Category Archives: fertility

Green tea and male fertility

A new study has found that an extract from green tea affects sperm quality (1). The research, published last month in the journal Molecular Nutrition and Food Research, found that low doses of a chemical compound (epigallocatechin gallate or EGCG) which is present in green tea can improve sperm quality.

Sub-fertility among men is common, and numbers of men affected are increasing. Recent data suggests that 1 in 5 men between the ages of 18-25 now have fertility problems linked to semen quality (2). In around 50% of cases, the cause of male subfertility is unknown, and in such cases nutritional and lifestyle measures are often recommended as a means of boosting sperm quality.

In this recent study, researchers exposed human sperm samples to a range of concentrations of EGCG, a chemical compound present in green tea. Results showed that, at low concentrations, EGCG was associated with increased sperm motility, viability, and phosphorylation of proteins controlling cell survival.

The aim of the study was to find out whether the extract from green tea increased the sperm’s ability to fertilise an egg by improving a process called ‘capacitation’. Capacitation is simply a series of biological processes needed to ‘activate’ the sperm so that it can fertilise the waiting egg.

At low and medium doses, the results were positive. The researchers reported that “depending on the used concentration, ECGC/estrogen receptors are able to improve fertilisation potential of the human male gamete, evidencing the specific effects on motility, viability and energy expenditure in human sperm”. In short, the sperm treated with ECGG helped sperm to swim well. It also increased the number of living sperm, and supported essential signalling inside the sperm.

Will CoenzymeQ10 help you?

At very high concentrations, ECGC had the opposite effect. Such results highlight the need for further research in this area.

There is in fact a growing amount of research surrounding the potential benefits of nutrients in boosting male fertility, with previous studies assessing the effectiveness of nutrients such as l-carnitine and coenzyme Q10.

Previous studies support the value of antioxidants in boosting male fertility (3). The high antioxidant value of green tea is well known, and this characteristic may therefore play a role in its fertility-boosting potential. Sperm damage is thought to occur when highly reactive particles called free radicals circulate in the body, causing damage to sperm cells. This damage may reduce fertility by lowering sperm counts or reducing the sperm’s ability to fertilise an egg. For this reason, antioxidants, which fight those free radicals, are thought to be helpful.

Further controlled trials are certainly needed to provide solid guidelines on the benefits of nutrients in treating male fertility. My feeling is that further research will serve to confirm the crucial role for diet and lifestyle in this area.  The European Science Foundation recently reported new figures showing a rapid increase in male reproductive disorders. This indicates that these fertility issues are caused by environmental factors or changes in our lifestyle rather than genetic factors, meaning that they may be entirely preventable with the a natural approach focussing on nutrition and lifestyle.

Written by Nadia Mason, BSc MBANT NTCC CNHC.


1.De Amicis et al (2012) Epigallocatechin gallate affects survival and metabolism of human sperm Mol Nutr Food Res Nov;56(11):1655-64.

2. Male Reproductive Health – Its impacts in relation to general wellbeing and low European fertility rates. ESF Science Policy Briefing 40, October 2010.

3. Showell et al (2011) Antioxidants for male subfertility. Cochrane Database Syst Rev. Jan 19;(1):CD007411.


Myo-inositol: a safe and effective supplement for PCOS

Recently, there has been a lot of interest in the role of inositol in the treatment of polycystic ovarian syndrome (PCOS). A recent systematic review has weighed up the evidence behind the claims (1).

The systematic review looked at the clinical outcomes of myo-inositol supplementation as a treatment for PCOS. Specifically, it examined the effects of myo-inositol on ovarian function and metabolic and hormonal parameters in PCOS sufferers.

What is inositol?

Inostiol is crucial for a whole range of processes from nerve signals to the breakdown of fats

Inositol is a substance that occurs naturally in the human body, and is also present in foods such as fruits, seeds, grains and nuts. It was once thought to be a member of the B Vitamin group, but this is not strictly true – vitamins are essential nutrients that the body cannot make on its own, whereas our body can actually synthesise inositol from glucose.

Inositol is used by the body to form signalling molecules, and so it is crucial for a whole range of processes, from nerve signals to the breakdown of fats. There are several different forms of inositol, and the two forms that are considered helpful in PCOS are myo-inositol and d-chiro-insolitol.

