The results of a recent study may change the way wine is made and manufactured for consumers.
Researchers at the Basque Center on Cognition, Brain and Language and Yale have discovered that people’s brains are activated significantly more when they taste low-alcohol content wines than when they taste high-alcohol content ones — in fMRI studies conducted by the researchers, the brain regions that are sensitive to taste intensity lit up more. The findings suggest that higher alcohol content overshadows the taste and aroma of wine whereas lower proof wines offer drinkers a more pleasant sensory experience. The study was published online in the journal PLOS One on March 18.
“When participants had to subjectively rate the wines, their objective brain responses differed from their subjective ratings,” said senior author and Hebrew University psychology professor Ram Frost. “I think the beauty of this study is that it does not rely on subjective information. The study looks at what the brain is really telling us.”
For years, the winemaking industry has increased the alcohol content of wine, thinking that it would lead to better-selling products, Frost said. He wanted to know whether the industry’s assumption was supported by scientific evidence suggesting that consumers prefer more alcoholic wines, which led him to the study.
Twenty-six healthy yet relatively inexperienced wine drinkers between the ages of 22 and 42 were selected to participate in the study. Each subject participated in four consecutive sessions during which they were given three different types of taste stimuli — red wine with a low alcohol content, red wine with a high alcohol content and a tasteless solution. During each tasting session, subjects’ brains were being monitored by fMRI, which uses blood flow levels in the brain to detect activation.
Co-author Manuel Carreiras, scientific director of BCBL and research professor at Ikerbasque, the Basque Foundation for Science, said he and his colleagues tried to control as many variables as they could. All wines administered were red and the pH levels of the two wines were nearly identical. The low level wines ranged from having an alcohol content of 13–13.5 percent, and the high level wines were between 14.5 percent and 15 percent alcohol. Though activation levels differed when subjects drank the different wines, they reported that they could not taste a difference between the two.
The fMRI scans showed a significantly greater level of activation in the regions of the insula and cerebellum, which play a role in consciousness, emotion and motor control. The cerebellum has previously been shown to be sensitive to taste intensity perception. Frost said that the beauty of the study is that it shows that the participants’ objective brain responses differ from their subjective perceptions of preference.
Frost said the study has many important implications for the wine industry, which he thinks should be teaming up with scientists to test assumptions about wine and improve their products using objective data.
But Yale assistant professor of psychiatry and psychology Hedy Kober, who was not involved in the study, said that although the researchers found differences in brain activity, brain activity is not indicative of what people actually prefer. The claims the study’s authors make from the data, she said, are “exaggerated at best.”
Assistant professor of marketing at INSEAD Hilke Plassmann said that because the cerebellum and insula regions perform many functions, both regions are not constantly involved in taste-intensity processing. As a result, it is difficult to conclude from the fMRI scan results that taste-intensity processing is actually affected by alcohol content. The fact that different wines were used in the study is also an “obvious flaw,” Plassmann added, noting that the study could have been improved by administering the same wine, but varying its alcohol content.
Carreiras said he and his colleagues have several ideas to test in the future with the goal of determining why people prefer some wines over others.
As of 2012, more than 88 percent of wine produced in the U.S. was produced in California.