Chocolate is more stimulating than kissing, according to new research. The volunteers, all aged in their 20s, had electrodes attached to their scalps and wore heart monitors during the two tests. The researchers compared their resting heart rates with those during the chocolate and kissing tests. What researchers found is that both kissing and chocolate eating increased the type of activity signaling alertness and relaxation, but in some individuals, chocolate produced a greater effect, which also lasted longer than that from kissing. Chocolate contains caffeine and theobromine (both mental stimulants), phenylethylamine, which raises our blood pressure and heart rate, and tryptophan, which helps release serotonin (sugar also produces that effect). The texture of chocolate makes it highly pleasurable to eat. Chocolate has lots of antioxidants, just like green tea. Chocolate eating has also been linked to low blood pressure and increased insulin sensitivity. Although women are generally thought to be bigger fans of chocolate than men, the research found the same reactions to chocolate in both sexes. Experts warn that chocolate should only be consumed in moderation.