Story at-a-glance
- A daily “tomato pill,” composed of 7 milligrams (mg) of the antioxidant lycopene, may help to prevent heart disease
- Those taking the “tomato pill” for two months had significantly improved forearm blood flow, which suggests the lycopene improved the functioning of the participants’ blood vessels
- Lycopene may significantly reduce your risk of stroke and has shown potential anti-cancer activity as well
- Cooked tomato-based foods, such as organic tomato sauce, tomato paste, and spaghetti sauce, are among the best dietary sources of lycopene
- Lycopene is a fat-soluble nutrient, which means eating it with some dietary fat is essential in order for it to be properly absorbed
This can be predictive of future heart disease because narrowed blood vessels may trigger a heart attack or stroke. Sure enough, those taking the “tomato pill” for two months had significantly improved forearm blood flow while those taking a placebo pill did not.
This suggests the lycopene improved the functioning of the participants’ blood vessels. Undoubtedly, lycopene is one antioxidant worth including in your diet.
In some cases, it may be necessary to obtain nutrients in supplement form, such as when it’s not practical (or possible) to consume enough of the nutrient to achieve a therapeutic effect from dietary sources alone. But this doesn’t appear to be the case with lycopene…
You Can Protect Your Heart with Dietary Lycopene
Lycopene — a carotenoid antioxidant that gives fruits and vegetables like tomatoes and watermelon a pink or red color — is one nutrient you’ll want to be sure you're getting enough of, but you probably don’t need a “tomato pill” to do so.
Lycopene's antioxidant activity has long been suggested to be more powerful than other carotenoids such as beta-carotene, and research has even revealed it may significantly reduce your stroke risk (while other antioxidants did not). The 2012 analysis 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. A 2014 meta-analysis also revealed that lycopene decreased stroke risk (including stroke occurrence or mortality) by more than 19 percent.
Lycopene May Help Prevent and Treat Cancer
Lycopene has been shown to have potential anti-cancer activity, likely due to its antioxidant properties. Studies have shown that people with a diet high in lycopene from tomato-based foods have a lower risk of certain cancers, particularly prostate cancer.
In 2004, an analysis of 21 observational studies showed that consuming tomato products had a protective effect against prostate cancer. A 2014 meta-analysis of 10 studies also showed that dietary lycopene may protect against the risk of ovarian cancer among postmenopausal women.
There is also some evidence from animal studies that lycopene may help with cancer treatment as well. One study found that lycopene treatment reduced the growth of brain tumors while another showed frequent lycopene intake suppressed breast tumor growth in mice.
In human liver cancer cells, lycopene also helped to inhibit cell growth (by 20 percent), while lycopene-treated cells showed less DNA damage than did placebo-treated cells, further demonstrating the anti-cancer properties of lycopene.
How Much Lycopene Is in Commonly Consumed Foods?
It's estimated that 85 percent of dietary lycopene in North Americans comes from tomato products such as tomato juice or tomato paste. If you eat right, it should be relatively easy to get therapeutic levels of lycopene in your diet. For instance, the featured study used supplements with 7 milligrams per serving, which yielded potential heart-health improvements.
It is important to note, however, that canned foods should be avoided not only because of bisphenol-A (BPA) in the liners but also because canned tomatoes will have high levels of methanol. If you are cooking the tomato sauce, this is not a problem as the methanol boils off, but drinking canned tomato juice is a bad idea.
For comparison, you can get four times the amount of lycopene used in the featured study just by eating half a cup of spaghetti sauce and twice that amount in one slice of watermelon! The following chart shows the estimated lycopene content of some commonly consumed foods:
Product Serving Size Lycopene mg/serving) Tomato juice 250 mL (1 cup) 25.0 Tomato ketchup 15 mL (1 tbsp) 2.7 Spaghetti sauce 125 mL (1/2 cup) 28.1 Tomato paste 30 mL (2 tbsp) 13.8 Tomato soup (condensed) 250 mL prepared 9.7 Tomato sauce 60 mL (1/4 cup) 8.9 Chili sauce 30 mL (2 tbsp) 6.7 Cocktail sauce 30 mL (2 tbsp) 5.9 Watermelon 368 g (1 slice: 25 x 2 cm) 14.7 Pink grapefruit 123 g (1/2) 4.9 Raw tomato 123 g (1 medium) 3.7 Source: Heinz Institute of Nutritional Sciences, www.lycopene.com.
Cooked Tomatoes Have More Lycopene
If you’re a fan of tomato sauce, you’re in luck, as lycopene is one example of a nutrient that becomes more bioavailable when it’s cooked. Research shows that cooking tomatoes (such as in tomato sauce or tomato paste) increases the lycopene content that can be absorbed by your body. It 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 percent, 17 percent, and 35 percent, respectively
- Overall antioxidant levels increased by 28 percent, 34 percent, and 62 percent, respectively
Ideally, make your own tomato sauce at home… but if you opt for a store-bought variety, make sure it comes in a jar, not a can. As mentioned, you’re best off avoiding canned tomatoes and tomato sauces, as can liners tend to contain potent estrogen mimics such as BPA, which is also a toxic endocrine-disrupting chemical.
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 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 use only fresh tomatoes or jarred… and while you’re at it, make that sauce organic as well…
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