Although reducing consumption may have a place as a temporary measure in smoking cessation, the authors of this Norwegian study said the only way to avoid serious health problems was to quit smoking.
The findings were based on long-term monitoring of more than 51,000 men and women, all of whom were aged between 20 and 34 at the start of the study.
Among men, deaths from lung cancer and cancers associated with smoking were not significantly lower in those who had cut back compared with heavy smokers.
In women who cut back their daily consumption, there were no significant differences in death rates from specific causes, including early death from cardiovascular disease, compared with those who continued to smoke heavily.
The authors concluded, in the journal Tobacco Control, that people could be misled if they were advised that cutting back on smoking would help prevent disease.