Carotenoids are beneficial substances foods proudly display. They’re the pigments that give fruits and vegetables their enticing tones of orange and red.
As antioxidants, carotenoids help protect cells from the ravages of time and environment. The most potent antioxidant of the carotenoid group is lycopene, the pigment that gives foods such as tomatoes, watermelons, ruby grapefruits, blood oranges and guavas their red blaze. Lycopene is growing in reputation because of its potential role in the prevention of cancer — especially prostrate cancer — and cardiovascular disease.
To understand lycopene’s protective potential, let’s review what antioxidants do and why it’s so helpful when plants proudly announce their presence. Oxygen has a dual personality. It’s both a life-giving nutrient and a life-threatening toxin.
We need oxygen along with a variety of vitamins and minerals to convert carbohydrates, fats and proteins into energy. But energy production generates byproducts in the form of highly reactive oxygen molecules that can’t wait to get into mischief. Oxygen in this state carries an electron missing its partner, making it unstable.
Looking to leach an electron off any vulnerable molecule, reactive oxygen forms connections in unwelcome locations. This “oxidation” damages cell membranes, proteins and DNA, potentially undermining any number of vital functions. Damaged DNA can lead to the rapid and endless cell division that characterizes cancer.
Reactive oxygen is also generated by the immune system in its attempt to rid us of disease and by environmental pollutants. The body anticipates the normal exposure to reactive oxygen and makes a battery of defensive “anti-oxidants,” molecules that protect cells by donating an electron to blunt the reactive site of the crazed oxygen and render it harmless.
But time and environment undermine our internal defenses. A diet rich in fruits and vegetables comes to our aid, supplying us with a back up of antioxidants. Some, such as vitamins C and E, are essential nutrients with vital duties to perform. A host of others, such as lycopene have properties that make them attractive candidates to recruit for our defense.
There are many properties that make lycopene potentially valuable. As antioxidants go, it’s pretty powerful, ranking above vitamin E in protective effect. Lycopene dissolves in fat, so it travels through the blood in lipoproteins, the tiny spheres that carry fat and cholesterol to tissues. That puts it in close proximity to LDL cholesterol.
By preventing the oxidation of LDL cholesterol, lycopene may lessen its attractiveness to walls of vulnerable coronary arteries. Less oxidized LDL cholesterol means less accumulation of deadly plaque even if the total cholesterol has not been reduced.
There’s some evidence lycopene may step beyond its antioxidant job description to inhibit cancer cell growth either by stimulating the intercellular communication that regulates cell growth or by inhibiting growth factors cancer cells need. A recent study indicates lycopene may recruit the body’s natural cancer fighting ability by stimulating an “antioxidant response element.” This mechanism is so important the FDA is reviewing the clinical data and scheduled to announce their decision this month for allowing a health claim for men’s prostate health.
Another valuable property of lycopene is durability: The processing of tomatoes does little to damage the valuable lycopene, while concentrating lycopene into tomato sauce or tomato paste. This makes it more available by increasing absorption. Still another benefit is that lycopene appears to work synergistically with other advantageous plant chemicals. The whole effect seems to be greater than the sum of the phytochemical parts.
Lycopene has a half-life in tissues of about two to three days. That means we have to keep it in our diet to receive its benefit. “The good news,” says Dave Thomas, director of marketing for LycoRed Natural Products, La Crosse, Wis., “is lycopene isn’t just for tomatoes anymore. A number of lycopene-enhanced products are rolling out to market, such as cereals and meat analogues. But the fortification of beverages — both powdered and liquid — is really becoming a big area for lycopene fortification.” That’s something to think about over the breakfast bowl.