How is inositol helpful in PCOS?

The researchers found evidence that suggests myo-inositol is helpful in PCOS because it decreases levels of excessive androgens. The study also found evidence that the nutrient improves the ovarian response to hormones called gonadotropins, helping to achieve regular menstrual cycles and successful ovulation.

Women with PCOS often have a defect in the way that their body processes insulin. This has a knock-on effect on other hormones and proteins. Sex hormone binding globulin (SHBG) is decreased, testosterone levels are raised, and the results are problems with acne, hirsutism (excessive hair growth) and fertility.

The insulin-signalling pathway is heavily dependent on myo-inositol. Supplementing extra myo-inositol therefore appears to correct the mal-functioning insulin pathways, reducing the signs and symptoms of PCOS.

The blights of PCOS: ovulation problems, acne and hirsuitism

Other studies echo these findings. A previous randomised controlled trial investigated the effects of myo-insolitol supplements versus placebo on ovarian function (2). Ninety-two women with PCOS were given either 2g myo-inositol twice daily, or a placebo pill for 16 weeks. At the end of the study, significantly more women in the inositol group were found to have normal levels estrogen and progesterone, and experienced normal ovulation. The women in the myo-inositol also showed a significant amount of weight loss over the study period. The researchers concluded that the results indicate “a beneficial effect of myo-inositol in women with oligomenorrhea and polycystic ovaries in improving ovarian function.”

A further study investigated the benefits of myo-inositol on symptoms such as acne and excessive hair growth in women with PCOS (3). After three months of supplementation, levels of insulin, testosterone and luteinizing hormone were significantly reduced. At the six-month mark, both hirsutism and acne had also decreased. The researchers concluded that myo-inositol is a “simple and safe treatment that ameliorates the metabolic profile of patients with PCOS, reducing hirsutism and acne.”

Myo-inositol is not considered toxic even at high doses. It has been supplemented in doses up to 18g daily without significant side-effects, though digestive symptoms may be experienced at this level (4). Of course, it is not at all necessary to supplement at such as high dose for PCOS where results are seen at levels of around 2-4g daily.

I always consider the two most important questions to ask when considering supplementation to be ‘is it safe?’ and ‘is it effective?’ In light of the supporting evidence for the safety and effectiveness of this particular nutrient, I would not hesitate to use myo-inositol alongside a low G.I diet as an initial therapeutic approach to address PCOS.


  1. Unfer V, Carlmango G, Dante G, Facchinetti F (2012) Effects of myo-inositol in women with PCOS: a systematic review of randomized controlled trials. Gynecol Endocrinol 28(7):509-15.
  1. Gerli S, Papleo E, Ferrari A, Renzo GC (2007) Randomized, double blind placebo-controlled trial: effects of Myo-inositol on ovarian function and metabolic factors in women with PCOS. European Review for Medical and Pharmacological Sciences 11: 347-354.
  1. Zacchè MM, Caputo L, Filippis S, Zacchè G, Dindelli M, Ferrari A (2009) Efficacy of myo-inositol in the treatment of cutaneous disorders in young women with polycystic ovary syndrome. Gynecol Endocrinol 25(8):508-13.
  1. Lam S, McWilliams A, leRiche J, MacAulay C, Wattenberg L, Szabo E (2006) A Phase I Study of myo-Inositol for Lung Cancer Chemoprevention. Cancer Epidemiol Biomarkers Prev 15: 1526.

CoQ10 aids male fertility

A new study involving 287 infertile men suggests that the nutrient Coenzyme Q10 improves both sperm quality and pregnancy rate.

The study, published in the International Urology and Nephrology Journal, assessed men with idiopathic oligoasthenoteratozoospermia (OAT), meaning that the men had unexplained reduced sperm count and reduced sperm quality.

CoEnzyme Q10
CoEnzyme Q10 may be useful in supporting male infertility and sperm motility

The trial measured the effects on pregnancy rate of supplementation with 300mg of CoQ10 twice a day for 12-months. Over the 12-month period, the overall pregnancy rate was 34.1%. In contrast, the pregnancy rate in non-supplemented infertile men during the same time is around 6.4%.

