Daily intake of enriched skimmed-milk powder can reduce the number of flares in patients with poorly controlled gout, a randomised trial has concluded.

The researchers investigated 120 patients, mostly middle-aged Caucasian men, who had experienced at least two gout flares in the previous four months.

They were randomised to drink a daily vanilla shake for three months, containing either lactose powder control, skimmed-milk powder control, or skimmed-milk powder enriched with a glycomacropeptide (GMP) and a milk fat extract (labelled G600). The two additives had previously been shown to have anti-inflammatory effects in experimental models of gout.

The frequency of gout flares was reduced in all three groups, but the decline was greatest in those randomised to GMP/G600.

“Greater improvements were also observed in pain and fractional excretion of uric acid, with trends to greater improvement in tender joint count,” the researchers said.

Similar adverse event rates and discontinuation rates were observed in all three groups.

Dietary modification was frequently recommended as a strategy to prevent and treat gout, but this was the first reported randomised controlled trial of dietary therapy for active gout, they said.

Observational studies had suggested a clear relationship between higher intakes of low-fat dairy products and a lower risk of developing gout, and short-term studies had shown that large amounts of milk proteins or skimmed milk had a urate-lowering effect. In the present study, however, changes in urate levels were insufficient to explain the benefits of the low doses of milk products that were administered.

The results of this proof-of-concept trial could not yet be generalised to all patients with gout, the researchers warned.

“The patients in this study had poorly-controlled gout with high flare-rates, inadequately controlled serum urate and relatively low use of allopurinol,” they said.

Annals of the Rheumatic Diseases
doi: 10.1136/annrheumdis-2011-200156

The substantial contribution of poor diet to cardiovascular and cancer-related deaths is highlighted in a new study showing it accounts for 81 per cent of the excess mortality in Wales and Northern Ireland compared with England.

The study found improving the average diet in Wales, Scotland and Northern Ireland to a level already achieved in England could have a substantial impact on reducing geographical variations in chronic disease mortality rates in the UK. Such improvements were “small” and “achievable”, according to the authors.

The study used mortality data for coronary heart disease, stroke and 10 diet-related cancers for 2007-’09 to calculate mortality gaps between UK countries.

It also considered estimates of mean national consumption of 10 dietary factors. These suggested that Northern Ireland, for example, consumed 4 per cent more saturated fat, 7 per cent more salt per day and 20 per cent less fruit and vegetables per week than England.

Total energy intake and fruit and vegetable consumption were the main dietary determinants of geographical variations in mortality, the study found.

The authors suggested that so-called ‘fat taxes’ may be best placed to reduce geographical inequalities in health if they were paired with subsidies for fruit and vegetables.

They stressed, however, that their results were based on modelling hypothetical scenarios and relied on observational data.

BMJ Open 2011; doi:10.1136/bmjopen-2011-000263.

The long-term safety of vitamin and mineral supplements is in question after research has found that some may in fact increase mortality risk.

Multivitamins were associated with a 2.4 per cent increased absolute risk of mortality in older women compared with non-use, the 18-year observational study of 38,772 women found.

The absolute risk of mortality was raised by 4 per cent with vitamin B6, some 6 per cent with folic acid, some 3.6 per cent with magnesium, some 3 per cent  with zinc and 18 per cent with copper.

In addition, iron increased the risk of death by 4 per cent — an association that was dose-related.

However, in contrast to recent concerns raised (BMJ 2011; doi:10.1136/bmj.d2040) over the risk of myocardial infarction with calcium supplements, these were found to reduce the absolute risk of mortality by 3.8 per cent  compared with non-use. No clear dose-response relationship was observed.

Iron was suggested to catalyse reactions and promote oxidative stress, which might be a possible mechanism behind the strong association with increased mortality, the researchers wrote in the Internal Medicine Journal.

Although the benefits of supplements — such as an improvement in quality of life — could not be ruled out, the results raised concerns regarding their long-term safety, they wrote.

“Based on existing evidence we see little justification for the general and widespread use of dietary supplements. We recommend they be used with strong medically-based cause, such as symptomatic nutrient deficiency disease,” the researchers wrote.

Supplements should not be used as a preventative measure in a well-nourished population because of the possibility of unwanted health consequences, an accompanying editorial said.

However, older men and women might benefit from vitamin D supplements, especially if they had insufficient vitamin D supply from the sun and their diet, they wrote.

