Wednesday, April 06, 2011

Dietary potassium intake prevents stroke (?)

These meta-analyses are only as good as the data input and, given past inconsistent results, just averaging the results is pretty brainless. One needs to look at the comparative quality of the studies to arrive at an intelligent conclusion. What would an average of 5 poor studies and one good study tell you?

Eating three bananas cuts your risk of a stroke, scientists say. A banana for breakfast, one for lunch and one in the evening would provide enough potassium to reduce the chances of suffering a blood clot on the brain by around 21 per cent.

The findings, by British and Italian researchers, suggest thousands of strokes could be prevented by the consumption of other potassium-rich foods such as spinach, nuts, milk, fish and lentils.

Although some previous studies have suggested bananas could be important for controlling blood pressure and preventing strokes, results have not always been consistent.

In the latest research, published in the Journal of the American College of Cardiology, scientists analysed data from eleven different studies - dating back to the mid-Sixties - and pooled the results to get an overall outcome.

They found a daily potassium intake of around 1,600 milligrammes, less than half the UK recommended daily amount for an adult of 3,500mg, was enough to lower stroke risk by more than a fifth.

The average banana contains around 500 milligrammes of potassium, which helps to lower blood pressure and controls the balance of fluids in the body. Too little potassium can lead to an irregular heartbeat, irritability, nausea and diarrhoea.

Researchers from the University of Warwick and the University of Naples said potassium intake in most countries is well below the recommended daily amount. But if consumers ate more potassium-rich foods and also reduced their salt intake, the annual global death toll from strokes could be cut by more than a million a year. Researchers said in their report: 'It would translate into a reduction of as many as 1,155,000 stroke deaths a year on a worldwide scale.'

Strokes, which are usually caused when a clot forms and blocks the blood supply to the brain, kill around 200 people every day in the UK. Many more are left disabled and in danger of a second or even third attack which could kill them. Treating and looking after the 100,000 people affected by strokes each year in the UK costs the NHS an estimated £2.3 billion. Only cancer and heart disease kill more people.

A spokesman for the Stroke Association said: 'This research suggests eating lots of potassium-rich foods, such as bananas, dates and spinach, could reduce your risk of having a stroke. 'High blood pressure is the single biggest risk factor for stroke and past research has indicated that potassium could help to lower blood pressure. 'This could go some way to explain the positive effects of potassium demonstrated in this study.'


Egyptian mummies show that fast food is not the culprit for clogged arteries

The pressures of modern living are regularly held responsible for causing heart attacks and strokes. But it seems these afflictions are not solely by-products of our hectic times.

Scientists yesterday announced they had detected the first known case of clogged arteries - or atherosclerosis - in the mummy of an Egyptian princess who lived 3,500 years ago.

It has long been known that ancient Egyptians suffered from plaque built-up in the arteries, but a University of California, Irvine-led study has concluded that the condition was far more prevalent than previously thought.

Lead researcher Dr Gregory Thomas said: 'Atherosclerosis is widespread among modern day humans and, despite differences in ancient and modern lifestyles, we found that it was rather common in ancient Egyptians of high socio-economic status living more than three millennia ago.'

Researchers performed computerised tomography (CT) scans, with particular attention to the cardiovascular system, on 52 Egyptian mummies to determine whether they had atherosclerosis.

Of the 44 that had detectable arteries or hearts, 45 per cent of them had calcium build-ups in their vessel walls.

The oldest among them was Lady Rai, an Egyptian princess who lived between 1580 and 1550 BC. The researchers believe she probably died when she was in her early 40s.

The nursemaid to Queen Ahmose-Nefertari, she lived about 300 years prior to the time of Moses and 200 years before King Tutankhamun.
Healthier lifestyle? Of the 44 Egyptian mummies scanned that had detectable arteries or hearts, 45 per cent of them had calcium build-ups in their vessel walls

Healthier lifestyle? Of the 44 Egyptian mummies scanned that had detectable arteries or hearts, 45 per cent of them had calcium build-ups in their vessel walls

All the mummies whose identities could be discerned were of high socio-economic status, generally serving in the Pharaoh's court or as priests or priestesses.

The diets of individual mummies could not be determined, but it was common at the time - especially among the upper classes - to eat meat in the form of cattle, ducks and geese.

But even though ancient Egyptians ate a leaner diet, and obviously did not smoke cigarettes, they ended up with the same disease as modern humans.

But that does not mean people should disregard modern research, warned the University of Cairo's Adel Allam, the co-author of the study. He said: 'Recent studies have shown that by not smoking, having a lower blood pressure and a lower cholesterol level, calcification of our arteries is delayed. 'On the other hand, from what we can tell from this study, humans are predisposed to atherosclerosis, so it behoves us to take the proper measures necessary to delay it as long as we can.'

Dr Thomas added: 'While we do not know whether atherosclerosis caused the demise of any of the mummies in the study, we can confirm that the disease was present in many. 'Our findings suggest that we may have to look beyond modern risk factors to fully understand the disease.'


1 comment:

Anonymous said...

The mummified remains belong to the wealthiest of ancient Egyptians. Skin fold analysis of some of these preserved bodies indicates that many of them were extremely fat. It seems that even in the absence of hamburgers it is possible to eat too much. Of course we have no way of knowing what poor Egyptians died of several thousand years ago. Oh and all of these people will have inhaled a great deal of smoke, cooking, heating, lighting and many rituals will all have utilised fire. Not tobacco smoke, but smoke nonetheless.