By Dr. Mercola
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.
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,1 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.”
Today’s Vegetables Aren’t as Nutritious as They Used to Be...
There was a trade-off, and that was size. The conventional tomatoes were significantly larger. However, while many unaware consumers equate size with quality, this simply isn’t the case. At least in the case of organic tomatoes, you get more even though it’s in a smaller “package.”
This does tend to hold true for other organic produce as well though. According to research published in 2009, American produce, while larger than ever before, contains fewer nutrients and tastes worse than it did in your grandparents' days.
In fact, the average vegetable found in today's supermarket is anywhere from 5 percent to 40 percent lower in minerals such as magnesium, iron, calcium and zinc than those harvested just 50 years ago. As the featured study suggests, jumbo-sized produce contains more "dry matter" than anything else, which dilutes mineral concentrations.
Other Studies Have Also Shown Organic Fruits and Veggies Are More Nutritious
Previous research has also shown there can be a nutritional difference between organic- and conventionally-grown vegetables. For example, a 2003 study in the Journal of Agricultural Food Chemistry2 found that organic foods are better for fighting cancer. And in 2005, scientists found that, compared to rats that ate conventional diets, organically fed rats experienced various health benefits. Rats that ate organic or minimally fertilized diets had:
- Improved immune system status
- Better sleeping habits
- Less weight and were slimmer than rats fed other diets
- Higher vitamin E content in their blood (for organically fed rats)
Other studies assessing the nutritional composition and difference between organic and conventional produce include:
- A 2010 study conducted by PloS ONE3 (partially funded by the USDA), which found organic strawberries to be more nutrient-rich than non-organic strawberries
- In 2009, the American Association for the Advancement of Science featured a presentation on soil health and its impact on food quality.4, 5 Conclusion: Healthy soil leads to higher levels of nutrients in crops
- Even the Centers for Disease Control and Prevention conducted their own behavioral study that found higher risk of ADHD in children with higher levels of organophospates (pesticides)6
But perhaps one of the best studies out there on the benefits of organic versus conventionally-grown foods is the 2007 Quality Low Input Food Project7 -- a $25-million study into organic food, and the largest of its kind. The researchers grew fruit and vegetables, and raised cattle, on adjacent organic and non-organic sites, and discovered that:
- Organic fruit and vegetables contain up to 40 percent more antioxidants
- Organic produce had higher levels of beneficial minerals like iron and zinc
- Milk from organic herds contained up to 90 percent more antioxidants
The results were so impressive they stated that eating organic foods can even help to increase the nutrient intake of people who don’t eat the recommended five servings of fruits and vegetables a day. Besides the potential for improved nutrition, other reasons for choosing organic, and ideally locally-grown food include better food quality, better taste and, in the case of local food: increased freshness since the food has not traveled over thousands of miles.
Another Important Boon of Organic = Reduced Toxic Load
Many “health” experts insist there is little difference between organic and conventionally raised produce, but their arguments are flimsy at best. For example, a 2012 meta-analysis by Stanford University8 received widespread media coverage, and with few exceptions, conventional media outlets used it to cast doubt on the value of an organic diet. You had to be a reader of alternative media to get the real scoop on this study...
In a nutshell, the meta-analysis, which looked at 240 reports comparing organically and conventionally grown food (including 17 human studies), found that organic foods ARE safer, and probably healthier than conventional foods — if you are of the conviction that ingesting fewer toxins is healthier and safer for you. Interestingly, the Stanford study also found that organic foods tend to have higher levels of phenols, specifically.
While I believe organic foods grown in healthy soils can be more nutritious than their conventional counterparts grown in depleted soils with synthetic chemicals, a major benefit of organically grown foods really is the reduction in your toxic load. Agricultural chemicals, such as synthetic fertilizers, herbicides and pesticides, can cause a wide variety of health problems, including:
- Disruption of your endocrine system
- Immune system suppression
- Male infertility and miscarriages in women
The Health Benefits of Tomatoes
Tomatoes are rich in flavonoids and other phytochemicals that have anticarcinogenic properties. They’re also an excellent source of lutein, zeaxanthin, vitamin C, which is most concentrated in the jelly-like substance that surrounds the seeds, as well as vitamins A, E and B-complex vitamins, potassium, manganese and phosphorus. Other lesser known phytonutrients found in tomatoes include:
- Flavonols: rutin, kaempferol, quercetin
- Flavonones: naringenin, chalconaringenin
- Hydroxycinnamic acids: caffeic acid, ferulic acid, coumaric acid
- Glycosides: esculeoside A
- Fatty acid derivatives: 9-oxo-octadecadienoic acid
Getting back to lycopene — a carotenoid antioxidant that gives fruits and vegetables like tomatoes and watermelon a pink or red color — this is one nutrient you’ll want to be sure you're getting enough of.
Lycopene's antioxidant activity has long been suggested to be more powerful than other carotenoids such as beta-carotene, and recent research revealed it may significantly reduce your stroke risk (while other antioxidants did not). The 2012 analysis9 followed over 1,000 men in their mid-40s to mid-50s for more than 12 years.
After controlling for other stroke risk factors, such as older age and diabetes, they found that men with the highest blood levels of lycopene were 55 percent less likely to have a stroke than those with the lowest. Other antioxidants, including alpha carotene, beta-carotene, alpha tocopherol (vitamin E) and retinol (vitamin A), showed no such benefit.
The high blood levels of lycopene were said to be a marker for intake of tomatoes and tomato-based products, as these are a particularly concentrated source. It's estimated that 85 percent of dietary lycopene in North Americans comes from tomato products such as tomato juice or tomato paste.10 In addition to lowering your risk of stroke, lycopene from tomatoes (including unsweetened organic tomato sauce) has also been shown to be helpful in treating prostate cancer.
Tomatoes Must be Eaten with Fat for Proper Absorption, and Two Other Caveats
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.
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.11
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,12 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
Return to 'the Way Things Were...'
The simplest way back toward health is to focus on whole, organic foods, grown or raised as nature intended. Meaning, it’s grown using sustainable farming practices, and without the use of chemical additives, pesticides and fertilizers. You can even grow your own. Picking the types of seeds can go a long way in helping your garden be plentiful and even determines how juicy or hardy your vegetables are. Heirloom seeds are seeds that have been carefully cultivated to produce the best plants possible; they're hardy and bountiful. You can find packages containing 26 of the popular heirloom seeds in my Heirloom Variety Seed Collection, available in my online store.
As the featured study attests, fruits and vegetables grown according to organic standards are typically nutritionally superior, but even if they weren’t, organic produce will limit the amount of toxic residues you end up consuming, which is a major benefit in and of itself.
As for tomatoes, they’re one of the most potent sources of lycopene, shown to have anti-cancerous activity and the potential to reduce stroke risk. Just remember to consume your tomatoes, whether raw or cooked, with some type of fat, such as olive oil, since lycopene is a fat-soluble nutrient. Also remember to choose organic varieties, whether whole tomatoes or tomato paste, ketchup or sauce, and avoid anything that comes in a can, since the acidity of the tomatoes will increase toxic BPA release from the liner in the can.