For a long time I looked at ketchup as a “decadent” condiment, mostly because of its high sugar content. But now I look at it differently and must admit it is quite good, provided you get a decent quality one. I was also surprised to learn, through an anti-aging physician who is also a great Chinese food cook, that ketchup is one of the frequent ingredients of sour and sweet sauce recipes. I had no idea it was that simple! So what makes it an interesting food? Well, most of us know by now that tomatoes are a great source of lycopene, which is the pigment that gives this fruit its color and one of the most powerful antioxidants. As such, it reduces the amounts of free radicals in your body and consuming lycopene can help reducing the risk of cancers, mainly in the prostate, stomach and lungs. It also seems to have a protective action against cardiovascular diseases. Lycopene is only found in a small variety of fruits and vegetables, mainly the ones that are red (watermelon, guava, pink grapefruit, etc.). What you might not know is that the form of lycopene (trans-) that is found in raw tomatoes is not well absorbed by the organism. The form that is well absorbed is the isomer cis-lycopene. The good news is that heat allows the “trans-” to become “cis-.” Therefore all the preparations made from cooked tomatoes, including ketchup, tomato juice, tomato soup, tomato sauce, are excellent sources of absorbable lycopene! In addition, the fact that ketchup is a more concentrated form of tomato than fresh tomatoes makes it even more interesting. More good news is that lycopene is fat soluble. This means eating it with a small amount of oil makes it easier to absorb. That is what is so interesting about studying traditional cuisines: you start to understand that there are reasons for the choice of ingredients and combination of foods. Part of my family is from Mediterranean origin and at home we use a lot of tomato sauce and olive oil-based dishes that are delicious. Now you can see that they are not only tasty but they are an excellent way to get your antioxidants!
I want to add something about green tomatoes that I remember from pharmacy school. I was told never to eat raw green tomatoes, and here is why: tomatoes (and eggplants and potatoes) belong to the Solanaceae or Nightshade family and therefore contain toxic alkaloids (mainly solanine) when green or unripe. Fortunately, heat destroys those alkaloids and makes eating green tomatoes harmless. (That is why we eat them fried.) I was also told that vinegar has the same effect and I guess this is why we pickle green tomatoes. So in any cases, avoid eating large quantities of raw green tomatoes. The same is true about the green parts of eggplants and potatoes that turn green when exposed to light. But who would eat them raw anyway?