‘Health boosters—how?’

Popeye promotes spinach for strength, while Sesame Street has a superhero that helps kids choose crunchy vegetables over candy. With Halloween around the corner, two recent studies from European researchers could serve as healthful reminders on why chocolates and other sweets are a “sometimes” food while leafy greens are “always” on the menu.

In the Oct. 28 issue of the journal Cell, British and American researchers studying mice found that the presence or absence of cruciferous vegetables in the animals’ diet can influence the health of their immune systems at the gut level.

Rich in nutrients

Named for the family to which they all belong, cruciferous vegetables include broccoli, cauliflower, cabbage, mustard and bok choy. Studies show these vegetables and their relatives are rich in nutrients, and some have been linked to lower risk levels for certain cancers. In the study, the team found that these vegetables are also a rich source of cell-surface proteins. In the gut, these proteins act as indicators on the state of immune system.

“Such a clear-cut interaction with the diet was unexpected,” said senior author Marc Veldhoen, an immunologist at the Babraham Institute in the United Kingdom, in a statement. “After feeding otherwise healthy mice a vegetable-poor diet for two to three weeks, I was amazed to see 70 to 80 percent of these protective cells disappeared.”

There are many thousands of tiny microorganisms living in the guts of many living creatures, including human beings. These microbes help break down the food ingested to keep the body going, and in turn receive food and shelter for keeping their host alive. Veldhoen and his colleagues found that proteins in the vegetables helped maintain the microbial activity in the guts of mice.

Using several groups of mice, the team found that those who received meals lacking the cruciferous vegetables took longer to heal from injuries, or were slower in releasing antimicrobial proteins, compared to those who received vegetables in their diet. The researchers think humans might make a similar response to the presence or absence of bok choy and its relatives in their guts, bolstering the importance of these vegetables in the human diet.

Similar

The study is similar to one published in the Feb. 2 issue of the journal Cell Metabolism. Swedish researchers focused on the question of how green, leafy vegetables like spinach can be good for human health. The answer involves the chemical compound nitrate found in these vegetables and its effect on the so-called “powerhouse of the cell”—and there are trillions of cells in the human body.

The researchers asked the study participants to avoid eating any foods rich with nitrates such as vegetables, tea and cured meats. Half of the group was then given small doses of nitrate, the equivalent to what one might receive from eating a serving of vegetables, while the other half of the study participants received a placebo. Exercises revealed that the participants who had received the nitrate doses used less oxygen than those who had the placebos, suggesting that the cells in the body were more efficient with this chemical compound in the system.

“The importance of our everyday diet in health and disease is attracting immense scientific interest,” the team concluded. “It is tempting to speculate that boosting [this] pathway may be one mechanism by which vegetables exert their protective effects.”

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