Q&A: Dr. Jessica Cooperstone

Dr. Jessica Cooperstone, a professor and researcher at Ohio State University, in conjunction with a team of researchers, is currently exploring how tomatoes impact human health and perhaps combat cancer. To learn more, read her paper on the topic at go.nature.com/2Qmjq19

Q: What was the genesis of this research?

A: Dr. Jessica Cooperstone: Carotenoids, a major class of pigments, are responsible for the yellow, orange and red colors of many different fruits and vegetables. Plants make carotenoids to function as accessory pigments, meaning they exist in conjunction with chlorophyll and are involved in light harvesting. It is thought that the carotenoids may act to help dissipate excess light during this photosynthesis, and thus protect the plant against light-induced damage. It has been hypothesized that carotenoids may act in a similar way in people who eat them — though this has not explicitly been shown. There are some data in humans that show that when people eat diets supplemented with tomatoes, they respond less dramatically to UV light than those not eating tomatoes, suggesting that something about tomato consumption can modulate a person’s response to UV light. We were interested to know if this translates out to skin cancer and decided to test this in a model of prevention, which we conducted in mice.

In this study, we fed mice one of three diets: 1) a control, typical purified mouse diet used in laboratory studies, 2) the control diet supplemented with 10 percent red tomato powder, 3) the control diet supplemented with 10 percent “tangerine” tomato powder. The tangerine tomato — it is called tangerine because it is orange in color and has no relation to the citrus fruit — lacks a certain enzyme that causes it to accumulate lycopene, the major pigment in tomatoes, in a different way as compared to a red tomato. This lycopene in the tangerine tomato is in a different configuration, making it appear orange, and also making the lycopene more bioavailable — which we have shown previously. We saw that animals eating either tomato diet had about a 40 to 50 percent reduction in tumor number as compared to those animals not consuming tomato.

Q: What is your research group most interested in finding out?

A: It is not surprising that what we eat has an effect on our health. Our group is particularly interested in understanding what specifically it is about fruits and vegetables that imparts the benefits we see in those who are eating fruit and vegetable-rich diets. If we can understand which compounds are particularly active, we can then breed, manage for and process to enhance these healthy, beneficial compounds. But without target compounds, nutrition-driven crop development is impossible.

Q: Could eating certain foods help prevent certain diseases, or at least help?

A: Foods are not drugs and therefore generally do not cure diseases. I think as part of a balanced and healthy diet, this study — and many, many others — demonstrate that tomatoes can impart benefits. I’m working to further understand those benefits. My long-term goal is to continue studying foods and chronic diseases, so we can make science-based recommendations based on a preponderance of evidence. And I would still recommend that people wear sunscreen — [it is] the best thing you can do for yourself if you want to decrease your risk for skin cancer. There is some data in the literature that suggests continued tomato consumption can provide an SPF of about 2, so certainly not a sunscreen replacer.

Chris is assistant editor of sister publication Produce Grower magazine..