experts’ opinions

People who quit smoking sometimes gain weight, and a new study finds that former smokers may face an increased risk of developing diabetes as a result.

Smoking itself is a risk factor for Type 2 diabetes, but the risk is even higher for former smokers within the first six years of quitting, according to a study from Hsin-Chieh Yeh of the Johns Hopkins University School of Medicine and colleagues. Recent quitters have a 70% increased risk of diabetes, researchers found.

The risks were highest in the first three years after quitting, but returned to normal 10 years later.

Parkinson's disease is a debilitating neurodegenerative movement disorder characterized by damage to the nigrostriatal dopaminergic system. Current therapies are symptomatic only and may be accompanied by serious side effects. There is therefore a continual search for novel compounds for the treatment of Parkinson's disease symptoms, as well as to reduce or halt disease progression. Nicotine administration has been reported to improve motor deficits that arise with nigrostriatal damage in parkinsonian animals and in Parkinson's disease.

We reviewed 46 published reports associating cigarette smoking and Parkinson's disease. Although the majority indicated an approximate halving of smoking frequency in persons with Parkinson's disease, many observers have suggested that the effect could be a spurious result.

The relationship between smoking and neurological diseases has always been controversial. Even the expected association between smoking and increased risk for cerebrovascular disease has been debated for years.

It was at the end of the 1980s that smoking became definitively accepted as a risk factor for ischemic stroke. More recently, two other neurological diseases have been studied in relation to smoking: Parkinson's disease (PD) and Alzheimer's disease (AD).