Sperm samples were also collected before and after supplementation. The results showed that supplementation with CoQ10 improved mean sperm concentration by 113.7%. It also improved motility (forward movement of the sperm) by 104.8% and raised the number of normal forms by 78.9%.

There are a number of reasons why CoQ10 may boost male fertility. In sperm cells, CoQ10 is concentrated in the midpiece of each sperm, acting as an energy promoting agent. The energy for movement and all other energy-dependent processes in the sperm cell depend on this crucial nutrient. CoQ10 is also an antioxidant, preventing lipid per oxidation thereby reducing damage to sperm membranes.

In cases where couples are having difficulty conceiving, it is very common for medical treatment to be focussed on the female partner only. This treatment pathway fails to address the health of the male partner which could be addressed with nutritional changes.  It does appear that couples are short-changed when they are referred for invasive medical treatments, when nutritional changes could in fact be a far less invasive and stress-free alternative. A recent review of male subfertility concluded that “The concept of unilateral care of the female partner, which has gained momentum in the reproductive health community, especially with the advent of in vitro fertilization and intracytoplasmic sperm injection, is counterproductive, and should be discouraged.”

This trial was open-label, meaning some caution is needed in interpreting the results. However, the study will hopefully pave the way for future research in this area.

While couples may not wish to rely exclusively on nutritional supplements and dietary changes to address subfertility, this approach could be used alongside medical treatment to improve chances of success. “Medical treatment with nutraceuticals helps improve sperm parameters, and even if the response is not adequate, increases the response to assisted reproductive technology.” (2)

Coenzyme Q10 is present in beef, pork, oily fish and nuts. However, to reach therapeutic levels of this nutrient, supplementation would be necessary. The recommended dose range of CoQ10 for male subfertility is 60 mg to 200 mg daily.

Written by Nadia Mason, BSc MBANT NTCC CNHC


1. The effect of coenzyme Q10 supplementation on partner pregnancy rate in infertile men with idiopathic oligoasthenoteratozoospermia: an open-label prospective study. MR Safarinejad. Int Urol Nephrol. Vol 44, no3 (2012) 689-700.

2. S. Kalra, B. Kalra, N. Agrawal: Nutraceutical Management Of Male Subfertility: An Update  . The Internet Journal of Family Practice. 2010 Volume 8 Number 2. DOI: 10.5580/1c4a

3. Image Courtesy of graur codrin


Vitamin D in pregnancy linked to children’s body fat

Vitamin D and Pregnancy

New research has linked levels of body fat in children to the Vitamin D intake of their mothers. Children are more likely to be fatter if their mother had low levels of Vitamin D during pregnancy.

The research was conducted by scientists at the Medical Research Council Lifecourse Epidemiology Unit (MRC LEU), University of Southampton. This study looked at the vitamin D status of 977 pregnant women, and then investigated the body composition of their children at three weeks old, and at the ages of 4 and 6.

The analysis took factors such as maternal height, age, number of children, education, and smoking into consideration, as well as vitamin D intake from food and supplements. The study also took into account other factors such as the amount of weight gain in pregnancy, or the amount of physical activity of the children.

Vitamin D in Pregnancy
Good Vitamin D in Pregnancy is very important. Recent research suggests it could support healthy weight levels childhood.

After controlling these variables, the findings from this study showed that the children who were born to mothers who had low vitamin D status in pregnancy had more body fat when they were six years old.

The researchers suggest that Vitamin D deficiency in the womb might ‘pre-programme’ the baby to gain excess body fat later in childhood.

Professor Cyrus Cooper, Director of the unit that conducted the research said that the study underlined life-long effects of maternal nutrition: “The observations that maternal vitamin D insufficiency might be associated with reduced size at birth, but accelerated gain in body fat during early childhood, add to the considerable amount of evidence suggesting that vitamin D status during pregnancy may have critical effects on the later health of offspring.”

Study leader Dr Siân Robinson maintained that further research is needed, but emphasised the importance of understanding the consequences of nutrition in pregnancy. “In the context of current concerns about low vitamin D status in young women, and increasing rates of childhood obesity in the UK, we need to understand more about the long-term health consequences for children who are born to mothers who have low vitamin D status.”

