Why some like it hot – Introduction to the ‘evolutionary gastronomy’
Once I spotted a book in our London Metropolitan University library and I found it extremely interesting. It was called Why some like it hot: Food, Genes and Cultural Diversity written by Gary Paul Nabhan. The main idea was to look into the human evolution from the dietary point of view, discussing a dynamic relationship between our food and our genes and the background of the cultural diversity in food choices worldwide. The author visited several different places on Earth: Mexico, Crete, Sardinia, Bali, Java or Hawaii, he talked to the domestic people and consulted the findings with various scientists and scientific materials. Because of the interesting content I have decided to write a brief overview of the book as a reminder for the future and also that more people can learn few interesting facts about this topic. In the following series you will discover how the food eaten by our ancestors thousands of years back in time have formed our ethnic cuisines today; how these diets have been forming our biochemistry and physiology making us thrive on this particular diet and falling ill when significantly shifting away from it; or, the other way round, how modifying a traditional diet can actually save lives because of various evolutionary physiological traits present in some people. The author also mentioned why it is important to preserve the cultural culinary knowledge and practice, which is slowly disappearing in the modern globalized world, especially when a particular culture thrived on their traditional diet but today it does not due to the massive culinary shift mentioned earlier. This traditional diet refers to “food getting, food preparation, and food consumption“. But, firstly, we must understand why ‘ethnic food tradition matters‘ and that the ‘one size fits all‘ approach, promoted by governments to culturally diverse public, has its limitations.
In the Introduction chapter, the author mentioned the Online Mendelian Inheritance in Man Gene Map project which includes the list of ‘disease genes’. These were allocated at particular chromosomes as part the Human Genome Project. For example, there are genes for sucrose intolerance – in regards to which the author wonders how this gene has survived in the modern, sucrose abundant, diet during the 20th century. Very interesting was the statement which makes it misleading to blame only genes for various traits:
“In fact… all of our traits – bar none – emerge from the mutually-dependent activity of both genetic and environmental factors.”,
citing Moore (2001) as the source of this statement. Furthermore, there is not a single form of gene for this or that. They are “polymorphic, taking various forms, each of which interacts with dietary chemicals in slightly different ways“. This practically means that even if you have a specific gene, it does not make you react to various stimuli the same way as somebody else does, having a different form of that gene, especially when the dietary exposure (amount, concentration, whether being one-off or repetitive) also vary.
“In some cases, the combination of a particular gene and the presence of a particular food in an ethnic diet can protect many individuals of that ethnicity from an infectious or nutritional disease. In other cases, a gene-food interaction can literally kill the carrier of a particular allele… At the same time, those carrying other alleles suffer no health risks at all. There are doses of variations on these themes, depending upon whether one or more genes are involved as well as the potency of the food, beverage, or drug that the carrier ingests.“
The point here is the knowledge that “certain genes encode the ways in which our bodies produce the enzymes that drive our metabolism“. The author himself admitted that he suffers from attention-deficit alternating with hyper-focus which is characteristic with ‘wildly‘ variable levels of dopamine. He is also red-green color blind – a result of faulty gene for producing enzymes which enable the rest of us to see a full range of colors within a visible spectrum of light. However, these traits do not seem to be too relevant to the diet and health. Instead I mention a condition called phenylketonuria. The sufferer cannot metabolize usual amounts of phenylalanine in the diet due to a deficiency in various enzymes, resulting in accumulation of phenylalanine in the blood, leading to gradual mental impairment and other serious health consequences when not treated with a strict diet from the birth, basically. Other gene/diet related conditions include lactose intolerance, gluten or even alcohol intolerance… Some people have high levels of homocysteine in their blood, predisposing them to early onset of cardiovascular diseases, unless they consume a lot of folic acid (vitamin B9), abundant in greens and fresh vegetables. It was estimated that more than three quarters of the population carry one or more of such genetic traits.
However, a genetic condition leading to enzyme deficiency can be advantageous in some situations. A specific condition called favism, which protects people from malaria but leads to detrimental consequences after a dietary exposure to the fava beans or even their pollen during the blooming season, has been discussed in one chapter dedicated to this genetic trait.
It is important to note that peoples genetic make up over time was not formed only by the diet of their ancestors but also the diseases they were facing helped to profile their genetic traits. Those with mutation in some genes were found to better resist the infection than the rest of the population and carried this genetic trait further, promoting its spread across the population when constantly or repeatedly facing the specific infection. This example sets a base for discussion: when something could be considered a ‘genetic disorder‘ and when it should be called an “environmentally specific adaptation that actually increase our fitness in certain settings or on certain diets”? It really depends on the context whether you are suffering or protected by a specific enzyme deficiency, or both, as it was the case of favism on Sardinia.
Towards the end of the Introduction chapter, the author highlighted that: “some features of ethnic cuisines persist because they aided our survival under particular environmental stresses, while others are more “ornamental”, like the proverbial icing on the cake”.
The book was very interesting to read and in some parts it was even entertaining and made me laugh. I hope you will enjoy this overview and maybe it will make you to get the copy of the original book. It was written in a very reader-friendly way but educating in the topic at the same time. The author says:
“If I tried to make up stories as odd as some of the ones you are about to read, I doubt that anyone would believe me. They remind us of just how diverse humankind is in its genes, its tastes and its ethnic histories.“
So, let’s start the ‘culinary and evolutionary odyssey‘ and learn about the mutual interaction between our genes and the food we eat.
Go to Chapter one: Discerning the Histories Encoded in Our bodies – or how the author witnessed in person the consequences of the major dietary shift from the healthy traditional diet to the one promoting diseases in Pima Indians of Mexico.
Below is the scanned front of the book, published in 2004.
Chapter 2: Searching for the ancestral diet
Chapter 5: Discovering why some (don’t) like it hot
Chapter 6: Should we change places, diets or genes?
Chapter 7: Rooting out the causes of disease