Canada's doctors told to stop using swine flu vaccine

GlaxoSmithKline has advised doctors in Canada to stop using a batch of its swine flu vaccine, amid reports of severe side-effects in some patients.

The batch of some 170,000 doses was put on hold because of the reported higher than usual number of patients having anaphylactic reactions.

This may include breathing problems, raised heart rate and skin rashes.

The pharmaceutical company said it was investigating the reports, which could lead to the withdrawal of the batch.

The reports say one in 20,000 people suffered adverse reactions to the batch of GlaxoSmithKline's Aperanix vaccine.

Aspirin 'only for heart patients'

Low dose aspirin is widely given to people who have had heart problems
The use of aspirin to ward off heart attacks and strokes in those who do not have obvious cardiovascular disease should be abandoned, researchers say.

The Drugs and Therapeutics Bulletin (DTB) study says aspirin can cause serious internal bleeding and does not prevent cardiovascular disease deaths.

It says doctors should review all patients currently taking the drug for prevention of heart disease.
The Royal College of GPs says it supports the DTB's recommendations.
Low-dose aspirin is widely used to prevent further episodes of cardiovascular disease in people who have already had problems such as a heart attack or stroke.

Given the evidence, the DTB's statement on aspirin prescription is a sensible one
Prof Steve Field, Royal College of GPs

This approach - known as secondary prevention - is well-established and has confirmed benefits.
But many thousands of people in the UK are believed to be taking aspirin as a protective measure before they have any heart symptoms.

Controlled trials
Between 2005 and 2008, the DTB said four sets of guidelines were published recommending aspirin for the "primary prevention" of cardiovascular disease - in patients who had shown no sign of the disease.

These included people aged 50 and older with type 2 diabetes and those with high blood pressure.
But the DTB said a recent analysis of six controlled trials involving a total of 95,000 patients published in the journal the Lancet does not back up the routine use of aspirin in these patients because of the risk of serious gastrointestinal bleeds and the negligible impact it has on curbing death rates.

Dr Ike Ikeanacho, editor of the DTB, said: "Current evidence for primary prevention suggests the benefits and harms of aspirin in this setting may be more finely balanced than previously thought, even in individuals estimated to be at high risk of experiencing cardiovascular events, including those with diabetes or elevated blood pressure."

'Sensible statement'
Professor Steve Field, chairman of the Royal College of General Practitioners, said the DTB was an excellent source of independent advice for medical professionals.
He said: "Given the evidence, the DTB's statement on aspirin prescription is a sensible one.
"The Royal College of General Practitioners would support their call for existing guidelines on aspirin prescription to be amended, and for a review of patients currently taking aspirin for prevention."

June Davison, senior cardiac nurse at the British Heart Foundation said: "It is well established that aspirin can help prevent heart attacks and strokes among people with heart and circulatory disease - so this group of people should continue to take aspirin as prescribed by their doctor.

"However, for those who do not have heart and circulatory disease the risk of serious bleeding outweighs the potential preventative benefits of taking aspirin.
"We advise people not to take aspirin daily, unless they check with their doctor.
"The best way to reduce your risk of developing this disease is to avoid smoking, eat a diet low in saturated fat and rich in fruit and vegetables and take regular physical activity."

Schoolgirl dies after cancer jab

The vaccine works by making girls immune to strains of a STI
A 14-year-old girl has died after being given a cervical cancer jab as part of a national immunisation programme, but the exact cause of death is unknown.
The pupil was taken ill at Blue Coat CofE School in Coventry shortly after she received the Cervarix vaccine. She died in the town's University Hospital.
The batch of the vaccine used has been quarantined by the local NHS.
The injection offers protection against a sexually transmitted disease, which is linked to most cervical cancers.
A routine programme of vaccinating 12- and 13-year-old girls started in September 2008 across the UK using the Cervarix vaccine made by GlaxoSmithKline. A catch-up campaign is now under way for older girls.
The injection offers protection against the human papilloma virus (HPV), the most common cause of cervical cancer.
'Urgent investigation'
The girl, who has not yet been named, died at lunchtime on Monday.

