Daddy’s Diet

Men's health

Daddy’s Diet

How a fathers’ lifestyle influences the health of future generations

We all know that a woman who is trying to conceive should eat a healthier and more nutritious diet. In addition, she should abstain from drugs, alcohol and cigarettes. This is because these factors can affect her chances of becoming pregnant, as well as have a negative effect on her developing fetus should she fall pregnant. Even a woman’ level of emotional stress could influence her fertility and pregnancy success. But does the same apply to men? How does a man’s lifestyle affect conception and the health of his offspring?

Unlike women, men’s reproductive health is under-emphasised and men are largely left out of pre-conception planning. This is despite the fact that male infertility is on the rise, with lower sperm counts and damaged sperm becoming more prevalent. Now, however, new studies are beginning to show that a father’s lifestyle can impact the possibility of pregnancy, as well as the long-term health of his children.

More than genes

Though the saying goes, “It’s all in genes,” scientists have discovered there’s more to our genetic inheritance than that. Beyond our DNA code is epigenetics, which can be defined as, “a heritable layer of biochemical information associated with DNA, and transmitted via the sperm and egg.”

According to Sarah Kimmins, PhD, who holds a Canada Research Chair in Epigenetics, Reproduction and Development and is an Associate Professor at McGill University, Montreal, “We are now beginning to understand that sperm epigenome contains a lifetime memory of paternal experiences. Everything is a man’s daily lifestyle, including his environment, diet, exercise, alcohol and smoking have the potential to disrupt (or support) the setting of the sperm epigenome, which is then passed on to future generations.”
Danger of chemicals

Besides lifestyle, says Kimmins, other factors that can contribute to male infertility are “Chronic conditions like obesity, cardiovascular disease and metabolic disorders, as well as paternal age and heightened stress.” Furthermore, the researchers at McGill University also believe that, “Reduced fertility may be in part attributable to the dramatic increases in chemical production and consequent human exposure.”

Their studies show that there are now about 80,000 chemicals registered for commercial use. We are exposed to these chemicals daily, be it at work, in household products, in the environment, as well as food and cosmetics. As an alarming result, high levels of common toxicants, like bisphenol A and phthalates can now be detected in urine and blood analysis of not just adults, but children too.

While only a handful of research groups worldwide are addressing the cause and effect of lifestyle and chemical exposure to human infertility and epigenetic inheritance, it is becoming increasingly that a father’s way of life plays a vital role in determining his child’s development and health. As such, Kimmins suggests that, “Men should become more involved in pre-conception planning and young men must be educated that their choices today may influence health beyond their own.”

Unravelling a Mystery

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Unravelling a Mystery

Epigenetics as a possible cause for male infertility

One of the common problems subfertile couple faced is the issue concerning sperm quality and quantity.  In the past, male issue had deemed to be responsible for 15-20% of the reason for subfertility. However, over the last 10 years, this issue had become more prevalent and it is estimated that around 40-50% of couples are suffering from male fertility issues.

A recent study in French men between 1989 and 2005 found a significant widespread declines in sperm quality , with average sperm counts falling while percentages of abnormally formed sperm rose. These findings are a “serious public health warning,” the authors wrote. The same findings were observed world wide suggesting a global decline in male fertility.

What can possibly be the culprit causing such decline? Could it be the air we breathe? Could it be the water we consume? Could it be the pesticides, fertilizers, genetically modified food and etc?

There is no straightforward answer to this.

According to a 2011 study called Starting Families Asia, which surveyed 1000 women from 10 countries (including Malaysia), there is a widespread lack of knowledge about male fertility issues throughout Asia. The study showed that, “51% of women do not know that a man may be infertile even if he can achieve an erection, and 49% do not realise that a man may be infertile even though he produces sperm.”

Despite the lack of awareness, male infertility is a common problem, affecting 1 in 20 men. And among married couples struggling with infertility, 40% of the cases may be attributed to the man. Though it has been extensively studied, male infertility remains a complex problem and the underlying causes are usually unknown. However, a study by researchers at the University of Southern California (USC) has suggested that the underlying cause for male infertility is epigenetics – the way that DNA is processed and expressed.

