Healthy Cold Tomato Soup Recipe

Recipe From Dr. Mercola

If you have planted tomatoes in your garden this year, you may have realized, too late, that you planted more than you need. Late summer is also a perfect time to snag great deals on tomatoes at farmer's markets, where you may be able to pick up a half-bushel of freshly grown tomatoes for a fraction of the cost at your supermarket.

The question then is, what should you do with all of these tomatoes? If you've grown tired of eating them in salads or whole, like an apple, as a snack, making homemade tomato sauce is one of the best uses of large amounts of tomatoes.

They can also be canned, turned into salsa or, for a somewhat different treat, used to make a gazpacho-like cold tomato soup.

Did You Know?
  • Cold Tomato Soup with Farro is a light, refreshing, gazpacho-like soup rich in antioxidants and flavor
  • Tomatoes are an excellent source of lutein, zeaxanthin, and 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
  • Tomatoes are also a particularly concentrated source of lycopene, a carotenoid antioxidant that may significantly reduce your risk of stroke and prostate cancer
  • One recent study found that men who eat more than 10 servings of tomatoes each week reduce their risk of prostate cancer by about 20 percent
  • Organically grown tomatoes have been shown to have higher levels of antioxidants than conventionally grown tomatoes

Summer Soup Recipe: Cold Tomato Soup

If you've been saving your soup recipes for fall and winter, this is one that's perfect on a hot summer day. Light, cool, and refreshing, this soup recipe, posted by the New York Times,1 is perfect for using up your late summer tomatoes (although you might find it so delicious, you'll want to make it all year round).

Cold Tomato Soup with Farro

Prep Time: 10 minutes (plus 24 to 30 hours fermenting time) Total Time: 24 to 30 hours fermenting time Serving Size: 3

Ingredients

  • 1 long European or Japanese cucumber
  • 1 1/2 pounds ripe tomatoes, quartered
  • 2 slices red onion, soaked for 5 minutes in cold water, drained, and rinsed
  • 2 large garlic cloves, halved, green germs removed
  • 2 tablespoons sherry vinegar
  • 2 tablespoons extra-virgin olive oil
  • Salt to taste
  • 1/4 cup broth from the farro, an ancient, less allergenic form of wheat (optional)
  • 2 to 4 ice cubes (optional)
  • 1 cup cooked farro or spelt (*see below)
  • Slivered fresh basil leaves or very small whole basil leaves and additional olive oil if desired for garnish

Procedure

  1. Cut cucumber into 2 equal pieces. Peel and roughly chop one piece, and cut the other piece into 1/4-inch dice, for garnish.
  2. Working in 2 batches, blend roughly chopped cucumber, tomatoes, onion, garlic, vinegar, olive oil, salt, farro broth, and ice cubes (if using) in a blender for 2 minutes or longer, until smooth and frothy. Taste and adjust salt. Transfer to a bowl or container (a metal bowl is the most efficient for chilling) and chill for 1 to 2 hours.
  3. Place about 1/4 cup cooked farro (or spelt) in each soup bowl. Ladle in the soup. Garnish with diced cucumber and basil. Drizzle on olive oil if desired and serve.

    *To cook farro or spelt, soak 1 part farro with 3 parts water for 1 hour or longer. Bring to a boil, add salt to taste, reduce the heat, cover, and simmer 50 minutes, or until the grains begin to splay. Some brands of farro are softer than others and yield a softer, starchier grain. 1 cup raw farro yields 3 cups cooked.

Tomatoes Are an Antioxidant-Rich, Cancer-Fighting Food

Tomatoes are rich in flavonoids and other phytochemicals that have anti-carcinogenic and other healthful properties. They're also an excellent source of lutein, zeaxanthin, and 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, and quercetin
  • Flavonones: naringenin and chalconaringenin
  • Hydroxycinnamic acids: caffeic acid, ferulic acid, and coumaric acid
  • Glycosides: esculeoside A
  • Fatty acid derivatives: 9-oxo-octadecadienoic acid

Tomatoes are also a particularly concentrated source of lycopene — a carotenoid antioxidant that gives fruits and vegetables like tomatoes and watermelon a pink or red color.