We are conducting an urgent and full investigation into the events surrounding this tragedy
Dr Caron Grainger
Dr Caron Grainger, joint director of public health for NHS Coventry and Coventry City Council, said their sympathies are with the girl's family and friends.
She said: "The incident happened shortly after the girl had received her HPV vaccine in the school. No link can be made between the death and the vaccine until all the facts are known and a post-mortem takes place.
"We are conducting an urgent and full investigation into the events surrounding this tragedy."
A small number of girls at the school had also reported mild symptoms such as dizziness and nausea but they were not admitted to hospital.
In a statement posted on the school's website, headteacher Dr Julie Roberts said during the immunisation, "one of the girls suffered a rare, but extreme reaction to the vaccine".
"A number of other girls also reported being unwell and some were sent home," she said.
"If your daughter has received a vaccine today we ask that you are extra vigilant regarding any signs or symptoms."
She listed possible reactions as mild to moderate short-lasting pain at the injection site, headache, muscle pain, fatigue and a low-grade fever.
'Tragic death'
It is thought about a million girls have already safely received the vaccine.
When the national immunisation project was announced, there was some controversy about the selection of Cervarix over Gardasil, which is used by the majority of vaccination programmes worldwide.

It is important we have the results of further investigations as soon as possible to establish the cause of this sad event
Department of Health

Q&A: The cervical cancer vaccine
Dr Pim Kon, medical director at GlaxoSmithKline UK, which makes Cervarix, said: "Our deepest sympathies are with the family and friends of the young girl.
"We are working with the Department of Health and MHRA (Medicines and Healthcare products Regulatory Agency) to better understand this case, as at this stage the exact cause of this tragic death is unknown."
The global pharmaceutical company added that the vast majority of suspected adverse reactions have related either to the symptoms of recognised side effects or were due to the injection process and not the vaccine itself.
Different vaccine
Public health minister Gillian Merron said: "Our deepest sympathies are with the family. It is important we have the results of further investigations as soon as possible to establish the cause of this sad event."
In the UK, about 3,000 women are diagnosed with cervical cancer every year and about 1,000 die from it.
The department said Cervarix had a strong safety record.
Shadow Health Secretary Andrew Lansley said the tragedy needed to be investigated "as a matter of urgency".
He said: "This again raises the question which we have asked for some time, as to why the government won't publish the assessments it made of the relative merits of the two HPV vaccines and why we therefore use a different vaccine to most other comparable countries."
There are more than 100 types of HPV but only 13 of them are known to cause cancer.
Cervarix protects against two strains of HPV that cause more than 70% of cases of cervical cancer in women.
Vaccination is not compulsory and consent is required before it is administered to the under-16s.

Could a fat jab ease chronic knee pain?

By PAT HAGAN

Tiny globules of fat that are injected into painful joints could be a radical new treatment for osteoarthritis.
Thousands of the fat particles - each one no bigger than a speck of dust - are injected to protect the cartilage inside the joint from further damage.

Cartilage is the spongy material in the hips, knees, spine, wrists and shoulders that acts as the body's shock absorber, stopping the bones rubbing together.

'Holy grail': Chronic knee pain could be eased by injecting tiny globules of fat into the joint
But injury, illness or wear and tear can cause the cartilage to start breaking down. As bones come into contact, the friction makes the joints swollen and painful.

Around eight million Britons suffer from osteoarthritis. Many rely on anti-inflammatory painkillers though these carry the risk of damage to the stomach if used long term.
Every year, thousands of patients end up having joint replacement surgery.
The scientists who have developed the fat jab hope it will prevent the need for this surgery, or at least postpone it for several years.

The fat molecules, which are manufactured in a laboratory, are soft enough to help cushion the impact from everyday activities, but strong enough not to be destroyed under the strain of a working joint.
The treatment was developed in Israel by scientists at the Hebrew University of Jerusalem and the Technion Institute of Technology.

