Scientists have identified a potential seventh taste — a sensitivity towards carbohydrates — which may be behind the craving for starchy foods such as bread, pasta and rice.
Researchers from Deakin University in Australia have shown that sensitivity to carbohydrates, which they call the seventh taste, increases intake of starchy food and a larger waistline.
The team had previously named fat as the “sixth taste”. The fat taste studies explored the tongue’s ability to detect fat as a distinct taste similar to people’s ability to sense sweet, sour, bitter, salty and umami — the five traditional or classic tastes.
Carbohydrates had long been assumed invisible to taste, said Russell Keast, Professor at Deakin University.
“It is typically sugar, with its hedonically pleasing sweet taste, that is the most sought after carbohydrate,” said Mr. Keast, who led the research published in the Journal of Nutrition .
“But our research has shown that there is a perceivable taste quality elicited by other carbohydrates independent of sweet taste,” he said. The research looked at two carbohydrates, maltodextrin and oligofructose, both found in common foods like bread, pasta and rice.
Sensitive taste buds
Initial testing by Julia Low from Deakin University showed that these carbohydrates could be sensed in the mouth.
The study later analysed preferences of 34 adults and found significant correlations between how sensitive someone was to carbohydrates, their dietary intake and their waist measurement. “Those who were most sensitive to the carbohydrate taste ate more of these foods and had a larger waist,” Ms. Low said.
“We specifically looked at waist measurements as they are a good measure of the risk of dietary related diseases,” Ms. Low added.
Mr. Keast said this line of taste research was important because the increasing problem of diet-related chronic illnesses, such as obesity, required a greater understanding of the drivers of the food we consume.
“Increased energy intake, in particular greater intakes of energy-dense foods, is thought to be one of the major contributors to the global rise of obesity,” he said.
“Interestingly, what we found in the fat taste studies was that the people who were more sensitive to fat consumed less fatty foods, but it is the other way around for carbohydrates,” Mr. Keast said.
“What that could mean is that individuals who are more sensitive to the ‘taste’ of carbohydrate also have some form of subconscious accelerator that increases carbohydrate or starchy food consumption. But we need to do much more research to identify the reason why,” he added.