The consequences of epigenetic modification

Epigenetics are processes that alter gene activity, without changing the DNA sequence. They have a vital role to play in the body’s many processes, including those involved in conception, such as implantation, placentation and fetal growth. When these epigenetic processes are modified, due to genetic and environmental factors, the consequences are usually unfavourable.

To identify the link between epigenetic modification and male infertility, USC researchers studied the epigenetic state of DNA from semen samples of male patients at an infertility clinic. Their findings showed that, “Sperm DNA from men with low sperm counts or abnormal sperm had high levels of methylation. However, DNA from normal sperm samples showed no abnormalities of methylation.”

DNA methylation is the result of biochemical changes that happen during epigenetic reprogramming, and according to Rebecca Sokol, M.D., MPH, Pofessor of Obstetrics and Gynecology at the Keck School of Medicine of USC, “Disturbance of epigenetic programming can result in abnormal gene activity or function, even if there is no change in DNA sequence.”

The findings of this ground-breaking study show that there is a link between epigenetic defects and abnormal semen development. In addition, says Sokol, “It is plausible to speculate that male infertility may be added to the growing list of adulthood diseases that have resulted from fetal origins.”

Conclusion

As the results of this study point to underlying mechanisms that can cause epigenetic changes, the next step is for researchers to identify what causes these changes to sperm DNA. Once they have been identified, we will be one step closer to preventing certain types of male infertility. At present, it is believed that one of the possible causes of epigenetic alterations is chemical exposures. It has even been suggested that exposure to chemicals as a fetus may lead to adult diseases.

 

Get Some Sun!

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The link between Vitamin D and fertility

Caucasian women love showing off a sun-kissed tan, so much so they would dedicate a good portion of their holidays to sunbathing. We Asian women, however, are the exact opposite, preferring to keep out of the sun, sometimes taking considerable pains to do so. This aversion to the sun is largely due to the desire to maintain a fair complexion, but is driven in part by concerns over harmful UV rays. This penchant for shunning the sun, however, has had an undesirable side effect on Asian women, as we are known to have lower levels of Vitamin D despite living in tropical climates.

Few people realise that vitamin D plays a significant role, not only in their general health, but their fertility as well. It has been shown that people living in countries with strong seasonal contrasts have always had fewer pregnancies during winter and more in summer, resulting in a baby boom around spring. Scientists have discovered that this ebb and flow has to do with exposure to the sun.

Over the years, this link between Vitamin D and fertility has been extensively investigated, but it has been further detailed in a systemic review published in 2012 by the European Journal of Endocrinology. The review, by Elisabeth Lerchbaum and Barbara Obermayer-Pietsch from the Medical University of Graz, Austria, assessed studies that evaluated the relationship between vitamin D and fertility in women and men, as well as in animals.

Here’s what the review, entitled ‘Vitamin D and fertility: a systematic review,’ found:

  1. Vitamin D receptors (VDR) and vitamin D metabolising enzymes are present in the reproductive tissues of both men and women.
  2. Laboratory mice deprived of VDR tend to suffer significant gonad (sex gland) insufficiency, decreased sperm count and motility, and abnormalities in the microscopic structure of tissues in the testis, ovary and uterus.
  3. Vitamin D is involved in female reproduction including IVF outcome (clinical pregnancy rates) and polycystic ovary syndrome (PCOS).
  4. In PCOS women, vitamin D supplementation might improve menstrual frequency and metabolic disturbances.
  5. Vitamin D might influence steroidogenesis of sex hormones (estradiol and progesterone) in healthy women.
  6. In men, vitamin D is positively associated with semen quality and androgen status.
  7. Vitamin D treatment might increase testosterone levels.

While the results are encouraging, the researchers emphasise that vitamin D supplementation alone can’t improve fertility issues. However, what is certain is that it is a safe and inexpensive treatment that can be a boon to conception. So if you’re trying to conceive, don’t shy away from the sun! Instead, aim to get about 15 minutes of sun each day and take care not to overexpose yourself to UV rays.

In my next post, I’ll be discussing another topic related to fertility and nutrition – the findings of the Dutch Famine Birth Cohort Study. Stay tuned!