In today’s blog, we are going to talk about fertility. You might be surprised to know that nutrition can influence fertility in men as well as women. There is evidence that suggests that the sperm quality of some of our men living in the UK is on the decline.  That is both in terms of numbers and in quality. Some of this is due lifestyle factors and some to do with other factors, and nutrition falls into this.

The effects of weight on fertility

It is known that many women have low intakes of some essential nutrients that are well below the recommended guidelines.  In particular during the pre-conceptual period and especially during adolescence and young adulthood.
Essential nutrients such as iron, calcium, zinc, vitamins A, B6, C and folate seem to be ones that are lacking the most. There may be lots of reasons for this, money, poor cooking skills, lack of nutritional knowledge.  It may be due to self-imposed dietary restriction for weight loss. Or, it could just be down to how we’ve been brought up, and the foods we were given as children. Especially if we have been introduced to high energy foods, high in the big baddies, saturated fat, salt and sugar and low in the big goodies, vitamins, minerals and fibre.
Evidence has shown that if we are undernourished, then we have a shorter and less efficient reproductive life span than if we are more well-nourished. It is an interesting notion that you can look at women who are overweight or obese and think of them as being well-nourished.  However malnutrition can happen to us women who are overweight just as much as those of us who are underweight. Especially if we are having higher intakes of empty calorie foods that are low in the aforementioned essential nutrients.

The effects of our weight on fertility

Our weight is an issue when it comes to female fertility. Very low BMI and body fat percentage is an influencing factor in our menstruation and ovulation.  This due to the significant reduction of oestrogen produced in the ovaries and adipocytes (fat cells to you and me). Oestrogen is not readily produced in those of us who are very underweight, with a very low, fat mass. Conversely, fertility may also be affected in those of us who are very overweight or obese.  The adipose tissue (sounds so much more genteel than fat) produces too much oestrogen, throwing off the delicate hormonal balance. Hence, a normal BMI (between 20 and 25) is considered our Goldilocks porridge, and is just right.

There are other lifestyle factors that are known to impact on our ovulation, and can affect fertility and pregnancy outcomes.  These include how much alcohol we consume, whether we smoke and how much exposure we have to second-hand smoke.

Polycystic ovarian syndrome (PCOS)

PCOS is another condition that can seriously affect our fertility.  It is thought to affect one in ten of us in the UK.  However, there is a lot of variation in the severity of the condition.  About half of us don’t  experience any symptoms at all. PCOS is a very often undiagnosed hormonal issue, with a cluster of symptoms that can be associated with other conditions that can affect us. PCOS is usually diagnosed via blood tests for hormonal levels and ultrasound scans for the detection of polycystic ovaries. However, it is easily missed because of variances in our hormonal levels throughout the menstrual cycle.

Signs that you may have PCOS include symptoms such as

• Irregular or infrequent periods
• Excessive androgens (male hormones) that can cause facial hair and/or acne
• A high number of follicles on the ovaries which can become filled with fluid giving the appearance of ovarian cysts
• Obesity.

It can also lead to mental health issues for us in the shape of anxiety and depression. Women who develop PCOS can become resistant to the effects of insulin.  This may increase the risk of developing other health conditions in later life such as type 2 diabetes, heart disease, high blood pressure. There is also an increasing risk of developing uterine or breast cancer if it is not managed properly.

PCOS can have a profound impact on fertility

PCOS can also have a profound impact on fertility because of hormonal imbalances, particularly in younger women. Treatments for PCOS include hormone therapy, but lifestyle changes are also key with weight loss, physical activity and good nutrition. Some foods need to be omitted or limited in the diet of someone with PCOS. Soy and soybean products such as tofu need to be limited due to phyto-oestrogens.  And dairy because of the potential for increasing insulin levels. Processed and refined foods need to be avoided too. Women with PCOS need to ensure a high fibre diet.  Following a Mediterranean dietary pattern, or the DASH diet (Dietary Approaches to Stop Hypertension), has been shown to be very effective in reducing weight and insulin resistance.
The DASH diet was actually developed in response to increasing prevalence of high blood pressure.  It is comprised of foods that are low in sodium and fat, particularly saturated fat and cholesterol. But it has also been shown to be protective against osteoporosis, type 2 diabetes and heart disease. I will come back to PCOS in a later blog post which will have a focus on women’s reproductive health and I will include endometriosis and adenomyosis.

The causes of male infertility

The question of fertility is not isolated to just the female.  Over a third of fertility issues are due to male infertility.  Again, lifestyle and nutrition play an important role. It is thought that as much as 20% of our adult male population in the UK have issues with sperm quality being lower than it should be.  50% of the cases attending IVF clinics are due to male fertility issues.
There is evidence to suggest that male sperm counts have been on the decline over the last 50 or 60 years or so.  Some of the causes are thought to be because of increased exposure to environmental pollutants, such as insecticides, radiation and electromagnetic waves. Weight is also an influencing factor in male fertility. Excessive body fat can impact on the balance of the sex hormones, such as testosterone. Whereas too low body weight can influence the quality and/or quantity of sperm.

Very high activity levels, such as overtraining in the gym, has been shown to have an adverse effect on the balance of male hormones, lowering testosterone and thus sperm count. And the use of anabolic steroids often associated with weight training and used to increase muscle mass and to improve athletic performance, can cause testicular damage, again lowering testosterone levels.

Lifestyle factors

Excessive alcohol intake is another factor linked to the poor production, impaired motility and quality of sperm.  As is smoking and recreational drug use. There is no evidence as yet about the impact of E-cigarettes or vaping on fertility, what has been noted though is that while there is a benefit to transitioning to E-cigarettes or vaping from smoking cigarette tobacco, detrimental respiratory effects have been observed in individuals who take up vaping with having first smoked cigarettes.

Sexually transmitted infections are also another factor affecting both male and female fertility. Infections such as chlamydia are on the increase and are linked to reductions in fertility. Although, unbelievably, there is some evidence to suggest that young men in countries such as the UK where heavy industry is on the decline, prefer to engage in video gaming and Netflix, and are less inclined to engage in sexual activity‼

Potentially, one of the most significant changes over the last 40 years or so, is the delay in ‘trying for a baby’ in both males and females. Many couples are now in their mid to late 30’s before attempting to conceive and of course sperm quality declines with age and as such so does fertility. It is thought this phenomenon is due to career pathways and social change with the expectation and presumption that women pursue careers in exactly the same way that men do.

The ‘Perfect Storm’

If you would like to know more about male fertility, there is a very interesting presentation by Professor Allan Pacey from the University of Sheffield who has a specialist research interest in male fertility. He describes what he sees as the 6 specific areas that create what he describes as the ‘perfect storm’ in terms of male fertility: fewer sperm, age before conceiving, more STI’s, rising cases of testicular cancer, general health and diseases, and having less sex.

See the link below.

https://www.youtube.com/watch?v=jEvYMync8V
The take home messages here are…

• Nutrition on its own, may not be able to prevent issues with fertility.
• Your nutrition has consequences for health in terms of underweight and overweight which are known causes.
• Eat a wide range of foods, that are as near to their natural state as possible
• Include at least 5 portions of fruit and veg, taste the rainbow
• Eat good sources of protein, iron such as lean meat and poultry and…
• Omega 3 fatty acids found in oily fish, nuts and seeds (especially linseed and chia seeds).
• Include dairy or non-dairy alternatives for calcium, iodine etc. and…
• wholegrains and legumes for a wide range of vitamins and minerals, all of which can help to ensure weight is stable and health is optimal.

We could almost think of is as preparing the oven for the bun!