Tuesday, 16 October 2012

Food for Thought

I just heard an interesting tidbit on CBC. The whole thing was about what can be labelled natural food and what can not. Well, by Canadian standards anything that is processed can not be labelled as natural since ( and I think the example given here was ginger ale) it does not occur in nature in the way it is sold. So ginger ale may contain all natural components, but it itself can not be natural. I am not going to debate this at this point.

However, what it did make me think of is the fact that many people in our society have no idea what they are eating. “I wash apples with water before I eat them. That gets rid of all the pesticides, right?” Well, no, not really, but even this is not the point that I want to talk about today...yes, I know, normally it would be a given to thumb-up on organic food and “chemicals are bad” and so on. Yes, that is all fair game, but today I would like to make a little point about nutrition in food.

I have been involved with nutritional analysis for 4 years now and even after knowing a lot more than your average consumer about nutritional labels and values in foods I still learn new things about the things we eat every day. Here is the first and foremost one that I have learned;
Don't believe the label.
Yes, that's right, the labels are not always a true indicator of what you are eating. This has to do with several factors and I will explain them here one by one.

  1. Database labels
Not every label has been produced after tedious and expensive chemical analysis of the food. It is possible (and legal) to utilize computer programs that have certain foods and food components saved in a database with all their nutritional values, which are mostly derived from analytical test experiments. So if I make a donut and use x grams of flour and y grams of sugar and so on, I can add my recipe into the computer program and the program will produce an average of what this food should contain. So far the theory. Needless to say, that there can be faults associated with doing the labels this way. Here is one example:
I was starting to analyze different foods for their sugar contents and while I was evaluating the method I went to buy a number of different foods from a store nearby. Amongst the foods I selected there were freeze-dried strawberries. According to their label, those strawberries did not contain any sugar. “Hmm,” I thought, “either this label is wrong or these are not real strawberries.” Any fruit will contain sugars, they don't grow without it. When I analyzed those strawberries the sugar content was 44%. 
What happened? How could the two sets of results be so starkly different? 0 sugar content vs. 44%?
Well this is my explanation, and I don't know whether this is the way it happened, but it seems the most plausible to me: The nutritional values for the product were taken from actual (fresh) strawberries. Since freeze-dried fruit is a lot lighter than fresh fruit, the serving size (measured mostly in grams) was a lot smaller than that for fresh strawberries. And -and here is one of the pitfalls of reading a label- some are done by 100 g and some by serving size, which can be anything from 1 g to 250 g or 1 cup or 1 oz. or whatever (ever seen the calories on the label of a pack of chips? They never seem so bad, until you see that the value is per 10 chips!!). So care has to be taken. In this case the serving size of freeze-dried strawberries was 25 g, I think. About as much as one fresh strawberry would weigh. The sugar amount of one strawberry is so small that it may be declared as 0 on a label (once you get a value under a certain threshold the number can actually be declared as 0, same as the nickel content in some kinds of “nickel-free earrings”). Therefore, for an equal amount of weight, we can also declare the amount of sugar on a serving of freeze-dried strawberries as 0, right? Wrong.
And here is the mistake. During the freeze-drying process only water gets removed. The sugar does not get removed but gets concentrated, hence the 44% result. This is what the people who made this specific label did not take into account and this is how such an error can occur. It can take a long time for something like that to get noticed too.

  1. Incorrect analysis
    Incorrect analysis is something that can always happen. Trust me, chemists might wear white coats, but they are no gods. Mistakes happen. Although, that being said, quality assurance systems nowadays make analytical mistakes few and far between. However, I do remember a case where a product was hauled off the shelves by the food inspection agency due to a false claim of Vitamin A on the label. The product contained a large proportion of sweet potatoes, Vitamin A was declared at 75% RDI (Recommended daily intake that is, we can get to this later if people are interested). However on second testing by both the inspection agency and by the lab that initially did the analysis, it turned out that the product only contained 45% RDI of Vitamin A. What happened? It turned out that the product was tested before it even hit the shelves the first time around. The batch that was inspected by the agency however, was close to its best-before date. Due to the nature of Vitamin A the contents had changed over time. Vitamin A is quite labile (unstable, breaks down) and the concentration in any food will decrease over time. 

  2. Differences from “as is” vs “as consumed”
    What I mean by differences between “as is” and “as consumed”, is simply that many foods that we buy we will alter before consumption. For example, a deep frozen pizza. Ever wondered why some veggie pizzas are shown to contain Vitamin C? This is due to the bits of peppers and other veggies in the topping. Now, just like Vitamin A, Vitamin C is extremely labile and once you yank the pizza through an oven at 200 ºC, Vitamin C will be a thing of the past for this specific food item. This can be said for many foods where the product is tested in a different state as when it is consumed. Processing in general will alter the components of food in many cases.
There is a whole lot more to be said about food components and the labelling thereof. I always wonder who really understands food labels and how many consumers are out there that do not know what exactly is in a food. There are a great deal of misconceptions that have arisen simply out of a disconnectedness from the production and processing of the stuff that we eat. I mean, we all know that burgers and broccoli are all being made in the supermarket........and tomatoes don't contain sugar......I could go on and on with examples but I will leave it here. I think it is important to understand nutritional claims and to pay attention on how we nourish our body. I am no super healthy living dude, but I make a conscious effort to give my body what it needs. Of course, there is always time for chocolate and ice cream.

Just a bit of “food for thought”.

If anyone has any specific questions or queries on food labelling, let us know in the Comments section below!

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