OLIVE OIL AND SALAD COMBINED MAY EXPLAIN THE MEDITERRANEAN DIET SUCCESS

Olive oil and salad combined 'explain' Med diet success

By Michelle RobertsHealth editor, BBC News online

The combination of olive oil and leafy salad or vegetables is what gives the Mediterranean diet its healthy edge, say scientists.

When these two food groups come together they form nitro fatty acids which lower blood pressure, they told PNAS journal.

The unsaturated fat in olive oil joins forces with the nitrite in the vegetables, the study of mice suggests.

Nuts and avocados along with vegetables should work too, they say.

Inspired by traditional cuisine of countries such as Greece, Spain and Italy, the Mediterranean diet has long been associated with good health and fit hearts.

Typically, it consists of an abundance of vegetables, fresh fruit, wholegrain cereals, olive oil and nuts, as well as poultry and fish, rather than lots of red meat and butter or animal fats.

While each component of the Mediterranean diet has obvious nutritional benefits, researchers have been puzzled about what precisely makes the diet as a whole so healthy.

Chemical reaction

Prof Philip Eaton, from King's College London, and colleagues from the University of California in the US believe it is the fusion of the diet's ingredients that make nitro fatty acids.

In their study, part-funded by the British Heart Foundation, the researchers used genetically engineered mice to see what impact nitro fatty acids had on the body.

Nitro fatty acids helped lower blood pressure by blocking an enzyme called epoxide hydrolase.

Prof Eaton said: "Humans have this same enzyme so we think the same happens in people."

This explains why a Mediterranean diet is healthy, even though it contains fat, he says.

"With the fats in the Med diet, if taken together with nitrates or nitrites, there's a chemical reaction and these combine to form nitro fatty acids.

"It's nature's protective mechanism. If we can tap into this we could make new drugs for treating high blood pressure and preventing heart disease," he said.

He said human trials were planned.

Dr Sanjay Thakrar of the British Heart Foundation said: "This interesting study goes some way to explain why a Mediterranean diet appears to be good for your heart health. The results showed a way in which a particular compound could combat high blood pressure, which is a major risk factor for heart disease.

"However, more work is necessary as these experiments were conducted in mice and this compound could also be having its effect through other pathways."

BAD SLEEP ALTERS THE BADY DRAMATICALLY

Bad sleep 'dramatically' alters body

By James GallagherHealth and science reporter, BBC News

A run of poor sleep can have a potentially profound effect on the internal workings of the human body, say UK researchers.

The activity of hundreds of genes was altered when people's sleep was cut to less than six hours a day for a week.

Writing in the journal PNAS, the researchers said the results helped explain how poor sleep damaged health.

Heart disease, diabetes, obesity and poor brain function have all been linked to substandard sleep.

What missing hours in bed actually does to alter health, however, is unknown.

So researchers at the University of Surrey analysed the blood of 26 people after they had had plenty of sleep, up to 10 hours each night for a week, and compared the results with samples after a week of fewer than six hours a night.

More than 700 genes were altered by the shift. Each contains the instructions for building a protein, so those that became more active produced more proteins - changing the chemistry of the body.

Meanwhile the natural body clock was disturbed - some genes naturally wax and wane in activity through the day, but this effect was dulled by sleep deprivation.

Prof Colin Smith, from the University of Surrey, told the BBC: "There was quite a dramatic change in activity in many different kinds of genes."

Areas such as the immune system and how the body responds to damage and stress were affected.

Prof Smith added: "Clearly sleep is critical to rebuilding the body and maintaining a functional state, all kinds of damage appear to occur - hinting at what may lead to ill health.

"If we can't actually replenish and replace new cells, then that's going to lead to degenerative diseases."

He said many people may be even more sleep deprived in their daily lives than those in the study - suggesting these changes may be common.

Dr Akhilesh Reddy, a specialist in the body clock at the University of Cambridge, said the study was "interesting".

He said the key findings were the effects on inflammation and the immune system as it was possible to see a link between those effects and health problems such as diabetes.

The findings also tie into research attempting to do away with sleep, such as by finding a drug that could eliminate the effects of sleep deprivation.

Dr Reddy said: "We don't know what the switch is that causes all these changes, but theoretically if you could switch it on or off, you might be able to get away without sleep.

"But my feeling is that sleep is fundamentally important to regenerating all cells."