Inside plants

Tomato products may lower the risk of prostate ­cancer

CAROTENOIDS are just about everywhere you look, at least in the natu­ral world. These chemicals produce red, yellow, orange, and sometimes purple colors in plants and microorganisms, which use them to protect themselves against damaging sun rays, aid in photosynthesis, and stabilize cell membranes.

In animals (including humans), some carotenoids help cells communicate, facilitate cell growth, and protect the body from ultraviolet radiation and cancer. In the commercial realm, we use carotenoids to color foods, pharmaceuticals, and cosmetics.

Carotenoids include carotenes, lutein, and lycopene. The body can convert some carotenes, most notably beta-carotene, into vitamin A, a reaction that occurs either in the liver or the intestines. Vitamin A is vital for good vision, healthy skin, bone growth, and other body functions.

Carotenoids, including lycopene, can only be absorbed properly when eaten with some form of fat, since fat dissolves them and carries them through the body. Additionally, foods that contain carotenoids may need to be cooked, pureed, or finely chopped. This is especially true when the carotenoid is lycopene, which is found in calendula (Calendula officinalis), watermelon, tomato, guava, red grapefruit, bitter melon (Momordica charantia), carrot, rose hips, and apricot.

The pros of pizza

Some studies suggest that lycopene protects against coronary artery disease and colon, breast, and prostate cancer. In fact, researchers have shown that lycopene accumulates in the prostate gland. A statistical study, spanning six years and published in 1995, focused on the diets of nearly 50,000 American men. The data show a relationship between lycopene-rich foods and a lower risk of prostate cancer. Of forty-six foods, only four showed a significant connection to lower prostate cancer risk: tomato sauce, tomatoes, pizza with tomato sauce, and strawberries. All of the tomato products are primary sources of lycopene (the strawberries are not). The study recommends increased vegetable and fruit ­consumption, especially of tomato-based products that have been cooked and concentrated into paste or sauce.

Studies such as this one only highlight statistical associations; they don’t prove that something prevents or cures a disease. “Proving” requires that humans take part in controlled research studies and that these studies can be duplicated.

Clinical clues

To date, controlled studies indicate that carotenoids work synergistically with one another and other phytochemicals. In other words, they perform better when they team up. Just how carotenoids work together is open to debate, however, and studies have produced varying results.