The use of calcium supplements required further study, the authors wrote.
Archives of Internal Medicine
2011; 171: 1625-1634

Neither vitamin D intake nor 25(OH) D levels are linked with the risk of islet autoimmunity (IA) or progression to type I diabetes in young children, research shows, contrary to some previous studies.

Vitamin D intake and 25(OH)D levels were measured periodically in 198 children who had developed IA during follow-up in the DAISY cohort of 2,644 US infants and young people. This included 128 patients who had plasma 25(OH) D levels assessed at nine months of age.

Neither variable was found to be linked with increased risk of IA, after adjusting for family history of type I diabetes, HLA-DR3/4, DQB1*0302 genotype and ethnicity, the authors noted in Diabetologia.

The study measured autoantibodies at nine, 15 and 24 months of age. Vitamin D intakes were assessed by food frequency questionnaires of parents for children aged 2-9, and of the children themselves when they reached 10.

The authors acknowledged that their findings were “somewhat contradictory” to previous epidemiological studies that suggested a protective effect of vitamin D supplementation in infancy on risk of type I diabetes.

“Our study, which uses a powerful combination of prospectively collected reports of vitamin D intake and a biomarker of vitamin D status, does not support an association between a child’s usual vitamin D intake or 25(OH)D levels… and the risk of IA or progression to type I diabetes,” they concluded.

Additional hypotheses that remained to be tested included the exact role of supplementation during infancy, and whether only very high levels of vitamin D were protective — or conversely, only extremely low levels were a risk, they wrote.

Diabetologia 2011 DOI: 10.1007/s00125-011-2278-2

Vitamin D supplements can significantly extend life in older women, according to a recent Cochrane Review.

Reviewing 50 randomised trials with more than 94,000 participants — mainly women with an average age of 74 — researchers found that taking vitamin D3 for two years reduced mortality by about 6 per cent.

“This means that you need to give about 200 people vitamin D for around two years to save one additional life,” said the study’s lead author.

The researchers found no significant benefits of taking other forms of vitamin D such as vitamin D2 or the active forms, alfacalcidol or calcitriol, but stressed more research was needed to confirm this finding.

They also found that vitamin D3 carried a risk of kidney stones when combined with calcium, while alfacalcidol and calcitriol both significantly increased the risk of hypercalcaemia.

The studies included in the Cochrane Review mainly involved women in institutions or dependent care who were likely to be vitamin D-deficient and at risk of falls and fractures.

Participants took supplements for an average of two years, with a typical vitamin D dosage of 800IU. The typical calcium supplement dosage was 900mg daily.

Cochrane Database of Systematic Reviews 2011; Issue 7.

They may make up a classic dinner, but red meat and potatoes are “strongly associated” with long-term weight gain, a study finds.

The 20-year study of more than 120,000 healthy US adults found a daily serving of potatoes — boiled, mashed or fried — was associated with a weight gain of 0.6kg every four years.

A daily serving of unprocessed red meats was linked to a gain of 0.4kg every four years — equivalent to drinking sugar-sweetened beverages every day, the study found. Potato chips were the worst offenders, with consumption linked to a four-year increase of 0.8kg. In contrast, daily servings of nuts, fruits, wholegrains, vegetables and yoghurt were linked to long-term weight loss, with yoghurt associated with the greatest weight loss of 0.4kg every four years.

“Weight gain often occurs gradually over decades, making it difficult for most people to perceive the specific causes,” the study authors wrote in the New England Journal of Medicine.

The research team said differences in weight gain seen for specific foods and drinks could relate to varying portion sizes, patterns of eating, effects on satiety or displacement of other foods or beverages.

Potential mechanisms for why yoghurt contributed to less weight gain were unclear, but “intriguing evidence” suggested that colonic bacteria might influence weight gain.

NEJM 2011; 364:2392-404

Physiological adaptations occur during pregnancy, enabling more efficient absorption of calcium from foods

Prof Fionnuala McAuliffe and Ciara McGowan examine the specific nutritional and dietary needs of pregnant women to achieve the best possible health of both mother and baby.

Nutrition is essential for growth, development and for protection against disease. Pregnancy is a time of rapid growth and development and there is no other stage in a woman’s life where good nutrition is more important.

Amongst healthcare professionals, it is widely known that good nutrition is an essential ingredient for a healthy pregnancy outcome. However, there is growing appreciation of the long-term impact of prenatal nutrition, which affects the health status of both mother and infant well beyond pregnancy.

