The proposition might seem hyperbolic, but a new study published in Journal of Nutrition supports the proposition that a high fat meal has the opposite effect as does the proverbial “an apple a day.”
The study, conducted by, among others, the Penn State Vascular Health Interventions Lab, found that “[t]he consumption of a single high-fat meal has been associated with a transient impairment of vascular function.” What does this mean? According to the study squib, one’s consumption of one high-fat meal can cause higher blood pressure following the meal (both systolic and diastolic), as well as higher “peripheral resistance.” In practical terms, the study found that among the 30 students stested, those that had a high-fat breakfast suffered higher blood pressure and higher peripheral resitance than those that had a low-fat breakfast, when subjected to tasks including mathematics, public-speaking, submerging their arms in ice water, and having a blood-pressure cuff on their arm.
We all know what blood pressure is, and generally, we understand that higher blood pressure is a bad thing. So, then, what is peripheral resistance? It’s essentially the ability of the miniature blood-vessels of the body, or arterioles, to relieve the blood pressure of the arteries by accommodating arterial blood. Put simply, when your total peripheral resistance increases, your cardiac output decreases. One analogy about TPR goes thus: if there’s high resistance in a tunnel, then less water can go through; if there’s low resistance, more water can pass.
One high fat meal thus increases the resistance in the vascular system, and increases blood pressure. Ars Technica quotes lead author Dr. Travis Campbell:
… it’s been well documented that a high-fat diet leads to artherosclerosis and high blood pressure, and that exaggerated and prolonged cardiovascular responses to stress are associated with high blood pressure in the future. So when we learn that even a single, high-fat meal can make you more reactive to stress, it’s cause for concern because it suggests a new and damaging way that a high-fat diet affects cardiovascular function.