In the previous article, we explained about cholesterol in general. Here, we would like to focus on how cholesterol affects male fertility.
Cholesterol is required for the production of sperm. However, abnormal cholesterol levels could affect the volume of seminal fluid, sperm count and morphology, leading to reduced male fertility.
Mature sperm production is the work of the testes. Homeostasis has been described as the “relatively stable equilibrium between interdependent elements.” Cholesterol homeostasis is a result of many complex processes which occur in the liver. This cholesterol homeostasis is very important for testicular functions, such as the following:
Steroidogenesis – is the process for biosynthesis (production of molecules in living cells) from cholesterol to steroid hormones, using the testes and adrenal glands.
Sertoli cells – these are important cells essential for production of male sperm. They assist in the process from immature male sex cells to become spermatozoa with motility.
Germ cell differentiation – Sertoli cells also provide growth nutrients for germ cell survival and differentiation. The germ cells differentiate to produce male and female gametes (mature male or female germ cells which are able to join together to form a fertilized egg).
Hence, any alteration in the concentration levels of plasma (total) cholesterol can negatively affect the male reproductive function. High cholesterol has been linked to male infertility.
LDL: High levels of LDL – the “bad” cholesterol leads to plaque building in the arteries and clogging of blood vessels. The impact on the blood flow can affect fertility as well. Also, high LDL has a derogatory effect on hormone levels as well. When the body does not produce a sufficient amount of certain hormones, it could lead to infertility. If the hormone activity is abnormal, the sperm will not attach or survive.
Testosterone: Low testosterone does not directly cause infertility. Testosterone is required for sperm production but other hormones are also involved. However, low levels of testosterone could result in less production of sperm. Studies have shown that high cholesterol is linked with decreased testosterone levels.
Dyslipidemia: This is caused when the LDL and triglycerides levels are very high and the HDL level is too low. Dyslipidemia leads to oxidative stress, which is known to affect sperm DNA quality.
Oxidative stress: High oxidative stress causes changes in the membranes of the sperm cells which affect morphology and motility and can cause damage to their DNA. Sperm are rich in PUFA (polyunsaturated fatty acids) which is required for healthy sperm production, increasing motility and improving development of testes and spermatogenesis. However, they can be negatively affected by oxidative stress causing cell damage.
On the contrary, sperm require ROS (reactive oxidative stress) to complete their maturation determining the integrity level of paternal DNA as well as other important steps in the fertilization process.
While some physicians may advise a PUFA-based supplementation to the diet to help sperm disorders, it is important that an antioxidant supplementation is provided as well, to make it effective.
Impact of Cholesterol on Male Fertility: A Deeper Dive
While cholesterol is essential for sperm production, it is critical to manage both elevated cholesterol levels and low cholesterol to maintain proper reproductive health. Cholesterol impacts multiple facets of sperm quality, from count to sperm head morphology and motility, making it a key factor in male fertility.
Elevated Cholesterol Levels and Male Infertility
The effects of elevated cholesterol levels on male fertility are often underestimated. High cholesterol levels in the body, particularly high LDL, have been shown to contribute to a host of reproductive issues. LDL cholesterol leads to the formation of arterial plaque, which restricts blood flow. This reduced circulation can affect the delivery of essential nutrients and hormones to the testes, impairing sperm production.
Moreover, high LDL cholesterol disrupts the delicate balance of sex hormones such as testosterone. Testosterone plays a vital role in sperm production, but it is not the only hormone involved. When high cholesterol levels are present, it can lower testosterone production, indirectly causing reduced sperm output and lower sperm count.
Studies have shown that abnormal lipid levels, including elevated cholesterol levels, are correlated with poor sperm head morphology and lower sperm motility. These sperm characteristics are crucial for successful fertilization, meaning men with high LDL levels may face difficulties when trying to conceive.
Dyslipidemia and Oxidative Stress
Dyslipidemia, characterized by high LDL and triglycerides combined with low HDL, exacerbates the issue by creating oxidative stress within the body. Oxidative stress is a condition where the body’s production of reactive oxygen species (ROS) outweighs its antioxidant defenses. This imbalance can damage sperm cells, especially their membranes, further affecting sperm head morphology and DNA integrity.