Indeed there are growing concerns about levels of Vitamin D in young women. An estimated 50% of those in the UK are believed to have insufficient levels of this essential nutrient. It is currently recommended that pregnant women should supplement 10 micrograms of Vitamin D each day. Unfortunately many women are unaware of this recommendation and supplementation is not routine.

If you are currently pregnant, or trying to conceive, a suitable multi-vitamin is one of the best steps you can take to safeguard the health of your future children. Vitamin D levels are listed in either micrograms (mcg) or International Units (IU). 10 micrograms is equivalent to 400 International Units.

Alongside supplements, safe sun exposure is the best way to ensure that you’re getting the Vitamin D you need. While protecting the more sensitive skin on your face with a good sun block or a hat, you can expose your arms or legs to give yourself a Vitamin D boost. During the hot summer months, fair skinned women should start with just a few minutes exposure each day, while their skin builds up its natural protection. Foods such as oily fish, eggs and fortified breakfast cereals can also help you to boost your Vitamin D status.

Under the NHS Healthy Start scheme, pregnant women are entitled to free Vitamin D supplements. Alternatively you can take a good quality multi-vitamin and mineral formula that provides 10mcg of Vitamin D alongside the full spectrum of vitamins and minerals to support a healthy pregnancy.

Written by Nadia Mason, BSc MBANT NTCC CNHC


1. UniversityofSouthampton. “Children’s body fat linked to Vitamin D insufficiency in mothers” ScienceDaily, 23 May 2012. Web. 27 May 2012.



Nutrition in pregnancy and lactation

Pregnancy is a time for substantial changes in a woman’s body in many ways, including hormonal, mental and physical. This growth and development process needs fuel and constant support, and the overall nutritional status of the mother is central to the outcome of the pregnancy and health of the baby.

Birth defects, birthing complications and health risks in childhood and adulthood are substantially reduced if the mother has a healthy diet. This not only provides the baby with the fuel to grow and develop, but it also helps after birth as it influences the milk produced during lactation which sets the child up for the future.

A recent review of nutritional requirements in pregnancy and lactation was published in the Professional Nursing journal (1) which explained the increases in the nutritional demands for the pregnant/lactating female and the importance of this both in the short and long term.

The authors described how the energy intake requirements increase during pregnancy and lactation. Peaking in the third trimester, the accompanying weight gain needs to be steady and consistent based on the mothers pre-pregnancy weight (from 32.5-45lb weight gain in underweight mothers, to 12.5-22.5lb in overweight mothers). The authors also commented on research findings for macronutrients; reporting required increases in protein by 25g a day, especially in the final quarter of the pregnancy and an average serving of fish or chicken is approximately 22-24g.

Extra Carbohydrates are required through pregnancy
Extra Carbohydrates, such as wholemeal bread and one macronutrient that is required through pregnancy.

The diet also needs to consist of 50-65% carbohydrates with a daily minimum of 175g carbohydrates during pregnancy and 210g during breastfeeding. This is equivalent to a daily serving of 250g of wholewheat pasta with 3-4 slices of wholemeal bread.

Essential fatty acids such as omega 3 are vital during this stage of life. An intake of at least 200mg/day of DHA is reportedly needed for reducing birthing complications. Two portions of fish are recommended each week, however due to high mercury contents shark, swordfish and king mackerel should be avoided. Good options would be sardines, herring or salmon. Fatty acids excluding vitamin A may be supplemented in pregnancy and Udos Choice is a popular addition to many pregnancy health regimes.

Micronutrient demands are also escalated during this time and any nutritional deficiency in the mother can considerably impact on the unborn child’s development. As a result the authors commented on the essential need for dietary increases in iron, folic acid, zinc, selenium, chromium, iodine, riboflavin, niacin, vitamins A, B6, B12, C, and pantothenic acid. Additionally, they recommend a multivitamin including these nutrients but without large doses of vitamin A (as this is related to increased birth defects). These nutrients are associated with reduced risks to the child and a better pregnancy outcome.

The authors also reported findings that supplementing calcium in pregnancy is also associated with decreases in complications such as pre-eclampsia, gestational hypertension and pre-term birth as well as improved birthing outcomes.

