Could bacteria have triggered our heart attack epidemic
22:43 GMT, 12 March 2012
Good news at last – deaths from heart attacks are down and falling fast, according to research from Oxford University published a few weeks ago.
This showed the death rate has dropped by an extraordinary 50 per cent in just ten years. There were also fewer heart attacks.
The researchers said half the decline was because we’ve cut back on smoking and take statins to lower cholesterol. The other half they put down to better emergency care.
Deaths from heart attacks are down and falling fast, according to research from Oxford University
But this comes as something of a surprise because as a population we are actually getting unhealthier: our rates of diabetes and obesity are soaring and they push up heart disease risk. What’s more, even if we aren’t obese or have diabetes, 60 per cent of us don’t take nearly enough exercise and we are still eating too much heart-clogging fat and sugar. So could there be some other reason for the fall in deaths from heart attacks
‘The Department of Health naturally wants to claim the drop in heart attacks shows their prevention strategies are working,’ says Edwin Gale, emeritus professor of clinical sciences at the University of Bristol. ‘But it does look as if the benefits of bringing down risk factors like high blood pressure, raised cholesterol and too much fat and sugar could be riding on an existing downward trend.’
Professor Gale is referring to the fact that deaths from heart attacks have been dropping for decades and some experts say they don’t really know why. When it comes to prevention, it’s widely agreed that bringing down blood pressure and stopping smoking have helped to lower risk, but there is disagreement about just how important cholesterol, obesity and exercise are.
Japanese scientists found periodontal bacteria in blood clots of patients who had suffered a heart attack (stock picture)
Some suggest our current obsession with
these means we’re in danger of ignoring the part played by other factors
such as stress and microbial infection. The mystery of the falling heart attack figures has been investigated by Dr James Le Fanu, a leading GP and author.
‘People generally assume heart attacks have been around for ever,’ he says. ‘In fact, they haven’t. They first appeared on the medical radar in the 1930s and by the end of the war the number of deaths they caused had shot up ten times.’ They kept on rising until the end of the 1960s when, just as mysteriously, they started to decline. ‘Low-fat diet became the big explanation by the 1970s,’ says Le Fanu. ‘But it’s not convincing.’
As he shows in his book, The Rise And Fall Of Modern Medicine, fat consumption in various countries stayed at around 40g daily between 1960 and 1980, while deaths from heart attacks fell. It is only slightly lower in the UK now.
So what caused the rise in the first place Le Fanu suggests it could be due to a microbial infection. ‘The pattern of a fast rise in deaths and then a decline is typical of an infectious epidemic,’ he says. One possible culprit is the bacteria in the mouth that normally cause gum decay (known as periodontal bacteria). Inflammation is a feature of heart disease and the body responds to infection with inflammation.
Just last month the American Heart Journal reported that Japanese scientists had found periodontal bacteria in blood clots of patients who had suffered a heart attack. ‘These bacteria might have a role in plaque inflammation and instability,’ commented the lead researcher. Other studies have found similar links, although exactly how the process works is unclear.
‘It is tempting to speculate that the rise and fall in heart attacks may be due to differences in the rates of infection,’ says Dr Yoon Loke, senior lecturer in clinical pharmacology at the University of East Anglia medical school. Another more controversial theory is that the decline in deaths since the Sixties is linked to stress: as the very high stress levels caused by the Great Depression and then World War II dropped away, so did heart attack deaths, goes the thinking.
There is little denying that stress can be dangerous. Several years ago, a large study of more than 24,000 people published in The Lancet recorded: ‘Persistent severe stress makes it two-and-a-half times more likely that an individual will have a heart attack compared with someone who is not stressed.’
Dr Malcolm Kendrick, a GP and author of The Great Cholesterol Con, argues that stress is an ignored factor in heart disease. ‘We are not talking about a stressful day at the sales,’ he says. ‘But you see a fast rise in deaths from heart disease in war zones and places where there has been major social breakdown, like the Soviet Union after the Berlin Wall came down. Compared to that, social conditions in Europe and the U.S., where heart attack rates are falling, have been pretty stable.’
You see a fast rise in deaths from heart
disease in war zones and places where there has been major social
The British Heart Foundation (BHF) denies there is anything mysterious going on. It concurs with the Oxford researchers, saying that half the decline in deaths is down to improved emergency treatment and that the rest is due to people following the standard advice for cutting heart risk.
More recently, that includes taking statins, the drugs that lower cholesterol. Indeed, the BHF suggests statins might have saved us from the effects of rising obesity and diabetes. ‘The late 1980s was also the time that obesity and type 2 diabetes rates began to rise,’ says a spokesman. ‘It’s a plausible hypothesis that, without the introduction of statins, we could now be looking at an increasing rise in heart attack deaths rather than a fall.’
Remarkably, in fact, the BHF claims certain lifestyle changes such as eating a low-fat diet, keeping your weight down and exercising have never had much effect. This may come as a shock to anyone who’s been watching what they eat, taking measures such as removing the skin from roast chicken.
‘Compared with cutting smoking, and lowering hypertension (high blood pressure) and cholesterol levels, obesity, fat consumption and exercise have a relatively weak influence on the risk of coronary heart disease,’ says the BHF.
Other experts don’t agree that statins have been that successful, or that relying on drugs is the best way to keep us healthy. Two major recent studies have found that as many as 1,000 otherwise healthy people have to take them for just one person to avoid dying from a heart attack.
‘Drugs can be beneficial if you’re ill or have a seriously raised risk, but many people are being over-diagnosed and over-medicalised,’ says Professor Gale. ‘The best advice for staying healthy is to remain slim and eat sparingly but well, take exercise and swallow as few pills as you can.’
This means there still seems to room for debate about what exactly has been cutting deaths from heart attacks. So apart from taking steps to handle stress better and maybe being more aware of the risks of gum disease, what else should you be doing
If a low-fat diet isn’t the solution, maybe a low-carbohydrate one will turn out to be more effective. It certainly seems to be better for keeping blood sugar down. High blood sugar is one of the factors fuelling the rapid rise in diabetes. Finding how best to avoid developing heart disease in the first place is still important because even if you don’t die from a heart attack thanks to excellent emergency care, you may be at risk of other things, says Dr Loke.
‘Heart attack survivors are much more likely to die from a nasty debilitating condition called heart failure.’ This causes extreme tiredness and weakness, breathlessness and swelling in the legs, ankles and feet. Dr Loke warns: ‘Over two million people are living with heart failure in the UK and the number is rising.’