In order to move ahead in a quick and direct fashion, sperm cannot simply rely on moving their tail. They need to perform a kind of rotation. This motion allows them to compensate for their tail, described by the researchers as asymmetric.
Because the asymmetry of the tail’s movements does not allow them to move in an optimal fashion, they need to move their head at the same time that the tail rotates to advance forward. Their movement can be compared to that of otters “corkscrewing through water,” rather than the swimming style of eels, which has long been the belief.
Indeed, the first scientist to observe and record his thoughts on these reproductive cells — Antonie van Leeuwenhoek in the 17th century — had used the model of the eel’s swimming style to establish a comparison. But his observation, made with one of the first ever microscopes to be used in history, was in fact the result of an illusion created by seeing them from above with a 2D microscope.
This new finding could have a real impact on men’s health, as understanding how sperm move could be helpful in diagnosing causes of male infertility as well as developing new tools to help assess the health of sperm. It is good news for the treatment of infertility, which the researchers note, is caused by male factors in over half the cases.
Quality of sperm based on your weight
New research has found that maintaining a healthy weight could help boost the quality of a man’s sperm.
Carried out by a team at the Rovira i Virgili University in Spain, along with researchers from the University of Utah (the US), the Ahvaz Jundishapur University (Iran), and the National University of Córdoba (Argentina), the study looked at 88 existing articles which investigated how weight — including being low weight, normal weight, overweight or obese —could affect a man’s sperm quality.
The findings, published in the journal Obesity Reviews, showed that being overweight and/or obesity were both associated with various measurements of low semen quality including semen volume, sperm count and concentration, sperm vitality (the percentage of living healthy sperm in semen), total motility (the ability of sperm to move efficiently) and normal morphology (the shape of the sperm).
The results also showed that being underweight was also associated with low sperm normal morphology. The researchers said that their review is the most comprehensive analysis to date of the existing research and suggests that maintaining a healthy body weight could be important for increasing sperm quality and potentially a man’s fertility, particularly significant given that infertility affects between 10% and 15% of all couples of reproductive age.
Recent research has found that sperm quality can also be boosted by taking supplements of selenium, zinc, omega-3, coenzyme-Q10 and carnitines, which have been shown to improve sperm mobility and morphology. A small trial found that eating 60 grams of almonds, hazelnuts, and walnuts daily significantly improved sperm count, vitality, motility and morphology. A research published last year also showed that eating a healthy diet and avoiding sugar could improve sperm quality within just two weeks.
Why some women have repeated miscarriages
A Japanese study has indicated that the presence of a newly identified antibody may be responsible for repeated miscarriages in some women. The joint research carried out by scientists at Kobe and Osaka universities in Japan followed the discovery in 2015 of an autoantibody that could also be responsible for diseases such as thrombosis.
The research — published in June in the journal Arthritis and Rheumatology — involved 227 women who had experienced at least three pregnancies which were not carried to term. These are difficult experiences for women and couples hoping to start a family, especially since the cause of this situation remains largely misunderstood.
Study participants were tested for the presence of the newly discovered autoantibody in their bodies, for which 23% of them were positive. For nearly a fifth of these patients, the cause of their miscarriage had not been identified.
The researchers hope to gain a better understanding of the underlying mechanisms which lead to repeated pregnancy loss as well as thrombosis and pregnancy-related hypertension. This in turn could lead to new treatment methods. According to the scientists, the results of their research may be a key to helping resolve problems relating to the low birth rate and aging population in Japan, where around 1.4 million women experience recurrent pregnancy loss.