If you are  considering starting a family or are already pregnant or lactating, you may wish to source a multivitamin without vitamin A such as the Bio Health One-A-Day Bio-Caps that contains folic acid, calcium and iron as well as a good quality, pure essential fatty acid supplement. Folic acid and iron can help prevent Spina Bifida and pregnancy-related anaemia, so ensuring intake of these nutrients is particularly important. A wide ranging, balanced diet is essential and should not be replaced by supplements.  This considered focus on your health plan may help to provide your child with a healthy future and reduce the risks of complications during these demanding times.

Written by Lauren Foster


(1) Labuschagne, I.L., Ackerberg, T.S. & Lombard, M.J. (2012) Optimal nutrition during pregnancy and lactation. Professional Nursing,16(1), 26-29.


Micronutrients before pregnancy boost baby’s immune system

Women who supplement with micronutrients before pregnancy may be boosting the immune health of their baby from birth to adult life, a new study suggests.

Micronutrients are vitamins and minerals, such as the B vitamins and the minerals zinc and selenium, that are required by the body in very small quantities in order to perform many crucial bodily processes.

Micronutrient supplementation before pregnancy can improve your child's immune system
Micronutrient supplementation before pregnancy can improve your child's immune system

The new research took place in Gambia, where individuals born during the ‘wet’ season (when there is less food and nurients available), have higher rates of infection and disease. The women in the study were given either a micronutrient supplement or a placebo until they became pregnant. The study then tested samples of DNA from babies at birth again at 9 months old.

The results suggested that the supplemented mothers had babies with healthier immune systems as a result of methylation changes. “These changes are part of the normal development of the immune system provided adequate nutrition is available.” Explained lead researcher Professor Affara. “Where this is not the case, the result is likely to be reduced ability to fight infection and hence susceptibility to infectious diseases.”

The type of changes in the supplemented mothers were created by a better rate of ‘methylation reactions’. Methylation refers to a special set of chemical reactions in the body. These reactions work like a ‘switch’ in your body, activating beneficial chemicals, and deactivating harmful ones. The methylation cycle is important for immune function, and so if methylation is not working optimally, then our ability to fight infection is impaired.

Professor Affara added: ” If we have an improved understanding of what nutrition is important, we can target nutritional intervention to improve health in later life.”

While many of us are aware of the importance of nutrients such as folic acid in pregnancy, it is becoming increasingly evident that the whole spectrum of vitamins and minerals have an important role to play. The current study certainly indicates that mothers who ensure optimum nutrition before pregnancy are supporting the immune health of their children not only at birth, but throughout their child’s life.

Written by Nadia Mason, BSc MBANT NTCC CNHC


The paper ‘Periconceptional maternal micronutrient supplementation is associated with widespread gender related changes in the epigenome : a study of a unique resource in the Gambia’ will be published in the April 2012 edition of Human Molecular Genetics.


Antioxidant supplements may be helpful for male sub-fertility

A recently published review paper (1) which assessed a number of published trials has found that antioxidant supplements may be of benefit to couples who have had difficulties conceiving naturally.  The review paper has found that the partners of men who take antioxidant supplements are more likely to become pregnant.

Male sub-fertility affects around one in 20 men.  Free radicals produced in the body (also known as reactive oxygen species) are known to cause damage to cells, and in particular sperm cells, which may result in lowered sperm counts and interfere with their ability to fertilise eggs.  Antioxidants, including certain vitamins and minerals, may help to reduce the damage caused by free radicals.

The review (1) focused on 34 trials involving 2,876 couples undergoing assisted reproductive techniques such as in vitro fertilisation and sperm injections. Most men in the trials had low sperm counts or low sperm motility.  Many types of antioxidants were investigated in the trials, for example vitamin E, L-carnitine, zinc and magnesium.

