The result is that the parties are "ignoring" the real financial problems of the service, according to former NHS chief executive Sir David Nicholson.
Speaking to BBC Radio 4, he said the service was busy building up large financial deficits - but politicians were talking about expanding services, such as providing seven-day working.
He said it caused him "very great concern", warning of vacancy freezes later this year as hospitals hit financial problems.
Both the Conservatives and Liberal Democrats have pledged to increase spending by £8 billion but only by 2020. The figure has been set by NHS England and its chief executive Sir Simon Stevens. Labour has only committed to £2.5 billion and Sir David said it would be "helpful" if Labour agreed to the £8 billion.
NHS England's plan involves achieving some £22 billion of savings in the service, partly through local reorganisations of services, and Sir David said this was a "big ask."
He said: "There is no healthcare system in the world that's delivered this scale. But you could get close.
"But it means actually a united political clinical and managerial leadership in the NHS with a proper debate and discussion with the population about what this all means in practice."
* Rob Webster, chief executive of the NHS Confederation, added: “What is clear is that the gap between demand and resources by 2020 will be at least £30bn – more if you add social care. That can be closed by two means – income and efficiency. With the extra funding set out in the Five Year Forward View, the NHS will need to find unprecedented levels of efficiency savings of at least £22bn. If parties put less in, then we will need to be even more efficient or cut services.
“If we are to succeed, the political parties must be straight with the public about the huge scale of the savings and increases in productivity required over the next parliament. It means we will need to fundamentally change the way we provide care for millions of patients which itself will require funds for “double running” services and investment in estates, IT and innovation.”
This means that all doctors should undergo training throughout their careers in research and teaching skills, according to the British Medical Association.
This would mean that clinically led services would be shaped by the "best available evidence", a report from its medical academic staff committee says.
All doctors would be able to understand and weigh evidence and all career structures should include education and exposure to research, it says.
The NHS, in turn, should value, support, reward and celebrate scientific endeavour.
Committee chair Dr Peter Dangerfield said: “It’s vital for the continued improvement of patient care that all doctors are encouraged and supported to develop their scientific and research skills and expertise throughout their career.
“Clinical academics are clear about the advantages of having a medical workforce where every doctor is a scientist and a scholar, and we hope to persuade managers and leaders in the NHS of its importance.
"There is already a clear link between hospitals which deliver excellent standards of care and the value they place on research."
Synthetic cannabinoids use chemicals similar to cannabis - but "are likely" to trigger damage to human DNA, according to the Austrian researchers.
The substances are being marketed as legal highs and appearing in incense mixtures.
Researchers in Vienna have tested them on human cells in laboratory conditions.
Over a seven-year period, the European Union counted some 240 psychoactive substances disguised as incense blends, bath salts or plant fertilisers. About 140 contained synthetic cannibinoids.
Researcher Siegfried Knasmüller, from the Institute for Cancer Research at the MedUni Vienna, said yesterday: "The substances are directly active, in other words they are not activated via enzymes that metabolise foreign substances.
"The respiratory organs and the digestive tract especially are subjected to increased concentrations of these drugs. Our investigations on human cell lines in the laboratory have shown that synthetic cannabinoids, in the high concentrations found in cells in the oral cavity or in the lungs, for example, are likely to trigger damage to the DNA that may have significant consequences for the consumers of such substances.
"They damage chromosomes, and this is directly associated with cancer."
The Finnish researchers say they sought to eliminate the factors that make it hard to pin-point the direct effect of statins on diabetes risk.
The researchers studied nearly 9,000 men who did not have diabetes at the outset of the research.
They say that accounted for factors such as waist size, alcohol drinking, fitness and smoking before calculating that people who took statins faced a 46% increased risk of developing diabetes.
The risk was also linked to the size of the dose of statins.
The findings were reported in the journal Diabetologia.
Researcher Professor Markku Laakso, of the University of Eastern Finland and Kuopio University Hospital, Finland, said the findings suggested a greater risk of diabetes than earlier reports.
He said: "The association of statin use with increased risk of developing diabetes is most likely directly related to statins decreasing both insulin sensitivity and secretion."
Diabetologia 16 April 2015