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“Popcorn and breakfast cereals… may contain ‘surprisingly large’ servings of healthy antioxidants”, The Guardian reported. The newspaper said that the nutritional value of the foods was previously attributed to their high fibre content. However, research suggests the benefit of grain-based foods lies in “the significant presence of antioxidants known as polyphenols”.

The news is based on research presented at a conference in the US. The research claims that popcorn and wholegrain breakfast cereals contain similar levels of antioxidants as fruit and vegetables. However, this is a preliminary report that has not yet been published and it is probably too soon to conclude that popcorn can boost health or protect from cancer.

The theoretical effect of polyphenols in improving important measures of health or in preventing disease will need to be confirmed in further research. The salt and sugar content of most commercial popcorn should also be considered before consuming large quantities of it.

 

What are polyphenols?

Polyphenols are chemicals found in fruit and vegetables as well as in foods such as chocolate, wine, coffee and tea. Berries, walnuts, olives and grapes all contain polyphenols.

Polyphenols are a type of antioxidant thought to remove free radicals from the body. Free radicals are chemicals that have the potential to cause damage to cells and tissues in the body. Apparently, polyphenols have up to 10 times the antioxidant effect of vitamins C and E.

 

How do polyphenols affect you?

Observational studies that have examined the link between these foods and health have claimed that it is their polyphenol content that reduces the risk of death, heart disease, cancer and other illnesses.
Fibre used to be commonly believed to be the active ingredient for these benefits but, recently, polyphenol antioxidants have been thought to be more important.

 

Where did the study come from?

This study was conducted by Dr Joe Vinson, a chemist, and colleagues from the University of Scranton in Pennsylvania. The study received internal funding from the University of Scranton. It was presented at the 238th National Meeting of the American Chemical Society in August.

 

What did the research involve and what were its findings?

The researchers measured the total polyphenol concentration in commercial hot and cold breakfast cereals and snacks. They did this by mixing the food with an alkali that released the polyphenols that were bound to the fibres in the food. The researchers then used standardised tests to measure the levels of polyphenols.

They found that “whole-grain cold cereals have significantly more [polyphenol] antioxidants than processed grain types.” Wheat has more than corn, which has more than oats or rice. Among the salty snacks, popcorn has the most antioxidants per gram.

 

What did the scientists say?

The researchers claim that wholegrains provide a significant 10% of a person’s daily polyphenol intake in the average US diet and that about two thirds (66%) of these wholegrains are from cereals, pasta, crackers and salty snacks.

The lead scientist is quoted as saying that raisin bran has the highest amount of antioxidants per serving, “primarily due to the raisins” and that porridge oats have “disappointingly low levels”.

 

How reliable is this research?

This research has not been published, so it is not possible to say how well it was conducted. It appears to have answered the question it set out to address, which is what the polyphenol content of some foods is. However, between the presentation of this study at a conference and its portrayal in the media, the relevance of these findings to human health have been exaggerated. For example:

• Wholegrain foods are already known to be healthy. Any mention in the newspapers of their potential benefits, such as for the prevention of cancer or heart disease, were not investigated by this study.
• There is no general comparison of the other content of these foods. For example, the fibre content is mentioned but not analysed. Salt and sugar content are also important and before any claim of universal benefits from popcorn are made the relative content of these will need to be assessed.
• It is possible that the polyphenol content of food is one of the factors determining antioxidant activity. However, it is not the only antioxidant, and more research will be needed to determine which antioxidant (if there is one) could be responsible for the healthy effect of wholegrain food.

If people choose popcorn as part of their diet, they should be careful to avoid sugary and salty versions.

Links To The Headlines

Popcorn and cereals – the new superfoods? The Guardian, August 19 2009

Popcorn and cereals as rich in antioxidants as fruit and vegetables. The Daily Telegraph, August 19 2009

Why eating popcorn is good for your health. Daily Mail, August 19 2009

Popcorn can fight cancer. Daily Star, August 19 2009

It’s top of the pops. The Sun, August 19 2009

Links To Science

Vinson J. Erk K. Wang S-J, et al. Total polyphenol antioxidants in whole grain cereals and snacks: Surprising sources of antioxidants in the US diet. Oral presentation  ACS conference 2:00 PM-4:00 PM, Tuesday, August 18, 2009

Whole grain cereals, popcorn rich in antioxidants, not just fiber, new research concludes. Eurekalert 2009

“A romantic candle-lit dinner can give you cancer”, according to the Daily Mail. The newspaper says that, while candles can add a hint of romance to a meal or make taking a bath a real luxury, the smoke produced by many “is laced with toxins linked to cancer, asthma and eczema”.

