Women are more disgusted by smells in the second half of their menstrual cycle because their immune systems are suppressed and they are more at risk of infection, research shows.
- Scientists from Jagiellonian University Medical School in Krakow surveyed 93 women
- Women found were more disgusted in the luteal phase of the menstrual cycle
- Researchers say women are more sensitive to sources of infection during this stage
Women find bad smells and other people’s illnesses repugnant during the second half of their monthly cycle, a study suggests.
The appearance of germs becomes more disgusting to women because they are more vulnerable to infection at that stage of the menstrual cycle.
The study from Jagiellonian University Medical School in Kraków, Poland, surveyed 93 women between the ages of 18 and 45 at different times in their cycles.
They asked the participants to imagine seven different disgusting scenarios and asked them to rate their dislike after looking at 20 photos.
Women find bad smells and other people’s illnesses more repulsive during the second half of their monthly cycle, suggests a study from Jagiellonian University Medical School in Kraków, Poland.
The participants said they most revolted at the idea of sitting next to someone with open wounds or someone with a strong body odor.
Of the photos they had to look at, the photo of a crowded subway turned out to be the most disgusting.
Scientists said this showed that women have developed an increased sensitivity to potential sources of infection in the luteal phase – the second half – of the menstrual cycle.
Dr. Andrzej Galbarczyk, an author of the study published in the scientific journal Evolution and Human Behavior, said this has evolved as a method of protecting a fertilized egg when they have become pregnant.
The body is more likely to shed an egg if the immune system is suppressed, he told The Times.
He said: ‘As a result, women are more vulnerable to pathogens and infections during the luteal phase of the menstrual cycle.
Therefore, during periods of reproductive immunomodulation – periods of increased susceptibility to infections – women should feel more disgusted and engage in more behaviors associated with avoiding infections.
‘These changes can be caused by a combination of different hormones or factors.’
It comes after a study in February that found that people who shed easily developed this trait as a natural way of preventing infections.
Scientists found that people with a low threshold to feel disgusted are less likely to be infected with bacteria or viruses.
Researchers at Washington State University said this proves that Charles Darwin’s 19th-century theory that disgust evolved as a self-defense mechanism is indeed true.
Dr. Aaron Blackwell, study co-author, said, “We found that people with higher levels of disgust had lower levels of inflammatory biomarkers indicative of bacterial or viral infections.
“While the study shows that disgust works to protect against infection, it also showed that it varies between different environments, based on how easily people can avoid certain things.”
Charles Darwin first theorized that people developed a sense of disgust as a way of avoiding contaminated food in 1872.
Later studies have shown that disgust helps protect people in affluent parts of the world where it is possible to avoid a pathogen if you think one is present.
For example, if a package of chicken is taken out of the refrigerator and has an unpleasant odor, it could be thrown in the trash because other meals are available.
However, no research has been done to test the theory in environments where people cannot avoid similar warning signs.