By Sarah Yang, UC Berkeley Media Relations
A red colobus monkey prepares to munch on the bark of Eucalyptus grandis , a non-native estrogenic tree in Kibale National Park. Greater consumption of estrogenic plants is linked to altered hormone levels and changes in behavior, finds a new UC Berkeley-led study. (Julie Kearney Wasserman photo)
Eating certain veggies not only supplies key nutrients, it may also influence hormone levels and behaviors such as aggression and sexual activity, says a new study led by researchers at the University of California, Berkeley, that could shed light on the role of diet in human evolution.
The research is the first to observe the connection between plant-based estrogenic compounds, or phytoestrogens, and behavior in wild primates – in this case, a group of red colobus monkeys in Uganda.
The more the male red colobus monkeys dined on the leaves of Millettia dura, a tropical tree containing estrogen-like compounds, the higher their levels of estradiol and cortisol. They also found that with the altered hormone levels came more acts of aggression and sex, and less time spent grooming – an important behavior for social bonding in primates.
The study, published in the current issue of the journal Hormones and Behavior, suggests how potentially important consuming phytoestrogens is in primate ecology and evolution.
“It’s one of the first studies done in a natural setting providing evidence that plant chemicals can directly affect a wild primate’s physiology and behavior by acting on the endocrine system,” said study lead author Michael Wasserman, who conducted the research as a graduate student at UC Berkeley’s Department of Environmental Science, Policy and Management. “By altering hormone levels and social behaviors important to reproduction and health, plants may have played a large role in the evolution of primate – including human – biology in ways that have been underappreciated.”