Last month, researchers at the Linus Pauling Institute at Oregon State University reported more evidence affirming the health benefit of compounds found in red grapes and blueberries. But this time, there was a new twist.
Analyzing how the immune system might be affected by various compounds, researchers looked at 446 different substances. They discovered just two that stood out from the crowd – the resveratrol found in red grapes and a compound called pterostilbene found in blueberries.
However, they also found both of these compounds worked much more effectively in association with vitamin D. When sufficient vitamin D is added to the mix, these compounds significantly increased the expression of the CAMP gene (cathelicidin antimicrobial peptide), a key factor in immune function.
Adding Vitamin D to the Equation
The scientists explained that resveratrol in red grapes has been the subject of dozens of studies for a range of possible benefits, from improving cardiovascular health to fighting cancer and reducing inflammation. But this research is the first to show a clear association with vitamin D that increased CAMP expression by several times.
“Out of a study of hundreds of compounds, just these two popped right out,” said Adrian Gombart, an LPI principal investigator and associate professor in the OSU College of Science. “Their synergy with vitamin D to increase CAMP gene expression was significant and intriguing. It’s a pretty interesting interaction.”
The Camp Gene
The CAMP gene has been the subject of much study, and it has been shown to play a key role in the “innate” immune system – the body’s first line of defense against bacterial infection. The innate immune response is especially important as many traditional antibiotics increasingly lose their effectiveness.
Researchers are still learning how vitamin D, working with other compounds, regulates the CAMP gene and boosts immune function. The unique biological pathways involved are found in only two groups of animals – humans and non-human primates. Their role in boosting the immune response could be one reason those pathways have survived through millions of years of evolution.
Bioavailibility Still a Question
Despite the interest in compounds such as resveratrol and pterostilbene, researchers cautioned that bioavailability remains a question. The findings were made in laboratory cell cultures and do not prove that similar results would occur as a result of dietary intake. Still, they add more evidence that some foods may have a significant ability to improve the immune response.
Continued research could lead to a better understanding of how diet and nutrition affect immune function, and possibly lead to the development of therapeutically useful natural compounds that strengthen the immune system. Some applications that could evolve may include topical use to improve barrier defense in wounds or infections.