subject: Cruciferous Veggies: The Key to Good Gastro-Intestinal Health [print this page] Do you know someone who can eat almost anything, like fatty and spicy foods, without suffering unpleasant consequences? Actually, during our youthful years, many of us could get away with such unhealthy overindulgence. But as we age, so do our digestive systems, resulting in an inability to endure the abuse they once could. In fact, if we don't take special care to follow a nutritious diet, the consequences can be far more than uncomfortable.
By contrast, making vegetables - specifically the cruciferous family, including broccoli, cabbage and Brussels sprouts - a part of our diet, on a regular basis, seems to lead to health. Why? A significant amount of medical research has identified a cruciferous component as potent in protecting the digestive system from conditions like ulcers, pathological bacteria, even cancer.
Turning On 200 Genes
For example, research by Paul Talalay, professor and medical scientist at Johns Hopkins University Medical School, led to the discovery of a chemical in cruciferous vegetables, known as sulforaphane. Talalay's laboratory was the first to show sulforaphane has the magical' effect of turning on a specific (and large - over 200) set of genes that act to protect our cells from toxins, free radicals and inflammation.
Talalay's work was the catalyst for numerous scientific investigations in laboratories around the world. The race was on to determine how, exactly, sulforaphane activated these cell-protective, potentially disease-preventative genes. (See Juvenon Health Journal Volume 7, No. 7, July 2008, "Cruciferous veggies: the latest on why they're good for us.")
Talalay later discovered that the highest concentration of sulforaphane is found in broccoli sprouts. His research prompted not only the appearance of this form of the vegetable on supermarket shelves, but also sprout-specific research.
Bacteria-fighting Broccoli Sprouts
A group of investigators from the Tokyo University of Science in Japan took the research a step further, investigating the effects of a diet rich in broccoli sprouts on the pathology associated with a specific bacteria, Helicobacter pylori or H-pylori. A significant percentage of humans are infected with this pathogen, some showing symptoms while others are asymptomatic. Several years ago, H-pylori was linked to gastritis, ulcers and stomach cancer.
The researchers devised a protocol to examine the effects of the broccoli sprout-rich diet on H-pylori infected mice, an established animal model to study this disease. They compared the mouse model results to those obtained from H-pylori-infected humans who were on a diet enriched with either broccoli sprouts or a placebo, alfalfa sprouts (no sulforaphane).
Soothing Sulforaphane
Mimicking the human study, the mice were divided into two groups. The experimental group was fed an extract of broccoli sprouts containing sulforaphane for eight weeks. The control group was fed an alfalfa-sprout extract for the same time period.
At the end of the eight weeks, microscopic examination of the stomach lining revealed a dramatic improvement in tissue health for the broccoli sprout-treated mice, as compared to the controls. In addition, blood work showed a significant decrease in markers of inflammation that are produced by inflammatory cells (TNF alpha, and Interleukin-1 beta) as well as markers of DNA damage (8-OHdG) and cell death. These results seem to indicate that sulforaphane is acting to sooth the cells of inflammation and prevent damage.
Molecular Mission
So, how does sulforaphane elicit its cell-protective effects? Theoretically, by activating a specific protein molecule in the cell, Nrf2, which then travels to the cell's control center, the nucleus, and trips the "on" switch for numerous cell-protective genes.
To test this theory, the Japanese investigators genetically engineered a group of mice to be lacking the Nrf2 gene and protein molecule. They compared this group's response to broccoli sprouts to a group of normal mice capable of making the Nrf2 protein. Both groups of mice were infected with the H-pylori bacteria, and fed identical diets. The mice deficient in Nrf2 were not protected by ingesting broccoli sprouts, clearly suggesting the role of this protein in mediating the sulforaphane-induced protection from H-pylori infection.
A Man or a Mouse
Do humans have the same response to broccoli sprouts? Fifty subjects, determined to be infected with H-pylori, participated in a study. They were divided into two groups, one agreeing to consume 70 grams (2.5 oz) of broccoli sprouts and the other the same amount of alfalfa sprouts per day for eight weeks. At the end of this period, blood was taken and analyzed for the production of cell-protective gene products, normally activated by Nrf2, as well as other markers of inflammation.
The results showed a remarkable two-to-three-fold increase in cell-protective enzymes and a decrease in markers of inflammation for the broccoli-sprout group. Analysis of this group's stomach lining also revealed a decrease in the quantity of H-pylori.
Good Gastro-intestinal Health
Environmental factors, such as diet, contribute to whether a person infected with the H-pylori pathogen develops ulcers or cancer in the digestive system. Animal and human studies support the health-promoting effects of cruciferous vegetables in particular. The evidence also suggests these "veggies" may have a systemic effect: they may help establish a more balanced production of inflammatory and anti-inflammatory molecules, holding inflammation and associated disease in check.
Other dietary steps to improve our chances of maintaining a healthy gastro-intestinal system? Avoid excessive amounts of salt and burned meat, as well as kinds of fish and other foods that produce certain toxins (nitrates, etc.) when mixed with stomach fluids. And make sure your diet contains lots of fruits, berries, legumes, whole grains and other vegetables, in addition to our cruciferous friends.
Cruciferous Veggies: The Key to Good Gastro-Intestinal Health
