University study shows Mediterranean diet not always healthy

New research suggests that people in the poorer areas of Italy, mostly in the south, have more salt in their diets than those in the more affluent north

A new study by a University of Warwick expert indicates that the Mediterranean diet isn’t necessarily healthy.

Francesco Cappuccio, Professor of Cardiovascular Medicine and Epidemiology at the University of Warwick’s Warwick Medical School has conducted 30 years of research into the diets of populations around the world.

Despite Italy being renowned for its healthy Mediterranean diet, his new research suggests that people in the poorer areas of the country, mostly in the south, have more salt in their diets than those in the more affluent north, even taking into account factors such as differences in regional cuisine and salt from sources other than diet.

Professor Cappuccio’s study has recently been published in BMJ Open. He said: 'As an adult you need just 1mg of salt a day but most of us consume eight times that. Dietary salt, primarily sodium chloride, is commonly used for food preservation and seasoning. In most Westernised countries, like the UK, approximately 75% of salt consumed is hidden in processed and restaurant foods whereas only about 15% comes from discretionary use such as added at the table or in cooking by the consumer or food handler and 10% from natural sources.' 'National guidelines advise that adults should eat no more than 6g of salt a day, which is approximately equivalent to one teaspoon and children should eat less. Previous studies show that a 5g per day higher salt intake is associated with a 24% higher risk of stroke,' he added.

Prof. Cappuccio who is a World Health Organisation adviser, is now calling on the government to stop food manufacturers and distributors producing and selling unhealthy, cheap, salty junk food.

He said: 'The 2010 Marmot Review in the UK and work conducted by the World Health Organisation reveal that people from poorer backgrounds not only die sooner but spend more of their lives with disabilities. Inequalities in nutritional and socio-economic status translate ultimately into inequalities in health.'

'The government can do something about this by discouraging manufacturers from producing cheap, salty food and distributors from selling them. These are the types of foods consumed by those on lower incomes because they are inexpensive but ultimately they have a detrimental effect on your health.'

The study, the Geographic and socio-economic variation of sodium and potassium intake in Italy, also unearthed a significant north–south divide. Participants living in less affluent southern Italy (Calabria, Basilicata and Puglia) had significantly higher salt intake than elsewhere. In a previous study, Prof. Cappuccio found similar results across Britain where salt intake is higher further north in Scotland compared with more affluent, southern parts of the British Isles. He believes that his latest study demonstrates that social inequalities in salt intake are a Europe-wide problem.

The research examined 3857 men and women aged between 39-79 years. They were chosen randomly across 20 Italian regions as part of a bigger national cardiovascular survey. The research team measured the amount of sodium in the urine of participants, an indication of salt consumption. They found that across Italy there was an association between salt intake and income and educational attainment. Those in lower skilled jobs had 6.5% more sodium in their urine (high salt consumption) compared with those in top managerial jobs. There was a similar relationship between education as those who were educated to just junior school level ate 5.9% more salt that those with university degrees.

During the past 15 years, the British government conducted one of the most successful salt reduction campaigns in the world with an average reduction of salt consumption of 1.5g a day over eight years. However in research published last year (2014), Professor Cappuccio demonstrated that there is still social inequality.

He said: 'Since 2010-11, with the introduction of the Responsibility Deal – a sharp policy change making food industries responsible for improving nutrition - the sustained action previously exerted on manufacturers to reformulate their food with less salt has slowed down. This setback will undoubtedly lead to wider health inequalities with worse consequences seen in those groups of society who most of all need effective prevention. We now have convincing evidence in Britain and across Europe that more regulatory actions and mandatory enforcements are needed to deliver a reduced-salt environment for all to benefit from.'

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