Superfoods: GMO edition

We’ve all seen those silly lists of so-called superfoods. A quick Google turned up 450,000,000 results, with the expected offenders on the first page: WebMD, Dr. Oz, Oprah, and some women’s magazines. It’s nice to imagine that we can cure all sorts of ills if we just drink some exotic berry juice or add a certain spice to all of our meals. But the reality is that there’s usually very little scientific evidence for the claims that are being made.

Instead of relying on that expensive juice or supplement to reverse aging, lose weight, improve memory, “cleanse”, or whatever the claim of the week might be, we are all better off taking advantage of the full dietary diversity of fruits, vegetables, grains, beans, nuts, and animal products that we are lucky enough to have access to.

conventional food risks GMO risks
Photo by distopiandreamgirl via Flickr.

If we “eat the rainbow” and vary our diet daily then we gain the advantages that all of the foods provide, including fiber, vitamins and minerals, antioxidants, and more. Plus, the more fruits and veggies in our diets, the less likely we are to reach for foods with less benefits and higher calories and fat. I’m not a dietician, but I don’t think any dietitians would argue with that.

Claims about antioxidants are particularly shaky. The truth is, “it isn’t clear whether [improved health with fruits and vegetables] is because of the antioxidants, something else in the foods, or other factors. High-dose supplements of antioxidants may be linked to health risks [and] antioxidant supplements may also interact with some medicines.” (MedlinePlus)

Eating the rainbow gives us all of the benefits and very little risk, if any. If I see a boxed or bottled product advertising their superfood status or boosted antioxidant levels, I generally stay away. However, if there are plants that have unique characteristics then I’m happy to add them to my diet in moderation. Purple corn, purple tomatoes, purple peppers… they all add additional antioxidants plus they are fun because they are purple! They go in my rainbow rotation along with many other foods of various colors.

Purple tomatoes: More than just hype?

Non-GE and GE tomatoes engineered for anthocyanins. Image from John Innes Centre.
Non-GE and GE tomatoes engineered for anthocyanins. Image from John Innes Centre.

I’m skeptical of superfood claims, which is why I’m so conflicted on the tomatoes that have been genetically engineered to have high levels of anthocyanins (a type of antioxidant).

On the one hand, purple tomatoes are cool. Maybe they would help kids (and adults) to eat more salads (I’m not really seeing purple tomato sauce working, even if it stays purple during cooking). Many people can’t afford blueberries so these tomatoes could make anthocyanins  available to more people.

Maybe the researchers will be able to definitively show a health benefit (although I’m not holding my breath).

Maybe the tomatoes are just a great money-making idea and they’ll sell a lot of purple tomato juice (hey-o who wants a purple bloody mary? I do!). On the other hand, purple tomatoes perpetuate the idea that one superfood can cure cancer, and that really doesn’t sit right with me.

I see 3 outcomes from further studies.

Best case scenario: eating or drinking the purple tomatoes at normal consumption levels (simple swap of purple instead of red) will prove to have a health benefit.

Middle scenario: the purple tomatoes have a health benefit, but only at very high consumption levels such that it would have to be consumed in a pill. If a one-for-one switch of purple tomatoes for red ones in the diet could have some extraordinary health effect, that would be awesome. People who can’t afford blueberries would be able to access the anthocyanins and we all benefit. If it turns out the anthocyanins must be consumed at high levels, then the real benefit is greatly decreased, because many people will not be able to afford supplements.

Worst case scenario: there is no benefit (or a harm).

In short, I’m happy to congratulate the scientists on their work. They had success even though many other groups have failed to increase anthocyanins in other ways, and this is a great project. But I’m holding out on saying this is a nutritional success until we have more data. Until then, the purple tomatoes are just a really cool novelty, and there’s nothing wrong with that.


  1. There are tomatoes that sort of blueish out there now, varieties like Indigo Rose and OSU Purple. I don’t think they are blue on the inside like this tomato though, and I hear the color is highly dependent on the tomato getting enough light. I just got myself some seed of a variety called Dancing With Smurfs that I plan on planting in a few days to try a blue variety for myself. I love things that are different colored than the normal varieties. I’ve had white tomatoes, red sweet corn, pink fleshed apples (which make very pretty pink cider, until it oxidizes anyway), and I’ve got a purple sweet potato sprouting around here somewhere. There’s bunches of differently colored fruits and veges out there.

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