By Dr. Mercola
A daily "tomato pill," composed of 7 milligrams (mg) of the antioxidant lycopene, may help to prevent heart disease, according to a new study published in PLOS ONE.1 To gauge its effectiveness, researchers measured forearm blood flow in volunteers with heart disease.
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, but if you've read my newsletter before, I bet you know what I'm thinking…
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.2
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.3
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.4 A 2014 meta-analysis of 10 studies also showed that dietary lycopene may protect against the risk of ovarian cancer among postmenopausal women.5
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.6
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.7
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.8 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:9
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,10 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…
Organic Tomatoes Have More Antioxidants
According to a study published in the journal PLOS ONE,11 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. 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."
Even organic ketchup has been found to contain 57 percent more lycopene than conventional national brands.12 Additionally, 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 – or add your organic unsweetened ketchup to a rare-cooked grass-fed beef burger…
There Are More Reasons to Eat Tomatoes Than Just Lycopene
One of the problems with opting for a tomato "pill" as the featured study suggested is that you only get one component of the tomato, in this case lycopene. There's not a pill on Earth that could actually replicate the complex nutritional makeup of a tomato. In addition to lycopene, tomatoes are 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 and 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
If you want to learn even more about tomatoes and other fruits and vegetables, visit our Food Facts library. Most people are not aware of the wealth of nutrients available in healthful foods, particularly organic fruits and vegetables. By getting to know your food, you can make informed decisions about how to eat healthier and thereby boost your brain function, lower your risk of chronic disease, lose weight, and much more.
Food Facts is a directory of the most highly recommended health foods to add to your wholesome diet. Its purpose is to provide you with valuable information about various types of foods including recipes to help you maximize these benefits. You'll learn about nutrition facts, scientific studies, and even interesting trivia about each food in the Food Facts library. Remember, knowing what's in your food is the first step to choosing and preparing nutritious meals each and every day. So visit Mercola Food Facts today to get started.