• Question: Do we know every compounds in the food we eat ?

    Asked by Zozo to Andrew, Dilip, Emma, John, Ruth on 17 Nov 2015.
    • Photo: Ruth Hamill

      Ruth Hamill answered on 17 Nov 2015:

      I don’t think so, no. Most commonly consumed foods would be classified as G.R.A.S., however, this means they are generally recognised as safe because there is a long history of consuming them with few ill-effects.

    • Photo: John Gleeson

      John Gleeson answered on 17 Nov 2015:

      Nope! That’s what’s kind of exciting. A lot of food scientists spend their days digging through food trying to figure out all the individual parts that give flavour, taste, structure or even the beneficial properties.

      We do know a lot of them though so we know what’s safe. If you’re putting an additive like a colour we need to know it’s safe and how much we can use. So we try to make sure we know as much as possible. But food is so different. Different breads might have different compounds because of the type of grain it’s made out of!

    • Photo: Andrew Quigley

      Andrew Quigley answered on 17 Nov 2015:

      Along with the unknown compounds in food naturally, there can also be compounds that contaminate foods over time, usually from the packaging.

      A good example of this is plastic packaging. There are some compounds called phthlates that leach out of certain types of plastic into food. This is quite common in the plastics used in water bottles.

      Even though we don’t know all the compounds that are there naturally, there’s also potentially a whole host of compounds that can be present that are never listed on the ingredients!

    • Photo: Emma Feeney

      Emma Feeney answered on 18 Nov 2015:

      Hi Zozo. To add to the great answers above, we are still discovering more about the compounds that we already know about in foods. Milk is a great example of this. I work as part of Food for health Ireland (FHI), and a big part of what they do is trying to understand the components of milk.

      We know that milk contains casein and whey proteins, but what are are still learning about is that something special happens when they are digested.

      As the proteins get broken down, some of the smaller bits of proteins – peptides – can have ‘bioactivity’. This means that some of the small parts of the proteins, when they get digested, can confer immuno-protective effects , blood pressure lowering effects, and other functions.

      Since milk is fed to young mammals, these things would all be important for growth and development. Some of the sugars in milk (oligosaccharides) also have bioactivity.

      So we are still learning about foods that you would think are really well-characterised by now. Imagine what we will know in a few hundred years time?!