Monday December 15 2014
Does chilli chomping make you a real man?
“Men who like spicier food are 'alpha males' with higher levels of testosterone,” The Daily Telegraph reports. A small French study found an association between a preference for spicy foods and elevated testosterone levels; but no evidence of a direct link.
Testosterone is a steroid hormone that in popular culture has long been associated with male virility. Men with high levels of testosterone are alleged to be more sexually active, domineering, brave and willing to take risks – the so-called “alpha male”.
So, is a liking for spicy foods a sign of “alpha male” risk taking and bravery? Is ordering the hottest thing on the menu a 21st Century equivalent of a tribal initiation ceremony? The quick answer is that we don’t know.
The study in question measured spice preference and testosterone level at the same time. This means it cannot prove cause and effect. It is possible that spicy food, or anticipation of spicy food, leads to higher testosterone levels. An effect that has been seen in rats.
Food preferences probably have genetic, psychological and social elements of influence. So actual behaviour regarding spice preference is likely to differ, depending on the situation. A man might be more likely to tackle a vindaloo while on a lively stag do than on his wedding day, for instance, not least to prevent any adverse effects on the wedding night.
Where did the story come from?
The study was carried out by researchers from The University of Grenoble, France. No funding source was stated.
The study was published in the peer-reviewed science journal Physiology and Behavior.
The UK media generally reported the study accurately, but failed to discuss any of the limitations and so took the findings at face value.
What kind of research was this?
This was a laboratory study testing human preferences for spicy food and how they might relate to testosterone levels in men.
Testosterone is a hormone released by the testicles of men and the ovaries of women. Although both genders secrete it, men secrete much more. It plays a key role in sexual growth and development and some research has linked high levels to financial, sexual and behavioural risk taking. They have also linked it to so-called “alpha male” behaviour, which can include domination and aggression.
This study ignored social influences and focused on whether there was a link between spice preference and testosterone level.
What did the research involve?
The study recruited 144 men aged between 18 and 44 living in Grenoble, France, and tested their preference for salt and spice in a number of ways under controlled conditions.
Recruits visited a testing centre and were first asked to rate how much they liked spicy and salty foods on a four point scale. They then sat down to a plate of mashed potato and were asked to flavour the mash to their taste with little sachets of Tabasco sauce (a hot sauce made from tabasco peppers) and salt, which was recorded.
They ate the mash and again rated how hot and salty the food was on a six point scale. Interestingly, the scale went up to “excessive burning sensation” for salt and “risks of temporary extinction of the sense of taste, risks of vomiting” for Tabasco. Finally, after finishing they were asked if their meal was too spicy or salty on a five point scale.
At some point all participants gave a saliva sample, which was used to measure their testosterone levels. It wasn’t clear whether this was tested before, during or after the meal.
The analysis looked for correlations between the different ratings of spice preference and level of testosterone.
As far as we can tell the tests were conducted in isolation so there was no social element to the study.
What were the basic results?
There was a positive and statistically significant correlation between testosterone and the quantity of hot sauce that individuals voluntarily and spontaneously ate (r=0.294). This means the more testosterone men had, the more hot sauce they put on the mash. A correlation of 0.29, is generally considered a weak correlation, as positive correlations can vary from 0 (no correlation at all) to 1 (perfect correlation).
Correlation between reported preference for spicy food (before the task) and testosterone was not statistically significant.
Age affected many of the results. Once this was accounted for, the only significant correlations were:
- number of spicy doses put on the mash (r=0.32)
- evaluation of the meal’s spiciness after eating (r=0.30)
- preference for spicy food (r=0.19)
There was no correlation between testosterone levels and preference for salt for any measures.
How did the researchers interpret the results?
The authors concluded simply: “This study suggests that behavioural preference for spicy food among men is related to endogenous testosterone levels.”
Furthermore they indicated that: “To our knowledge, this is the first study in which a behavioural preference for spicy food has been linked to endogenous testosterone in a laboratory setting. The juxtaposition of using highly accurate laboratory measurement with a diverse community sample of male participants ensures adequate levels of both internal and external validity. This study provides new insights into the biology of food preference by expanding our understanding of the link between hormonal processes and food intake”.
This small human laboratory study found higher testosterone levels were linked to adding more spice to food in adult men. However, due to the study’s design, and a number of limitations cited below, it does not prove this link.
Many factors probably influence preference for spicy food. These could include physiological measures such as testosterone, but also involve social, genetic and psychological elements. For example, adding spice to food could be a learned habit, for example from family, or innate, passed on in genetics due to difference in the way spice is tasted on the tongue. We do not know how important each of these factors is in spice preference, relative to one another.
The study measured spice preference and testosterone level at the same time. This means it cannot prove cause and effect. It is possible that spicy food, or anticipation of spicy food, leads to higher testosterone levels. This sort of effect has been observed in rats, the study authors tell us.
The research team also highlighted a less obvious limitation in their research: colour. They indicated they used a red Tabasco spice sachet. Intriguingly, previous studies have shown a link between higher testosterone in men and a preference for colours signifying dominance and aggression, such as red. This could have played a role in influencing the results, but we don’t know how strongly.
Overall, the study suggests there might be a physiological reason for spice preference (testosterone level), but does not prove it. There are likely to be many factors involved and we do not yet know which are the most important. On further investigation testosterone might turn out be a very important factor, or more marginal. Given the weak correlations in this study, we would suspect it might be on the weaker side.
A final word of advice would be that while spice can be nice, we would never recommend eating food that causes you actual physical pain.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.