In tests, the scientists injected the fat particles into hip joints.
The results, published in the arthritis journal Wear, showed the fat jabs reduced the rate of cartilage destruction by 40 per cent compared with 10 per cent with an existing therapy, hyaluronic acid.
(Hyaluronic acid is sometimes injected into damaged joints to help keep cartilage lubricated and spongy.)

The fat jabs are a form of nanotechnology - a technique using moleculesso small they can't be seen with the naked eye, yet which are capable of delivering powerful medicines or treatments deep inside the body. This stops healthy tissue being exposed to the potential side-effects.

The size of the molecules also means they can't be detected by the body's defence systems so they won't be cleared away.
The molecules developed for the new arthritis treatment are no more than one millionth of a millimetre in diameter and are engineered to pass into the cells within the joint, something previously not possible.

Professor Philip Conaghan, from the Arthritis Research Campaign, said a treatment that stopped cartilage breakdown was the 'holy grail' for osteoarthritis researchers.
But he said there was no guarantee this would actually reduce pain.
'One of the complexities is that we're not sure whether the pain comes from the bone underlying the cartilage or inflammation in the tissue lining the joints.
'So we should be careful about thinking that a treatment that reduces cartilage loss will necessarily improve pain. But we all hope it will.'

Heart Surgeon Admits Huge Mistake!

by Dwight Lundell MD 02/03/2009
We physicians with all our training, knowledge and authority often acquire a rather large ego that tends to make it difficult to admit we are wrong. So, here it is. I freely admit to being wrong. As a heart surgeon with 25 years experience, having performed over 5,000 open-heart surgeries, today is my day to right the wrong with medical and scientific fact.

I trained for many years with other prominent physicians labeled “opinion makers.” Bombarded with scientific literature, continually attending education seminars, we opinion makers insisted heart disease resulted from the simple fact of elevated blood cholesterol.

The only accepted therapy was prescribing medications to lower cholesterol and a diet that severely restricted fat intake. The latter of course we insisted would lower cholesterol and heart disease. Deviations from these recommendations were considered heresy and could quite possibly result in malpractice.

It Is Not Working!

These recommendations are no longer scientifically or morally defensible. The discovery a few years ago that inflammation in the artery wall is the real cause of heart disease is slowly leading to a paradigm shift in how heart disease and other chronic ailments will be treated.

The long-established dietary recommendations have created epidemics of obesity and diabetes, the consequences of which dwarf any historical plague in terms of mortality, human suffering and dire economic consequences.

Despite the fact that 25% of the population takes expensive statin medications and despite the fact we have reduced the fat content of our diets, more Americans will die this year of heart disease than ever before.

Statistics from the American Heart Association show that 75 million Americans currently suffer from heart disease, 20 million have diabetes and 57 million have pre-diabetes. These disorders are affecting younger and younger people in greater numbers every year.

Simply stated, without inflammation being present in the body, there is no way that cholesterol would accumulate in the wall of the blood vessel and cause heart disease and strokes. Without inflammation, cholesterol would move freely throughout the body as nature intended. It is inflammation that causes cholesterol to become trapped.

Inflammation is not complicated — it is quite simply your body’s natural defense to a foreign invader such as a bacteria, toxin or virus. The cycle of inflammation is perfect in how it protects your body from these bacterial and viral invaders. However, if we chronically expose the body to injury by toxins or foods the human body was never designed to process, a condition occurs called chronic inflammation. Chronic inflammation is just as harmful as acute inflammation is beneficial.

What thoughtful person would willfully expose himself repeatedly to foods or other substances that are known to cause injury to the body? Well, smokers perhaps, but at least they made that choice willfully.

The rest of us have simply followed the recommended mainstream diet that is low in fat and high in polyunsaturated fats and carbohydrates, not knowing we were causing repeated injury to our blood vessels. This repeated injury creates chronic inflammation leading to heart disease, stroke, diabetes and obesity. Let me repeat that. The injury and inflammation in our blood vessels is caused by the low fat diet that has been recommended for years by mainstream medicine.