Several other newspapers have picked up on a piece of research presented at the 238th National Meeting of the American Chemical Society (ACS) this week. The presentation suggests that burning candles made from paraffin wax is an “unrecognised source of exposure to indoor air pollution”.

The research behind the news and presentation has not yet been published, so a full appraisal of its quality is not possible at this time. It appears that this news has come from brief press releases and a presentation abstract that feature details on a comparison carried out between beeswax and paraffin wax candles.

 

What is the basis for these current reports?

Online press releases from EurekAlert! and National News mention research carried out at the South Carolina State University and orally presented at the 238th National Meeting of the American Chemical Society (ACS). Limited information is given about the methods of the study that underlies these claims.

According to the National News press release, researchers burned paraffin candles for about five or six hours. They found that the candles produced chemicals that are “harmful” and potentially carcinogenic. News reports say that candles made from beeswax or soy are safer, but it is also unclear how the researchers tested these.

Among the gases produced by paraffin-based candles, the researchers apparently found specific chemicals that have been linked to cancer, such as formaldehyde. However, there is not enough information about the results of this study to have a sensible discussion about whether the doses or types of chemical produced are a cause for concern.

 

What did the scientists do?

The scientists set out to investigate the chemical emissions from burning paraffin wax candles made by different manufacturers. They burnt the candles in a chamber (8 x 8 x 26 inches) which pumped the gases into a glass ampoule containing highly absorbent activated coconut charcoal.

After five to six hours of burning, the contents of the ampoule were analysed using a type of mass spectrometer that precisely identifies the chemical constituents of the gases. The paraffin-based candles produced clear sharp peaks indicating the presence of many products such as toluene, alkanes and alkenes, as well as some ketones and aldehydes. The scientists say their “results proved largely reproducible”.

 

How does this research affect me?

Until this research is published in a journal it is not possible to scrutinise the methods used and to establish how relevant its findings are to human health. It is possible that the study may never be published, as a great deal of research presented at conferences does not make it into peer-reviewed journals.

The abstract available does not describe any comparisons with beeswax candles, so it is not possible to say what the fumes from beeswax candles contain. The levels of gaseous chemical emissions from the paraffin-based candles are also not given, so relating these findings to any minimum safety levels is not possible.

One of the researchers has been quoted as saying that, “An occasional paraffin candle and its emissions will not likely affect you, but lighting many paraffin candles every day for years or lighting them frequently in an un-ventilated bathroom around a tub, for example, may cause problems”.

Several cancer experts have offered their opinions on these findings. Dr Joanna Owens, science information manager at Cancer Research UK, said that, "when talking about cancer risk, it’s important to focus on things we have hard evidence for. There is no direct evidence that everyday use of candles can affect our risk of developing cancer.

“In terms of cancer, a far more significant type of indoor air pollution is secondhand cigarette smoke. Lifestyle factors such as smoking, alcohol, obesity, unhealthy diets, inactivity and heavy sun exposure account for a much larger proportion of cancers."

Dr Noemi Eiser, Honorary Medical Director of the British Lung Foundation, said, "We would like to reassure people that occasional use of paraffin candles should not pose any risk to their lung health.
 
"However, we would advise people to take sensible precautions when burning candles, such as opening a window to keep the room ventilated to minimise the amount of emissions breathed in."

Links To The Headlines

Romantic candles could cause cancer, say scientists. The Daily Telegraph, August 20 2009

How a romantic candle-lit dinner can give you cancer. Daily Mail, August 20 2009

Candle-lit dinners ‘can cause cancer’. The Metro, August 20 2009

CANDLES CANCER. Daily Star, August 20 2009

Several newspapers reported today that cases of liver cancer have tripled. The Mirror said that alcohol is to blame, as well as obesity and the blood infection hepatitis C. It reports that all three cause cirrhosis (scarring) of the liver, a condition that can develop into liver cancer. It said the “startling” figures from Cancer Research UK show that the number of cases of liver cancer has risen to 3,108 in 2006 from 865 in 1975.

 

What is the news based on?

These stories are based on the latest statistics published by Cancer Research UK about cancers starting in the liver (primary liver cancers) in 2006. The statistics look at how common the cancer is, how it has changed over time and how figures in the UK compare with those from other parts of the world. These statistics do not cover cancers that have spread to the liver from other parts of the body.

 

How have rates of liver cancer changed?

Primary liver cancer used to be rare in the UK, for example, in 1975 only 865 cases were reported in the UK. While these cancers are still uncommon, the number has grown substantially, and in 2006 3,108 cases were diagnosed. This is equivalent to an increase from about 1.4 people in 100,000 developing primary liver cancer in 1975 to about 3.9 people in 100,000 in 2006.

