Evolution made you a misanthrope :)

Well that’s a strange title.. but let me explain 😉

Evolution of Immunity

Evolutionary approach to studying human behavior is focused on the adaptive value of the behavior… so we are asking questions like “why has X behavior evolved and what costs and benefits it brings?” When our sensory system (vision, smell…) is faced with a disease-connoting cues (e.g. a sick person), two defensive systems get activated:

The immune system
The behavioral immune system

Mounting an immune response in the body is quite costly in terms of energy spent and it is required only after the body has contacted pathogens.. but the behavioral immune system activates our basic emotions (fear, disgust) and behaviors that prevent contact with potentially dangerous objects (in terms of transmitting disease), so saving our body precious energy needed for the actual physiological immune response 😉

This behavioral immune system is trying to be over-careful, though, and will react not only to actual disease-reminding stimuli, but also to stimuli that resembles signs of disease (but may not logically be dangerous- like a sterilized glass that used to have a roach in it… there glass is perfectly clean but people are still disgusted when drinking from it… or a person with a disability- they’re not actually contagious).

So, first of all, what does this have to do with being a misanthrope?

Well, this emotional response to things that are dangerous to health (whether truly or only perceived..) is stronger in people who think themselves vulnerable to disease. Such people show a HIGHER level of an averse response to:

  • physically disabled people (Park et al. 2003)*
  • older adults (Duncan&Schaller, 2009)
  • Immigrants (Faulkner etal. 2004)
  • obese people (Park, Schaller & Crandall, 2007)
  • some animals (Prokop et al. 2010)
I know these are not roaches..just chocolate (which i adore), yet i can’t imagine even touching these without disgust

Being open to new experiences and being an extrovert is associated with larger social networks (having more friends&acquaintances), but ALSO with higher risk of being infected by pathogens (the more folks you get in contact to, the more changes to catch something). Again, a stronger negative response is seen in those that perceive themselves to be more vulnerable or come from areas with high pathogenic load (=lots of diseases). So if you’re not a people person, there’s nothing particularly “abnormal” about you.. Indeed, you are quite a well-adapted fellow 😀

And second- what does this have to do with food??

Usually everything I post has something to do with health and diet.. so I need to make a connection here. Researchers hypothesized that, similarly to the behavioral avoidance of disfigured people triggered by this over-protective emotional immunity, new technologies might activate behavioral avoidance. New technology like genetic modification or highly processed foods in general.

Researchers decided to see if they can predict attitudes toward GMOs by people with different levels of pathogen sensitivity. And they did find that people who felt themselves more vulnerable to infectious diseases had significantly more negative attitudes toward GM products (Prokop et al., 2013). Of course, there are many many reasons people do not like GMOs- rational and emotional, but this is a pretty cool finding nevertheless.

So, many things about us and our personality might be an important adaptive response.. does not mean we can not override these “instincts” with some logic (e.g. knowing obese individuals are not in any way going to make you sick thus not stigmatizing them).

Continue reading

SPICE up your health!

Could SPICY FOOD make you HEALTHIER!?

While spicy foods are not particularly pleasant to the taste (the sensation they can create can be even that of pain) many people love spicy food! Indeed, spices have been highly valued and fought for throughout history! So other than enhancing the taste of food, perhaps there are other more potent reasons for their importance throughout the world?

Image

I’m reading a fascinating study* on the subject, and the authors hypothesize that adding spices to food is beneficial since they contain substances that inhibit or kill food-spoilage microorganisms (we know certain spices have antioxidant & antibacterial properties; others are powerful fungicides).

In short, the authors looked at traditional cookbooks, spices used in meat-based dishes, and country’s climate (since meat products in hot temperatures would spoil fastest).

The most used spices for the ~4,580 recipes analyzed were onion and pepper, followed by garlic, capsicums, lemon/lime juice, parsley, ginger, and bay leaf. The average spice was found to inhibit ~ 67% of bacteria (garlic, onion, allspice, and oregano inhibit EVERY bacterium they’ve been tested on!). It was found that more powerful spices were used more frequently in hotter climates= recipes from those countries have more antibacterial potential! Lemon and lime juice use appears to be strange- it is used a lot, while it has one of the lowest effects against bacteria. These juices, however, are syngergists (as well as pepper)! They act synergistically to enhance antibacterial effects of other spices.

HMMM…

Now as I was reading this, I thought- maybe hotter countries simply have more spices growing there? The authors found out that there was no relationship between a country’s mean annual temperature & number of spice plant species growing there.

Another problem I imagined- what about cooking? Perhaps heat destroys some of the antibacterial and other effects of spices? Turns out spices are thermostable and have similar effect even after steam-distillation.Image

INTERESTING fact I didn’t know- plant secondary compounds & essential oils can contain mutagenic, carcinogenic, and allergenic effects.. and while protecting oneself from food-borne illnesses outweighs the dangers of these chemicals, it would explain why kids and some pregnant women might dislike spices. [in the modern obesogenic food environment with french fries and twinkies, potentially negative health of spices should not be on top of our concern list]. Also important- medicine is pretty much a low dose of poison…so spices have been used to counteract ailments of all sorts (e.g. garlic for pneumonia, worms, etc). Animals are capable of self-medicating with strong-tasting vegetation as well.

In CONCLUSION, the authors believe that the main reason for spicy foods is to take advantage of the antimicrobial actions of the secondary compounds in plants… which contributes to survival, health, and reproduction. Therefore, many people (especially in hot climates) prefer spicy food. If you like it HOT- GOOD FOR YOU 😀

* Billing, J., & Sherman, P. W. (1998). Antimicrobial functions of spices: why some like it hot. Quarterly Review of Biology, 3-49.

p.s. this of course is not to be the only explanation why spicy foods are liked, there is also social learning and what not 😉