnourished, which won’t be good for sperm production. Better to adjust the balance of what you eat, increase your exercise a little, and reduce your weight that way.
Ideally, you should follow the guidelines set out in the Nutrition and Lifestyle chapters.
Try also to eat a proportion of your foods, especially fresh fruit and vegetables, raw. And when you do cook, try steaming and grilling rather than boiling or frying, which will preserve more of your food’s nutritional value.
It is probably a good idea to cut out all highly processed foods, if you can, as they are alarmingly high in hidden fats, sugars and chemical preservatives. In addition, the nutritional content of food is greatly reduced during processing. Opt for whole foods where you can.
If this feels rather overwhelming, start gradually, introducing a different change into your diet week by week as you adjust.
Water
When it comes to what you drink (and alcohol is covered separately: see page 62), make sure you are not over – doing your caffeine intake. Caffeine is mildly addictive, so if you are used to drinking a lot it may take a while to kick the habit. There is also some evidence to show that if a man has a high caffeine intake before conception, the risk of premature birth is increased. Tea contains tannin, which is less of a stimulant than caffeine, but excess quantities will deplete you of iron.
Most men do not drink enough water. Sperm need to swim!
Start changing your drinking habits first of all by increasing your water intake – most of us drink too little, generally, to be adequately hydrated.
What Do Sperm Need?
There is a lot of research available now about free radical damage to sperm, but thankfully there’s a lot you can do to improve this. To produce sperm your body needs a good intake of certain nutrients, which may need supplementing if they are not readily available from your diet. Research has shown that certain vitamins and minerals improve overall sperm counts – I’ve seen it many times. It is important, however, to remember not to exceed the recommended daily allowance (RDA) of any one item, even if you have heard that it might be beneficial, unless under supervision from a health professional. An excess of one item can deplete others, so a balance is needed.
Also see the Nutrition chapter for more advice on how to improve your diet to increase the chances of conception.
Vitamin C
A well – known antioxidant, under normal conditions vitamin C protects sperm from oxidative damage, and certainly improves sperm quality in men who smoke. However, some men have a condition of their sperm called ‘agglutination’ where sperm clump together and fertility is reduced. In these cases, vitamin C supplementation of up to 1 gram a day helps reduce agglutination – and was shown to increase fertility in one group of men in a controlled study.
Zinc
Semen is rich in zinc, and men lose a certain amount of this mineral per ejaculate. Zinc is often referred to as the ‘fertility mineral’ and its presence in foods like oysters, which are said to have aphrodisiac properties, may reinforce this idea! Certainly an insufficiency of zinc can lead to both reduced numbers of sperm and impotence in some men. It has also been found that the levels of