What are the biggest culprits of chronic inflammation? Quite simply, they are the overload of simple, highly processed carbohydrates (sugar, flour and all the products made from them) and the excess consumption of omega-6 vegetable oils like soybean, corn and sunflower that are found in many processed foods.

Coffee 'may reverse Alzheimer's'

A possible treatment for dementia?
Drinking five cups of coffee a day could reverse memory problems seen in Alzheimer's disease, US scientists say.
The Florida research, carried out on mice, also suggested caffeine hampered the production of the protein plaques which are the hallmark of the disease.
Previous research has also suggested a protective effect from caffeine.
But British experts said the Journal of Alzheimer's disease study did not mean that dementia patients should start using caffeine supplements.

The results are particularly exciting in that a reversal of pre-existing memory impairment is more difficult to achieve
Dr Gary Arendash
University of South Florida
The 55 mice used in the University of South Florida study had been bred to develop symptoms of Alzheimer's disease.
First the researchers used behavioural tests to confirm the mice were exhibiting signs of memory impairment when they were aged 18 to 19 months, the equivalent to humans being about 70.
Then they gave half the mice caffeine in their drinking water. The rest were given plain water.
The mice were given the equivalent of five 8 oz (227 grams) cups of coffee a day - about 500 milligrams of caffeine.
The researchers say this is the same as is found in two cups of "specialty" coffees such as lattes or cappuccinos from coffee shops, 14 cups of tea, or 20 soft drinks.
When the mice were tested again after two months, those who were given the caffeine performed much better on tests measuring their memory and thinking skills and performed as well as mice of the same age without dementia.
Those drinking plain water continued to do poorly on the tests.
In addition, the brains of the mice given caffeine showed nearly a 50% reduction in levels of the beta amyloid protein, which forms destructive clumps in the brains of dementia patients.
Further tests suggested caffeine affects the production of both the enzymes needed to produce beta amyloid.
The researchers also suggest that caffeine suppresses inflammatory changes in the brain that lead to an overabundance of the protein.
Earlier research by the same team had shown younger mice, who had also been bred to develop Alzheimer's but who were given caffeine in their early adulthood, were protected against the onset of memory problems.
'Safe drug'
Dr Gary Arendash, who led the latest study, told the BBC: "The results are particularly exciting in that a reversal of pre-existing memory impairment is more difficult to achieve.
"They provide evidence that caffeine could be a viable 'treatment' for established Alzheimer's disease and not simply a protective strategy.
"That's important because caffeine is a safe drug for most people, it easily enters the brain, and it appears to directly affect the disease process."
The team now hope to begin human trials of caffeine to see if the mouse findings are replicated in people.
They do not know if a lower amount of caffeine would be as effective, but said most people could safely consume the 500 milligrams per day.
However they said people with high blood pressure, and pregnant women, should limit their daily caffeine intake.
Rebecca Wood, chief executive of the Alzheimer's Research Trust, said: "In this study on mice with symptoms of Alzheimer's, researchers found that caffeine boosted their memory. We need to do more research to find out whether this effect will be seen in people.
"It is too early to say whether drinking coffee or taking caffeine supplements will help people with Alzheimer's.
Neil Hunt, chief executive of the Alzheimer's Society, said previous research into caffeine had suggested it could delay Alzheimer's disease and even protect against vascular dementia.
"This research in mice suggests that coffee may actually reverse some element of memory impairment.
"However much more research is needed to determine whether drinking coffee has the same impact in people.
"It is too soon to say whether a cup of coffee is anything more than a pleasant pick me up."

When unhealthy foods hijack overeaters' brains

By LAURAN NEERGAARD, AP Medical Writer

WASHINGTON – Food hijacked Dr. David Kessler's brain. Not apples or carrots. The scientist who once led the government's attack on addictive cigarettes can't wander through part of San Francisco without craving a local shop's chocolate-covered pretzels. Stop at one cookie? Rarely. It's not an addiction but it's similar, and he's far from alone.

