Better Diet Quality may Improve Cognition in Children

Author: Eero Haapala

A recent Finnish study shows that better diet quality is related to better cognitive performance among 6–8 year old children. The results published in the British Journal of Nutrition are part of the Physical Activity and Nutrition in Children (PANIC) Study conducted at the University of Eastern Finland. The study investigated the relationships of the Baltic Sea type and the Dietary Approaches to Stop Hypertension (DASH) dietary patterns to cognition in a population based sample of 428 children aged 6–8 years. Stricter adherence to the Baltic Sea type and the DASH dietary patterns, indicated by a higher consumption of vegetables, fruit and berries, fish, whole grain products, and a lower consumption of red meat, was associated with better cognitive performance. Of the components of these dietary patterns particularly higher consumption of vegetables, fruit and berries and fish and a lower consumption of red meat was related to better cognition. The associations of dietary patterns with cognition were stronger in boys than in girls. In conclusion, a poorer diet quality was associated with worse cognition in children and the relationship was stronger in boys than in girls.

This article is freely available for two weeks via the following link: journals.cambridge.org/bjn/panic

Source: Better Diet Quality may Improve Cognition in Children « Journals in the News « Cambridge Journals Blog

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Do higher vitamin E levels have a protective effect on pulmonary condition in Cystic Fibrosis?

The  July Nutrition  Paper of the Month is entitled ‘Vitamin E intake, The affect of  levels and pulmonary function in children and adolescents with cystic fibrosis’

Cystic fibrosis (CF) is a life-threating genetic disorder, characterised by chronic pulmonary inflammation that causes a gradual, progressive decline in pulmonary function, partly due to oxidative stress. Most patients have pancreatic insufficiency, leading to intestinal malabsorption of fat and fat-soluble vitamins. Therefore, lifelong treatment with fat-soluble vitamins such as vitamin E has become standard care.

It has been suggested that higher vitamin E levels, expressed as serum α-tocopherol levels, have a protective effect on pulmonary condition in CF. However, serum α-tocopherol levels are compromised during a pulmonary exacerbation and recover with resolution of the inflammation. Likewise, chronic pulmonary inflammation may reduce levels, and the suggested association between vitamin E levels and pulmonary function might be secondary.

Whether current recommendations for vitamin E supplementation are optimal for preventing deficiency and whether higher serum α-tocopherol levels have beneficial effects on pulmonary function are subjects of debate. The present paper studied the association between vitamin E intake (dietary intake plus prescribed supplementation), the coefficient of fat absorption and chronic inflammation on serum α-tocopherol levels, and the long-term effect of both serum α-tocopherol levels and chronic inflammation on pulmonary function in paediatric patients with CF.

Results

In our study sample, we found no clear effect of vitamin E intake, the coefficient of fat absorption or chronic inflammation on serum α-tocopherol levels. Moreover, patients with CF received vitamin E supplementation at half the CF-specific recommended dosage; nevertheless, serum α-tocopherol levels were normal.

Furthermore, we found that chronic inflammation was inversely associated with pulmonary function and we found no association between serum α-tocopherol levels and pulmonary function. Paradoxically, we even found an overall trend towards a lower pulmonary function in those with higher serum α-tocopherol levels.

Conclusions

Our results suggest that the CF-specific vitamin E recommendations are higher than necessary to prevent deficiencies. Therefore, vitamin E dosages of 50% of the recommendations could be used, at least initially. We found no evidence that higher serum α-tocopherol levels had protective effects on pulmonary function in paediatric patients with CF. Moreover, the finding of higher serum α-tocopherol levels in patients with lower pulmonary function casts doubt on the hypothesis that vitamin E has therapeutic benefits.

This paper is freely acvailablke via the following link for one month: journals.cambridge.org/ns/jul15

Authors: Janna W. Woestenenk, Nancy Broos, Rebecca K. Stellato, Hubertus G. M. Arets, Cornelis K. van der Ent and Roderick H. J. Houwen

Nutrition Society Paper of the Month

Each month a paper is selected by one of the Editors of the five Nutrition Society Publications (British Journal of Nutrition, Public Health Nutrition, Nutrition Research Reviews, Proceedings of the Nutrition Society and Journal of Nutritional Science). This paper is freely available for one month.

Pregnant women lack guidance on iodine intake levels


Pregnant women are not getting enough information about the need to include iodine in their diets, despite high awareness of general advice for pregnancy nutrition.

While 96% of pregnant women surveyed by researchers were aware of general nutritional recommendations for pregnant women, only 12% were aware of iodine-specific advice.

