The anti-inflammatory effect of a vegan versus American Heart Association-recommended diet in coronary artery disease

Coronary artery disease^[1] (CAD) is the leading cause of cardiovascular disease (CVD) related death in the U.S. It is characterized by a reduction of blood flow to the heart due to atherosclerosis^[2] (hardening and plaque buildup) of at least one coronary artery (blood vessel supplying blood to the heart). This can lead to the heart tissue getting fewer nutrients and less oxygen than it requires. In an era where LDL cholesterol can be controlled with medications (predominantly statins), but CVDs are still the number one^[3] cause of mortality, researchers and clinicians are seeking additional tools to reduce risk. Anti-inflammatory therapy^[4] is one tool that appears promising, especially when oxidized LDL^[5] is a primary component of atherosclerotic blockage.

The link between oxidized LDL and atherosclerosis is inflammation, which is also a mechanistic link^[6] between other traditional risk factors for CAD (i.e. obesity, smoking) and endothelial (blood vessel inner lining) dysfunction that drives CAD. Indeed, people with CAD generally have elevated levels^[7] of C-reactive protein (CRP), a protein^[8] produced during the acute phase of inflammation that helps the body recognize and remove foreign pathogens and damaged cells, and whose levels correlate with CAD presence and severity. Reductions in high sensitivity CRP (hsCRP, where high sensitivity refers to a more sensitive measurement method) have been noted as^[9] a potent marker of reduced adverse cardiovascular events in people with established CAD. While evidence^[10] suggests that CRP does not play a causal role in CAD, its presence is nonetheless predictive of CAD risk, since it shares a pathway with the inflammatory process that does cause CAD, which you can see in Figure 1.

Various dietary components, primarily from whole plant-based foods^[11], appear to reduce inflammation^[12] and CVD risk factors^[13]. A dietary inflammatory index^[14] has even been developed that might be able to predict hsCRP levels and has shown a positive association^[15] with several cardiovascular risk factors. While the American Heart Association (AHA) has a very specific set of lifestyle and dietary recommendations^[16] in place to combat CVD, multiple diets (i.e. Mediterranean^[17], DASH^[18], and vegetarian^[19]) have demonstrated CVD-protective and/or anti-inflammatory potential.

Few studies have compared the anti-inflammatory effects of different dietary strategies. The study under review compared the influence of a vegan (whole plant-based food) diet against the AHA-recommended diet^[20] on hsCRP and related CVD risk factors.

People with coronary artery disease have elevated levels of an inflammatory marker CRP. Anti-inflammatory therapy has demonstrated promise for prevention of adverse cardiovascular events. Whole plant-based foods appear to reduce inflammation and CVD risk factors. While the American Heart Association recommends a diet for CVD prevention, it has not been compared to other diets with similar anti-inflammatory potential. The study under review compared the effect of a vegan versus AHA-recommended diet on hsCRP and related CVD risk factors and markers.