This article gives an overview of the importance of nutrition in pregnancy and focuses on maternal energy intake and weight gain, and four essential nutrients in pregnancy.

Maternal energy intake
Pregnancy has the potential to lead to excessive maternal weight-gain. Women now enter pregnancy approximately 10kg heavier than they did 20 years ago. Being overweight or obese before or during pregnancy increases a woman’s risk of adverse obstetric outcomes, including: pre-eclampsia; operative delivery; foetal macrosomia; and gestational diabetes.

Most countries do not designate specific weight-gain goals for pregnancy, but rather give general advice regarding weight gain. In Ireland, we follow the US Institute of Medicine (IOM) weight-gain goals, which were revised in 2009 and are available online at www.nap.edu/catalog.php?record_id=12584.

The IOM recommends that women with singleton pregnancies gain between 11.5-16kg, 7-11.5kg or 5-9kg, depending on whether they are a healthy weight, overweight or obese before pregnancy, respectively.

These ranges were drawn from observed weight gains of women delivering full-term, healthy infants without complications. A systematic review by Abrams et al in 2000 reported that gaining weight within these ranges is associated with the best outcomes for both mother and infant.

Weight gain in pregnancy comprises the products of conception (the foetus, placenta and amniotic fluid), the increases in various maternal tissues (uterus, breasts, bloods and extra-cellular fluid) and increases in maternal fat stores. Extra calories (kcal) are essential during pregnancy to allow for the energy deposited in maternal and foetal tissues and for the increase in energy used by the body. There is an increase in metabolism during pregnancy and an increase in the amount of energy spent during daily activities.

The total energy cost for the entire duration of pregnancy is approximately 80,000 calories (kcal). This equates to approximately an extra 200-300 kcal per day for the second half of pregnancy. However, exact energy requirements during pregnancy remain controversial because of inconclusive evidence on maternal fat-deposition and assumed reductions in physical activity levels as gestation progresses.

Micronutrients of specific concern
Micronutrients are vitamins and minerals that are needed in very small quantities in the diet. During pregnancy, the requirement for some micronutrients increases substantially and the consequence of their absence can be severe.

•  Folic acid
Folic acid requirements increase from 300µg to 500µg/day in pregnancy. Folic acid greatly lowers the risk of neural tube defects (NTDs) such as spina bifida. All women planning or capable of pregnancy are recommended to take a daily supplement containing 400µg of folic acid at least four weeks before conception and up until the end of the first trimester.

This recommendation has been in place in Ireland since the early 1990s. However, the level of compliance with supplement usage is uncertain as an estimated half of all pregnancies are unplanned. If the pregnancy is unplanned, a folic acid supplement should be commenced as early as possible as the neural tube closes around the 28th day following conception. So, after this time, the extra folic acid does not provide neural tube protection.

The Lifeways study in Ireland reported in 2008 that only 45 per cent of women took a folic acid supplement in the three months before conception.

Lower levels of usage have also been reported. Folate (the natural form of folic acid) is mainly found in green vegetables. However, countries such as the US have added folic acid to their flour and grain products since 1998 with a notable reduction in the incidence of NTDs.

•  Calcium
Calcium plays a crucial role in maintaining maternal bone health during pregnancy whilst ensuring adequate foetal bone development. Full-term infants contain approximately 20-30g of calcium, most accrual occurring during the third trimester of pregnancy. Calcium requirements increase from 800mg to 1,200mg in the second half of pregnancy.

Physiological adaptations occur during pregnancy, enabling more efficient absorption of calcium from foods. Calcium may also play a role beyond skeletal health. A Cochrane systematic review in 2010 concluded that calcium supplementation (at a dose of 1g/day) appears to approximately halve the risk of pre-eclampsia.

It may also reduce the risk of pre-term births. Pregnant women should try to eat five portions of dairy products per day. If they can achieve this level of intake, a calcium supplement is not needed.

•  Vitamin D
The Irish recommended daily allowance (RDA) for pregnancy is 10µg of vitamin D per day. In November 2010, after careful examination, the IOM revised its Dietary Reference Value up to 15µg for pregnancy.

Like calcium, vitamin D plays a crucial role in promoting normal foetal skeletal growth and development during pregnancy. Severe maternal deficiency causes infantile rickets. However, insufficiency is associated with shorter gestation, lower infant birthweight, reduced intrauterine long-bone growth and poor bone mineralisation in childhood.