The study, published in the British Journal of Nutrition, estimated the median intake of iodine during pregnancy was 190 micrograms (ug) per day, with 74% consuming less than the World Health Organisation (WHO) recommended intake of 250ug daily.

Iodine is required for the production of thyroid hormones, which are crucial for fetal development with links between iodine deficiency and developmental impairments.

Dr Emilie Combet, who led the reserch at the University of Glasgow, said: “Women aren’t receiving the message about the importance of iodine in pregnancy, meaning they cannot make informed choices to ensure they get the amount they require.”

Iodine deficiency affects 1.9 billion people globally and is the most preventable cause of intellectual disability. The UK is ranked 8th in a list of iodine-deficient countries in the world.

The main sources of iodine-rich foods are seafood and dairy products, and in some countries iodine-fortified salt or bread. In the UK, the Reference Nutrient Intake (RNI) for adults is 140ug per day, with no proposed increment for pregnant and lactating women.

Unborn children and young infants are entirely reliant on their mother for iodine supply, making babies and pregnant or lactating mothers the most vulnerable groups of the population.

At present there is no recommendation for routine iodine supplementation in the UK unlike folic acid and Vitamin D, or routine testing in pregnancy that would reflect iodine levels, as there is with iron.

The study surveyed 1,026 women across the UK who were pregnant or mothers of children aged up to 36 months. Participants were asked about their awareness of nutritional guidelines and completed a food frequency questionnaire.

Knowledge of iodine-rich foods was low, with 56% unable to identify any iodine-rich food and the majority wrongfully believing dark green vegetables and table salt had high levels. Most, 84% were unaware that iodine from diet is important for the healthy development of the unborn baby, and only 11% had heard about iodine from a healthcare professional.

Dr Combet said: “Iodine is crucial during pregnancy and the first months of life, to ensure adequate brain development, but achieving over 200ug a day of iodine through diet requires regular consumption of iodine-rich foods such as milk and sea fish. Not everyone will have the knowledge, means or opportunity to achieve this.

“There is an ongoing debate as to whether there should be some form of fortification of food with iodine. Iodine-fortified salt is common in other countries, but using salt as the delivery method has raised concerns since it is perceived to clash with public health messaging around reducing salt intake to combat high blood pressure. However, other countries have demonstrated that both measures could be held simultaneously. We need to work toward a solution.

“The most important issue to come from this study, however, was the lack of awareness of the important role iodine plays in fetal development and how to consume adequate levels of this essential mineral. This is something that needs to be addressed. Our current Yorkhill Children Charity – funded project us developing tools and resources for health care professionals and women either pregnant or planning a pregnancy.”

This paper is freely available for 2 weeks

Related links

Dr Emilie Combet: researcher profile

Media enquiries: stuart.forsyth@glasgow.ac.uk / 0141 330 4831

Socio-economic inequalities in diet in UK adults

The December Nutrition Society Paper of the Month is from British Journal of Nutrition and is entitled “Socio-economic dietary inequalities in UK adults: an updated picture of key food groups and nutrients from national surveillance data”.

Study written in the British Journal of Nutrition found that those higher up on the socio-economic ladder are generally healthier and are less likely to be obese, and what people eat varies across different social groups.  It’s a reasonable assumption that these two phenomena are connected, but in the UK social inequalities in diet have not been comprehensively assessed in recent years.  While plenty of studies have documented socioeconomic differences in fruit and vegetable consumption, less is known about other food groups and nutrients, including fish and processed meat.  We also need to better understand the extent to which inequalities in diet differ across different indicators of socioeconomic position such as income, education and occupation.  This matters because unless we can understand the social and economic pattern of diet we will struggle to find the right strategies to improve public health for everyone.

Our study examined foods and nutrients eaten in a nationally-representative sample of 1491 UK adults stratified by socioeconomic position (SEP).  Data came from the rolling programme of the National Diet and Nutrition Survey 2008-2011. We calculated average intakes of five foods and nutrients across three indicators of SEP: equivalised household income, occupational social class, and highest educational qualification. The choice of foods and nutrients for this study was informed by the Scientific Advisory Committee on Nutrition’s (SACN) 2008 report on the nutritional status of the British population. This report expressed concern over whether people in the UK were eating enough fruit, vegetables and oily fish; and whether they were eating too much red and processed meat, sugar and saturated fat.

