Brussels sprouts, anyone? Takers likely to have a gene variant

My meal of choice in the days when I was single and flatting was a baked potato smothered in cheese, sour cream and Brussels sprouts.

My flatmates and friends were horrified in varying degrees, depending on their appetite for the much-maligned Brussels sprouts.

My brother even gave me a Brussels sprout artwork - so mad did he think I was! To this day, I can easily devour a plateful of Brussels sprouts in any form - boiled, fried, baked or as cold leftovers. For me the trend of adding bacon to Brussels sprouts is unnecessary - the humble sprout does not need porcine support.

Imagine my delight at finding little purple Brussels sprouts in the supermarket last week - my family's response, however, was somewhat mixed. You see, of the five of us, two are fans (a son and myself), two are haters (a daughter and a son) and one is in between (husband) - a Brussels sprout likability gene perhaps? I decided to investigate.

In food there are molecules that have shapes that lock on to proteins on the surface of our tongues. This locking process fires up our nerves to send signals to our brain telling us whether we have experienced a sweet, salty, bitter or umami (meaty) taste. These interactions are quite specific; for example, a sweet receptor on the tongue will not detect a bitter taste. Like most genetic traits, our perception of taste is controlled by many genes and other factors such as aroma.

There is one taste gene variant that has been well characterised which is said to influence whether we like the bitter taste of Brussels sprouts or not. It is known as the TAS2R38 gene (produce a name like that and scientists wonder why no-one understands them).

This gene makes a protein which interacts with a chemical, phenylthiocarbamide (PTC), to give the taste sensation of bitterness. The PTC phenomenon was actually discovered before DNA was discovered, in 1931, when a chap in a lab was pouring powdered PTC into a bottle and creating a bit of a stink, which he didn't notice (as he had probably had a mutated TSA2R38 gene) unlike his colleagues who made a bit of a fuss.

So there we have it - it would seem my TAS2R38 gene is in a form which allows me to love Brussels sprouts and I have passed that form on to one of my three offspring, the other two inheriting a ''sensitive'' form from my husband. Other foods which are thought to have a strong genetic likability influence include coriander (which I also love, but others apparently find soapy and inedible), liquorice (less fond of) and blue cheese (yum).

Interestingly, olfactory and taste genes are often located in mutational hot spots in our genomes and it is thought the reason for this is some sort of evolutionary advantage in recognising bitter or unusual-tasting food in order to avoid poisonous foods.

Like most traits, how we taste food is also influenced by our environment, whether we smoke, how old we are and what our parents exposed us to as children. I remember being warned not to eat curries while I was breastfeeding, which I ignored - after all, how many Indian women have eaten highly spiced food while breastfeeding with no ramifications for the baby? In saying that, if I sit down and eat a genuine Indian-spiced curry, it is not long before I am weeping in pain.

Similarly, the average Kiwi's palate for sweet food is far more extensive than the average Chinese person, where refined sugar is not a large part of their diet.

Our genes, environment, age and health all contribute to our tastes and relationship with food. In response, the commercial imperative for food companies is either to mass produce food that is bland, but amenable to most tastes (McDonald's cheeseburgers), or increasingly to develop personalised food and food plans, potentially based on our genetic make-up.

Will there ever be a point where we are able to genetically modify ourselves so that we only like healthy foods?

Who knows, but I certainly won't be altering my Brussels sprout mutation.

-Anna Campbell is managing director of AbacusBio Ltd, a Dunedin-based agri-technology company.

Comments

Genetic inheritance and "in loco parentis" message of 'good for you' from the Superego, triggers gustatory anticipation.

 

banners_top_banner.jpg

banners-bottom_banner.jpg