Portugal: High-fat diet can impact male fertility down two generations – study

A study by researchers at the Institute of Biomedical Sciences Abel Salazar (ICBAS), in Porto, concluded that food produces impacts on male fertility that can be transmitted and inherited by two generations. 

In a statement, the institute revealed on Monday that in the study, published in the journal “Molecular Nutrition & Food Research”, researchers from the Multidisciplinary Biomedical Research Unit of ICBAS described the biomarkers that allow the identification of a “metabolic memory” present in the testicles.

The alterations are a “consequence of the ingestion of a high-fat diet” and may be inherited by two generations, that is, father-son-grandson, having “implications in male fertility”. 

The team, led by researcher Marco Alves, had already determined, in previous work, that excessive fat intake during the early stages of life alters the lipid content and metabolism of the testicles, “negatively affecting reproductive capacity during the rest of life” and “resulting in changes that are not reversible with a change to a balanced diet”.

In this study, also conducted in animal models (mice), the researchers “went further” and described the transgenerational effects that are passed on from parents eating a high-fat diet to children and grandchildren who followed a balanced diet. 

“The offspring showed, in the testicles, an alteration in choline metabolism”, that is, a nutrient essential for the regulation of various functions, such as brain function, and the development of sperm.

The research also showed changes in mitochondria activity, antioxidant defences and the presence of various lipids. 

“These changes promote a pro-inflammatory environment in the testicle, altering the sperm count and quality,” ICBAS points out, noting that transgenerational effects are also observed when the father’s fat intake is only until puberty. 

Quoted in the statement, researcher Marco Alves points out that reproduction “is also a reflection of diet”. 

“Our food choices will have consequences on our children and, quite possibly, also on our grandchildren,” he says, adding that these effects may have even more impact in assisted reproduction processes, since the sperm is chosen randomly without taking into account biomarkers such as those identified in the study.

“The increase in infertility is clearly associated with the increase in metabolic diseases (overweight, obesity and diabetes, among others), and this association has already been recognised by the World Health Organisation,” highlights Marco Alves. 

The metabolic memory in the testicle is transmitted by the Sertoli cells, which ensure all the structural and metabolic needs during the process of sperm formation. 

The stimuli picked up by these cells besides altering their own gene expression, also alter epigenetics. 

“Knowing these alterations and the transmission mechanisms will allow selecting the best spermatozoids and the best time frame to perform in vitro fertilisations, improving the efficiency of assisted reproduction techniques and opening new therapeutic opportunities in male infertility,” adds the researcher.

Besides the ICBAS team, the study also included researchers from the Pharmacy School of the University of Porto, the University of Aveiro, the Polytechnic Institute of Guarda and the Portuguese Protective Association of Diabetics (APDP).

The work also resulted from several international partnerships, including the University of Zagreb and the University College of London.