Tomato season has arrived here in Virginia – a good enough reason to love summer even if there were no other. Fresh, vine-ripened tomatoes are the only ones I eat. I never touch those things they sell in the supermarket, except when I encounter one in a restaurant.
And while all varieties of this fruit are good for you, new research shows that two kinds in particular may have powerful cancer-preventive properties.
Read on to discover what this summertime treat can do for you. . .
Continued below. . .
People tend to think of tomatoes as vegetables because we use them in so many savory (as opposed to sweet) preparations, but they are a fruit.
A powerful fruit, it turns out. Research has long shown that lycopene, an antioxidant carotenoid that gives tomatoes their rich color, has cancer-fighting power.
I’ve covered the benefits of lycopene before (Issue #660) so I won’t go into much detail about it here. However, new research suggests that whole tomatoes contain many other beneficial compounds beyond lycopene. Meaning you’ll be better off eating the fruit than taking the supplement.
Tomatoes can help prevent stomach cancer
Stomach, or gastric, cancer often begins in the stomach lining and can spread to other parts of the body. It usually starts very slowly and may go undetected for years before a diagnosis. According to the World Health Organization, it’s the 4th leading cause of cancer-related deaths.1
About six out of ten people diagnosed with gastric cancer are aged 65 or older. The risk is higher in men than in women, but can be influenced by many risk factors besides gender.2
Some risk factors that influence the development of stomach cancer are infection with Helicobacter pylori. H. pylori is a gastric pathogen that causes chronic inflammation of the stomach and significantly increases the risk of ulcers and cancer.
Another risk factor is a diet rich in smoked or salted food, especially when combined with a low intake of fresh fruits and vegetables.3
While adding fruits and vegetables to your diet will help reduce the risk of stomach cancer, research shows that eating tomatoes can be especially helpful.
A 2014 study tested the antioxidant and anti-proliferative effect of five kinds of tomatoes (San Marzano Rosso, San Marzano Giallo, Corbarino, Black Tomato and San Marzano/Black Tomato hybrid). The researchers discovered the San Marzano Rosso tomatoes scavenged the most free radicals and inhibited the greatest number of cancer cells.4
Another study, this one published in the May 2017 issue of the Journal of Cellular Physiology, found that both San Marzano and Corbarino tomato cultivars, from Southern Italy, inhibit gastric cell cancer growth.
The researchers tested total lipophilic extracts (chemicals that dissolve in fat or oil) of these two varieties against several strains of lab-cultured gastric cancer cells, of varying aggressiveness.
They found the phytochemical in the tomatoes stopped cancer cells from migrating, stopped their cell cycle progression and induced apoptosis (programmed cell death). It did all this without harming nearby healthy cells.5
The researchers concluded that “San Marzano and Corbarino intake might be further considered as nutritional support not only in cancer prevention, but also for cancer patient diet.”
Whole tomatoes, not supplements,
give you the most benefits
What’s interesting is that, in these studies, the researchers attribute the benefits not to one part of the tomato, like lycopene, but rather all (or several) of the nutrients together.
There’s confirmation elsewhere that we need to look beyond lycopene. Another study found that the pectic polysaccharide from sour raw tomato could also prevent gastric cancer growth, stop progression and induce apoptosis in gastric cancer cells.6
Pectic polysaccharides act as prebiotics, meaning they feed the good bacteria in your gut. Feeding the friendly gut flora can improve a wide range of conditions as well as reduce your risk of developing colon cancer. (To learn more about the microbiome and colon cancer, see Issue # 539).
A review of 72 studies published in the Journal of the National Cancer Institute found that 57 studies reported an inverse relationship between tomato intake and cancer “at a defined anatomic site.”
They discovered tomatoes had an effect in fighting prostate, lung and gastric cancers, as well as cancer of the pancreas, colon and rectum, esophagus, oral cavity, breast, and cervix.7
The review concluded that “Numerous other potentially beneficial compounds [besides lycopene] are present in tomatoes, and, conceivably, complex interactions among multiple components may contribute to the anticancer properties of tomatoes.”
So to reap the greatest benefit, eat whole tomatoes whenever you can instead of merely taking a supplement.
Get the most out of your summer tomato bounty
Some of this research focused on a couple of types of tomatoes, but this doesn’t show that other varieties lack the same or similar benefits. I kind of suspect the studies were financed by growers or processors of San Marzano and Corbarino tomoatoes, or by the Italian government. Who knows?
San Marzano tomatoes are an heirloom variety of plum, or Roma tomatoes, much favored in Italian recipes. They’re smaller and more oval-shaped than standard “beefsteak” varieties.
They have deep red flesh, a sweet flavor and low seed count, which makes them perfect for making sauce, tomato paste and layering on margarita pizzas.
If they’re not available fresh in your local grocery you may be able to find them at your Farmer’s Market.
If all else fails, San Marzano tomatoes are available whole, peeled and canned in grocery stores, specialty shops and online.
Corbarino tomatoes are smaller even than San Marzanos. They’re a kind of grape tomato that sometimes grow into larger pear-shaped fruits. They originally come from the foothills of Mount Vesuvius, a few miles east of Naples, Italy. Many people claim they are the most delicious tomatoes in the world…
These little tomatoes are good for making bruschetta, in salads and eating right off the plant.
Corbarinos are harder to come by fresh here in the States. However, small markets may carry them, and companies in the US sell the seeds, so you could plant your own. They’re also readily available canned or jarred as sauce.
However, don’t skip out on tomatoes if these particular varieties are unavailable where you live. Any kind of fresh, organic tomato will provide loads of health benefits and help reduce your risk of developing many kinds of cancer.