Liver cancer is the 18th most common cancer in the UK (based on 2006 figures), but is more common in other parts of the world. As there is a long delay between exposure to risk factors and the development of liver cancer, experts suggest that the number of new cases each year will continue to rise.

Primary liver cancer is more common in men than women (63% of new cases are in males). Rates increase sharply with age, and the highest rates occur in the oldest age groups. Most cases of liver cancer (about 70%) occur in people aged over 65 years. For those aged 85 and over the incidence rate per 100,000 men is 47, while for women it is 24.

Cancer Research UK has estimated that the lifetime risk of developing primary liver cancer is one in 180 for men and one in 292 for women in the UK.

 

What are the risk factors for primary liver cancer?

Risk factors for primary liver cancer include:

• Viral infections, such as hepatitis B or C.
• Excessive alcohol consumption.
• Being overweight.

Cancer Research says experts believe these three factors are the main contributing factors to the rise in cases of primary liver cancer in the UK. As these risk factors become more common, so does liver cancer.

Hepatitis and alcohol both cause cirrhosis and this itself is a risk factor for primary liver cancer. The reasons for the link between overweight and increased risk of primary liver cancer are unclear, it may be linked to an increased risk of diabetes and of non-alcohol related liver disease in overweight people.

Other causes of cirrhosis (including the inherited disease haemochromatosis and direct poisons such as aflatoxin, which is a contaminant found in some mouldy foods) can also increase risk of the cancer.

 

What is hepatitis C?

Hepatitis C is a virus. It spreads from person to person by blood-to-blood contact (for example through drug users sharing needles) and in rare cases it can be passed on by unprotected sex. Some of the increase in liver cancer seen may be due to use of hepatitis-C-contaminated blood products in the 1960s and 1980s. Since 1991, all blood products have been checked before use, so they are no longer a risk.

Some people who are infected with hepatitis C will clear the virus from their bodies, but many people develop mild to moderate liver damage, although they may not all experience symptoms. About a fifth of people who contract hepatitis C will eventually develop liver cirrhosis and some will develop liver cancer. Experts report that it can take 20 to 40 years between hepatitis C infection and onset of liver cancer. Therefore, even if new cases of infection were stopped, the number of cases of cancer would continue to rise for some years.

 

What are the symptoms of liver cancer?

Cancer Research reports that the symptoms of liver cancer include weight loss, a swollen tummy (abdomen), yellowish skin, dark coloured urine and pale coloured stools. Other symptoms include loss of appetite over a few weeks, being sick, feeling full or bloated after eating (even after a small meal), pain or discomfort in the abdomen, or a high temperature and sweating. In people with known chronic hepatitis or cirrhosis a sudden worsening of health could also indicate the possibility of liver cancer.

 

What can I do to reduce my risk of liver cancer?

Reducing your alcohol consumption and maintaining a healthy weight will help to reduce your risk of liver cancer, as well as offering other health benefits. In addition, people should avoid blood-to-blood contact, for example by avoiding sharing needles or unsafe sex. If you suspect that you may have hepatitis C seek medical attention, as there are treatments that can reduce the progression to cirrhosis. If you know that you have hepatitis C you should avoid drinking alcohol.

Links To The Headlines

Tipple whammy. The Mirror, August 20 2009

Sharp rise in liver cancer blamed on binge drinking and obesity, The Guardian, August 20 2009

Primary liver cancers ’soaring’. BBC News, August 20 2009

There is now a ‘rapid test to diagnose the common womb condition of endometriosis’, the Daily Mail has reported. The newspaper says that a quick tissue sample can be taken while the woman is awake, avoiding the need for surgery under a general anaesthetic.

This well conducted study has demonstrated that it may be possible to make a diagnosis of endometriosis through biopsy samples taken from the lining of the womb. This study found the new test to be highly accurate in identifying women with endometriosis, picking up 98% of women detected using the standard surgical method. It had slightly lower accuracy in  correctly providing a negative test result in a woman who definitely did not have the condition, meaning that you could have less confidence in a positive test result.

As the authors say, this was a pilot study and the results would need to be verified in a much larger sample of women. Whether the predictive accuracy of this test is acceptable would also need to be considered. In addition, before it could be introduced, consideration would need to be given to the resources that would be required to implement this test, where the test would be available (for example, in gynaecological clinics) and which women would be eligible for the test.

 

Where did the story come from?

Moamar Al-Jefout and colleagues of the University of Sydney, Australia, and Mutah University, Jordan, carried out this research. The study was funded by the Department of Obstetrics and Gynaecology of the University of Sydney. It was published in the peer-reviewed medical journal Human Reproduction.

