Apparently, eating “less than one rasher of bacon per day” is enough to turn your swimmers into floaters.
This story was covered by most of the popular online news resources, but if you ask me, they got this wrong way around. If I wanted men to pay attention to this story I would have created the headline:
“EATING BACON WILL REDUCE THE RISK OF GETTING YOUR GIRLFRIEND PREGNANT”
Instant. Internet. Sensation.
It is based on an “abstract” that was presented at a fertility conference last week. Every year, over 4,000 fertility experts attend the International Federation of Fertility Societies and American Society for Reproductive Medicine (IFFS/ASRM) conference, where they discuss their latest findings in fertility research.
An abstract is basically a very short description of a study, and can be presented as a poster or a short talk. It is often a way of getting some new research out there before you have done the extra work that might be needed to make it into a full scientific paper for a journal. This doesn’t mean that abstracts are less important in terms of science, but they don’t have to provide the detail of their methods and analysis, which would normally allow us to have a look inside the workings of the study.
In this particular abstract, 156 men attending a fertility clinic in Massachusetts were asked to fill in a food questionnaire and provide some “samples”. Hopefully not at that same time.
The researchers then looked to see if there was a relationship between certain dietary factors and total sperm count or sperm quality (the percentage of sperm that appear healthy or “normal”). Importantly, they adjusted their data to take into account body mass index (BMI), smoking status, age and “dietary pattern”, which may affect the sperm. Ignoring the fact that food questionnaires are notoriously dubious, and that we don’t know what dietary factors they adjusted for, let’s look at what they found:
- Men who ate more than 0.38 servings of processed red meat per day had 1.4% units less “normal” sperm than those who ate under 0.38 servings.
Now, the rational first response to this is: “BACON DOESN’T COME IN FRACTIONS”, but never mind.
They also don’t say what the “1.4% units less normal sperm” means. However, The Daily Mail interviewed the lead researcher, Dr. Afeiche. She is quoted as saying that:
5.5% of sperm had a “normal” appearance in those eating the equivalent of “less than a rasher of bacon per day”, compared to 7.2% normal sperm in those abstaining from fractions of bacon.
You’re right, the difference between 5.5 and 7.2 is not 1.4.
Despite some poor maths somewhere, Dr. Afeiche also found that eating fish improved the quality of sperm:
- Men eating the most “dark” fish (ie salmon and tuna) had 34.0% more total sperm than those eating the least dark fish.
- Men who ate the most white fish (ie cod and halibut) had 1.6% more ”normal” sperm than those eating the least white fish.
The enterprising amongst you will have noticed that if you wrap monkfish in pancetta, you will still get an overall improvement in your “normal” sperm count.
I would never pretend to be an expert in fertility, but just looking at those two trends tells me that overall patterns of lifestyle are likely to be key, rather than just blaming one particular component. We know from numerous large studies that those who eat more red meat, especially more processed red meat, eat less fish and vegetables. They are also more likely to be overweight and more likely to smoke.
This is backed-up by some other abstracts that Dr. Afeiche and colleagues presented at the meeting. In the same group of men:
- Higher alcohol and caffeine intake were not associated with a change in sperm quality, but the more alcohol men drank, the more likely they were to have been smokers.
- In those who did smoke (currently or previously), the more alcohol they drank, the lower their percentage of “normal” sperm, though all groups still had healthy levels (more than 4%) of normal sperm.
- The most physically active men had 48.2% more sperm than the least physically active men.
- Weight training and being outdoors improved sperm count, but running and cycling did not.
As all this data comes from abstracts, I can’t give you more than the numbers and a broad opinion. So, in order to provide the best possible overview of what people have found regarding lifestyle and fertility this year, I had a dig around the other abstracts at the conference, and found the following:
- Women who never drink alcohol appear to be more likely (90.9% chance) to have a successful pregnancy with “assisted reproduction” compared to those who drink (70.7%).
- Women with higher cholesterol and lipid levels took significantly longer to achieve pregnancy, or failed to become pregnant within a year of one particular study.
- Giving monkeys a “Western diet” high in fructose and fat changed the structure of their ovaries such that they appear less fertile.
- The higher your protein intake from dairy products, the lower your antral follical count, which is a marker of reduced fertility. However, high levels of protein from other sources did not have this effect.
- Women who are infertile are 3 times more likely to have coeliac disease. One study diagnosed 70 cases of coeliac disease in 839 women presenting for an infertility evaluation, and infertility was the only symptom associated with the disease.
- Men with higher phthalate levels in their blood took significantly longer to get their partner pregnant. Phthalates are breakdown products of plastic that often come from eating or drinking from tins, or bottles and containers made of plastic.
- Higher blood lipid (fat) and cholesterol levels reduced the quality of sperm but did not affect how long it took to achieve pregnancy.
Another abstract mentioned the “Food for Fertility” programme that they are running at a fertility clinic in Seattle. Of course, these doctors didn’t say what they recommend, because then you wouldn’t pay for the course. However, their abstract mentions preparing their patients for fertility treatments by focusing on “physical activity, eating healthier, stress, sleep and social support”. The diet they promote is “anti-inflammatory”, “low glycaemic-index”, and helped 9 women reduce their BMI from 37.1 to 35.8 over seven weeks.
