1. Selenium and heart disease: possible protection
New research from the University of Oveido in Spain shows the mineral selenium may help reduce levels of homocysteine, one of the key markers of heart disease, thereby protecting against the world's biggest killer.
2. Glycaemic Index and breakfast: what's the link?
Although GI has been related to diseases such as diabetes, obesity and those with CVD, the applicability of the glycaemic index (GI) in the context of mixed meals and diets is still under debate. Danish Researchers have evaluated the predictability of the GI in composite breakfast meals and come up with some interesting results.
3. Fibre ingredients: now on the rise
Cancers of the gut are one of the major causes of death from cancer, but a new review shows cancers of the digestive organs - pharynx, oesophagus, stomach or colorectum - are amongst the most preventable through changes in diet. Consumer interest in health-providing food products is currently driving the market for fibre ingredients.
4. A new hidden food allergen: lupin
Immunoglobulin E (IgE)-mediated food allergy is an important cause of acute anaphylaxis and anaphylaxis-related death. An article in the Medical Journal of Australia by researchers from the Clinical Immunology and Allergy Unit at the Royal Adelaide Hospital has identified a new source of potentially serious food allergy - lupin.
Starch firm petitions FDA: 'keep up with Australia'
The US FDA is expected to release proposed rules on how information about carbohydrates should appear on the nutrition facts panel of food labels next year. Proposals before the FDA to break fibre out of the 'Total Carbohydrate Content' listing on the label are designed to bring US rules into line with Australia and Europe.
No ban on kids TV ads in UK: for now
Britain's TV advertising watchdog, Ofcom, has concluded there is no need for tighter regulations on advertising of food products to children. Research showed television advertising does have a modest direct effect, but the significance was small compared to other factors.
Wheat bran antioxidants: link to cancer prevention
Preliminary findings of collaborative research conducted at Kansas State University and Wichita State University suggest that the antioxidant components of wheat may help prevent colorectal cancer tumours. The research focuses on a class of antioxidants found in wheat bran that appear to block the formation of mutagenic compounds.
Full stories:
1. Selenium and heart disease: possible protection (back to contents)
New research from the University of Oveido in Spain shows the trace mineral selenium may help reduce levels of homocysteine, one of the key markers of heart disease, thereby protecting against the world's biggest killer.
A Spanish research team reported that, in a group of elderly people, those with the highest selenium intake had a 63 per cent decreased risk of higher total homocysteine concentrations.
A cohort of 202 institutionalised elderly in Northern Spain were the subjects of this research on the cross-sectional association among selenium, folate and homocysteine. In previous studies, low selenium status has been associated with increased risk of cancer, cardiovascular disease and other pathologies, so selenium studies have primarily focused on its role in antioxidant defenses.
In this study, dietary selenium and serum selenium were assessed. Serum selenium is directly dependent on the quantity and the way in which selenium is ingested in the daily diet. Serum selenium was inversely associated with homocysteine levels, explaining 5.8% of homocysteine variance, while serum folate accounted for 2.2% of the variance. Even when serum levels of folate were low, subjects with the highest selenium concentration had moderately low homocysteine.
This data suggests that selenium may play a dual protective role against heart disease by serving as an antioxidant and by helping to convert the homocysteine to methionine, a harmless amino acid.
Previous studies have suggested a link between selenium deficiency and diseases as diverse as cancer, heart disease, arthritis and AIDS. It's also known that most people do not consume the recommended daily amount of the mineral, which is found in wholegrains, vegetables, nuts, and also in fish.
Previous studies have also indicated an association between raised levels of total homocysteine and stroke and heart disease. Folic acid, pyridoxine (vitamin B6), and cobalamin (vitamin B12) are also known to reduce plasma homocysteine levels, but lowering homocysteine has not yet been confirmed an effective strategy for reducing risk of stroke.
The new study also found an inverse association between protein intake and homocysteine levels in men, which could be mediated by the addition of selenium, they say.
Low selenium levels in humans have also been associated with an impact on the immune system, and a recent UK study found subjects lacking the nutrient had lower resistance to the polio virus.
2. Glycaemic Index and breakfast: what's the link? (back to contents)
Although GI has been related to diseases such as diabetes, obesity and those with CVD, the applicability of the glycaemic index (GI) in the context of mixed meals and diets is still under debate. While several tables have been published with lists of the GI of single food items, most of the time people do not eat single foods, but combine them in mixed meals.
Several studies have provided support for the predictability of the GI in mixed meals. Others, however, argue that other macronutrients of a meal - such as protein, fat, dietary fibre and sugar - interact with the carbohydrates and reduce the predictability of GI.
Researchers from the Department of Human Nutrition at the Royal Agricultural University in Denmark set out to evaluate the predictability of the GI in composite breakfast meals as predicted from table values.
The study was a randomised crossover meal test including twenty-eight healthy young men. Thirteen breakfast meals and a reference meal were tested. All meals contained 50g available carbohydrate but differed considerably in energy and macronutrient composition. Venous blood was sampled for two hours and analysed for glucose and insulin.
The research team found no association between the predicted GI and the measured GI in a wide range of different European breakfast meals. They found that the best prediction model of GI included the fat and protein content of the test meal, explaining 93% of the variation.