Lycopene's antioxidant activity has long been suggested to be more powerful than other carotenoids such as beta-carotene, and research has revealed it may significantly reduce your stroke risk (while other antioxidants did not).

In addition to lowering your risk of stroke, lycopene from tomatoes (including unsweetened organic tomato sauce) may help protect against DNA and cell damage, and has also been shown to be helpful in treating prostate cancer.

One recent study found that men who eat more than 10 servings of tomatoes each week reduce their risk of prostate cancer by about 20 percent.2 The cold tomato soup recipe above lends even more nutrition than eating tomatoes alone, as it combines them with antioxidant-rich onions, garlic, and basil and olive oil.

The olive oil is especially important in this recipe, as it provides a healthy source of fat. Lycopene is a fat-soluble nutrient, which means eating it with some dietary fat is essential in order for it to be properly absorbed.

Choose Organic Tomatoes for Even More Nutrition

Choosing organic tomatoes for this recipe is important for two primary reasons. One, they will not contain the pesticide residues that are prominent on most conventionally grown produce. Secondly, organically grown tomatoes are even more nutritious than their conventionally grown counterparts.

One study found growing tomatoes according to organic standards results in dramatically elevated phenols content compared to tomatoes grown conventionally, using agricultural chemicals.

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.3 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 may be in a smaller "package." Tomatoes may also be waxed after harvest to withstand the long journey to market unscarred and to protect against the many hands that touch it. While the wax is supposed to be food-grade and safe, there are different types used:4

  • Carnauba wax (from the carnauba palm tree)
  • Beeswax
  • Shellac (from the lac beetle)
  • Petroleum-based waxes

The natural waxes are far preferable to toxic petroleum-based waxes, which may contain solvent residues or wood rosins. Produce coated with wax is not labeled as such, but organic produce will not contain petroleum-based wax coatings (although it may contain carnauba wax or insect shellac). This is another reason to choose organic tomatoes. Tomatoes purchased from a farmer's market are far less likely to be waxed than those purchased at a supermarket.

The Case for Cooked Tomatoes

The featured recipe uses fresh tomatoes, and since it is a cold soup, it doesn't call for cooking. However, tomatoes are one exception where cooking may enhance their nutritive value. Research shows that cooking 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:5

  • 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 six, 17, and 35 percent, respectively
  • Overall antioxidant levels increased by 28, 34, and 62 percent, respectively

If you're planning to try the featured recipe, you could cook the tomatoes as described (to 190° F for about 30 minutes) before using them. This would likely boost the soup's nutritive value, although it would also alter the flavor and texture of the soup. Either way, the soup will still be good for you.

Wait: Store Your Tomatoes on the Counter, Not in Your Fridge

If you bring home several pounds of tomatoes or more, you might be tempted to store them in the fridge. Don't, as storing a tomato at refrigerator temperature (39°F) causes its volatiles to break down, which will negatively impact its flavor. Storing tomatoes below 50°F may also lead to changes in texture, premature softening, surface pitting, and increased decay (this is true even prior to harvest). If you purchased your tomatoes at a grocery store, they probably weren't ripe to begin with (they're typically picked a few days before they're fully ripened to make them easier to ship). If you put an unripe tomato in your fridge, the ripening process will stop, so you'll certainly be left with a tasteless tomato.

But even if your tomatoes were homegrown or picked up from a local farmer's market (arguably the best sources of truly flavorful tomatoes), their flavor will quickly disappear if you put them in the refrigerator, due to a change in chemical structure. If you want your tomatoes to ripen quickly, put them in a brown paper bag; they will release ethylene gas that will help them to ripen quickly (this also works for green tomatoes). If you've already put your tomatoes in the fridge by mistake, there's a trick that might help to bring back some of their flavor: let them sit at room temp for 24 hours before eating.

One study found that tomatoes left to "recondition" at 68°F for a day were able to recover some of their aroma production, even if they'd previously been refrigerated for up to six days.6 Another option? Use up refrigerated tomatoes in a sauce recipe, where the added flavors from onions, garlic, and basil are likely to cover up the tasteless tomato. The other important benefit to using fresh tomatoes in your soups and sauces is that it allows you to avoid canned tomatoes, a primary source of exposure to toxic bisphenol-A (BPA) in the can linings.

+ Sources and References