(Organic Slant) Tomatoes grown on organic farms accumulate higher concentrations of sugars, vitamin C and compounds associated with oxidative stress compared to those grown on conventional farms.
Tomatoes, which are actually a fruit and not a vegetable, contain a number of valuable nutrients, and according to recent research, organically-grown tomatoes are even more nutritious than their conventionally-grown counterparts, according to research published February 20 in the open access journal PLOS ONE by Maria Raquel Alcantara Miranda and colleagues from the Federal University of Ceara, Brazil.
In their study, the researchers compared the weights and biochemical properties of tomatoes from organic and conventional farms. They found that tomatoes grown on organic farms were approximately 40% smaller than those grown by conventional techniques, and they also accumulated more compounds linked to stress resistance.
According to the authors, organic farming exposes plants to greater stress than conventional farming. They suggest that this increased stress may be the reason organic tomatoes had higher levels sugars, vitamin C and pigment molecules like lycopene, an anti-oxidant compound — all of which are associated with the biological response to stress. Based on these observations, the authors suggest that growing strategies for fruits and vegetables should aim to balance plant stress with efforts to maximize yield and fruit size, rather than trying to eliminate stress to increase yields.
One of the most well-known nutrients in tomatoes is lycopene — the compound that gives tomato its deep red color.
Lycopene is a vital anti-oxidant that has been shown to have potent anti-cancerous activity. This compound is not naturally produced in your body, so it must be supplied via your diet.
Other fruits and vegetables also contain lycopene, but none has the high concentration of lycopene that the tomato boasts.
Interestingly, when cooked, the bioavailability of lycopene increases rather than decreases, as is the case with many other raw foods, as heat has a tendency to destroy valuable nutrients.
That said, you’re best off avoiding canned tomatoes and tomato sauces as can liners tend to contain potent estrogen mimics such as bisphenol A (BPA), which is also a toxic endocrine disrupting chemical. Your best bet is to make your own organic tomato sauce from scratch, or buy organic sauce sold in glass jars.
Organic Tomatoes have 139 Percent Higher Phenolic Content, Study Shows
It seems perfectly sensible that food grown in healthier soil with natural fertilizers and no synthetic agricultural chemicals would be more nutritious. This is common knowledge among farmers, yet this age-old, common sense wisdom is greatly suppressed in the United States in order to protect the large-scale industrial farming model.
According to a recent study published in the journal PLOS One, growing tomatoes according to organic standards results in dramatically elevated phenols content, compared to tomatoes grown conventionally, using agricultural chemicals.
The researchers compared total phenol content in organic and conventional tomatoes grown in nearby plots in Brazil. This allowed for a more accurate comparison of the tomatoes, as both varieties were grown in similar soil- and climate conditions that might otherwise affect nutrient content.
According to the authors:
“This study was conducted with the objective of testing the hypothesis that tomato fruits from organic farming accumulate more nutritional compounds, such as phenolics and vitamin C as a consequence of the stressing conditions associated with farming system.”
The organic tomatoes were found to contain 55 percent more vitamin C, and 139 percent more total phenolic content at the stage of commercial maturity, compared to the conventionally-grown tomatoes. According to the authors:
“[T]his seems consistent with the more than two times higher activity of phenylalanine ammonia lyase (PAL) we observed throughout fruit development in fruits from organic farming.
Taken together, our observations suggest that tomato fruits from organic farming experienced stressing conditions that resulted in oxidative stress and the accumulation of higher concentrations of soluble solids as sugars and other compounds contributing to fruit nutritional quality such as vitamin C and phenolic compounds.”
Tomatoes Must be Eaten with Fat for Proper Absorption
Lycopene is a fat-soluble nutrient, which means eating it with some dietary fat is essential in order for it to be properly absorbed. So a slow-cooked tomato sauce that contains olive oil or another source of healthy fat, such as grass-fed beef, may be an ideal source.
Eden uses BPA-free cans
One caveat: when making your tomato sauce, start out with fresh tomatoes, as canned tomatoes typically have a lining that contains bisphenol-A (BPA) which is a potent estrogen mimic that have been linked to a number of health problems, including diabetes, heart disease, heightened risk of breast and prostate cancers, neurological effects, reproductive problems and obesity.
The current US federal guidelines put the daily upper limit of “safe” exposure at 50 micrograms of BPA per kilogram of body weight. According to endocrinologist Dr. Fredrick vom Saal, a tin can contains around 50 mcg of Bisphenol A (BPA), and when the cans contain acidic food such as tomatoes, it will leach more BPA from the liner into the food. According to Consumer Reports’ testing, just a couple of servings of canned food can exceed the safety limits for daily BPA exposure for children.
So, ideally avoid canned foods entirely and stick to fresh fruits and vegetables, or switch over to brands that use glass containers instead. One other point: if you eat a lot of ketchup, you might want to consider choosing an organic version (as well as one that is unsweetened, as regular ketchup is a common source of sugar and high fructose corn syrup). Organic ketchup has been found to contain 57 percent more lycopene than conventional national brands.
Cooked Tomatoes May be Better than Raw
Tomatoes differ from many other raw foods in that cooking them may in fact be better than eating them raw. Research shows that cooked tomatoes (such as in tomato sauce or tomato paste) not only increases the lycopene content that can be absorbed by your body, but also increases the total antioxidant activity. In one study, when tomatoes were heated to just over 190 degrees F (88 degrees C) for two minutes, 15 minutes and 30 minutes:
- Beneficial trans-lycopene content increased by 54 percent, 171 percent and 164 percent, respectively
- Levels of cis -lycopene (which is a form easily absorbed by your body) rose by 6, 17 and 35 percent, respectively
- Overall antioxidant levels increased by 28, 34 and 62 percent, respectively