A recent American research has revealed that smokers who choose to smoke as soon as they wake up early morning display higher nicotine levels than whose who wait till later in the day, and this has nothing to do with the number of cigarettes smoked.

For the sake of research, more than 250 healthy people who were regular smokers were studied, and scientists measured their levels of cotinine, a by-product of nicotine, which has been linked to increased risk of lung cancer.

The team of researchers, from the Penn State College, then went on to conclude that waiting to smoke until after breakfast reduces the amount of the dangerous chemical. Also, the study revealed that early morning smokers need more help to kick the habit.

Although exact reasons for the difference in levels of cotinine in those who smoke early morning and those who wait are still unclear, researchers think that early morning smoking might "reflect a more intense way of smoking", as their need seems to be greater than those who can wait.

The detailed study has been published in the Cancer Epidemiology, Biomarkers and Prevention.