10 simple rules to make CVD prevention count

‘Ten ways to make prevention count’, was the succinct title of a keynote address by Prof Rod Jackson to the recent NIPC National Prevention Conference in Galway.

Prof Jackson is in international specialist in the field of cardiovascular disease epidemiology; he is professor of epidemiology at the University of Auckland, New Zealand. His main research interest is to understand and influence trends in CVD event rates at both whole population and individual patient level. He is regarded as one of the leading specialists in the estimation of CVD risk. 

Addressing this theme at the NIPC conference, Prof Jackson gave a plain-speaking address on current issues and challenges facing CVD prevention. Listing the 10 ways he believed would best progress the prevention agenda, he said the first rule was to be optimistic.

Be optimistic

He said those who work in prevention are usually optimistic by nature but this often tended to be superficial, as there was also an underlying feeling that prevention doesn’t work. He said the opposite was in fact the case, pointing to the huge decline in the incidence of coronary heart disease, stroke and all vascular disease in Ireland. There had also been a dramatic general lowering of cholesterol levels. This, said Prof Jackson, clearly showed that in Ireland and many other developed countries CVD prevention was working. 

“People are listening to us. Prevention is working. We can, of course do better, but the changes we have seen are profound.”

He said those involved in prevention need to have a positive attitude and to people who say prevention doesn’t work, ‘just show them the data’.

Keep reducing saturated fat

Prof Jackson’s second message was ‘keep reducing saturated fat consumption’. He said we should not believe the recent media hype about the benefits of fat consumption. 

“You cannot sell a book that says ‘the experts were right. Saturated fat is bad for you’. What sells is a claim that ‘the experts were wrong – saturated fat is good for you’, or claims that all the evidence produced on saturated fat being bad for you was funded by the sugar industry. That sells books, even though 99% of experts still know that saturated fat is a major cause of coronary heart disease.”

Prof Jackson said there was definitive evidence from multiple trials that if you replace dairy fat with for example, sunflower oil, it reduces cholesterol. He said the evidence clearly showed that replacing saturated fats with non-saturated fats reduces LDL cholesterol, which is a major cause of heart disease. 

“The only thing you don’t want to replace saturated fat with is carbohydrate or trans fat. If you reduce LDL you reduce coronary risk.”

However, Prof Jackson said the missing piece from the jigsaw was the availability of long-term randomised trials which take a large group of people, change their saturated fat consumption and try to measure outcomes. The problem here is the difficulty in getting participants to stay on the diets for long enough. 

However, in spite of this there is still a wealth of evidence about the benefits of reducing saturated fat consumption. He emphasised that saturated fat was the underlying cause of coronary heart disease.

Smoking kills

Prof Jackson’s third message was simple-smoking kills.  He pointed to Ireland’s plummeting rates of death from lung cancer,  a disease largely attributable to smoking. He said Ireland was doing an excellent job in reducing smoking, which was a major contributory factor to cancer and heart disease.

Reduce salt, but be aware of levels

Fourthly, he said, it was important to emphasise that reducing salt reduces blood pressure and that there was a direct line between excessive salt consumption and stroke. There was currently some controversy about ‘how low you should go’ with salt consumption.

Prof Jackson rejected recent research claims that we have reduced our salt consumption to a level where we may be causing harm. He questioned the way salt consumption was measured in the data. He said our salt consumption in general, while it had been greatly reduced in recent decades, was still much higher than it should be.

Move more and prioritise prior CVD

His fifth point was the need for people to exercise much more, while number six was the need to actively treat patients with prior CVD as a priority.

Recent data from New Zealand showed that if you take the population aged 30 to 74, and identify those who have been hospitalised in the past with a heart attack or stroke (6% of this age group) over the next five years almost 40% of all heart disease/stroke events and deaths occurred in this percentage group.

He said if community secondary prevention programmes such as the Croi MyAction programme was provided to every one of these people, you could potentially halve the rate of CVD incidents. This would have a significant effect on hospital admission rates. This group of patients, he said, was undertreated but was easy to identify and to target for intervention.

Target those at high risk

Prof Jackson’s seventh point related to targeting patients without prior CVD who are at high risk. He said targeting patients in this category is difficult because potentially, everyone is at risk. “We need to go a step further than looking at individual risk factors, and we need to put them together.”

Prof Jackson stressed the importance of taking into account multiple risk factors, including smoking, high saturated fat intake and low HDL cholesterol. 

“Many people give a definition of hypertension as a BP of 140, but that 140 would mean something completely different if you are a 50-year-old woman with ideal risk factors, compared to someone with multiple risk factors. If you want to target and treat the people who may have risks equivalent to those with prior CVD you need to look at multifactorial risks. If we can identify those very high-risk people we can halve their risk. We need to focus primary prevention on the highest risk people.”

Using statins

Dr Jackson’s eighth point focused on how you treat these high-risk individuals. He said we need to give statins to those at highest risk. Citing a study published by the Oxford Group in The Lancet in 2012, he said there was now definite evidence in favour of high-risk primary prevention using statins. The greatest benefit with statins is shown in people who had very high risk before treatment was initiated, he said.

Blood pressure medication

Prof Jackson’s ninth point was that similarly, with blood pressure treatment, the ‘biggest bang for the buck’ comes from treating people who are at the highest risk.

Dealing with obesity and diabetes

And finally, the 10th point in Prof Jackson’s ‘rules’ was the importance of dealing with obesity and diabetes. This, he admitted, was a difficult area and he felt the reasons for the lack of success in dealing with obesity were very complex.

Recent research, he said, showed that the ideal BMI is somewhere between 20 and 25. Trends across the world show that obesity in English-speaking countries is increasing at a greater rate than in other countries. The mean BMI in these countries is around 27 or 28 while the ideal BMI is 23 to 24. Prof Jackson said he would regard diabetes as just another name for obesity, with BMI rates strongly linked to the risk of developing diabetes.

Ending on a note of optimism, Prof Jackson said in New Zealand, CHD death rates in all age groups are decreasing by around 3% per year – this is 90% lower than the rate in 1967. This meant the average New Zealander was gaining five hours of life expectancy per day. However, there was concern that the impact of increasing obesity and diabetes levels in recent years may stop this mortality decline in its tracks.

The greatest challenge

Prof Jackson said there had been a good deal of success in dealing with most of the challenges he had raised in his 10 points, but the obesity/diabetes issue remained the greatest challenge.

In the discussion session afterwards, Prof Ivan Perry of the Department of Public Health at UCC pointed out that there were some grounds for optimism on obesity. He said recent evidence indicated that overweight and obesity prevalence rates in Ireland have stabilised somewhat in recent years in both adults and children. 

As yet unpublished research carried out in his department at UCC and the Cork University Dental School and Hospital showed that obesity in children had peaked in the early 2000s, and there had been a small but significant fall in obesity in children aged 3 to 14 between 2002 and 2014. He said while there was still a long way to go on tackling obesity levels in Ireland, there were now some grounds for optimism.

The discussion heard of the difficulties doctors face in raising the issue of overweight and obesity with patients.

Prof Jackson said that what was really needed was a political solution to the obesity problem. This would come about through specific taxation and regulation measures taken by governments. “We have to deal with the junk food manufacturers.  We need to be treating them like the tobacco companies.”