Plant protein could help boost testosterone in ageing men

As men turn grey and middle age kicks in, testosterone runs lower than it did in younger years, in turn dragging down muscle and bone strength, as well as sex drive.

The hormone can be depleted in even younger men, particularly among the overweight who eat processed food or those who suffer from stress, which can trigger an excess of cortisol, another hormone that in turn can block testosterone production.

A protein-rich but balanced diet has long been recommended to help regain or sustain testosterone levels, or at least mitigate the effects of ageing.

A team of scientists at the University of Eastern Finland has found indications that plant-derived proteins, particularly if from vegetables, are best of all for testosterone maintenance, holding their own against meat-based sources and exceeding the effects of dairy, which was found to slightly reduce the hormone’s presence.

Published in the International Journal of Food Science and Nutrition, the findings were based on medical and diet data from the 1980s for around 2,500 Finnish men aged between 42 and 60.

“Concentrations of total testosterone and sex hormone-binding globulin were measured in blood samples,” the researchers said, adding that they accounted for factors such as age, body mass index, lifestyle and broader diet.

The effect of protein could depend on how healthy a balance of fibre, fruits, berries and vegetables, saturated, monounsaturated, polyunsaturated and trans fatty acids there is in a diet, the researchers explained.

At the same time, the team cautioned that the differences between how the various protein sources affected testosterone were small in real terms, even if “statistically significant.”

“The study cannot establish whether these differences have implications for health,” said Miika Wynne-Ellis of the University of Eastern Finland.

Broccoli, mushrooms and kale are among the best vegetable sources of protein, with peanuts, hemp seeds, lentils and chickpeas among the wider plant-derived options.