You Really Are What You Eat, Science Says

Summary

Anthelme Brillat-Savarin, Ludwig Feuerbach, and Victor Lindlahr all expressed the idea that ​“you are what you eat” in dif­fer­ent eras, which has now been sci­en­tif­i­cally sup­ported by researchers at the University of Oxford who found that diets can affect DNA sequences over gen­er­a­tions. The study showed that while adopt­ing health­ier diets can impact genetic makeup, dras­tic changes can­not occur in a sin­gle life­time due to the accu­mu­la­tion of small dietary changes over many gen­er­a­tions.

In 1826, Anthelme Brillat-Savarin, a French lawyer and politi­cian who nonethe­less gained fame as a gas­tronome, wrote in his book ​“Physiologie du Gout, ou Meditations de Gastronomie Transcendante:” ​“Tell me what you eat and I will tell you what you are?.

In 1836, the German philoso­pher and anthro­pol­o­gist Ludwig Feuerbach penned the line, ​“A man is what he eats,” in a noted essay of his.

American health food and weight loss pio­neer Victor Lindlahr rever­ber­ated ​“You are what you eat” in 1942, and in the 60s, the sweep­ing move­ment of the hip­pies made the same phrase one of their main slo­gans for healthy eat­ing.

What was empir­i­cally grasped by all these com­pletely dif­fer­ent peo­ple liv­ing in dif­fer­ent times is now sci­en­tif­i­cally grounded by researchers at the University of Oxford. In a ground­break­ing research that was pub­lished in the jour­nal Jenome Biology.

The University of Oxford Department of Plant Sciences unveiled genetic evi­dence that our diets can affect the DNA sequences of our genes, and that the folk truth of ​“We are what we eat” is backed by hard phys­i­o­log­i­cal evi­dence — always on a gen­er­a­tional timescale.

As Emily Seward, a doc­toral can­di­date in Oxford’s Department of Plant Sciences, explained to Olive Oil Times, to test this hypoth­e­sis researchers based their study on a model sys­tem com­pris­ing sim­ple groups of par­a­sites, eukary­otic par­a­sites (Kinetoplastida) and bac­te­r­ial par­a­sites (Mollicutes). ​“Parasites that share a com­mon ances­tor but for rea­sons not quite well under­stood have evolved to eat quite dif­fer­ent foods and infect dif­fer­ent hosts,” said Seward.

Using novel math­e­mat­i­cal mod­els the sci­en­tists devel­oped them­selves, they were dri­ven to the con­clu­sion that dif­fer­ent lev­els of nitro­gen, as man­i­fested in a par­a­site’s diet, did affect DNA com­po­si­tion. Parasites with diets low in nitro­gen and high in sugar diets were dis­tin­guished by DNA sequences that made use of less nitro­gen than par­a­sites with diets high in nitro­gen and pro­tein.

The results high­lighted the sci­en­tif­i­cally emerg­ing rela­tion­ship between cel­lu­lar metab­o­lism and evo­lu­tion. They also showed that it is fea­si­ble to pre­dict the diets of resem­bling organ­isms by ana­lyz­ing the DNA sequence of their genes.

Most of all, the study proved that by adopt­ing dif­fer­ent diets we can indeed change our genetic make-up, but (real­ity check) not as eas­ily as we would love to imag­ine: Though we can become health­ier by switch­ing towards health­ier nutri­tional choices, we can­not manip­u­late our DNA to the extent pre­vi­ous infor­ma­tion is wholly erased and replaced by new — at least over the course of our own life­time.

“There are so many fac­tors that can influ­ence the DNA sequence of an organ­ism. In the research, we are talk­ing about small dietary changes that accu­mu­late over the course of pre­vi­ous gen­er­a­tions. It’s a gen­er­a­tional thing in that many gen­er­a­tions take small steps toward chang­ing their genetic map. A dras­tic change can­not take place in a life­time. You can become health­ier, but you will not dras­ti­cally change your DNA,” said Seward.

• Emily Seward


• Dietary nitro­gen alters codon bias and genome com­po­si­tion in par­a­sitic microor­gan­isms