Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Eating estrogenic plants alters hormones in monkeys, may increase aggression and sex

20.11.2012
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.
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)

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.”

For 11 months, the researchers followed a group of red colobus monkeys in Uganda’s Kibale National Park and recorded what the primates ate. For behavioral observations, the researchers focused on aggression, as marked by the number of chases and fights, the frequency of mating and time spent grooming.

To assess changes in hormone levels, the researchers collected fecal samples once a week from each of 10 adult males in the group (a separate study examining phytoestrogens in females is ongoing). More than 407 samples were collected and analyzed for estradiol and cortisol levels.

The researchers found seasonal variation in the consumption of estrogenic plants, which made up 0.7 percent to as much as 32.4 percent of the red colobus diet in any given week. For red colobus adult males, higher consumption of estrogenic plants corresponded to higher levels of estradiol and cortisol, two steroid hormones important to reproduction and the stress response.

Phytoestrogens are also found in human foods, especially soy and soy-based products. Millettia dura, the tropical tree that was most important to red colobus monkey hormone levels and social behaviors, is a close relative of soy.

“With all of the concern today about phytoestrogen intake by humans through soy products, it is very useful to find out more about the exposure to such compounds in living primates and, by analogy, human ancestors,” said study co-author Katharine Milton, professor in UC Berkeley’s Department of Environmental Science, Policy and Management and an expert on the dietary ecology of primates. “This is particularly true when determining the influence of phytoestrogens on reproductive behavior, which is the whole keystone of natural selection.”

The study authors cautioned against overinterpreting the power of phytoestrogens in altering behavior, however. They emphasized that estrogenic plant consumption is just one of multiple factors influencing primate hormone levels and behavior. Notably, the primates’ own endogenous hormone levels were the stronger predictor of certain behaviors, while phytoestrogens played a secondary role.

The researchers noted that the tendency for certain behaviors to occur can be affected by complex interactions between endogenous hormones and phytoestrogens, in addition to factors such as the quality and quantity of food, competition for resources and mates and predation.

Nonetheless, previous research in laboratory and agricultural settings found that eating estrogenic plants could disrupt fertility and affect behavior in animals such as rodents, monkeys and sheep. Effects of phytoestrogen consumption in other studies have included more aggression, less body contact, more isolation, higher anxiety and impaired reproduction.

The UC Berkeley-led research is the first to observe the connection between estrogenic plant consumption and behavior in a wild primate.

To expand on this possibility, Wasserman and his colleagues are now examining the relationship between phytoestrogens and other primate species, including our closest-living relative, the chimpanzee, to determine how common estrogenic plants are in the diets of wild primates.

“Human ancestors took most of their diet from wild tropical plants, and our biology has changed little since this time, so similar relationships as those found here are expected to have occurred over our evolutionary history,” said Wasserman, now a post-doctoral scholar at McGill University’s Department of Anthropology in Montreal, Canada.

However, the researchers noted that the red colobus diet contains a high percentage of leaves, while the diet of chimpanzees, other apes and human ancestors consists primarily of fruits. Thus, one of Wasserman’s current goals is to compare the presence of phytoestrogens in wild leaves and fruits.

“If phytoestrogens make up a significant proportion of a fruit-eating primate’s diet, and that consumption has similar physiological and behavioral effects as those observed in the red colobus, then estrogenic plants likely played an important role in human evolution,” said Wasserman. “After studying the effects of phytoestrogens in apes and fruit-eating primates, we can then get a better sense of how these estrogenic compounds may influence human health and behavior.”

Other co-authors of the study are Colin Chapman and Jan Gogarten from McGill University, and Daniel Wittwer and Toni Ziegler from the Wisconsin National Primate Research Center at the University of Wisconsin-Madison.

The National Science Foundation and the International Primatological Society helped support this research.

Sarah Yang | EurekAlert!
Further information:
http://www.berkeley.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>