A new study has found that people who consume tofu and other plant-based foods might enjoy a better sex life than meat-eaters. Picture: Steve Lawrence

London - They are often considered a more spindly counterpart to their meat-eating friends.

But it seems vegetarians might have the last laugh when it comes to matters in the bedroom.

For a new study has found that people who consume tofu and other plant-based foods might enjoy a better sex life than meat-eaters.

It’s thought that certain plant products can influence hormone levels and heighten sexual activity.

The research, published in the journal Hormones and Behavior, is the first to observe the connection between the so called sex hormones phytoestrogens, found in plants, and behaviour in wild primates.

In this case, it was a group of red colobus monkeys in Uganda. As primates, experts say we humans would likely experience similar effects from the compounds.

The research was carried out by Michael Wasserman, while he was a graduate student at UC Berkeley's Department of Environmental Science, Policy and Management.

Over 11 months, Wasserman and his team followed a group of red colobus monkeys in Uganda's Kibale National Park and recorded what the primates ate.

The researchers focused on aggression, which they measured by the number of chases and fights, the frequency of mating and time spent grooming, and the scientists also collected faecal samples to assess changes in hormone levels.

The researchers found that the more male red colobus monkeys dined on the leaves of Millettia dura, a tropical tree containing oestrogen-like compounds, and closely linked to soy, the higher their levels of estradiol, the “sex hormone” and cortisol the “stress hormone”.

They found that with the altered hormone levels the monkeys spent more time having sex, and less time grooming.

Wasserman told Sciencelive: “By altering hormone levels and social behaviours 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.”

In a separate study Researchers from Bellarmine University in Louisville, Kentucky, have found that men believe eating meat makes them more manly.

Professor Hank Rothgerber , who has published his research in the journal Men and Masculinity, said that meat eating was linked with “manhood, power, and virility”.

The research comes after the animal rights charity PETA has also insisted that fruit and veg are the key to virility.

A bizarre video, featuring various men gyrating with an assortment of phallic-shaped fruit and vegetables as their manhood, became a viral sensation on YouTube to back up the point.

From a tennis player sporting a giant carrot, to a car wash mechanic with a banana, PETA says the video is “a light-hearted way to show that spicing things up in the bedroom can be as simple as changing things up in the kitchen”.

The charity maintains that cholesterol in meat, eggs and dairy products can clog our arteries and slow the flow of blood to all the body's organs – including those that are vital in the bedroom.

Vegan meals, on the other hand, contain none of the animal fat or cholesterol found in meat, eggs and dairy products.

Vegans are also, on average, fitter and slimmer than meat-eaters and less prone to heart disease, strokes, diabetes, obesity and cancer, the charity claims.

“When it comes to making love, carnivores can be as sluggish as the blood trying to squeeze through their clogged arteries – but vegans have the stamina to keep the party going all night long,” said PETA UK associate director Mimi Bekhechi. - Daily Mail