There is considerable interest in vitamin D recently, as poor vitamin D status is also associated with non-skeletal diseases, including: diabetes, cardiovascular disease, certain cancers and mental health disorders. Since September 2010, Ireland has in place a National Infant Supplementation Policy, whereby all infants must be given a 5µg supplement from birth.

Vitamin D is principally obtained from sunlight. Because Ireland lies on latitude of 50-55°N where sunshine exposure is limited for much of the year, opportunities for cutaneous production of vitamin D are minimal. We rely solely on dietary sources for much of the year: oily fish, eggs and liver being the richest sources, while fortified breakfast cereals, milk and margarines provide smaller amounts.

Consumption of liver and raw or undercooked eggs is not recommended during pregnancy, while intake of tuna fish — another good source — is restricted. These factors further reduce pregnant women’s chances of reaching their req-uirement for vitamin D.

Questions have been raised over the role of food fortification and also a possible supplementation policy for pregnant women. However, more research is necessary to determine the benefit, correct dosage and timing of vitamin D supplementation in pregnancy.

•  Iron
Iron requirements increase to 15mg/day, even with improved absorption during pregnancy. The total pregnancy requirement for iron is approximately 1,000mg, mainly in the second and third trimesters. Adequate iron intake prevents maternal iron deficiency anaemia (IDA) and ensures adequate oxygen supply to the foetus.

The prevalence of IDA varies between countries, but the World Health Organization (WHO) estimates that approximately 2.5 million pregnant women have IDA. Immigrant women and women from lower socioeconomic groups have the highest risk of developing it. It is likely that many women enter pregnancy with low iron stores.

IDA is associated with a reduced ability to tolerate haemorrhage, poor maternal weight-gain, increased risk of infections, poor wound healing, and post-partum depression. For infants, IDA reduces infant birthweight and increases the risk of pre-term birth and perinatal mortality. Many pregnant women in Ireland are recommended to take an iron supplement when they enter the second trimester. However, it is unclear whether supplementation of non-anaemic pregnant women is helpful.

A Cochrane review in 2006 stated that there is not enough information available to recommend routine iron supplementation in pregnancy.

Additionally, the amount of iron absorbed from supplements is very little and side effects include abdominal discomfort and constipation. If women need an iron supplement, they should take it alone and not as part of a pregnancy multivitamin (other nutrients such as calcium and magnesium present in multivitamins can inhibit absorption) and it should not be taken with milk.

Iron from food sources is better absorbed and tolerated than supplements. Two types of iron are found in foods: haem iron and non-haem iron, the former being best absorbed. Haem iron is found in red meats such as beef and lamb. Liver, an excellent source of haem iron, is not recommended for pregnancy. Non-haem iron is found in green vegetables, egg yolks, dried fruit, beans and fortified breakfast cereals.

Absorption of non-haem iron is promoted by vitamin C (from fruit and vegetables) included at the same meal and inhibited by fibre, tannins (found in tea and coffee) and phytates (found in bran cereals).

Irish data
In an ongoing study at the National Maternity Hospital, Dublin, nutrient intakes were examined from the food diaries of 250 pregnant women. Only 5 per cent of women met requirements for folic acid, 15 per cent for calcium and iron, and a mere 1 per cent of women met vitamin D recommendations.

A quarter of women consumed the recommended ‘five-a-day’ of fruit and vegetables, while only 3 per cent consumed five portions of dairy products per day. Over half of the women surveyed consumed more than three servings of foods high in fat and sugar.

The women in this study were mainly well-educated, middle-income women. These results clearly highlight the need for more education about the importance of healthy eating in pregnancy.

Most pregnant women are highly motivated to make positive behaviour changes, giving healthcare professionals a great opportunity to encourage and support these changes. Making healthy dietary changes in pregnancy may have benefits well beyond gestation for both mother and baby.

References on request.

• Ciara McGowan, PhD Research Dietitian, University College Dublin and the National Maternity Hospital. Member of the Irish Nutrition and Dietetic Institute.

www.indi.ie

• Prof Fionnuala McAuliffe, Consultant Obstetrician, National Maternity Hospital & School of Medicine and Medical Science, University College Dublin.

Putting on a little weight as you get older may be no bad thing — in fact, it might just be the secret to longevity.

Australian research suggests that over-70s live longest if their BMI is between 26 and 27, despite guidelines recommending a target of 25 or less.