We found that, not only did the sample as a whole not meet recommended intakes, those of a lower SEP fared the worst.  For the food groups, the least educated adults ate 128grams a day less fruit and vegetables than the most educated; the lowest occupational class consumed 26grams a day more red and processed meat than those in higher managerial occupations; and the highest income group were four times more likely than the lowest to have consumed any oily fish.  The amount of calories from sugars (non-milk extrinsic sugars) was around two percentage points higher in the lower SEP groups. No pattern of saturated fat consumption was found for any of the socio-economic indicators.

So, what does this mean for action to tackle health inequalities?  Our study provides up-to-date evidence about specific food groups  that are of concern for public health nutrition, and is a reminder of the importance of monitoring dietary trends in a time of entrenched and rising inequality. It also adds important detail in terms of how different aspects of life experience and social position can affect what we eat. For instance, income or occupation may affect our material ability to access a healthy diet, or education may equip us to make healthier choices. When developing policies and interventions to tackle unhealthy diet, it is vital to take into account these different aspects of our lives.

This paper is freely available for one month via the following link: journals.cambridge.org/ns/dec14

Organically Grown Foods May Offer Greater Health and Safety than Foods Conventionally Grown

Scientists have long recognized the dangers of cadmium (Cd) exposure to the human body. This heavy metal is emerging as a major cause of vascular disorders, common cancers, osteoporosis, and kidney disease, and can also cause damage to the body’s reproductive and neurological systems. While tobacco smoke can be a significant source of exposure for smokers, the primary source of cadmium exposure for nonsmokers is through consumption of contaminated plant-based foods.
A survey of all previous pertinent research (meta-analysis), appearing recently in the British Journal of Nutrition, concluded that organically grown foods are on average 48 percent lower in Cd than conventionally grown foods. Now, in an invited commentary appearing in the same journal, Saint Luke’s Mid America Heart Institute cardiovascular research scientist James J. DiNicolantonio, Pharm.D., and Mark F. McCarty, B.A., place this finding in the context of the growing epidemiology linking Cd exposure to adverse health outcomes, and conclude that consistent consumption of organic foods over a lifetime could be expected to favorably influence health and mortality risk.
“For years, nutritionists and consumers have struggled with the question, ‘is organic really better?’” said Dr. DiNicolantonio. “What analysis of this research reveals is that, due to the serious health impacts of cadmium exposure and the markedly lower levels of Cd in organically grown foods, the long-term consumption of such foods is likely to be notably protective with respect to a wide range of common pathologies.”
Citing previous studies, DiNicolantonio and McCarty suggest that Cd contamination of chemical fertilizers may be primarily responsible for the higher Cd content of conventionally grown foods.
Dietary Cd is found primarily in grains, green vegetables, root vegetables, tubers, organ meat, and shellfish; hence, in nonsmokers, most Cd exposure derives from plant foods usually thought to be healthful. Although tiny amounts of Cd are excreted in the urine, the human body has no physiological mechanism for regulating its Cd levels, so levels tend to accumulate over time, with a half-life of 10-30 years. Clinically available chelation therapies are not helpful for coping with chronic Cd exposure, as most Cd accumulates in the interior of cells where chelating drugs cannot reach. Fortunately, research has shown that dietary zinc functions to counteract Cd toxicity. Cd is an important inducer of oxidative stress, and rodent studies suggest that the antioxidant activity of spirulina may also lessen the adverse health impact of Cd already in the body.
Nonsmokers who consistently choose organic foods throughout life, as compared to nonsmokers who rely on conventional agriculture, could be expected to experience about half the Cd exposure. By surveying recent epidemiological findings correlating body Cd levels with mortality risk, DiNicolantonio and McCarty estimate that consistent use of organic foods could result in a 20 percent reduction in total mortality.
“Choosing organic foods, avoiding tobacco smoke, and preventing or correcting iron deficiency, are three smart strategies for keeping your body burden of Cd relatively low,” DiNicolantonio notes. “Iron deficiency increases the intestines’ absorption of dietary Cd, and this probably explains why women tend to have higher body levels of Cd than men.”
The recent meta-analysis of organic foods also found that such foods tend to be about 30 percent higher in antioxidant phytochemicals, likely because many of these phytochemicals function to protect plants from pests; crops treated with pesticides may have less need for this protection. DiNicolantonio and McCarty point to research suggesting that higher dietary intake of polyphenolic antioxidants such as flavonoids may provide some protection to the vascular system.
The Commentary, “Are organically grown foods safer and more healthful than conventionally grown foods?” is  freely available for 30 days at journals.cambridge.org/bjn/organicSep14

The original review, “Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses” is an open access paper available at journals.cambridge.org/bjn/organic

Effect of oat intake on glycaemic control and insulin sensitivity

Diabetes blog

The August Nutrition Society Paper of the Month is from the British Journal of Nutrition and is entitled ‘Effect of oat intake on glycaemic control and insulin sensitivity: a meta-analysis of randomised controlled trials’.

