From what I've read, cigarette smoking makes no difference if you smoke or not, but when it comes to a trigger in CH's!  Second hand smoke can be a trigger in some folk.

Abstract

Unique to cluster headache (CH) compared with all other primary headache conditions is its association with a personal history of cigarette smoking. Studies have indicated that greater than 80% of CH patients have a prolonged history of tobacco usage prior to CH onset. How tobacco exposure can lead to CH has not yet been elucidated. As secondhand smoke exposure during childhood has been linked to multiple medical illnesses could CH also be the result of childhood exposure to tobacco smoke? The United States Cluster Headache survey is the largest survey ever done of CH sufferers living in the United States. The survey addressed various clinical, epidemiologic, and economic issues related to CH. Several survey questions dealt with the issue of personal and parental smoking history. Results from the survey suggest that CH can result from secondhand cigarette smoke exposure during childhood as greater than 60% of non-smoking CH patients had parents who smoked. Strengthening the probable association between secondhand smoke exposure and the development of CH is the fact that double the number of survey responders developed CH at or before 20 years of age if during their childhood they lived with a parent who smoked cigarettes.

Abstract
BACKGROUND:

Many human and animal studies have shown the influence of nicotine and caffeine on pain perception and processing. This study aims to investigate whether smoking or caffeine consumption influences trigeminal pain processing.
METHODS:

Sixty healthy subjects were investigated using simultaneous recordings of the nociceptive blink reflex (nBR) and pain related evoked potentials (PREP) following nociceptive electrical stimulation on both sides of the forehead (V1). Thirty subjects were investigated before and after smoking a cigarette, as well as before and after taking a tablet of 400 mg caffeine.
RESULTS:

After smoking PREP showed decreased N2 and P2 latencies indicating central facilitation at supraspinal (thalamic or cortical) level. PREP amplitudes were not changed. NBR showed a decreased area under the curve (AUC) indicating central inhibition at brainstem level. After caffeine intake no significant changes were observed comparing nBR and PREP results before consumption.
CONCLUSIONS:

Smoking influences trigeminal pain processing on supraspinal and brainstem level. In the investigated setting, caffeine consumption does not significantly alter trigeminal pain processing. This observation might help in the further understanding of the pathophysiology of pain disorders that are associated with excessive smoking habits such as cluster headache. Previous smoking has to be taken into account when performing electrophysiological studies to avoid bias of study results.

The capital of the cluster world is the hypothalmus. The hypothalmus is also the capital of the habits and addictions. To me, it stands to reason that Clusterheads would score a higher percent of smokers than the general population.

Abstract
BACKGROUND:

The rate of illicit drug use in cluster headache (CH) patients is unknown.
METHODS:

Two hundred and ten CH patients (162 males and 48 females) attending two headache clinics provided information about their lifetime use (once or more in their lifetime, LTU), recent use (once or more in the past year, RU), and current use (once or more in the past 30 days, CU) of illicit drugs. General population data (IPSAD®Italia2007-2008) served as the control group.
RESULTS:

LTU of each illicit drug but hallucinogens, RU of cannabis, cocaine, amphetamines and ecstasy, and CU of cannabis and cocaine were significantly higher in the male CH patients than in the general population, whereas no difference was found between the CH women and the controls. In the CH group, 28.5% of patients reported having used illicit drugs for the first time after CH onset and 71.5% before CH onset. Compared with the controls, the male CH group showed a greater prevalence both of lifetime sustained intensive use of any illicit drug and of current intensive use of cannabis.
CONCLUSION:

The results of this study indicate that male CH patients are prone to overindulge in illicit drug use. This finding possibly reflects a common biological susceptibility that predisposes these subjects to CH and to addictive behaviour.

I may very well have misunderstood the study. I'm with Jon in mistrusting many of them, anyway. Most go into it with a preconceived notion and data is manipulated to say what they want it to say.
Jerry

Callico wrote on Jun 16^th, 2016 at 12:44pm:

Some professors, scientists, researcher, etc must be "published" regularly as part of their job/ pay checks. It brings in big $$'s to universities, manufacturers.
63%' no, 72%, wait, 79, 88%, yeah 88% of all statistics are made up on the spot.