The figures, from almost 25,000 older Australians in the ongoing ‘Men, Women and Ageing’ longitudinal study, join an emerging body of evidence suggesting that being overweight becomes less of a health hazard the older people get.

Over-70s could also relax a little when it came to alcohol, the researchers suggested. The risk of all-cause mortality was lower in men having up to four drinks a day than those not drinking at all. However, the risk was reduced still further by having one or two alcohol-free days a week, they found.

For women, having one or two drinks per day was better than having none at all, but there was not enough data to establish whether having alcohol-free days made any difference.

Study leader Dr Deirdre McLaughlin, a researcher at the University of Queensland’s school of population health, said the findings were “a good-news story” for older people. Current health recommendations were largely extrapolated from younger age groups, she said, while very little research had been done specifically on over-65s.

Study subjects were recruited in 1996, at which time the women were aged 70-75 and men aged 65-79. They have been surveyed every three years since.

The study found no such surprises for exercise or tobacco use, however, with the results bearing out the expected increased mortality risk for sedentary adults and smokers.

The BMI findings build on a 2009 meta-analysis published in The Lancet, which found that BMI was a powerful predictor of mortality in younger adults but the effect waned past the age of 70.

Australasian Journal on Ageing 2010; online. Doi: 10.1111/j.1741-6612.2010.00498.x

Paula Mee offers some practical tips in helping patients with high blood pressure to manage the amount of salt in their diets.

Few patients with high blood pressure have dull headaches, dizzy spells or more nosebleeds than normal. Many have no signs or symptoms, even when blood-pressure readings are dangerously high. For many patients, the problem is picked up in routine appointments and they are taken somewhat aback after a number of blood-pressure checks, when their hypertension is confirmed — primary hypertension, with no identifiable cause, or secondary hypertension, caused by an underlying condition.

Of the vast majority with primary hypertension, some struggle with the fact that the condition tends to develop gradually over many years, yet they are only given a few months to see if they can positively improve it by changing their lifestyle. Some concede that they no longer bother with exercise or eating healthier, because their ‘blood pressure is normal’ again, when taking medication.

Here are 10 diet and lifestyle pointers for patients living with hypertension:
1.    If a patient has high blood pressure, they are more likely to have other components of metabolic syndrome. This is a cluster of disorders found together, including increased waist circumference, high triglycerides, low high-density lipoprotein or good cholesterol, high blood pressure and high insulin levels. The more of these you have, the greater your risk of developing diabetes, heart disease or stroke;

2.     It is not a question of medication or lifestyle changes; both are critical for effective treatment. Regardless of what medication the patient is taking, they will also need to make lifestyle changes to manage their blood pressure. These include eating less processed food with added salt, drinking alcohol in moderation, making time to exercise, quitting smoking and losing weight;

3.     The more a person weighs, the more blood they need to supply oxygen and nutrients to their tissues. As the volume of blood circulated through their blood vessels increases, so does the pressure on their artery walls. Even a modest weight loss (between 5lbs and 7lbs) can lower blood pressure;

4.    People who are inactive tend to have higher heart rates. Many of them are overweight too. The higher a person’s heart rate, the harder their heart works with each contraction — and the stronger the force on their arteries;

5.     The average daily salt intake in Ireland is high — approximately 10g in adults. That is about a dessertspoon in size. Although we need some salt in our diets, this intake is well in excess of most people’s requirements. The short-term target is to reduce the salt intake to 6g per day, with less for children. That is about a teaspoonful.

6.    If a person has hypertension, they should ‘shake’ the salt habit. Too much salt in one’s diet can cause fluid retention, which increases blood pressure and risk of stroke.

• Patients should be advised to add little or no salt when cooking. There is no need to add salt to water when cooking rice, pasta or potatoes — no matter what the pack says! They should learn to adapt recipes and flavour food instead with black pepper, herbs, garlic, spices or lemon juice;

• They should have the black pepper grinder on the table only — no salt;

• When shopping, they should avoid the obvious highly salty foods such as crisps, popcorn, salted nuts, anchovies, smoked fish, bacon/other processed meats and ready meals;

• Salt is present also in cheese, soups and sauces, and even in some foods in which you may not expect to find salt — bread, breakfast cereal and even biscuits;

• Watch out for lower-salt versions of stock cubes and seasonings like soya and Worcester sauce;

• Choose no-added salt or lower-salt versions of tinned foods such as sweetcorn and baked beans. Buy tuna or salmon canned in olive oil or spring water rather than brine;

7.    Patients should be advised to check the guideline daily amounts (GDAs) or the nutritional information on packs and try to pick lower salt options if they have a choice between two similar foods. Salt often appears as sodium on food labels. 6g of salt = 2.5g of sodium. To convert sodium to salt, multiply the sodium figure by 2.5.

