Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/6/2005
Publication Date: 8/1/2005
Citation: Kurilich, A.C., Clevidence, B.A., Britz, S.J., Simon, P.W., Novotny Dura, J. 2005. Plasma and urine responses are lower for acylated vs nonacylated anthocyanins from raw and cooked purple carrot. Journal of Agricultural and Food Chemistry. 53:6537-6542.
Interpretive Summary: Society is continually looking for ways to live a longer, healthier, more active lifestyle and in the process, demanding healthier food choices. At the same time, consumer concerns about the safety of artificial food dyes and legislative action that has dwindled the list of approved synthetic food dyes has led to an increased interest in finding new sources of natural food colorants. Anthocyanins (red, blue and purple pigments found in fruits and vegetables) may address both concerns. Promising research has shown that anthocyanins may serve an important role in promoting health by reducing the risk of atherosclerosis and cancer, ameliorating inflammation and acting as antioxidants. The most common sources of anthocyanins are berries. However, other sources do exist, including specialty purple carrots. Although consumption of anthocyanins is relatively high compared to other similar compounds, their absorption appears to be very low. The body's ability to absorb anthocyanins must be clarified before the health benefits can be understood. We have conducted a study of anthocyanin absorption from purple carrots in men and women. First, we have shown that these healthful pigments are absorbed from carrots, thus supporting the role of specialty purple carrots in a healthful diet. Second, we have shown that these large compounds cross the intestine intact, which helps us understand absorption of large nutrients in general. Third, we have shown that the body seems to have limited ability to absorb large amounts of anthocyanin, which indicates that smaller frequent servings may be more beneficial that a single large serving. This study is an important step toward understanding anthocyanin absorption by the body and in revealing a possible role of purple carrots in a healthful diet.
Technical Abstract: The bioavailability of anthocyanins from purple carrots was studied in 12 healthy men and women. The study was a crossover design with 3 treatments. Volunteers consumed 250 g raw, 250 g cooked and 500 g cooked carrots. Four of the five carrot anthocyanins (all cyanidin derivatives) were found intact in plasma by 30 min after carrot consumption and peaked between 1.5 and 2.5 hours. On average, 0.03% of the total oral anthocyanin dose was recovered in urine over a 24 h period. In comparing the treatments for total anthocyanin response, no differences were observed for plasma area under the concentration time curve, peak plasma concentration, or 24-hour urinary excretion. For specific cyanidin derivatives, plasma and urine responses did not differ except for cyanidin-3-(2'-xylose-6'-feruloyl-glucose-galactoside), for which plasma area under the curve was significantly lower when 250 g cooked carrots was compared to 250 g raw carrots or 500 g cooked carrots, and 24 h urinary excretion was higher for 500 g cooked carrots than 250 g cooked carrots. The % recovery of anthocyanins at the peak plasma concentration was significantly lower for the 500 g dose compared to either 250 g dose. Recoveries of cyanidin derivatives with a sinapoyl or feruloyl group were lower than those for simpler glycoside forms. These results suggest that bioavailability of anthocyanins from purple carrots is low, and absorption of anthocyanins from whole carrots is limited, possibly by saturation for doses at or above approximately 400 mg.