 

What kind of scientific study was this?

Endometriosis is a fairly common and troublesome gynaecological condition in which the lining of the uterus is found in other locations in the pelvis and abdomen, causing chronic pelvic pain and often difficulty conceiving. This study compared a potential new method of diagnosing endometriosis to a standard method of diagnosis used in clinical practice.

The current gold-standard method of diagnosis is performed under general anaesthetic using a type of keyhole surgery called a laparoscopy. In this diagnostic study the researchers compared the efficacy of a new, simpler test in which a biopsy (tissue sample) from the endometrium (the lining of the uterus) is taken via the vagina and then examined for the presence of nerve fibres. Prior reports have noted that in some women diagnosed with endometriosis small sensory nerve fibres have been detected in the functional layer of the endometrium (the layer adjacent to the uterine cavity which changes throughout the menstrual cycle). 

The study recruited a total of 103 women (average 34 years) who were scheduled to undergo investigation for chronic pelvic pain and/or infertility. Prior to the standard method of diagnostic laparoscopy the researchers took an endometrial biopsy through the vagina using a device called the Endosampler.

The presence of nerve fibres in the biopsy sample was then assessed in the laboratory by two histologists. Satisfactory biopsies were obtained from 99 of the 103 women in the total study set. A separate histologist assessed the tissue samples obtained through laparoscopy.

 

What were the results of the study?

In the 99 women who completed the study laparoscopy (the gold standard) provided 64 diagnoses of endometriosis of variable degrees of severity. The experimental biopsy method detected nerve fibres in 63 of these 64 women.

Of the 35 women who did not have endometriosis according to laparoscopy, the new method detected no nerve fibres in the functional layers of 29 women, while in six women there were nerve fibres present. These six women had significantly greater nerve fibre density (3.1 per mm2) than those with endometriosis identified through laparoscopy (2.7 per mm2). Women with both endometriosis and pain symptoms had significantly higher nerve fibre density compared to women with infertility but no pain.

The researchers calculated that for diagnosing endometriosis through the detection of nerve fibres obtained at biopsy:

• Sensitivity (accurately identifying a positive sample) was 98%.
• The specificity (accurately identifying a negative sample) was 83%.
• The positive predictive value (proportion of people with a positive test result who are correctly diagnosed as positive) was 91%.
• The negative predictive value (proportion with a negative test result who are correctly diagnosed as negative) was 96%.

 

What interpretations did the researchers draw from these results?

The authors conclude that the use of endometrial biopsy with detection of nerve fibres provides a reliable method of diagnosing endometriosis that offers levels of accuracy close to those of diagnosis through laparoscopic assessment.

 

What does the NHS Knowledge Service make of this study?

This well conducted study has demonstrated that it may be possible to make a diagnosis of endometriosis through endometrial biopsy. If this method proves viable it would potentially avoid the need for invasive surgery and anaesthesia, and help to reduce the often substantial delay that many women experience between first experiencing symptoms and receiving a definite diagnosis. However, as the authors say, the results of this pilot study would need to be verified in a larger sample of women.

This study found the test to be highly accurate in positively identifying women who had endometriosis, but to have slightly lower accuracy in correctly excluding endometriosis in women who did not have a diagnosis of the condition. According to laparoscopy, six women without endometriosis also had detectable nerve fibres, meaning less confidence in a positive test result.

These findings would need to be compared to those obtained in other samples, and then consideration would need to be given to whether these predictive figures were acceptable. In addition, before this test could be brought into practice, consideration would need to be given to the resources that would be required to implement this test, where the test would be available (for example, in gynaecological clinics), and which women would be eligible for the test.

Links To The Headlines

Non-surgical test ‘can identify painful womb condition’. The Daily Telegraph, August 19 2009

Rapid test to diagnose common womb condition endometriosis. Daily Mail, August 19 2009

Links To Science

Al-Jefout M, Dezarnaulds G, Cooper M et al. Diagnosis of endometriosis by detection of nerve fibres in an endometrial biopsy: a double blind study. Hum. Reprod. [Advance Access published] August 18 2009

"Exercise can be as addictive as heroin”, warned the Daily Mail, which said that exercise “junkies” experience the same sort of withdrawal symptoms as heroin addicts when they try to stop exercising.

The news story is based on research in rats, some of which were given an exercise wheel. The rats were injected with a drug called naloxone, which blocks brain activity that is usually associated with opioid (e.g. morphine) use. Rats that were more active had greater withdrawal symptoms after being injected with naloxone than rats that were inactive.

It is plausible that the improved cardiovascular health, strength, flexibility and general wellbeing associated with exercise can be addictive and may encourage people to continue exercising. Some studies show that opiate-mimicking chemicals are released in the brains of rats and humans during endurance exercise.

