Cut down or quit? Different answers for smoking and alcohol

For smoking

The 2018 BMJ review by Hackshaw and colleagues (141 cohorts) found that even one cigarette a day carries a large share of the coronary heart disease risk. The authors write that there is no safe level of smoking for cardiovascular disease. In the 2019 Cochrane review (51 studies), cutting down to quit did not differ from quitting abruptly, but those studies had a quit date. In short: use cutting down as a step towards quitting, not as the last stop.

For alcohol

In the 2017 Cochrane review by Kaner and colleagues (57 studies, 34,390 people), people using digital interventions drank about 23 grams less per week than controls (95% CI 15 to 30 grams). The evidence is of moderate quality.

The 2017 review by Roerecke and colleagues (36 trials) looked at blood pressure. Among people drinking up to two drinks a day, cutting down did not lower blood pressure significantly. Among those drinking six or more a day who halved their intake, systolic pressure fell by 5.50 mmHg. The same cut does not give the same result for everyone.

We found no source showing that gradual reduction beats quitting outright for alcohol, so we do not present one method as better than the other.

Which to choose

• Smoking: a plan with a quit date. Talk to a health professional about NRT if you want it.
• Alcohol: set a weekly limit, log for a while, and lower it slowly. Or take a break for a set time.
• If you drink heavily, or you get shaking or sleeplessness when you stop, do not stop suddenly. Ask a doctor.

Purrpose has three goals: quit, cut down with a weekly limit, or take a break. The limit comes down at the pace you choose.