The Brain on Food: Everyday Chemicals

Regard­ing all the foods that we con­sume as a drug­s is a won­drous way to exam­ine and com­pre­hend the com­plex inter­ac­tions and subtle forces behind how everything we put in our mouths affects “how our neur­ons behave and, sub­sequently, how we think and feel”.

In a com­pel­ling art­icle that sug­gests our shared evol­u­tion­ary his­tory with the plants and anim­als that we eat is the root cause of them hav­ing an affect on our body’s beha­viour, Gary Wenk, author of Your Brain on Food, briefly describes how some of the chem­ic­als present in ‘drugs’ such as chocol­ate, bana­nas, alco­hol and nut­meg affect us:

We have all exper­i­enced the con­sequences of our shared evol­u­tion­ary his­tory with the plants we eat. For example, unripe bana­nas con­tain the neur­o­trans­mit­ter sero­ton­in. When you eat an unripe banana, its sero­ton­in is free to act upon the sero­ton­in neur­ons with­in your digest­ive tract. The con­sequence is likely to be increased activ­a­tion of the muscles in the wall of your intest­ines, usu­ally exper­i­enced as diarrhea.

Many plants con­tain com­pounds that should be able to enhance your brain’s per­form­ance. For example, pota­toes, toma­toes, and egg­plants con­tain solan­ine and α-chaconine, sub­stances that can enhance the action of acet­ylcholine, a chem­ic­al in your brain that is vital to memory form­a­tion. Your mood might be enhanced slightly by eat­ing fava beans because they con­tain L-DOPA, a pre­curs­or to the pro­duc­tion of dopam­ine, the reward chem­ic­al in your brain. Wheth­er these food-borne com­pounds actu­ally affect your brain depends upon how much you con­sume and your own per­son­al physiology. This might explain why some people find it quite reward­ing to eat pota­toes or egg­plants.

Morphine-like chem­ic­als cap­able of act­ing upon the brain are pro­duced in your intest­ines when you con­sume milk, eggs, cheese, spin­ach, mush­rooms, pump­kin, and vari­ous fish and grains. Dairy products in par­tic­u­lar con­tain a pro­tein known as case­in, which enzymes in your intest­ines can con­vert into beta-caso­morph­in. In new­borns, that beta-caso­morph­in can eas­ily pass out of the imma­ture gut and into the devel­op­ing brain to pro­duce euphor­ia.

There’s much more like that in the art­icle, con­cluded with Wenk arguing that this shared evol­u­tion­ary his­tory is why plants and anim­als from oth­er plan­ets will prob­ably not harm or sus­tain us if we ever travel to dis­tant, Earth-like bod­ies.