However, until research in humans is carried out, the application of these findings to real life are limited. The balance of benefits and harms with exercise compared to heroin are too different to be summarised by the simple headlines that the newspapers have used.

 

Where did the story come from?

The research was carried out by Robin B Kanarek and colleagues from Tufts University, Massachusetts, USA. Funding was provided by the National Institute for Drug Abuse. The study was published in the (peer-reviewed) medical journal Behavioural Neuroscience.

 

What kind of scientific study was this?

The aim of this animal study was to investigate whether exercise is addictive. It involved 44 female rats, half of which were housed in a standard cage while the other half were housed in cages with activity wheels. The rats’ food and water intake and revolutions on the wheel were measured for a week. In the second week, access to food was restricted for half of the rats in each group to only one hour a day, while the rest of the rats were able to feed continuously.

Previous studies have found that calorie-restricted rats given running wheels increase their time on the wheel and reduce their food intake. The weight loss associated with this behaviour is called activity-based anorexia. Conversely, calorie-restricted rats in standard cages tend to adapt to their new feeding schedules, eating more when they can and eventually gaining weight.

In this study, once the bodyweight of the active rats had reduced to 80% of their weight at the beginning of the study, the researchers tested for withdrawal symptoms. They did this by injecting the rats with naloxone, which blocks activity in the brain usually activated by opioid use (naloxone is used in humans to reverse the symptoms of opioid overdose). The rats were then observed for one hour for symptoms of weight loss, shaking, teeth chattering, escape attempts, abnormal posture, salivation and diarrhoea. The withdrawal symptoms were given an overall score.

Withdrawal scores were compared between the four groups. The experiments were repeated with male rats to see whether there were gender differences in the response to exercise.

 

What were the results of the study?

Food intake prior to diet restriction did not differ between the active and inactive rats and their body weights were similar. Following food restriction, both active and inactive rats lost a similar amount of weight. However, the food-restricted rats were more active than those who had normal food availability.

Withdrawal scores differed between the groups. Food-restricted active rats had significantly greater withdrawal scores than rats in all other groups. Additionally, the number of wheel turns made by these rats seemed to be related to their withdrawal scores. The group with the second highest withdrawal symptoms were the active rats that were not food-restricted.

Similar results were seen in the experiments on male rats.

 

What interpretations did the researchers draw from these results?

The authors say that their findings support the theory that exercise induces opioid-like substances in the body that act in a similar way to chronic administration of opiate drugs.

 

What does the NHS Knowledge Service make of this study?

This animal study assessed the strength of an “induced exercise addiction” in rats. While it is plausible that the improved cardiovascular health, strength, flexibility and general wellbeing associated with exercise may be ‘addictive’ and may encourage people to continue exercising, until human studies have demonstrated this link more convincingly it is difficult to know how these findings can be applied to real life.

Some studies show that opiate-mimicking chemicals are released in the brains of rats and humans during endurance exercise, but whether the ‘addiction’ is anything like an opiate addiction is not yet known. The benefits and harms of exercise are too different to compare them with those of heroin. Simple headlines that suggest that exercise is as addictive as heroin over-simplify the issue and aren’t really supported by the findings of this preliminary study.

Links To The Headlines

Exercise can be as addictive as heroin. Daily Mail, August 19 2009

Excessive exercise could be as addictive as heroin, claim scientists. The Daily Telegraph, August 19 2009 

Links To Science

Kanarek RB, D’Anci KE, Jurdak N, Mathes WF. Running and addiction: Precipitated withdrawal in a rat model of activity-based anorexia. Behavioral Neuroscience 2009; 123: 905-912

Scientists have made “nanomagnets” that can guide stem cells to repair injuries, The Times has reported. It said the researchers have tagged stem cells with microscopic particles of iron, each “2,000 times smaller than the thickness of a human hair”, and used an external magnet to move them towards damaged arteries in rats. The technique has been shown to multiply by five the number of stem cells reaching targeted blood vessels.

This animal study investigated the targeting of endothelial progenitor cells, which are stem cells that are important in vascular healing. The research is encouraging, at least for vascular diseases, and, in time, the same techniques will no doubt also be tested for cancer therapies.

The researchers say that the nanoparticles used in this experiment are already approved for medical use by the US Food and Drug Administration, so human trials could begin within three to five years. If this is the case, then any treatments using this technique would be a minimum of a few years after that.

 

Where did the story come from?

This research was carried out by Panagiotis G Kyrtatos and colleagues from the Centre for Advanced Biomedical Imaging at University College London (UCL) and the UCL Institute of Child Health in London. The study was supported by the Child Health Research Appeal Trust, the British Heart Foundation, the Alexander S. Onassis Public Benefit Foundation and the Biotechnology and Biological Sciences Research Council.