Diabetes mellitus (DM) is one of the most serious chronic diseases, the incidence rate is consistently increasing all over the world however it used to be most common (especially type 2) in developed countries. The greatest increase in prevalence is, however, expected to occur in Asia and Africa. Perhaps a “Western-style” diet is the most important factor of the DM incidence increase in developing countries. There is no obvious cure for DM and the main management is keeping blood glucose levels as close to normal as possible, without causing hypoglycemia. A number of efficacy trials provided strong evidence for lifestyle change programmes in preventing type 2 diabetes among individuals with impaired glucose tolerance. Exploring a healthy diet and lifestyle to get the blood glucose levels controlled is critical for the prevention of type 2 diabetes.

Oat was recognized as a healthy food in the mid 1980s helping prevent heart disease and then it became more popular for human nutrition. Recent studies in food and nutrition have revealed the importance of its various components, such as dietary fiber especially, β-glucan, minerals and other nutrients. Oats and oat-enriched products have been proven to control blood glucose and are helpful in the treatment of diabetes. However, the results from clinical trials in humans investigating the effect of oat intake on glycemic control and insulin sensitivity are inconsistent. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) to quantitatively assess whether oat intake has beneficial effect on glycemic control and insulin sensitivity and aim to make some suggestions for diabetes diet based upon what we found.

What have we done?

We conducted a literature search in PubMed, ScienceDirect Online and the Cochrane Library (up to October 2013) for RCTs that assessed the effect of oat intake on glucose control and insulin sensitivity. A random-effects model was used when overall pooled studies showed significant heterogeneity. Otherwise, a fixed-effects model was adopted. Quality assessment was conducted according to the modified Jadad scale.The sensitivity analyses and dose-effect calculations were also done to strengthen this work.

What did we find?

A total of 569 articles were initially identified after duplicates removed and 15 eligible articles were selected for analysis. The total numbers of participants were 673 in all studies. There was a slight decrease in fasting glucose concentrations, glycated hemoglobin and HOMA-IR in subjects after oat intake, but the difference was not significant. Subgroup analysis suggest that additional long-term and high-quality RCTs conducted in human subjects with parallel design are needed to further investigate the effect of oat intake on fasting glucose, which may provide evidence for the therapeutic potential of oats in diabetic patients or preventing glucose dysregulation in those with risk factors for DM.

This paper is freely available for one month via the following link: journals.cambridge.org/ns/aug14

Consuming probiotics decreases the duration of common respiratory infections

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A review collating the work of dozens of researchers across the world, published this week in the British Journal of Nutrition, found that consuming probiotics decreased the duration of common upper respiratory tract infections (RTI) by up to a day.

This kind of assessment, called a systematic review, is widely accepted by many regulatory and policy-setting organizations worldwide as the best means to weigh evidence for a given intervention. This review on probiotics provides strong evidence for the value of probiotics as part of a healthy diet.

This systematic review examined studies that provided healthy adults and children with probiotics (specifically Lactobacillus and/or Bifidobacterium strains present in yoghurt or dietary supplements) or a placebo and then tracked symptoms once a RTI was experienced.

Combining the data from these studies demonstrated that those participants who consumed probiotics had significantly fewer days of illness per person, shorter illness episodes, and fewer days absent from daycare, school or work than participants who had taken a placebo. Importantly, the majority of these studies were considered to be well-conducted, so that their results – and hence the conclusions of the meta-analyses – are likely to be reliable.

The paper’s lead author, Dr. Sarah King, affiliated with York Health Economics Consortium in the UK, commented, “The core of nutrition science is to advise on the construction of a diet that helps maintain health and reduce risk of disease. This paper shows that with the addition of live lactobacilli and bifidobacteria to your diet, the duration of upper respiratory tract infections (e.g. colds) could be shortened. Combined with results from a 2011 meta-analysis published in the Cochrane Database of Systematic Reviews, which demonstrated that probiotics can reduce the incidence of upper RTIs, the implication of these findings are significant, and could translate into cost savings and quality of life improvements.”

The paper is available here as an open access publication.

The study was funded by the Global Alliance for Probiotics, which seeks to better understand the strength of evidence of probiotic interventions.

For more information on Global Alliance for Probiotics, see http://www.gap-probiotics.org/ For more information on York Health Economic Consortium, see http://www.yhec.co.uk/

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