Kessler's research suggests millions share what he calls "conditioned hypereating" — a willpower-sapping drive to eat high-fat, high-sugar foods even when they're not hungry. In a book being published next week, the former Food and Drug Administration chief brings to consumers the disturbing conclusion of numerous brain studies: Some people really do have a harder time resisting bad foods. It's a new way of looking at the obesity epidemic that could help spur fledgling movements to reveal calories on restaurant menus or rein in portion sizes.

"The food industry has figured out what works. They know what drives people to keep on eating,"
Kessler tells The Associated Press. "It's the next great public health campaign, of changing how we view food, and the food industry has to be part of it."

He calls the culprits foods "layered and loaded" with combinations of fat, sugar and salt — and often so processed that you don't even have to chew much. Overeaters must take responsibility, too, and basically retrain their brains to resist the lure, he cautions. "I have suits in every size," Kessler writes in "The End of Overeating." But, "once you know what's driving your behavior, you can put steps into place" to change it.

At issue is how the brain becomes primed by different stimuli. Neuroscientists increasingly report that fat-and-sugar combinations in particular light up the brain's dopamine pathway — its pleasure-sensing spot — the same pathway that conditions people to alcohol or drugs. Where did you experience the yum factor? That's the cue, sparking the brain to say, "I want that again!" as you drive by a restaurant or plop before the TV.

"You're not even aware you've learned this," says Dr. Nora Volkow, chief of the National Institute on Drug Abuse and a dopamine authority who has long studied similarities between drug addiction and obesity. Volkow is a confessed chocoholic who salivates just walking past her laboratory's vending machine. "You have to fight it and fight it," she said. Conditioning isn't always to blame. Numerous factors, including physical activity, metabolism and hormones, play a role in obesity. And the food industry points out that increasingly stores and restaurants are giving consumers healthier choices, from allowing substitutions of fruit for french fries to selling packaged foods with less fat and salt.

But Kessler, now at the University of California, San Francisco, gathered colleagues to help build on that science and learn why some people have such a hard time choosing healthier: _First, the team found that even well-fed rats will work increasingly hard for sips of a vanilla milkshake with the right fat-sugar combo but that adding sugar steadily increases consumption. Many low-fat foods substitute sugar for the removed fat, doing nothing to help dieters eat less, Kessler and University of Washington researchers concluded.

Then Kessler culled data from a major study on food habits and health. Conditioned hypereaters reported feeling loss of control over food, a lack of satiety, and were preoccupied by food. Some 42 percent of them were obese compared to 18 percent without those behaviors, says Kessler, who estimates that up to 70 million people have some degree of conditioned hypereating.

Oily fish 'can halt eye disease'

People with age-related macular degeneration (AMD) should eat oily fish at least twice a week to keep their eye disease at bay, say scientists.

Omega-3 fatty acids found in abundance in fish like mackerel and salmon appear to slow or even halt the progress of both early and late stage disease.

The researchers base their findings on almost 3,000 people taking part in a trial of vitamins and supplements.
The findings are published in the British Journal of Ophthalmology.
An estimated 500,000 people in the UK suffer from AMD, which destroys central vision.

Protective
Experts have already suggested omega-3 may cut the risk of getting AMD by a third, and now this latest work suggests these fats also benefit patients who already have the disease.

These findings appear to be consistent with previous research that has shown that eating omega 3 poly-unsaturated fats as part of a balanced diet may help prevent the development of age-related macular degeneration
A spokeswoman from RNIB

Progression to both dry and wet forms of advanced AMD disease was 25% less likely among those eating a diet rich in omega-3 fatty acids.

People with advanced AMD who also consumed a low-GI diet, eating of foods that release their sugar more slowly, and who took supplemental antioxidant vitamins and minerals like vitamin C and zinc appeared to reduce their risk of disease progression by even more - by up to 50%.

Substituting five slices of wholegrain bread for white bread every day out of a total intake of 250g of carbohydrate might cut out almost 8% of advanced age related macular degeneration over five years, say the authors.

Surprisingly, however, the supplements were counterproductive for those with early AMD, negating the benefits of omega-3 fats, and even appeared to increase the risk of disease progression.
Those who took all the antioxidant vitamins plus zinc, and who a high daily intake of beta carotene - found in yellow and green vegetables - were 50% more likely to progress to advanced disease.