The study was published in the peer-reviewed Journal of the American College of Cardiology: Cardiovascular Interventions.

 

What kind of scientific study was this?

The researchers explain that although there have been promising advances in using cells to repair blood vessels, delivering the cells to the target area remains a difficulty.

In this laboratory and animal study the researchers magnetically tagged human endothelial progenitor cells (EPCs) with superparamagnetic iron oxide nanoparticles (SPIOs) and moved them to an area of arterial injury using a magnetic device positioned outside the body. SPIO nanoparticles are very small particles usually between one and 100 nanometres wide (a nanometre is a millionth of a millimetre). EPCs are a type of stem cell that circulate in the blood and have the ability to become endothelial cells. Endothelial cells form the inner lining of blood vessels and are involved in the development of new blood vessels.

The researchers first isolated human mononuclear cells (white blood cells) from donor blood. A particular cell type, called CD133+, was then isolated and cultured (grown) for three weeks. The cells’ behaviour outside the body, survivability and ability to differentiate or change into endothelial cells was then studied.

The researchers labelled the CD133+ cells with iron oxide nanoparticles to see whether the magnetic particles stuck to the surface of the cells. Computer simulations of the cells’ movements were also carried out.

Finally, rats in which the carotid artery in the neck had been artificially stripped of its lining were injected with the tagged cells. An external magnetic device was applied to the carotid artery for 12 minutes after some of the injections.

 

What were the results of the study?

Computer simulations predicted that the cells could be moved to targeted areas when the blood flow was similar to the flow found in a rat common carotid artery.

In the rat experiments, 24 hours after the injections the number of tagged cells found at the site of injury in the carotid arteries was five times higher in the rats exposed to the magnetic device than in those that were not.

 

What interpretations did the researchers draw from these results?

The researchers say that by using an externally applied magnetic device they have been able to move EPCs to the site of common carotid artery injury. They claim that the technology could be adapted to move cells in other organs, such as the heart or the brain, and could be a useful tool for localising stem cell therapies in other diseases.

 

What does the NHS Knowledge Service make of this study?

This study is promising in that it has demonstrated the feasibility of steering cells around the body. However, research has not yet shown that the repair process itself was improved. The technique will also need to be tested in humans.

Though the researchers do not explicitly mention cancer, this is one of the areas in which similar technology could potentially be used. More research could test whether it is possible to guide antibodies, viruses or chemotherapy drugs towards tumours while avoiding healthy tissue.

The scientists have said that as the nanoparticles used in the experiment are already approved for medical use by the US Food and Drug Administration, human trials of the technology could potentially begin within three to five years. This is quite a short time in research terms and means that there could be many more studies of this type reported in the next few years, before any license for use in humans is granted.

Links To The Headlines

Tiny magnets that help heal injuries could be used to treat cancer. The Times, August 18 2009

‘Magnetic’ stem cells for hearts. BBC News, August 19 2009

How magnets may help to heal everything from damaged arteries to diseased hearts. Daily Mail, August 18 2009 

 

Links To Science

Kyrtatos PG, Lehtolainen P, Junemann-Ramirez M, et al. Magnetic Tagging Increases Delivery of Circulating Progenitors in Vascular Injury. J Am Coll Cardiol Intv 2009; 2: 794-802

“Adding folic acid to bread could be unnecessary and may even expose many to potentially negative health risks”, The Daily Telegraph has reported. Pregnant women are currently advised to take folic acid to help protect their child from developing birth defects such as spina bifida, and the Food Standards Agency has recommended that the vitamin should be added to flour.

While the US and Canada have introduced mandatory fortification of flour with folic acid, this new research looks at a sample of the population in Ireland, where fortification by manufacturers is voluntary. This new research does not seem to inform the debate about whether fortification of food should be mandatory. The researchers took blood samples from both adults and newborns, and tested for the unmetabolised form of folic acid. They found that many people were already getting folic acid through their daily diet. A small proportion of their total folate was unmetabolised, suggesting it was excess to requirements.

The authors say that excess folic acid may increase the risk of cancer and mask some types of anaemia. However, folate supplementation around the time of conception is known to have a strong protective effect against certain birth defects, and further research will be needed to balance any potential risk from the vitamin in other groups against this clear benefit for the unborn child.

 

Where did the story come from?

This research was carried out by Dr Mary R Sweeney from the School of Public Health and Population Science at University College Dublin and colleagues from elsewhere in Ireland and the United States. Two of the authors have declared that they have patents on compounds “in the folate field”.
The study was supported in part by a grant from the National Institutes of Health in the US and published in the journal BMC Public Health.

