Speaking at the Vitafoods conference in Geneva yesterday, he told food industry delegates that 80 per cent of salt intake was from processed foods, and that even a modest reduction in salt consumption could save lives.
"The commonest cause of death in Europe is strokes and heart attacks," he said.
"These diseases are totally preventable and are entirely due to diet and lifestyle. 80 per cent of all heart attacks are attributable to high blood pressure. The higher the blood pressure, the greater the risk of dying of a stroke."
He added that the idea that stress causes high blood pressure was "complete and utter nonsense".
"What puts up blood pressure is high salt intake, a lack of fruit and vegetables, weight, a lack of exercise and excessive alcohol. But by far the most important of these factors is salt."
Salt is of course a vital nutrient and is necessary for the body to function. But McGregor claimed that in the western world, an average daily salt consumption of between 10 and 12g is far too high.
"There is more evidence on the link between salt and blood pressure than for any other food constituent," he said. "Reducing salt consumption by 1g a day would reduce strokes in the UK by 5 per cent, which works out as 7,000 deaths a year."
Salt reduction however remains a controversial issue. The Salt Association for example cites a recent study that suggested that eating less salt than the amount recommended by US and UK governments could have adverse cardiovascular effects.
Dr Hillel Cohen, who put together the study with colleagues at the Albert Einstein College of Medicine in New York, theorised that low-sodium could raise the kidneys level of renin, a protein involved with raising blood pressure when sodium levels are low.
But McGregor argued that the evidence linking salt and high blood pressure is overwhelming. And one reason the food industry has such difficulty in accepting this, he claimed, was that a reduction in salt would lead to a loss in revenue, especially the soft drinks sector.
He acknowledged nonetheless that some advances in salt reduction, especially in the UK, had been made. A number of supermarkets had made progress Marks & Spencers salt reduction plan is currently on target, according to the FSA.
However, he attacked the high salt content of a number of foods targeted specifically at children.
"This is an absolute scandal," he told the hall. "I cannot believe we are prepared to feed our kids this rubbish food."
McGregor is heavily involved in the ongoing debate over salt reduction and is chairman of Consensus Action on Salt and Health (CASH).
"Reducing salt intake is the biggest improvement in public health since the introduction of clean water and drains in the 19th century," he said.