Tomatoes are part of the nightshade family of vegetables (Solanaceae). Once thought to be poisonous, humans were fortunate enough to find out otherwise. And while we all know they are technically a fruit, don’t tell the U. S. customs regulations that as they categorize them as a vegetable (as does the culinary world).
Whatever you want to call them, with around 7,500 varieties produced today, there is sure to be a tomato size, color and taste to fit everyone’s needs from sauces, to salads, to canning and drinks. And that is a good thing, because these little beauties carry quite the nutrient dense profile.
One cup of red raw tomatoes chopped or sliced has only 32 calories, 7 grams of carbohydrates, 2 grams of protein and zero grams of fat. BUT, that same amount is also a very good source of fiber, vitamins A, C and K, potassium and manganese, and good source of vitamin E, thiamin, niacin, vitamin B6, folate, magnesium, phosphorus and copper. They’re like a little multivitamin on a vine! (Is it too much to call them a multivine-amin?)
Tomatoes and Cancer
Previous research suggested that the lycopene in tomatoes strongly guarded against prostate cancer. In part, this was thought to occur because lycopene concentrates in prostate tissue. However, subsequent research into prostate cancer itself has revealed subtle differences within this cancer type that make it hard to fully assess a cancer/diet relationship. As such, in 2014 AICR downgraded their statements linking lycopene and prostate cancer to “Limited Evidence No Conclusion Possible”.
That said, the AICR continues to support the overall anticancer effects of lycopene as it has shown to stop the proliferation of several cancer cell types including breast, lung, endometrium and prostate cancer.
Tomatoes and Cardiovascular Health
While the high levels of antioxidants in tomatoes are a major boon to their anticancer reputation, they are also the reason why tomatoes are coming up as strong supporters for a healthy cardiovascular system. In animal and limited human studies, lycopene, and powerful antioxidant, has been associated with a decreased risk for atherosclerosis (thickening of the blood vessels) by lowering cholesterol levels.
This is not surprising considering that oxidation of LDL cholesterol and subsequent inflammatory response is the calling card for heart disease, currently the leading cause of death for both men and women in the U.S. A decrease in blood pressure was also seen in some of the lycopene studies. Tomatoes’ high potassium content most likely plays a role there as well.
Although most of the studies were done with concentrated lycopene supplements, it certainly supports the consumption of tomatoes as part of an overall healthy diet. And, don’t forget that lycopene concentration increases with processing, so it is higher in tomato sauce and tomato paste than fresh tomatoes. Perfect for enjoying year round!
Season, Selection and Storage of Tomatoes
Tomatoes like warmer climates and can grow year round, especially in hothouse environments. But in locations with seasonality, you will find sweet, local grown tomatoes only in the mid to late summer months. Look for vibrancy of color – red, orange, yellow, green and even purple – and know that all colors offer nutritional benefits (lycopene is color specific). The skin should be firm, but give a little to the touch and should be free of bruises and wrinkles.
Tomatoes are best kept out of the fridge as their flavor and sweet smell is maximized at room temp. They will continue to ripen post harvest so if you are not ready to eat them just yet they will last in the refrigerator for a couple of days. Just be sure to take them out of the fridge about 30 minutes prior to eating to bring them back up to room temperature.
There is quite a bit of chatter about canned tomatoes and BPA (bisphenol A) and lead content. Regarding lead, it is recommended to purchase tomatoes canned in the U.S. as we have stricter standards for lead levels here. On BPA, while it is true that the acid from the tomatoes can erode some of the lining and leach BPA into the tomatoes, a recent study in Canada showed levels to be below the limits set by the European Commission Directive (the FDA has yet to set levels in America). If this is still a concern, look for BPA free canned tomato goods (Muir Glenn is one example). And, as always, never purchase any can if it is dented, rusted or bulging at the ends.
Tomatoes and Vidalia Onions
For the summer months it seems fitting to go light – extra light. No cooking necessary, simply letting the true taste of the tomato be the star and accent its sweetness with the sweetness of a Vidalia onion.
I first had this dish in the hills of Hawaii, of all places, and have loved it ever since. Medium to large tomatoes are best here and I highly recommend a rimmed dish to catch the yummy juice.
- Cut the tomatoes into quarter inch thick slices. Layer them onto a rimmed plate or small platter in a single layer, but slightly overlapping.
- Thinly slice one half of a Vidalia onion and layer this on top of the tomatoes.
- Drizzle with olive oil (this is the time and place to use the good olive oil if you’ve got it), a dash of balsamic vinegar and salt and pepper to taste.
- Serve at room temperature and enjoy with a yummy baguette. I find the bread necessary to sop up all the delicious juice at the end.
- For optional enhancements, consider chopped toasted pistachios, a little crumbled blue cheese, capers or a few basil or parsley leaves.
Can’t get enough tomatoes? Try our tomato salad recipe.
SELF Nutrition Data. Tomatoes, red, ripe, raw, year round average. Accessed on July 19, 2015 from http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2682/2
Wikipedia. Tomato. Accessed on July 19, 2015, from https://en.wikipedia.org/wiki/Tomato
World’s Healthiest Foods. Tomatoes. What’s New and Beneficial about Tomatoes. Accessed on July 19, 2015 from http://www.whfoods.com/genpage.php/genpage.php?tname=foodspice&dbid=44
CDC. Heart Disease Facts. Accessed on July 19, 2015 from http://www.cdc.gov/heartdisease/facts.htm.
Palozza, P., Catalano, A., Simone, R. E., Mele, M. C., Cittadini, A. (2012). Effect of lycopene and tomato products on cholesterol metabolism. Annals of Nutrition & Metabolism: 61(2); 126-134.
American Institute for Cancer Research. Foods that Fight Cancer. Tomatoes. Accessed on July 19, 2015 from http://www.aicr.org/foods-that-fight-cancer/foodsthatfightcancer_tomatoes.html.