Sugar, proteins, AGEs and fertility

A woman’s pre-pregnancy diet could have a greater impact
on fertility and pregnancy than previously thought.
Image: Essential Baby 

by Kristy Sheridan

A woman’s pre-pregnancy diet could have a greater impact on fertility and pregnancy than previously thought, according to new research by Monash University and Hudson Institute of Medical Research scientists.

The study found that certain proteins, which become ‘toxic’ after exposure to sugar, trigger inflammation in the womb in infertile women with obesity. This may reduce the likelihood of a woman falling pregnant and could even contribute to pregnancy complications.


The study is led by Dr Jemma Evans, and co-authored by Professor Lois Salamonsen and Monash University undergraduate Gabriella Antoniotti at Hudson Institute, together with Associate Professor Melinda Coughlan from Monash University’s Department of Diabetes. The findings of the study have been published in the journal, Human Reproduction.

“We all know about the importance of a healthy maternal diet to ensure the health of the baby during pregnancy. Now, what is becoming clear is that what women eat while trying to conceive – particularly sugar and highly processed foods – can have a direct impact on fertility,” Dr Evans says.

What are advanced glycation end products (AGEs)?

• Advanced glycation end products (AGEs) are compounds which are formed when proteins, lipids or nucleic acids change during exposure to sugar.
• The pool of AGEs found in the human body can either be formed naturally within the body, or accumulate through dietary exposure to certain foods or beverages.
• AGEs are formed in foods by heat-processing such as frying, grilling, caramelising or roasting (examples include browned meat or toast). Highly processed foods have a high content of AGEs.
• Preclinical studies suggest that otherwise healthy proteins in the body can react with sugars (such as those consumed in foods or beverages) to form AGEs within the body.
• AGEs are known contributors to oxidative stress and inflammation and have been linked to the recent epidemics of diabetes and cardiovascular disease.

In the study, the team analysed samples from the uterus, including from women with obesity, who are more prone to infertility and pregnancy complications, and who are known to have elevated levels of AGEs.

“We discovered that these sugar ‘by-products’, or specific toxic factors, detrimentally alter the cells in the lining of the womb, making it harder for an embryo to implant,” Dr Evans says.

“We also found that AGEs interfere with placental development, which may contribute to pregnancy complications. This is the first time anyone has demonstrated in laboratory studies that specific toxic factors in the womb can compromise fertility.”

AGE levels can be reduced with a highly controlled diet or by a specific drug. A low-AGE diet has been shown to improve health outcomes in other diseases, such as reducing insulin resistance in diabetes, in as little as four weeks. To date, this controlled diet hasn’t been tested in relation to fertility.

Dietary intervention – clinical trial

To test the findings in women, Dr Evans is now designing a clinical trial of a simple eight-week dietary intervention to try to reduce levels of these toxic factors in the womb. The aim is to help more women fall pregnant and have healthier pregnancies.

Dr Evans says the womb is likely to respond to a short-term intervention, like a dietary change, to restore fertility because it regenerates every month.

“The endometrium is the only place in the body that completely regrows every 28 days. If successful, this simple dietary intervention may become a more holistic way to improve fertility and potentially avoid the need for costly interventions such as IVF.”

Reference
Antoniotti GS, Coughlan M, Salamonsen LA, Evans J. Obesity associated advanced glycation end products within the human uterine cavity adversely impact endometrial function and embryo implantation competence. Hum Reprod. 2018 Apr 1;33(4):654-665. doi: 10.1093/humrep/dey029.