If you want to know what is ‘a lot’ or what is ‘a low-salt food’:

• 1.25g salt (equivalent to 0.5g sodium) or more per 100g of a food is considered a lot;

• 0.3g salt (equivalent to 0.12g sodium) or less per 100g of a food is low salt/sodium;

• 0.1g salt (equivalent to 0.04g sodium) or less per 100g of a food is very low salt/sodium;

8. Advise your patients to eat a ‘rainbow’ of fruit and vegetables. These are a great source of potassium. Potassium helps balance the amount of sodium in the body’s cells. If a person does not eat enough potassium or retain enough potassium, they may accumulate too much sodium in their blood and then, blood pressure rises. People should fill their plates with colour. This will help to boost the intake of vitamins and minerals such as potassium.

The DASH (Dietary Approaches to Stop Hyper-tension) trials have found that a diet containing approximately 8-10 servings of fruits and vegetables, and 2-3 servings of low-fat dairy foods, can substantially lower blood pressure.

Patients should aim for an intake of at least five portions of fruit and vegetables per day. Swap the mid-morning scone or biscuits for a piece of fruit, for example, and fill half of the plate with vegetables at dinner time.

Top potassium-containing foods include: baked potatoes, avocados, lentils, carrots, kidney beans, orange juice, prune juice, milk, tomato juice, chickpeas, bananas and broccoli;

9. Patients should be advised to moderate their drinking. If they choose to drink alcohol, they should do so in moderation. Over time, heavy drinking can increase risk of stroke. Having more than two or three drinks in one night can also temporarily raise a person’s blood pressure, as it may cause the body to release hormones that increase blood flow and heart rate.

If a person is very stressed, smoking and excess alcohol may only increase high blood pressure further. Men are advised to drink no more than 21 units of alcohol a week and women are advised to drink no more than 14 units a week. A unit is a very small glass of wine or half a pint of beer or lager. A measure of spirits is 1.5 units. Binge-drinking increases risk of stroke so alcohol intake should be spread out over the week;

10.    Hypertensive patients should switch to healthier fats like omega-3 fats and monounsaturates, instead of saturated and trans fat. Oily fish like salmon, mackerel, herring, fresh tuna and sardines are rich in both omega-3 fats, which can help to protect against blood clots and reduce the risk of having a heart attack, as well as being good, vitamin D-rich foods.

• Paula Mee, Dietitian, BSc Dip Diet MSc in Health Sciences MINDI, www.paulamee.com

Cardiologists have shown for the first time in humans that fish oil supplements have anti-fibrillatory effects by reversing the structural or cellular-level abnormalities that occur in response to persistent atrial arrhythmias.

Saurabh Kumar and colleagues from the Royal Melbourne Hospital randomised 49 patients undergoing reversion of persistent atrial fibrillation (AF) or atrial flutter (AFL) to sinus rhythm, who were randomised to a control group (n=26) or an omega-3 group (n=23).

The treatment group, who took 6g of commercially-available fish oil a day for an average of 70 days prior to the procedure, demonstrated a significant reduction in the incidence of left atrial stunning after reversion of AF or AFL to sinus rhythm.

The group also demonstrated a marked attenuation of the expected fall in left atrial appendage (LAA) emptying velocities, greater preservation of LAA emptying fraction and a reduction in the grade and incidence of new or increased spontaneous echocardiographic contrast (SEC).

The researchers noted that these effects were independent of other factors proven to strongly influence the severity of left atrial stunning: duration of proceeding arrhythmia, type of arrhythmia (AF or AFL), presence of structural heart disease and left atrial size.

“The present data implicates that chronic n-3 PUFA supplementation may target components of cellular and/or structural changes that occur in response to persistent atrial arrhythmias and by doing so, may reverse tachycardia mediated atrial cardiomyopathy,” the researchers wrote in the journal Heart Rhythm.

They added that the results of their single-blinded trial — the first human study to show that fish oils can attenuate stunning regardless of the type and duration of preceding arrhythmia — could only be viewed as preliminary. “However, clear differences were noted between the two groups,” they concluded.

Heart Rhythm 2011; Online. doi:10.1016/j.hrthm.2011.01.014