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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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

How to measure mood in nutrition research

The January Nutrition Society Paper of the Month is from Nutrition Research Reviews  and is entitled “’How to Measure Mood in Nutrition Research”.

Mood is widely assessed in nutrition research, usually with rating scales. We have been researching the effects of food on mood for over twenty years, which has highlighted concerns about how mood is measured, one result of which is this review; we have been working on it intermittently ever since.

From early on, we had serious concerns because the mood effects of food are often fragile and hard to replicate, yet many foodstuffs are marketed and consumed on the assumption that they affect mood, at least by being pleasurable, and perhaps also by having functional effects on the nervous system. One of the striking but hard to substantiate claims made repeatedly since the 1960s was that sugar has drug-like effects by artificially elevating mood, followed by a rebound ‘sugar blues’ requiring further consumption of sugar. Consequently, we have largely focused on sucrose in our research.

There are some basic problems with how mood is measured. The questionnaires used to rate mood have not always been shown to be sensitive to relatively rapid ‘transient’ changes in mood because they were designed to compare mood over different days or weeks, as in the study of depression.  It is therefore possible that nutrition research often fails to detect mood effects of food that actually exist.

Another difficulty is that the use of different rating scales in different combinations, given at different times, in different experimental designs, propagates inconsistent and uncertain results. Mood rating can be affected by many aspects of an experiment other than the food given, and generally research participants should be blind to the experimental manipulation.

There are other more theoretical difficulties: It is commonly assumed that mood is what mood scales measure, most often arousal, and positive versus negative mood; It is also often assumed that rated mood is an unproblematic measure of experienced subjective mood, which is in turn related to underlying physiological condition. So for instance rating oneself aroused means you feelaroused and are aroused by measures such as skin conductance and heart rate. In reality, rated mood, phenomenological mood and physiological state are correlated with each other, but can vary separately and be affected by different causes. For instance, it is possible for mood ratings to change without there being an underlying conscious experience of change. As well as improving methods of rating mood, there is a need for a better theory of how mood and mood rating work. This review along with an earlier paper in Neuroscience and Biobehavioral Reviews is our attempt to improve practice in the assessment and understanding of mood in nutrition research.

– Professor Richard Hammersley

This paper is freely available for one month via the following link: journals.cambridge.org/ns/Jan15

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

Does the Baby-Friendly Hospital Initiative increase breastfeeding?

The July Nutrition Society Paper of the Month is from Public Health Nutrition and is entitled ‘Evaluating the impact of the Baby-Friendly Hospital Initiative on breast-feeding rates: a multi-state analysis’.

PHN NS POM image

Not only does breastfeeding improve the health of mothers and infants, but it also reduces health care costs and has a smaller environmental footprint than formula-feeding. Although currently three-quarters of US women start breastfeeding, women with lower education are much less likely to try. One known barrier is the lack of breastfeeding support that women receive in the hospital.

The Baby-Friendly Hospital Initiative (BFHI) was developed by the World Health Organization and UNICEF in 1991 to promote, protect, and support breastfeeding within the birth facility and after. While more than 20,000 hospitals and birth centers in 156 countries have been designated as Baby-Friendly, there are only 182 BFHI facilities in the US in 43 states and DC. Despite the success of the BFHI on breastfeeding practices internationally, research in the US has been limited. We wanted to determine whether the BFHI increased breastfeeding overall and, particularly, whether it improved breastfeeding among women with lower education.

Using data from 5 states, we compared breastfeeding outcomes between 11,723 mothers who gave birth in 13 BFHI hospitals and 13,604 mothers from 19 non-BFHI birth facilities. Although overall women who gave birth in BFHI hospitals were no more likely to start or continue breastfeeding than women from non-BFHI facilities, we showed that it benefited women with lower education. Only 78% of women with a high school degree or less started breastfeeding, but we found that those women who delivered in BFHI hospitals were 3.8 percentage points more likely to start breastfeeding than women with the same educational attainment who delivered in non-BFHI facilities. In contrast, 90% of women with more than a high school degree started breastfeeding, but giving birth in a BFHI hospital did not further increase their likelihood of starting or continuing breastfeeding.

What are the implications of these findings?

Women with low education benefited the most from giving birth in Baby-Friendly hospitals, suggesting that the BFHI may be one way to help decrease socio-economic disparities in breastfeeding. Currently only 7% of births in the US are in BFHI facilities. Our results support the recommendation to increase the number of BFHI-accredited birth facilities to encourage women to start breastfeeding, but more may be needed to help women continue breastfeeding after discharge.

This paper is freely available for one month via the following link: journals.cambridge.org/ns/jul14

Implications of inconsistent anaemia policies for children and adolescents in Africa

Africa_World_medicine

The January Nutrition Society Paper of the Month is from Public Health Nutrition and is entitled ‘Implications of inconsistent anaemia policies for children and adolescents in Africa’

Almost 50 % of children and adolescents in sub-Saharan Africa are anaemic, which has profound effects on their intellectual and physical development and their chance of survival. Evidence-based policies are essential in order to reduce anaemia, but as it results from interdependent factors there are difficulties in the development of cohesive policies for diagnosis, prevention and treatment. Nutritional requirements are also derived from food intake studies in healthy Western children and may not always be appropriate in a developing country situation.

