Vegetarian Diet in Patients With Ischemic Heart Disease
Vegetarian Diet in Patients With Ischemic Heart Disease
Open label, 4 week randomized, cross-over study to compare the effect of a vegetarian diet to
 a conventional (meat containing) diet based on the Swedish average meat consumption on a
 range of parameters with prognostic importance for cardiovascular disease.The study will be
 conducted in patients diagnosed with ischemic heart disease. We hypothesize that patients
 will benefit from a vegetarian diet as assessed by multiple risk markers for this type of
 disease with a primary focus on changes in oxidized LDL cholesterol.
Background

 Cardiovascular disease is the leading cause of death globally. Ischemic heart disease (IHD)
 contributes the most to this statistic and since 1990 the global burden of IHD has increased.
 It is estimated that 50 000 Swedish patients are hospitalized every year due to IHD. The risk
 of developing IHD is to a large extent determined by the existence and state of several
 modifiable risk factors including dietary habits, smoking, hypertension, diabetes mellitus,
 hyperlipidemia, high apolipoprotein B/ apolipoprotein A1-ratio, abdominal obesity, physical
 inactivity, alcohol consumption and psychosocial factors. High levels of oxidative stress,
 oxidized LDL cholesterol and the microbial metabolite trimethylamine N-oxide TMAO have been
 suggested to be associated with development of IHD.

 A plant-based (vegetarian) diet may provide cardiovascular health benefits through various
 mechanisms. Clinical studies suggest that a vegetarian diet has positive effects on
 low-density lipoprotein (LDL) cholesterol, oxidized LDL cholesterol, total cholesterol,
 triglycerides, apolipoprotein B, body mass index (BMI), inflammatory markers, blood pressure,
 arterial intima-media thickness, insulin sensitivity, glycated hemoglobin, (HbA1c) and
 fasting glucose levels. Through positive impacts on risk factors that a vegetarian diet is
 associated with a lowered incidence and mortality of IHD and an overall reduced mortality.

 A weakness of several prior long-term controlled studies comparing vegetarian and
 meat-containing diets is the lack of well-defined control diets leading to study
 heterogeneity. For example, some of the subjects on meat-containing diets consume great
 quantities of red meat, others eat substantial amounts of processed meat products and some
 eat mostly white meat and fish complicating interpretation of outcome. In cross-sectional or
 observational cohort studies comparing long-term vegetarians to long-term omnivores, results
 may be influenced by other lifestyle choices besides the studied diet, such as smoking and
 exercise.Furthermore, the participants in many previous studies were often healthy volunteers
 and not patients with overt cardiovascular disease.

 Purpose

 The objective is to perform an open label, 4 week randomized, cross-over study to compare the
 effect of a vegetarian diet to a conventional (meat containing) diet based on the Swedish
 average meat consumption on a range of parameters with prognostic importance for
 cardiovascular disease: lipids, inflammation, oxidative stress, BMI, HbA1c, apolipoprotein
 B/apolipoprotein A1-ratio, gut microbiota, endothelial function and quality of life. The
 study will be conducted in patients diagnosed with STEMI (ST-segment elevation myocardial
 infarction), non-STEMI (non-ST-segment elevation myocardial infarction) or angina pectoris
 and treated by percutaneous coronary intervention (PCI).

 Hypothesis

 The study hypothesis is that patients diagnosed with IHD can benefit from a vegetarian diet
 as assessed by multiple risk markers for this type of disease with a primary focus on changes
 in oxidized LDL cholesterol.

 Clinical relevance

 During the last decades the global mortality from IHD has remained unchanged regardless of
 development of new invasive and pharmacological treatments. Despite the fact that the
 prevalence and mortality from IHD have decreased in this country since 1990 and that the
 decrease most likely is due to lifestyle changes, IHD remains the leading cause of death in
 Sweden.
Inclusion Criteria:

 -  Stable ischemic heart disease and previous percutaneous coronary intervention (PCI.

 -  Under optimal medical treatment including aspirin and cholesterol lowering drugs
 (statins)

 Exclusion Criteria:

 -  PCI treatment during the last 30 days

 -  Inability to provide informed consent

 -  Already following a vegetarian or a vegan diet

 -  Known vitamin B deficiency

 -  Known food allergy

 -  Previous obesity surgery or gastric bypass surgery

 -  Life expectancy <1 year