Compared to men not taking a supplement, a couple was more likely to have a pregnancy or live birth if the man took antioxidants.  “When trying to conceive as part of an assisted reproductive program, it may be advisable to encourage men to take oral antioxidant supplements to improve their partners’ chances of becoming pregnant,” said lead researcher Marian Showell, who works in Obstetrics and Gynaecology at the University of Auckland in Auckland, New Zealand (2). “However, these conclusions are currently based on limited evidence.””We need more head-to-comparisons to understand whether any one antioxidant is performing better than any other,” (2)

More evidence is certainly needed before any firm conclusions can be made, however eating a healthy diet rich in fruit, vegetables and wholegrains will to provide the body with many antioxidant nutrients and could be useful to aid fertility.  I have previously written about diet quality, antioxidants and fertility here

Previous study authors have noted “that people who consume more fruits and vegetables are ingesting more antioxidants, and this is the important point“, “We saw that, among the couples with fertility problems coming to the clinic, the men with good semen quality ate more vegetables and fruit (more vitamins, folic acid and fibre and less proteins and fats) than those men with low seminal quality“.  “A healthy diet is not only a good way of avoiding illness, but could also have an impact on improving seminal quality.  What we still do not understand is the difference between taking these vitamins naturally and in the form of supplements(3).  If you decide you want to start taking an antioxidant supplement it is always best to check with your medical doctor first.

(1)Showell MG et al.  2011.  Antioxidants for male subfertility. Cochrane Database Syst Rev.  2011 Jan 19;1:CD007411. 

 (2)Press release.   Wiley-Blackwell (2011, January 19). Antioxidants may improve chances of conceiving in male subfertility. ScienceDaily. Retrieved January 24, 2011, from­ /releases/2011/01/110118200813.htm

(3)  Mendiola et al. A low intake of antioxidant nutrients is associated with poor semen quality in patients attending fertility clinics. Fertility and Sterility, May 2009; DOI: 10.1016/j.fertnstert.2008.10.075 Quote from press release Plataforma SINC (2009, June 3). Semen Quality May Depend Upon Antioxidants In Man’s Diet. ScienceDaily. Retrieved June 4, 2009, from

Written By Ani Kowal


L-carnitine may boost sperm quality and fertility

Male infertility has be linked to a number of different factors.  One issue is a condition known as asthenozoospermia.  This is when sperm lacks motility (motion).

Recently (1) a study in China looked at the effect of the nutritional supplement L-carnitine on men with asthenozoospermia.   A total of 135 men with asthenozoospermia were involved in the study.   68 received 2g of L-carnitine per day as well as vitamin E for three months and 67 received vitamin E only.  All the patients underwent semen analyses before and after the treatment and the pregnancy rates of their wives were recorded. 

Results showed that men taking the L-carnitine had significantly improved sperm motility after 3 months, in addition to this the rate of pregnancy was significantly higher (at 31.1%) in the group taking L-carnitine compared to the group taking vitamin E on it’s own (3.8%).  The authors of the study conclude that “L-carnitine, capable of significantly improving sperm motility and raising the rate of pregnancy, is a safe and effective therapeutic option for asthenozoospermia(1).

This study adds to previous  research that has indicated that L-carnitine supplementation can improve sperm motility (e.g. 2,3,4)

L-carnitine is a ‘dipeptide’, a compound which consists of two amino acids (lysine and methionine), the building blocks that form proteins.  The body can produce L-carnitine on its own, so it is not essential to take it in through the diet.  It is not known exactly why L-carnitine supplementation may be useful in men suffering with asthenozoospermia and further studies will be necessary before treatment with this compound can be widely recommended for the condition.  It may be that L-carnitine may be helpful via acting as an antioxidant in the body or due to it’s role in energy metabolism.  It will be interesting to read further evidence on the subject.  If you decide you would like to try supplementation with L-carnitine it would be wise to visit your medical doctor first.

(1)Wang YX et al.  2010.  [L-carnitine: safe and effective for asthenozoospermia] [Article in Chinese].  Zhonghua Nan Ke Xue.  16(5):420-2.

(2)Balercia G et al.  2005.  Placebo-controlled double-blind randomized trial on the use of L-carnitine, L-acetylcarnitine, or combined L-carnitine and L-acetylcarnitine in men with idiopathic asthenozoospermia. Fertil Steril.  84(3):662-71.

(3)Costa M.  1994.  L-carnitine in idiopathic asthenozoospermia: a multicenter study. Italian Study Group on Carnitine and Male Infertility. Andrologia.  26(3):155-9.

