Cardiologists are advising caution over new research showing that being obese could actually help improve the chances of survival after a heart attack.
The studies, led by a British Heart Foundation research fellow, Charalambos Antoniades, in-volved the analysis of tissue collected from patients undergoing heart surgery and concluded that the fat surrounding blood vessels could help fight heart disease.
Previously, scientists were puzzled over why the most overweight people lived longer after a heart attack than those with a healthy body mass index (BMI), a phenomenon dubbed “the obesity paradox”.
Alex Manché, chairman of the Cardiac Services Department, said he has always observed how the arteries that supply our heart muscle are surrounded by fat that sits on the outer layer of the muscle.
“Sometimes, the whole heart is covered with horrible-looking fat that completely obscures the muscle underneath. This situation is not uncommon in long-standing or uncontrolled diabetics. Whether this fat is a manifestation of advanced disease, or whether – as this research suggests – it represents the body’s defence against advancing disease has always been a mystery to me. I only get to see the ones with advanced disease, when they come to surgery.”
Obese patients have an increased risk of morbidity and mortality. For the time being, we cannot change our advice regarding lifestyle measures
Mr Manché agreed that the perception of fat has been changing over the years. There are many healthy fats and proteins that humans have thrived and evolved on. On the other hand, he continued, given our present sedentary lifestyles, carbohydrates can lead to trouble when consumed in excess.
Also, not all fat is the same. Abdominal fat that expands our waistline is known to be toxic, whereas fat deposited around the thighs and buttocks is not so bad.
Mr Manché said the obesity survival paradox is a more complex phenomenon. In certain critical situations, like undergoing a heart bypass operation or going on kidney dialysis, patients with a higher BMI have better survival expectancy, he added.
“But whether one should have these situations as one’s goal is certainly not advisable, at least in my book!”
Robert Xuereb, chairman of the Cardiology Department, is sceptical of the study, pointing out that the research – which has not yet been published as a paper – is not based on robust and evidence-based studies.
According to Prof. Antoniades, fat surrounding narrowed coronary arteries releases anti-inflammatory chemicals, which have a protective effect.
However, it is not clear which types of fat surrounding the blood vessels are actually protective and in what exact amounts, Dr Xuereb pointed out.
Undoubtedly, further research is needed to confirm this finding. Once confirmed, further studies will be required to find out how to enhance this “good fat” surrounding our arteries.
What is known is that obesity is associated with numerous other problems including heart disease, type two diabetes, high blood pressure, high cholesterol, certain cancers and sleep apnoea or sleep-disordered breathing.
“Obese patients have an increased risk of morbidity and mortality and a reduced life expectancy. Consequently, for the time being, we cannot change our advice regarding lifestyle measures to prevent coronary artery disease. We must strongly encourage our patients to lead a healthy lifestyle, to eat healthily, to exercise daily and to avoiding smoking, including second-hand smoke,” Dr Xuereb said.
kim.dalli@timesofmalta.com