Neal S. Parikh, MD
Kubota Y, Iso H, Sawada N, Tsugane S, The JPHC Study Group. Association of Breakfast Intake With Incident Stroke and Coronary Heart Disease: The Japan Public Health Center–Based Study. Stroke. 2016
The association between breakfast intake and good health is often touted in popular culture.
The authors cite studies demonstrating associations between skipping breakfast and multiple metabolic derangements and vascular risk factors including obesity, hypertension, dyslipidemia and glucose intolerance. Given these findings and the findings of a study of male US health professionals suggesting an inverse relationship between breakfast intake and coronary heart disease, the authors studied the association between breakfast intake and incident stroke and coronary heart disease.
The study was a population-based, prospective study using the Japan Public Health Center-Based (JPHC) study. Of 140,420 Japanese adults who were eligible, the study included 82,772 participants who had answered a breakfast intake questionnaire in the late 1990s and were free of prevalent stroke or coronary heart disease. Breakfast intake was defined as frequency of breakfast intake per week with daily breakfast as the reference. Covariates included age, sex, BMI, hypertension, hyperlipidemia, diabetes, blood pressure and cholesterol medications, smoking, exercise, sleep, stress, cohabitation, nature of employment, alcohol intake, caloric intake, and intake of vegetables, fruit, fish, soy, dairy, nuts, fat, fiber, and sodium. The outcomes were incident stroke (ischemic, subarachnoid hemorrhage, cerebral hemorrhage), MI, and sudden cardiac death.
The 82,772 participants provided 1,050,030 patient-years of follow-up. Participants who ate breakfast less frequently were less healthy and less likely to be on appropriate medication (e.g. for hypertension and hyperlipidemia). There were 4,642 cases of coronary heart disease and 3,772 strokes (including 1050 cerebral hemorrhages, 417 subarachnoid hemorrhages, 2,286 ischemic strokes).
After adjusting for potential confounders including dietary and lifestyle factors, total cardiovascular disease was associated with complete breakfast omission (HR, 1.14; CI 1.01-1.27) as was total stroke (HR 1.18, CI 1.04-1.34). An association was seen between breakfast omission and cerebral hemorrhage (HR, 1.36, CI 1.10-1.70) but not with coronary heart disease, subarachnoid hemorrhage, or cerebral infarction. The association between breakfast omission and stroke was only seen in non-users of anti-hypertensive medications.
The main limitation is that breakfast intake frequency was a time-fixed variable, which means that the methods did not account for the possibility of breakfast habits changing over time. Second, those omitting breakfast were less healthy, which raises the real possibility of residual confounding, especially as the confidence interval nearly crossed 1.0 for total cardiovascular disease.
Nonetheless, as the authors explain, there is a plausible causal pathway from breakfast omission to morning hypertension and cerebral hemorrhage. Additionally, to its merit, the study exhaustively controlled for vascular risk factors and dietary and lifestyle factors. This study suggests that failure to regularly eat breakfast is associated with cardiovascular disease, particularly hemorrhagic stroke. It may therefore indeed be healthful to eat breakfast daily.