 

What kind of scientific study was this?

This study featured two separate sub-studies, which were cross-sectional analyses of levels of blood plasma folate, plasma folic acid and red cell folate levels in a selection of men, women and their umbilical cords in Ireland, where fortification of foodstuffs with folic acid is voluntary.

Although adding folic acid to products like bread is a legal requirement in some countries, the authors also explain that folic acid is thought to mask a particular type of anaemia called pernicious anaemia, which can occur when people are deficient in vitamin B12. Folic acid hides some of the signs of this anaemia, but intakes of less than 1mg a day in adults are not thought to have this masking effect.  Research is also ongoing to explore whether folic acid can possibly accelerate the growth of existing cancers.

The main aim of this research was to provide a record of the unmetabolised folic acid levels in Irish adults (both fasted and un-fasted) and newborn infants (fasted) before the proposed implementation of mandatory folic acid fortification.

The researchers also tried to predict the increase in unmetabolised folic acid levels in the blood after fortification. Unmetabolised folic acid appears in blood tests when oral folic acid rises above certain threshold doses (about 200mg). The acid cannot be stored in the body, and must be continually replenished through the diet or from supplements.

Two groups of volunteers were selected. The first group were blood donors attending routine blood donation sessions at the Irish Blood Transfusion Service in Dublin. Whole blood samples were collected from 50 blood donors (42 men and eight women, age range 27-60 years) that had been eating normally before the sampling.

In the second group samples were collected from mothers and babies at the Coombe Women’s and Infant’s Hospital in Dublin. Blood samples were taken from 20 mothers about to undergo routine caesarean section (age range 26-39 years) and from the umbilical cords of their 20 babies immediately after caesarean section. All these women had been fasting for eight hours, and none were taking folic acid supplements.

The researchers wanted to relate the results of blood samples to answers given to a questionnaire on dietary intakes of folic acid. An interviewer administered a questionnaire covering the usual and recent dietary intakes of folic acid to all the adult subjects. This covered the main dietary sources of folic acid supplements and fortified foods available in Ireland.

Standard statistical tests were used and the researchers used regression to model the estimated average increase in plasma folate levels in the population that might occur as a result of mandatory fortification.

 

What were the results of the study?

The researchers say that unmetabolised folic acid was present in 49 out of 50 unfasted blood donors and that this constituted 2.25% of total plasma folate. In the caesarean group of fasting mothers the unmetabolised folic acid was present in 17 of the 20 babies. This equates to 85% of the babies (95% confidence interval, 62.1% to 96.8%) and 18 out of 20 fasting mothers (90%). This unmetabolised folic acid was 1.31% of total plasma folate.

The authors say there was a significant link between the total folate in the mother’s plasma and the mother’s unmetabolised folic acid concentrations. Levels of folic acid taken in through usual diet (assessed by questionnaires about food) correlated with maternal plasma folate concentrations. 

They also say they found a significant correlation between the maternal folic acid concentrations and cord blood folic acid concentrations.

 

What interpretations did the researchers draw from these results?

The researchers say that the reported levels of unmetabolised folic acid in the circulatory system are low: 1.31% in the fasting mothers and 2.25% in the unfasting volunteers (mostly men). They conclude that the fact that it was still present immediately after caesarean section in women who had not eaten for eight hours means that in people with cancer there would be a “constant/habitual exposure of existing tumours to folic acid, with the potential for accelerated growth”, and that “mandatory fortification might exacerbate this”. 

They state that their findings have implications for those with responsibility for drafting legislation in this area.

 

What does the NHS Knowledge Service make of this study?

This simple study measuring various types of folate in two small groups of men, women and babies does not seem to add anything to the debate about whether folate is harmful. In particular:

• It is to be expected that women or men who consume a normal diet have detectable levels of plasma folate, plasma folic acid and red cell folate levels in their blood. In fact, it would be unhealthy if they did not. It is not clear form this research what the significance is of the small amounts of unmetabolised folic acid found.
• Equally, it is unsurprising that lower levels of the unmetabolised form are found in anyone who has been fasting when compared to those who have not. The importance of this finding is not clear.
• To be useful in informing the fortification debate this study would have needed to compare the levels found in women or men who were taking fortified foods when compared to those who were not.

The researchers report that the evidence supporting harm from folic acid has come from two publications of the same randomised controlled trial. In this trial of people who had undergone treatment for colorectal adenomas (bowel growths), those who consumed folic acid supplements as part of the trial had an increased risk of more severe recurrence than the placebo group. The dose administered in the trial was 1mg (the accepted upper safe limit). In the second publication from this trial the suggestion was that oral folic acid increases the risk of prostate cancer. This and other trials will need to be assessed separately.

