“There is no safe level of smoking”—that’s the conclusion of National Cancer Institute researchers, based on data from 290,215 adults in the 2004-2005 NIH-AARP Diet and Health Study. “[S]moking even a small number of cigarettes per day has substantial negative health effects,” said Maki Inoue-Choi, PhD, lead author.
The participants responded to a questionnaire that assessed lifetime smoking intensity. Those who smoked between 1 and 10 cigarettes a day had an 87% higher risk of earlier death. But even people who smoked an average of < 1 cigarette per day over their lifetime still had a 64% higher risk of earlier death, compared with never-smokers.
The researchers also looked at specific causes of death. Not surprisingly, they found a “particularly strong” association for lung cancer mortality. But again, even people who consistently averaged < 1 cigarette per day over their lifetime had 9 times the risk of dying from lung cancer than never-smokers. Among those who smoked between 1 and 10 cigarettes a day, the risk of dying from lung cancer was nearly 12 times higher.
People who smoked between 1 and 10 cigarettes a day also had > 6 times the risk of dying from respiratory disease and about 1 and a half times the risk of dying of cardiovascular disease, compared with never-smokers.
The younger people were when they quit smoking, the lower their risk of early death.