On a different note, in a small randomised controlled trial of women with polycystic ovary syndrome (PCOS), a cinnamon extract improved menstrual cycle regularity compared to placebo. PCOS is associated with reduced fertility due to less regular menstrual cycles with irregular ovulation, and hormonal problems including type II diabetes. This ties-in with a recent meta-analysis, which showed that up to 6g (a large teaspoon) of cinnamon per day improves fasting glucose, triglyceride and cholesterol levels in type II diabetics. Cinnamon may therefore improve the reduced fertility that is associated with those metabolic problems in PCOS.
Though by no means comprehensive, this is the picture of the recently-studied lifestyle factors that can affect fertility. It indicates that a sensible approach to diet, sleep and stress could improve fertility in women. Diet and environmental toxins are important in men, as is lifting weights.
If all that fails, then recent advice suggests that you can predict your fertility by taking regular photographs of your cervix to assess the position and “texture”. Whatever makes you happy….!
1. M. Afeiche, A. Gaskins, T. Toth, C. Tanrikut, R. Hauser, J. Chavarro (Abstract at IFFS/ASRM 2013) - [O-98] MEAT INTAKE AND SEMEN PARAMETERS AMONG MEN ATTENDING A FERTILITY CLINIC.
2. Pan A, Sun Q, Bernstein AM, Schulze MB, Manson JE, Stampfer MJ, Willett WC, Hu FB. Red meat consumption and mortality: results from 2 prospective cohort studies. Arch Intern Med. 2012 Apr 9;172(7):555-63.
3. A. E. Karmon, T. L. Toth, M. Afeiche, C. Tanrikut, R. Hauser, J. E. Chavarro (Abstract at IFFS/ASRM 2013) - [O-37] ALCOHOL AND CAFFEINE INTAKE IN RELATION TO SEMEN PARAMETERS AMONG FERTILITY PATIENTS.
4. Rothmann SA, Bort AM, Quigley J, Pillow R. Sperm morphology classification: a rational method for schemes adopted by the world health organization. Methods Mol Biol. 2013;927:27-37.
5. A. J. Gaskins, M. Afeiche, C. Tanrikut, J. C. Petrozza, R. Hauser, J. E. Chavarro (Abstract at IFFS/ASRM 2013) - [O-405] PHYSICAL AND SEDENTARY ACTIVITIES IN RELATION TO SEMEN QUALITY.
6. D. Godfrey, J. A. Lee, V. Nedergger, E. Cervantes, B. Sandler, A. B. Copperman (Abstract at IFFS/ASRM 2013) - [P-953] ASSISTED REPRODUCTIVE REGISTERED DIETICIAN ASSESSMENT: DOES PRIOR ALCOHOL INTAKE AFFECT A WOMEN'S CYCLE OUTCOME?
7. E. F. Schisterman, R. W. Browne, D. Boyd Barr, Z. Chen, S. L. Mumford, G. M. Buck Louis (Abstract at IFFS/ASRM 2013) - [P-667] LIPID LEVELS AND COUPLE FECUNDITY: THE LIFE STUDY.
8. C. V. Bishop, W. K. McGee, E. Galbreath, M. B. Zelinski, J. L. Cameron, R. L. Stouffer (Abstract at IFFS/ASRM 2013) - [P-659] WESTERN-STYLE DIET (WSD) WITH AND WITHOUT TESTOSTERONE (T) EXPOSURE CHANGES FOLLICULAR STRUCTURE-FUNCTION IN YOUNG ADULT, FEMALE RHESUS MONKEYS.
9. Souter, M. Batsis, Y.-H. Chiu, M. Afeiche, R. Hauser, J. Chavarro (Abstract at IFFS/ASRM 2013) - [O-40] THE ASSOCIATION OF PROTEIN INTAKE (PI) AND ANTRAL FOLLICLE COUNT (AFC) AMONG WOMEN UNDERGOING INFERTILITY TREATMENTS.
10. K. C. Humm, L. H. Wu, A. Merport Modest, M. R. Hacker, D. Leffler, A. S. Penzias (Abstract at IFFS/ASRM 2013) - [P-1073] PREVALENCE OF CELIAC DISEASE IS HIGHER AMONG WOMEN WITH INFERTILITY.
11. G. M. Buck Louis, R. Sundaram, A. Sweeney, E. F. Schisterman, K. Kannan (Abstract at IFFS/ASRM 2013) - [O-2] BISPHENOL A, PHTHALATES AND COUPLE FECUNDITY, THE LIFE STUDY.
12. J. D. Simon, C. Dennett, A. Thyer (Abstract at IFFS/ASRM 2013) - [O-264] ASSESSING THE EFFECTIVENESS OF "FOOD FOR FERTILITY" PROGRAM.
13. D. H. Kort, C. Sullivan, A. Kostolias, J. C. DePinho, R. A. Lobo (Abstract at IFFS/ASRM 2013) - [P-696] CINNAMON SUPPLEMENTATION IMPROVES MENSTRUAL CYCLICITY IN WOMEN WITH POLYCYSTIC OVARY SYNDROME.
14. Allen RW, Schwartzman E, Baker WL, Coleman CI, Phung OJ. Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis. Ann Fam Med. 2013 Sep-Oct;11(5):452-9.