A study involving more than 1,000 men and women has confirmed what many others have suggested – that fertility and infertility are associated with dietary habits and nutrition, even if not exclusively caused by them. Produce Business UK highlights the findings which present opportunities for the fresh produce sector to raise awareness of its products’ intrinsic health benefits, especially among men
According to researchers, living healthy, active lives and eating fruits, vegetables, nuts and plant-based proteins rich in monounsaturated and polyunsaturated fats, such as avocados, almonds and walnuts, can boost fertility in both men and women. Non-smokers and those who avoided or limited alcohol are also more likely to conceive.
“While we know that infertility is a multifactorial disease, the infertile individuals in our study clearly had worse recreational and nutritional habits than the fertile,” explains researcher Professor Andrea Salonia, who is a director of the Urological Research Institute at the IRCCS Hospital San Raffaele in Milan, Italy.
The one-year trial presented “striking and statistically significant” results for diet, according to researchers. Fertile subjects reported more frequent regular consumption of vegetables, legumes, fruits and eggs. In addition, women were more likely than men to have a healthy diet overall – perhaps as a result of more public health fertility advice targeted towards women.
More fertile men consumed five vegetable portions per week than infertile men (44% versus 34%); the rates were similar in fertile and infertile women.
More fertile men consumed five fruit portions per week than infertile men (55% vs 46%); and more fertile women than infertile (73% vs 53%).
More fertile men consumed 2-4 eggs per week than infertile men (71% vs 62%), and more fertile women (73% vs 67%).
However, there were no differences observed between the two groups in the consumption of cereals, red meat, poultry and fish, and only legumes and fruits were statistically associated with female fertility. Overall, however, vegetables, legumes, fruits and eggs were all associated with better fertility.
“Artificial fats, such as trans fats, can disrupt fertility by increasing insulin insensitivity and inflammation, and thereby disrupting ovulation, conception, and early embryonic development,” Professor Salonia notes.
“Studies show that replacing trans fats with monounsaturated and polyunsaturated fats has the opposite effect by maintaining healthy cholesterol levels, easing inflammation, improving insulin insensitivity, and promoting fertility.
“Foods rich in monounsaturated fats include avocados, eggs, olive oil and almonds. Polyunsaturated fats, specifically omega-3 fatty acids found in salmon and walnuts, are also beneficial for fertility. Beans, nuts, legumes and other plant-based proteins provide a rich source of iron and folate, which are important for follicle development and ovulation.”
In men specifically, food that is rich in antioxidants, such as fruit and vegetables, could protect sperm development from oxidative damage, while zinc (available in legumes) and selenium (as found in eggs) have been shown to maintain testosterone levels in the normal range.
“Because of the increasing prevalence of obesity and metabolic diseases” said Professor Salonia, “a balanced and healthy diet would not only provide a benefit in terms of general health but also in male and female reproductive health.”
Several other statistically significant associations were also noted with regards to health:
* The fertile subjects of both sexes were more frequently non-smokers: for example, 91% of fertile women were non-smokers and 72% of fertile men.
* Fertile subjects consumed less alcohol per week than the infertile subjects: for example, 94% of fertile women drank less than one litre of alcohol per week and 65% of infertile male subjects.
* A higher proportion of fertile subjects reported a past use of “illicit drugs” (defined as marijuana, cocaine and LSD). For example, 84% of fertile women reported no past use of drugs, but 78% of infertile women did; 68% of fertile men reported no past use, but only 57% of infertile men.
The study compared the nutritional and recreational habits of 1,134 men and women who had had a baby within the past 12 months with those who had not had a baby. The participants attended hospital over 12 months where they were asked about their behaviour. The results were analysed according to gender.
The results of the study were presented at the annual meeting of the European Society of Human Reproduction and Embryology (ESHRE) in Lisbon, Portugal, by Professor Salonia and his colleagues.
Overall findings of the study:
Do you eat fruit every day? (% who answered yes)
Fertile men and women 64.8%
Infertile men and women 50.5%
Do you eat vegetables every day?
Fertile men and women 51%
Infertile men and women 47.8%
Do you consume pulses every day?
Fertile men and women 2.1%
Infertile men and women 0.7%
Do you smoke?
Fertile men and women 18.5%
Infertile men and women 25.3%
Do you drink alcohol?
Fertile men and women 42.5%
Infertile men and women 55.4%
Do you drink more than two litres of alcohol a week?
Fertile men and women 5.5%
Infertile men and women 9.1%
Have you ever used recreational drugs?
Fertile men and women 1.9%
Infertile men and women 3.3%
Do you drink coffee?
Fertile men and women 83.7%
Infertile men and women 90.6%