This most recent paper has contributed to an understanding of how folic acid is metabolised in the body, but there is a need for high-quality research to test the safety of folic acid fortification.

Links To The Headlines

Folic acid in bread ‘could be unnecessary and increase health risks’. The Daily Telegraph, August 18 2009

Links To Science

Sweeney MR, Staines A, Daly L  et al. Persistant circulating unmetabolised folic acid in a setting of liberal voluntary folic acid fortification. Implications for further mandatory fortification? BMC Public Health 2009, 9:295

A study has found particular gene mutations that put children at a higher risk of leukaemia, newspapers have reported. The Times said that “research into the development of acute lymphoblastic leukaemia (ALL)… suggests that individuals who inherit specific genetic variants are almost twice as likely to develop the disease”.

Acute lymphoblastic leukaemia is the most common leukaemia in children, and accounts for a quarter of all childhood cancers. This genome-wide association study identified three gene variations that are more common in children with ALL than in those without it.

The study is well-conducted, and its results significantly advance our knowledge of this condition. However, ALL is a complex disease and is likely to have many causes, some genetic and some environmental. These findings do not mean that researchers know how to prevent the disease in children found to have these mutations. Also, the variants discovered in this study will not be responsible for all cases of leukaemia. At the present time, genetic testing of children for these mutations is unlikely.

 

Where did the story come from?

The research was carried out by Dr Elli Papaemmanuil and colleagues from the Institute of Cancer Research in Surrey, and other academic and research institutes in the UK. It was funded by Leukaemia Research (UK) and the Kay Kendall Leukaemia Fund. The authors also acknowledge funding from Cancer Research UK. The study was published in the peer-reviewed medical journal Nature Genetics.

 

What kind of scientific study was this?

Acute lymphoblastic leukaemia (ALL) is the most prevalent childhood cancer in developed countries. Although its exact cause is not known, factors such as radiation exposure, some genetic disorders and environmental factors (exposure to certain chemicals and some infections) increase the risk of a child developing ALL.

This genome-wide association study looked for particular gene sequences (variants) associated with leukaemia in children. By pooling the results of two case-control studies, a total of 907 children with leukaemia and 2,398 controls without leukaemia were available for analysis. These children’s gene sequences were compared  in order to test for variations that were more common in the children with leukaemia. Only people of western European ancestry were included.

Between the groups, 291,423 gene variants were examined and compared. Where significant links were found between variants and disease status, the researchers discuss other studies that may explain the biological reasons for these associations. In one case, they investigated this further through experimentation.

 

What were the results of the study?

The researchers found that three gene variants in their pooled sample were more common in leukaemia cases than in controls. One variant was found on a gene called IKZF1, one on a gene called ARID5B, and one on a gene called CEBPE. All three of these variants were in genes involved in the differentiation (specialisation) of certain types of white blood cells.

 

What interpretations did the researchers draw from these results?

The researchers say that their study provides the first unambiguous evidence that common gene variants influence the risk of developing ALL in children. They say their results provide ‘new insight’ into the causes of this specific haematological cancer.

 

What does the NHS Knowledge Service make of this study?

This is a well-conducted study and the results are reliable. It identified several gene variants that are more common in children with acute lymphoblastic leukaemia (ALL). There may be other genes that play a role in the condition:

• The researchers acknowledge that the risk of ALL may be affected by ethnic differences. As this research was limited to western European children, the findings may not therefore apply to non-western Europeans or non-Europeans.
• The knowledge that certain variants are associated with leukaemia does not mean that researchers know how to prevent the disease in children with the variations. Leukaemia is a complex disease, and the risk of developing it is likely to be linked not only to genes, but also to environmental factors. In addition, not all cases of leukaemia may have these variations.
• More research is needed before we know whether the proteins that are encoded by these genes are suitable targets for leukaemia treatments.

Overall, this study advances our knowledge of a complex disease. The findings are robust, but replication in further studies involving different cases and controls would increase the confidence that the associations found in this research are real ones.

Links To The Headlines

Research links childhood leukaemia to parents’ genes. The Times, August 17 2009

Child leukaemia ‘genes’ revealed. BBC News, August 17 2009

Genes ‘could play significant role in development of leukaemia’. The Daily Telegraph, August 17 2009

Links To Science

Papaemmanuil E, Hosking FJ, Vijayakrishnan J, et al. Loci on 7p12.2, 10q21.2 and 14q11.2 are associated with risk of childhood acute lymphoblastic leukemia. Nature Genetics 2009; Published online: 9 August