A study published in the British Medical Journal on September 4, 2019, states that a vegetarian diet could well be good for an individual's heart.
This study conducted by the University of Oxford chose 48,188 participants on the basis of their food eating habits and continued following them up for 18 years.
They only included participants between the ages of 21-89 and those residing in Great Britain bearing NHS identification numbers.
None of the participants had a history of heart problems. Around 24,000 of the respondents consumed meat, 7,500 consumed fish but did not consume meat, and 16,000 who were vegetarians or vegans.
The participants were given a questionnaire to understand their dietary preferences, their socio-demographic characteristics which include age, education, gender, lifestyle factors such as smoking and alcohol consumption, physical exercise at the beginning of the study and in 2010.
NHS numbers of the participants were tracked and incidences (number of new cases) of ischaemic heart disease and stroke were tracked.
Findings of the study
The study finds that around 13% of fish-eaters and 22% of vegetarians and vegans had lower rates of ischaemic heart disease as compared to meat eaters. 10 fewer cases of ischaemic heart disease in 1000 population were observed in vegetarians.
On the flip side, vegetarians had 20% higher rates of total strokes than meat consumers. 3 more cases of stroke per 1000 population were observed in vegetarians.
Professors from Deakin University, Australia urged for more reasech in the area of vegetarianism leading to a higher risk for stroke. They stated that it was necessary for this study to be replicated.
For both the findings, the socio-demographic, the lifestyle and the biological characteristics were controlled during the analysis.
This implies that a causative relationship between factors other than diet cannot be established in this study.
Ischaemic Heart Disease
Ischaemic Heart Disease is the reduced supply of blood to the heart.
The artery providing blood from the heart either starts narrowing or closes altogether disrupting the flow of blood to the body. This leads to the walls of the muscles rupturing further leading to a heart attack.
Many studies have been conducted on lifestyle factors affecting heart attacks, but this study is the first one to conduct an 18 year follow up and understand the incidence of heart attack.
Strokes are of two types. This study examines both the types.
A total stroke is when blood supply to an area of the brain is cut off. The brain cells are oxygen deprived and begin to die.
Hemorrhagic stroke is when one of the arteries ruptures and bleeds into the brain. The damaged area ceases to function normally.
There aren't enough studies substantiating the effect of a vegetarian or vegan diet on the occurrence of a stroke.
Health Burden and Mortality
Cardiovascular diseases are the leading causes of death, globally.
About 17.9 million people died in 2016 due to cardiovascular diseases globally, according to the WHO. These represented 31% of deaths that year.
85% of these deaths are either due to heart attacks or strokes.
The WHO Director General, Dr. Tedros Ghebreyesus tweeted confirming that cardiovascular diseases are the leading causes of death and that the WHO has even updated its risk charts.
India had 2.1 million deaths due to cardiovascular diseases in 2015 of which 0.9 million were heart attacks by ischaemic heart disease and 0.4 million were by stroke.
This study was an attempt to ascertain the nation wide mortality rate due to cardiovascular diseases for the Million Death Study project set up by the Registrar General of India (RGI) in collaboration with global health experts to investigate the causes of deaths in India using nationally representative survey data.
Prior to this study, the country lacked data on the deaths due to cardiovascular disorders.