Tomatoes provide a nutritional powerhouse.* Yet, Tom Brady, the phenomenal quarterback of the New England Patriots, avoids tomatoes because he says they cause inflammation. Well, Tom Brady is obviously in great physical shape, and he probably eats a diet with many good qualities. Even so, Tom Brady’s opinion on tomatoes means as much as my opinion on how to win a Super Bowl. The real question is: Does scientific data say that tomatoes cause inflammation?
Before answering this question, let me define inflammation. In simple terms, inflammation is a series of destructive actions initiated by the immune system, usually in response to infection or injury. Sometimes inflammation can be seen and felt, like with a pulled muscle. Other times, the effects aren’t obvious. Inflammation actually benefits the body when the process is killing bacteria or breaking down damaged tissue. However, excessive inflammation produces bad effects such as rheumatoid arthritis, cardiovascular disease, joint pain and stiffness, and poor muscle recovery.
Plants can contain molecules that set off inflammation if eaten in high enough amounts. These molecules include solamine and related molecules found in what have been termed nightshade plants. The list of nightshades includes tomatoes, which contain molecules called tomatine and tomatidine. Vine ripened red tomato fruit have lower amounts of tomatine than tomato leaves or green tomatoes. Nonetheless, people like Tom Brady avoid all tomato foods. In addition, some people with rheumatoid arthritis claim their symptoms worsen when they eat tomato products. This second contention may actually be true, though no studies confirm it. If a food sensitivity to tomatoes combines with rheumatoid arthritis, then maybe tomatoes would increase inflammation in these people.
As for most other people, we can look at what published research says. One approach is to search Medline for “(tomato or tomatoes) and (inflammation or inflammatory).” Medline lists articles on life science research that have appeared in any of a large number of journals. In my search, I examined only studies of tomatoes or tomato products in people. I did not include animal studies nor research on supplements with lycopene, a nonessential, but very helpful nutrient found in tomatoes. I found 4 articles where tomato or tomato products either caused no inflammation or did not make existing inflammation worse. In addition, I found 12 articles where inflammation was reduced. How many articles did I find where tomato or tomato product consumption increased inflammation? It was a big fat zero. In addition, I found a journal article (1) that reported no unusually bad effects in a population that regularly eats tomato types with especially high tomatine contents (ie. pickled green tomatoes). The article further states that in a number of animal studies, tomato nightshade chemicals don’t show toxicity at reasonable doses. So, what is the data showing that tomatoes cause inflammation in most people? There is none.
One research article (2) does find that a tomato extract increases inflammation in mice with something like inflammatory bowel disease (IBD). Interestingly, the same article finds that tomato extract blocks inflammation outside the bowel in mice in other circumstances. The mouse IBD research must be interpreted cautiously. First off, the tomato extract may not have even had much tomatine. Secondly, the IBD-like inflammation was produced by adding a chemical called DSS to drinking water. This is not the way humans get IBD. Although this model can give information on certain aspects of IBD, a limitation exists. If DSS is given to mice along with something that affects intestinal reaction to DSS, it can increase or decrease the inflammation. These effects may not apply to human IBD. Thus, human research is needed here. In the meantime, as with arthritis, some people with sensitivities to both tomatoes and IBD may not react well to tomato intake. Also, people with a rare tomato allergy, or bad reactions to high acid foods, should lay off tomato products.
In conclusion, Tom Brady may say tomatoes produce inflammation, but a lot of research science says otherwise (at least for most types of people). As a scientist, I pick the research over what Tom Brady says.
*Tomatoes are one of the best sources of the B vitamin biotin. Tomatoes also contain substantial amounts of vitamin C and potassium. Furthermore, tomatoes have the non-essential, but valuable antioxidant lycopene. In addition, recent research indicates that tomato contains other nonessential, but possibly useful antioxidants (3). To obtain full benefits, tomato products should be eaten with some fat to help lycopene absorption. In the studies noted above where tomato products neither helped nor hurt with inflammation, the products may not have been eaten with fat
1. Friedman M. Anticarcinogenic, cardioprotective, and other health benefits of tomato compounds lycopene, α-tomatine, and tomatidine in pure form and in fresh and processed tomatoes. Journal of Agricultural And Food Chemistry. 2013;61(40):9534-9550.
2. Joo Y-E, Karrasch T, Mühlbauer M, et al. Tomato lycopene extract prevents lipopolysaccharide-induced NF-kappaB signaling but worsens dextran sulfate sodium-induced colitis in NF-kappaBEGFP mice. Plos One. 2009;4(2):e4562.
3. Mohri S, Takahashi H, Sakai M, et al. Wide-range screening of anti-inflammatory compounds in tomato using LC-MS and elucidating the mechanism of their functions. Plos One. 2018;13(1):e019120