(4)Cheng HJ, Chen T.  2008.  [Clinical efficacy of combined L-carnitine and acetyl-L-carnitine on idiopathic asthenospermia] [Article in Chinese] Zhonghua Nan Ke Xue.  14(2):149-51.

Written by Ani Kowal


Drinking cola could be bad news for reproductive health in men

A recently study published in the American Journal of Epidemiology (1) has found that men who drink large amounts of cola daily (around one litre) could be putting their reproductive health at risk.  Men drinking large volumes of cola were found to have sperm counts that were almost 30% lower than in men who did not drink cola.  It is important to note that most of the sperm counts in all men would still be considered normal by the World Health Organisation, however men with fewer sperm generally have a greater risk of being infertile.

The study(1) involved over 2,500 young Danish men who were going into military service in 2001-2005.  Those who did not drink cola had better sperm concentration and total sperm counts and also tended to lead healthier lifestyles (diet and exercise).  Men who drank a litre of more of cola daily had a significantly lower sperm count and also ate more fast foods and less vegetables and fruits.  When looking at caffeine from other sources, such as coffee and tea, the decrease in sperm quality was much less pronounced indicating that caffeine was not to blame.

The reason for cola having a negative impact on sperm counts is not fully understood yet.  It is unlikely to be due to the caffeine found in cola since coffee did not have the same effect on sperm counts even though the caffeine content of coffee is higher than cola.  It is probable that the other ingredients in cola, such as sugar, could be involved.  It could also be that the unhealthy lifestyles and diets in general in the high-cola drinkers could be to blame.  It is still not clear if the cola or the unhealthy lifestyle, or both, is to blame. Further research would be needed to elucidate the results (1).

The results are worrying since many young men and boys drink a lot of cola and also have poor diets.  It is not yet known how this may impact their reproductive health over their lifetime.

Last year I wrote about the links between diet and fertility in men and I would suggest reading that post for further information about how a healthy diet can impact reproductive health.  In particular the antioxidants found in vegetables and fruits may well protect sperm from damage.  In one of the studies mentioned in the post the authors  stated (2)In this study, we have found that people who consume more fruits and vegetables are ingesting more antioxidants, and this is the important point“, “We saw that, among the couples with fertility problems coming to the clinic, the men with good semen quality ate more vegetables and fruit (more vitamins, folic acid and fibre and less proteins and fats) than those men with low seminal quality“.  “A healthy diet is not only a good way of avoiding illness, but could also have an impact on improving seminal quality.  What we still do not understand is the difference between taking these vitamins naturally and in the form of supplements”.

A recent study (3) investigated the association between pre-conception dietary patterns and IVF outcomes in over 160 couples.  Couples eating a healthy “Mediterranean style” diet rich in vegetables, fruits, fish, legumes (beans and pulses) and wholegrains and low in snacks and meat had a greater success of achieving pregnancy.  The study was only an association study and does not prove that healthy eating can affect pregnancy outcome and fertility but the evidence is interesting and adds to the studies mentioned in the previous post on fertility.  Healthy diet and lifestyle can impact all areas of health!

(1)Jensen TK et al.  2010.  Caffeine Intake and Semen Quality in a Population of 2,554 Young Danish Men. Am J Epidemiol. 2010 Mar 25. [Epub ahead of print]

(2)Plataforma SINC (2009, June 3). Semen Quality May Depend Upon Antioxidants In Man’s Diet. ScienceDaily. Retrieved June 4, 2009, from

(3)Vujkovic M et al.  2010.  The preconception Mediterranean dietary pattern in couples undergoing in vitro fertilization/intracytoplasmic sperm injection treatment increases the chance of pregnancy. Fertil Steril. 2010 Feb 18. [Epub ahead of print]

Written by Ani Kowal


Can poor diet lead to lowered fertility in men?

Diet and its impact on male fertility has long been discussed and debated among scientific, medical and health professionals.  I first started to look at the link between what we eat and fertility, in men and women, whilst studying for my MSc.  The research has been steadily growing over the years and it seems likely that diet does impact fertility.