While controlled levels of reactive oxygen species are required for sperm maturation, excessive oxidative stress due to dyslipidemia can degrade sperm quality. To mitigate these effects, some physicians recommend PUFA-based supplements along with antioxidants to restore balance and promote healthy sperm development.
Managing Cholesterol for Better Fertility Outcomes
Maintaining normal cholesterol levels is key to preventing fertility issues in men. A combination of lifestyle changes and, in some cases, medications can help regulate cholesterol levels and improve reproductive health. Diets rich in whole grains, fruits, vegetables, and healthy fats are known to lower LDL and raise HDL levels, promoting better heart and reproductive health.
Moreover, regular exercise not only helps manage blood pressure and body weight but also plays a role in keeping cholesterol levels in check. Obesity, particularly abdominal obesity, has been shown to disrupt the balance of sex hormones and increase blood pressure, contributing to a higher risk of male infertility.
Heart Disease and Male Infertility: A Double Threat
It’s important to recognize that heart disease and infertility share several common risk factors, including elevated cholesterol levels. Men with cardiovascular issues often experience reduced blood flow to the testes, which negatively impacts sperm production and sperm quality. Maintaining normal cholesterol levels is thus essential not only for heart health but also for fertility.
Men who suffer from high cholesterol levels should consider getting a semen analysis if they are having trouble conceiving. This test will provide insight into sperm health, including count, motility, and sperm head morphology.
Conclusion:
While cholesterol is essential for the production of normal sperm, too high or too low cholesterol can have negative effects on fertility. While research is still ongoing on this subject, it is best, for general health as well, to keep cholesterol (both LDL and HDL) at a normal level. At the same time, if there is a plan to start a family or experiencing difficulties in conception, it is wise to have a semen analysis done.
At Andrology Center, we carry out semen analysis and DFI (sperm DNA fragmentation index) tests. These provide an accurate account of sperm quality and information on the level of sperm DNA integrity. We are proud to state that we are the only authorised laboratory in India to provide the authentic SCSA (sperm chromatin structure assay) test. With high tech equipment and standardized reporting formats, accurate diagnosis can be made which will help the fertility specialist to recommend the right ART treatment to the couple.
FAQs
How does hormone-sensitive lipase deficiency affect male fertility?
Hormone-sensitive lipase (HSL) is critical for breaking down stored fats into free fatty acids and glycerol. A deficiency in HSL leads to abnormal fat accumulation, which can disrupt lipid metabolism. This disruption affects the availability of cholesterol, which is essential for the synthesis of steroid hormones like testosterone. As a result, HSL deficiency can negatively impact testosterone levels, sperm production, and overall male fertility.
What is the connection between hormone-sensitive lipase and testosterone levels?
HSL helps regulate the release of cholesterol, which is a precursor for testosterone production. When HSL activity is low, the body cannot efficiently break down fats, reducing the availability of cholesterol for hormone synthesis. This deficiency in testosterone, a key hormone for sperm production, can contribute to male infertility.
How does obesity impact the blood-testis barrier?
Obesity increases the risk of oxidative stress and inflammation, which can damage the blood-testis barrier. This barrier is essential for protecting developing sperm cells. When compromised, it can allow harmful substances to affect sperm health, leading to a lower sperm count and poor sperm quality.
What proportion of adults have their cholesterol under control?
Around 30-35% of adults worldwide are estimated to have their cholesterol levels under control through lifestyle changes or medications. However, a large portion of the population struggles with managing elevated cholesterol levels, which puts them at risk for both heart disease and fertility problems.
What are some of the ways to lower high LDL cholesterol levels?
To lower high LDL cholesterol levels, individuals should adopt a heart-healthy diet, rich in fiber, whole grains, fruits, and vegetables while reducing saturated and trans fats. Regular exercise, weight management, and medications such as statins can also help in maintaining normal cholesterol levels.
What are some of the visible signs or symptoms of high LDL cholesterol?
High LDL cholesterol typically has no visible symptoms in its early stages. However, advanced cases can lead to physical symptoms like chest pain (angina) or pain in the extremities due to reduced circulation. In terms of fertility, men may notice difficulty conceiving or experience issues related to low sperm count or quality.
