Since current flu vaccines do not completely protect against influenza infection, researchers have been looking for alternative measures. Now, a new mouse study has shown that older mice are given extra protection from the flu with a diet that incorporates goji berries.
The research comes from scientists at the Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University. The study was recently published in the Journal of Nutrition.
To investigate the effects of goji berries - also known as wolfberries - the researchers conducted a study with older male mice, aged 20-22 months, and fed them either a control diet or a 5% goji berry diet for 30 days.
During this time, the mice were given two flu vaccines before the researchers infected them with the flu virus. The team then tested the mice for certain flu antibodies and assessed symptoms of the infection, including weight loss.
The researchers observed a higher antibody response in the mice that were fed the goji berries, as well as less weight loss, compared with the control group that only received the vaccine.
Senior author Dr. Simin Nikbin Meydani, director of the USDA HNRCA at Tufts University, talks about the potential of their findings:
"While previous studies have shown that wolfberries bolster immune response in mice, our results introduce their potential to reduce the age-related risk and severity of the flu virus in the presence of the vaccine."
In addition to observing the effects of the berries on mice, Meydani and colleagues isolated dendritic cells - immune cells that activate T-cells to fight infections - and treated them with a goji berry concentrate, allowing them to incubate for 1 week.
They found that this concentrate "enhanced maturation and activity of antigen-presenting dendritic cells," which basically suggests an enriched immune response.
The team notes that although they are excited about this step toward understanding the interaction between goji berries and the flu vaccine, they are still not clear on which elements of the berries actually produce this interaction.
Co-author Dr. Dayong Wu explains:
"Wolfberries are rich in complex carbohydrates known as polysaccharides, as well as vitamins, carotenoids and flavonoids. Future studies in rodent models would be necessary to understand which components appear to be stimulating the dendritic cells."
The researchers also say more research needs to be conducted in order to confirm whether goji berries would have a similar effect in humans.
"People's immune systems inevitably weaken with age, making them less responsive to the vaccine and more susceptible to the flu and its potentially serious complications," Dr. Meydani adds.
He notes that although the flu vaccine is recommended especially for older people, it is only "40% effective in protecting older adults against flu infection," which he says is significantly lower than in younger people.
"For those reasons," Dr. Meydani says, "it is important to investigate complementary approaches that may enhance the effectiveness of vaccination."
Medical News Today recently reported on a new test that uses sugar and gold nanoparticles to detect flu strains.