A group of Spanish researchers have published two (1,2) studies this year which look at the link between diet and semen quality in men.  The studies seem to suggest that dietary antioxidant nutrients play a key role in the prevention of damage to sperm. 

I have written about dietary antioxidants in many previous blog posts.  They have been linked to a reduction in the risk of many conditions raging from cancer to heart disease, dementia and arthritis.  One of the reasons why fruit and vegetables are so important in our diets is because they provide many antioxidant nutrients, such as vitamins C and E and various antioxidant bioflavonoids (bioactive plant chemicals). 

Anitoxidants help to prevent damage to cells in our body (including sperm cells) by mopping-up destructive unstable oxygen molecules known as ‘free radicals’, these free radicals create what is known as oxidative stress in the body.  There is mounting evidence that these destructive molecules, together with lowered bodily antioxidant defences, play a significant role in the development and aggravation of many diseases and health problems.  The body does produce its own antioxidants but also relies on vitamins, mineral and phytochemicals (bioactive plant chemical) from the diet, especially from colourful vegetables and fruits, for additional valuable supplies.

In the first research study (1) the authors found that men who ate large amounts of meat (especially processed meat) and full fat dairy products had poorer quality sperm than those who ate more fruit, vegetables and reduced fat dairy products.  The study was a case-control study in which 30 men with poor semen quality (cases) were compared to 31 men with normal sperm quality (controls).  The investigators recorded the dietary habits and food consumption of the men using a specialised food frequency questionnaire.  The authors conclude that “Frequent intake of [lipophilic] foods like meat products or milk may negatively affect semen quality in humans, whereas some fruits or vegetables may maintain or improve semen quality”.  This study points towards associations between diet and fertility.  It is certainly plausible that a healthy diet and lifestyle can impact upon the health of semen. 

The second study(2) published by the same group of scientists this year was set up in order to compare the specific nutrient intakes between 30 men with normal sperm quality and 31 men with poor sperm quality.  Dietary habits and nutrient consumption were recorded using a food frequency questionnaire.  The analysis found that control subjects, the men with normal sperm quality, had a significantly higher intake of carbohydrates, fibre, folate, vitamin C, and lycopene and lower intakes of proteins and total fat than men with poor sperm quality.  The authors conclude that “A low intake of antioxidant nutrients was associated with a poor semen quality in this case-control study of Spanish men attending infertility clinics”.

Vegetables and fruits are full of antioxidant nutrients and flavonoids which may well be protecting the sperm from damage.  The lead author of the paper, Jamie Mendiola, said in a press release(3): “In this study, we have found that people who consume more fruits and vegetables are ingesting more antioxidants, and this is the important point“, “We saw that, among the couples with fertility problems coming to the clinic, the men with good semen quality ate more vegetables and fruit (more vitamins, folic acid and fibre and less proteins and fats) than those men with low seminal quality“.  “A healthy diet is not only a good way of avoiding illness, but could also have an impact on improving seminal quality.  What we still do not understand is the difference between taking these vitamins naturally and in the form of supplements”.

The authors are going to continue researching this topic in another study and are particularly going to investigate the role that supplements may have on sperm quality.  Obviously I am a great advocate of healthy eating and the basis of any healthy diet is an abundance of vegetables, fruits, healthy fats from nuts/seeds/oily fish, protein from unprocessed lean meats, pulses, beans and unprocessed/unrefined wholegrain carbohydrates.  For individuals who feel they often lack the five or more recommended portions of vegetables and fruits daily may wish to consider taking a good quality multi-vitamin and mineral supplement in order to provide for any nutrient shortfalls, however supplements should never be seen as an alternative to healthy living


(1)Mendiola J et al.  2009. Food intake and its relationship with semen quality: a case-control study.  Fertil Steril.  91:812-818
(2)Mendiola et al. A low intake of antioxidant nutrients is associated with poor semen quality in patients attending fertility clinics. Fertility and Sterility, May 2009; DOI: 10.1016/j.fertnstert.2008.10.075
(3)Plataforma SINC (2009, June 3). Semen Quality May Depend Upon Antioxidants In Man’s Diet. ScienceDaily. Retrieved June 4, 2009, from¬ /releases/2009/06/090602083727.htm

Written by Ani Kowal