The researchers at Tufts University, Boston, believe omega-3 fatty acids offer protection against AMD by altering fat levels in the blood after a meal that can be damaging to the body.

'Moderation'
But they say it is not clear whether patients should also consider taking supplements as well as omega-3 because of their mixed findings.

They suggest that eating two to three servings of fatty fish, such as salmon, tuna, mackerel, shellfish, and herring every week, would achieve the recommended daily intake (650mg) of omega-3, substantially cutting the risk of both early and late stage AMD.

The UK's Food Standards Agency says people should eat at least two portions of fish a week including one of oily fish.
But they caution that too much oily fish is bad because it can contain low levels of pollutants that can build up in the body.
Most people can safely eat up to four portions a week, but girls and women who might have a baby and those who are pregnant or breastfeeding should limit their intake to two portions a week.

A spokeswoman from RNIB said good nutrition was very important for both general and eye health.
"These findings appear to be consistent with previous research that has shown that eating omega-3 poly-unsaturated fats as part of a balanced diet may help prevent the development of age-related macular degeneration, the main cause of severe sight loss in the UK. "RNIB hopes that this will further highlight why looking after your eyes should be a key motivation in maintaining a healthy lifestyle," she said.

Weekly curry 'may fight dementia

Eating a curry once or twice a week could help prevent the onset of Alzheimer's disease and dementia, a US researcher suggests.

The key ingredient is curcumin, a component of the spice turmeric.

Curcumin appears to prevent the spread of amyloid protein plaques - thought to cause dementia - in the brain.

But the theory, presented at the Royal College of Psychiatrists' annual meeting, has been given a lukewarm reception by UK experts.

“ If you have a good diet and take plenty of exercise, eating curry regularly could help prevent dementia ”
Professor Murali Doraiswamy Duke University
Amyloid plaques, along with tangles of nerve fibres, are thought to contribute to the degradation of the wiring in brain cells, eventually leading to symptoms of dementia.

Professor Murali Doraiswamy, of Duke University in North Carolina, said there was evidence that people who eat a curry meal two or three times a week have a lower risk of dementia.

He said researchers were testing the impact of higher doses - the equivalent of going on a curry spree for a week - to see if they could maximise the effect.

Animal studies

Professor Doraiswamy told the meeting: "There is very solid evidence that curcumin binds to plaques, and basic research on animals engineered to produce human amyloid plaques has shown benefits."

"You can modify a mouse so that at about 12 months its brain is riddled with plaques.

"If you feed this rat a curcumin-rich diet it dissolves these plaques. The same diet prevented younger mice from forming new plaques.

"The next step is to test curcumin on human amyloid plaque formation using newer brain scans and there are plans for that."

Professor Doraiswamy said a clinical trial was now underway at the University of California, Los Angeles, to test curcumin's effects in Alzheimer's patients.

He said research had also examined turmeric's therapeutic potential for treating conditions such as cancer and arthritis.

Good diet

He stressed that eating a curry could not counter-balance the increased risk of dementia associated with a poor diet.

“ Indian communities that regularly eat curcumin have a surprisingly low incidence of Alzheimer's disease but we don't yet know why ”
Dr Susanne Sorensen Alzheimer's Society
However, he said: "If you have a good diet and take plenty of exercise, eating curry regularly could help prevent dementia."

Professor Doraiswamy predicted it might be possible to develop a curry pill which had the same therapeutic effect.

However, Rebecca Wood, of the Alzheimer's Research Trust, stressed that people would need to eat a lot of curry - over 100g of turmeric curry powder - to get a clinical dose of curcumin.

She said: "Professor Doraiswamy's unpublished research applies only to animal models; his hypothesis has not been confirmed in human clinical trials.

"We look forward to the results of the human curcumin trial at UCLA."

Dr Susanne Sorensen, of the Alzheimer's Society, said: "Indian communities that regularly eat curcumin have a surprisingly low incidence of Alzheimer's disease but we don't yet know why.

