Cayenne pepper and chili powder add spiciness to this sweet yam dish.

Sweet Potato or Yam? Confusion dates back to Colonial era

Yams or sweet potatoes, which did you partake of over the holidays?  Chances are it was a sweet potato even if you thought it was a yam. What is the difference? A true yam from the Dioscoreacea plant family, origin Asia and Africa, is very rare to the United States. Sweet potatoes are in the Convolulceae plant family, origin tropical Americas, and are what is readily available in the United States.  But the label said “yams.” By USDA standards, it said sweet potatoes somewhere on the label as well.

There are many different kinds of sweet potatoes. The flesh of the sweet potato can be white to yellow; orange or orange-red. The skin of the sweet potato can be red, purple, yellow, orange or brown. The confusion started in the Colonial era when they started calling the varieties of sweet potatoes that become soft when cooked yams. Those that were firm when cooked were called sweet potatoes.  Sweet potatoes are grown all over the world. They grow in diverse farming conditions and have few natural enemies, so pesticides are rarely needed. They are very nutritious, so what’s not to love about sweet potatoes?

A friend of mine recently introduced me to a blog written by Robert Pavlis, a self-proclaimed “plantaholic” with a background in chemistry and biochemistry.  He has given me another reason to love sweet potatoes.  Scientists from Ghent University and the International Potato Center studied the DNA of sweet potatoes from all over the world.  What they found was that they all contained DNA from a bacteria genus called Agrobacterium.  This DNA has been there for thousands of years.  Agrobacterium is able to transfer its DNA into other species.  This makes me love sweet potatoes because they contain plant DNA and bacteria DNA. Sweet potatoes are the natural genetically modified organism (GMO)!

GMO is definitely a hot topic in the world today. A basic definition of a GMO is any organism that has had its DNA changed. Sweet potatoes, seedless grapes and seedless watermelons by this definition are GMOs. In fact, most all of the fruits and vegetables that we eat would fall into the category of a GMO. We rarely eat native fruits and vegetables that have not been bred to make food better. Some don’t like this definition and according to Pavlis, a definition commonly accepted by society would be, “A plant GMO was redefined as a process that (A) takes place in a lab and (B) has DNA from a different type of organism (i.e. not a plant) placed into the DNA of a plant.” Pavlis gave an example. In a lab, some fish genes were moved into Christmas trees, which then glowed. These trees would be GMO plants.

Pavlis gives an example to dispute this definition, especially part A, that makes me almost want to go back to college and do agricultural research. There’s a French wheat call Renan, which was produced by breeders who bathed wheat and two other species of plants in a carcinogen, colchicine, which affects the way chromosomes connect to each other. The breeders exposed them to X-rays to further alter the DNA. This produced a very disease-resistant wheat containing DNA from all three species and it was definitely completed in a lab. It is not considered a GMO by European standards because it was not accomplished by using the gene transfer technology, transgenesis, that has been used for modern day gene manipulation. To me, this process should qualify as a GMO. Clearly, being done in a lab is not important.

I don’t think that there will ever be an agreed-upon definition of GMO to make everyone happy. Pavlis stated, “I find it amusing and concerning that people have such strong views about something that is not well defined.” I am open-minded enough to know that maybe not all GMOs are good. Science and research will tell us technology is here to stay, whether it is in our food production or health care or electronics.

I encourage you to explore the writings of Robert Pavlis on his blog at

Smallsreed is a member of Trumbull County Farm Bureau and grew up on family diary farm in northeast Ohio.