This study evaluated the quality of these policies and the extent to which they were based on evidence relevant to the African context. Recommendations are made for improving the policy-making process.

What have we done?

A comprehensive and unrestricted database and website search for guidelines (as defined by WHO). We identified policies which targeted anaemia diagnosis, treatment and prevention in children and non-pregnant adolescents (18 years old) in Africa. Policy quality was assessed using   ‘The Appraisal of Guidelines for Research and Evaluation instrument (AGREE II)’ without any adaptation. A search for high-quality evidence in the Cochrane Library was performed to assess the evidence base for policies.

What did we find?

A total of 1247 documents were identified and screened and 46 were selected for analysis. There was policy consensus on usefulness of iron supplements, the need to treat co-morbidities and the use of blood transfusions for severe anaemia. Information about diagnosis was scarce, and messages regarding the control of anaemia were mixed. Few of the policies were tailored for the African context, and they were located on several websites hosted by different health programmes.

There were examples of ambiguities within individual policies and inconsistencies between policies on key issues. For example, the definitions for categories of anaemia severity were inconsistent, specific age groups were often not identified, and when target age groups were specified these varied between policies.

Does evidence support the anaemia policies?

Few policy documents described their evidence base, and it was not possible to draw conclusions on how policy changes were related to evidence, or the recommendations made. Anomalies within and between policies, and lack of generalisability, limited the option to pool data.

Is there any way forward?

Context-specific research is required to fill evidence gaps, to identify need for local adaptations, and for advice on clinical interventions. Global policy may need to be modified by WHO at the regional level to allow for these factors. Appropriate guideline development and peer review groups should be constituted and rigorous methods for policy updates and development should be established. A comprehensive review of existing research evidence concerning anaemia in African children is urgently needed so that knowledge gaps can be identified and prioritised and research commissioned to fill the gaps. Context-specific issues concerning, safety and benefits of iron supplementation in infection endemic areas, or in HIV infection, sickle cell disease, or young infants are important.

There are many issues and wider discussion is required on this important contributor to child survival.

This paper is freely available for one month via the following link: journals.cambridge.org/ns/jan14

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 NutritionPublic Health NutritionNutrition Research ReviewsProceedings of the Nutrition Society and Journal of Nutritional Science). This paper is freely available for one month.

Improving mood with the right food

Nutrition and mood

The December Nutrition Society Paper of the Month is from Nutrition Research Reviews and is entitled ‘Food-derived serotonergic modulators: effects on mood and cognition’

Food is a primary requirement to live. Yet, in Western societies where food is abundantly available, food could also be used as a powerful tool to increase mental well-being. Stress-related mental disorders like mood or anxiety disorders are the most prevalent and burdensome psychiatric disorders. They are characterized by low mood states and cognitive impairments like reduced learning and memory. Thus, the exploitation of resilience or mood/cognition enhancing food is of extreme value.

According to the world-wide web, high tryptophan (Trp) containing foods (e.g. chicken, soybeans, cereals, tuna, nuts, and bananas) improve mood. Trp is an essential amino acid and a precursor of serotonin, a monoamine that plays a central role in the regulation of emotion, mood and cognition. It is hypothesized that in mood disorders like depression central serotonin levels are low. Although ‘Trp-containing food for mood’ appears as an attractive concept to build resilience, it is likely that there is a delicate balance between Trp levels in food and optimal effects on mood and cognition, and that this delicate balance is influenced by the serotonergic state of the individual. Furthermore, while there is a correlation between high Trp levels in food and mood improvement, it is not as straightforward such that eating a bunch of bananas each day will help you get a better mood.

Hence, this review provides an overview of the effects of varying levels of food-derived Trp on mood and cognition in healthy individuals, and individuals at risk for mood disorders. We also discuss the effects of plant extracts with a modest ‘antidepressant’ functional profile.

Together the studies suggest that there is an inverted U-shaped curve for plasma Trp levels with low and too high Trp levels impairing cognition, and moderate to high Trp levels improving cognition. This relationship is found for both healthy and vulnerable subjects. Whereas this relationship may also exist for mood, the inverted U-shaped curve for plasma Trp levels and mood may be based on different Trp concentrations in healthy versus vulnerable individuals. That is, there is a much more profound decrease in mood of vulnerable subjects compared to healthy subjects in the lower brain Trp range.

When brain Trp levels are in the optimum range, mood in vulnerable subjects is comparable with mood in healthy subjects. And when Trp levels are further elevated, positive mood effects are detected with small increases in vulnerable healthy individuals, and only with large increases in healthy subjects.  Finally, mood in both healthy and vulnerable subjects is negatively affected when Trp levels are excessively high.

Ultimately, insight in the concentrations of Trp and other serotonergic components in food having beneficial effects on mood and cognition in healthy, but particularly vulnerable, subjects may help the nutrition industry to adapt food to support our mood and cognition.

This paper is freely available for one month via the following link: journals.cambridge.org/ns/dec13

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 NutritionPublic Health NutritionNutrition Research ReviewsProceedings of the Nutrition Society and Journal of Nutritional Science). This paper is freely available for one month.

via Food-derived serotonergic modulators: effects on mood and cognition « Medicine « Cambridge Journals Blog.

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