"Alzheimer's Society is keen to explore the potential benefits of curcumin in protecting the brain and we are conducting our own research into this area.

"A cheap, accessible and safe treatment could transform the quality of life of thousands of people with the condition."

How soup can help you lose weight

By Jack Challoner

In the battle to lose weight, hunger is the dieter's worst enemy. But research has revealed a simple aid to taming the appetite: soup. It's dieting's best kept secret says one science writer.

Imagine a typical lunchtime meal - say, chicken and vegetables with a glass of water. If you eat the food and drink the water, you will feel full for a couple of hours before hunger kicks in. But if you blend the food with the water - to make soup - you will stay hunger-free for much longer, and less likely to snack through the afternoon.

How can blending the food into soup make such a difference? The answer lies in the stomach. Scientists have used ultrasound and MRI scans of people's stomachs to investigate what happens after eating solid-food-plus-water meals compared with the same food made into soup.

After you eat a meal, the pyloric sphincter valve at the bottom of your stomach holds food back so that the digestive juices can get to work. Water, however, passes straight through the sphincter to your intestines, so drinking water does not contribute to "filling you up".

When you eat the same meal as a soup, the whole mixture remains in the stomach, because the water and food are blended together. The scientists' scans confirm that the stomach stays fuller for longer, staving off those hunger pangs.
The key to this low-tech weapon against hunger is a hormone called ghrelin. It is one of the major players in the body's appetite system.

Discovered as recently as 1999, ghrelin is released by specialised cells in the stomach wall.

'Cupcake circuit'
These cells produce a constant stream of ghrelin whenever the stomach is empty. The ghrelin travels via the blood stream to the brain's appetite centre, an organ called the hypothalamus. As a result, the hypothalamus screams "You are hungry - find food."

But whenever the stomach wall is stretched - when the stomach is full - the cells stop producing ghrelin, and the hypothalamus responds accordingly, turning off the appetite signal. The longer the stomach remains full, the longer you feel satisfied and the less you are likely to eat.

WHICH VARIETY IS BEST?
Vegetable soup is best
It produces a more consistent blend
And it generally has fewer calories than chicken or fish soup

The stomach gradually empties, more slowly for the soup than the solid meal plus water. The BBC staged an experiment for the programme 10 Things You Need to Know About Losing Weight to test this theory. In this experiment, and in previous experiments, participants reported feeling full for up to an hour-and-a-half longer than their solid meal counterparts.
Although some researchers refer to appetite as "the cupcake circuit", the mechanism behind human appetite evolved long before cupcakes were invented - at a time when food was scarce.

As a result, we are hardwired to eat high-calorie foods, which are unfortunately so abundant in the modern world.
Finding ways to control the appetite signal is crucial if we are to stave off the meteoric rise in obesity. Food scientists and pharmaceutical companies alike are on a major quest to find ways to do just that.

Could soup help address obesity?
Appetite is one of the most researched areas of weight-loss science. Unfortunately, the appetite system is complex, and still poorly understood.

There are probably dozens of hormones that play a role in regulating appetite. Of those that have already been discovered, there is one that is released after eating protein-rich meals (called PYY), one that is released by fat cells (leptin) and several that respond to the presence of any kind of food.

But of all the hormones that make up the appetite system, it is ghrelin that has caused the most interest. In addition to its role in sending the "stomach empty" signal to the brain, ghrelin also promotes fat storage. Even worse, it inhibits the breakdown of stored fat during times of weight loss. Inject ghrelin into the bloodstream of a rat and the animal eats insatiably - and quickly becomes obese.

In 2006, scientists at the Scripps Research Centre in the US developed a vaccine to counteract the influence of ghrelin, in an attempt to control appetite. It is still undergoing clinical trials - so for now, the best and simplest way to keep hunger at bay is to reduce your stomach's release of ghrelin: blend your food into a healthy, voluminous soup. The best sort? Vegetable soup, as it produces a more consistent blend and is generally lower calorie than chicken or fish soup.
Jack Challoner is a science writer and author of the website explaining-science.co.uk.