The researchers concluded it was "not possible to predict GI in composite breakfast meals using values from international GI tables". Based on their results, they said "it seems crucial to incorporate the total energy, fat and protein content of a meal in order to predict its GI". They also questioned "the practical usefulness of GI in the context of mixed meals and diet planning".
Cancers of the gut are one of the major causes of death from cancer, but a new review shows cancers of the digestive organs - pharynx, oesophagus, stomach or colorectum - are not purely genetic and are amongst the most preventable through changes in diet.
Professor Ian Johnson, author of the review and head of Gastrointestinal Health and Function at the Institute of Food Research, said: "The adverse effects of diet are caused by over-consumption of energy coupled with inadequate intakes of protective substances, such as micronutrients, dietary fibre and a variety of plant chemicals".
"Cancer is a complex multistage process that can take a large proportion of a person's lifespan to develop. Nutrition is potentially a powerful tool to interrupt many stages of that process, and could be much more effectively deployed by many people", he said.
Fibre ingredients on the market today range from prebiotic inulins, to traditional food ingredients such as guar gum as well as resistant starches. Consumer interest in health-providing food products is currently driving the market for fibre ingredients as food formulators are increasingly turning to new product recipes with a health promoting feature.
The walls of the gut are lined with a layer of cells, the epithelium, covered with a film of mucus. The epithelium is the first contact for food, bacteria and anything else ingested. It is the body's first line of internal defence, but can also be susceptible to the development of abnormalities over time.
The epithelium is normally renewed by rapidly dividing stem cells, which can also give rise to new growths called polyps. These usually remain benign, but some may acquire so many genetic abnormalities that they eventually form a cancerous tumour.
There is evidence that some food components including fibre, folate, polyunsaturated fatty acids, plant chemicals such as glucosinolates or flavonoids and gut fermentation products such as butyrate can provide protection at various stages of cancer formation.
For example, in research published in the same journal, enzymes called COX-2 that enable genetically abnormal cells to survive were suppressed by the flavonoid quercetin (Mutation Research 2004 Jul 13;551(1-2):245-54). Compounds can also increase the activity of detoxifying enzymes, and components in the diet have been shown to act synergistically in this way - so that they are even more effective when combined. These enzymes delete genetically damaged epithelial cells.
"Cancers of the colon and rectum are the most common cancers of the digestive organs worldwide", Professor Johnson said.
"But rates are much higher in developed countries. Colorectal cancer is clearly a disease of affluence and about 80 per cent of cases are attributable in some way to diet," he said.
Immunoglobulin E (IgE)-mediated food allergy is an important cause of acute anaphylaxis and anaphylaxis-related death. Researchers from the Clinical Immunology and Allergy Unit, Royal Adelaide Hospital have identified a new source of potentially serious food allergy - lupin.
The major allergenic foods are well known - peanuts and tree nuts, milk and egg, and crustaceans and fish - but peanut-allergic individuals are sometimes allergic to other foods from the legume family, such as soy.
Lupin, another legume related to pea, peanut and soy, is increasingly being recognised in Europe as a cause of allergic reactions and anaphylaxis. Lupin flour in food has been reported to produce urticaria and anaphylaxis and may also produce rhinitis and asthma through inhalation in an occupational setting.
Lupin, a legume, is either eaten whole as lupini beans, or used in the form of flour or bran in food manufacturing. Until recently, lupin was not common in Australian foods, but lupin flour and bran are now entering into food manufacturing, where they contribute protein content, fibre, and some textural properties. Currently, lupin is not covered by mandatory labelling regulations such as are in place for peanut, soy and several other allergenic foods.
The researchers are concerned that, "despite relatively restricted use, lupin sensitisation has already become clinically apparent in Australia. According to the current requirements of Food Standards Australia and New Zealand, lupin four, as a separate ingredient or as a component of greater than 5% of a compound ingredient, must be included in the ingredient list on the product label".
Despite this, they said lupin is not part of the mandatory allergy warning system.
They concluded that lupin should be considered in cases of unexplained food allergy and should be added to the list of ingredients requiring mandatory allergy warning labelling.
5. In the news and journals:
Starch firm petitions FDA: 'Keep up with Australia' (back to contents)
The US FDA is expected to release proposed rules on how information about carbohydrates should appear on the nutrition facts panel of food labels next year. Proposals before the FDA to break fibre out of the 'Total Carbohydrate Content' listing on the label are designed to bring US rules into line with Australia and Europe.
The complex issue of carbohydrate labelling fired up by the low-carb trend will move up a gear next month when the FDA is expected to release proposed rules on how information about carbohydrates should appear on the nutrition facts panel of food labels. Joining the dialogue, resistant starch supplier National Starch submitted a petition to the government body, proposing that fibre be broken out of the 'Total Carbohydrate Content' listing on the label.
The intention is to list fibre separately so the consumer is informed about the fibre content. Proven health benefits of fibre and a recent message from public health authorities that consumers should double their fibre intake mean that US consumers are already looking for fibre information on food labels.
But in the current climate where US consumers remain wary of high carbohydrate content as a result of the popular Atkins diet - that has an estimated 30 million followers - the current label might not only confuse the consumer, but also dissuade them from the buying the product.
Europe and Australia have a totally separate listing for fibre on the nutrition facts panel of the food label, a fact highlighted by the starch firm in the petition. National Starch proposed to the Food and Drug Administration that fibre be listed separate from 'Total Carbohydrates' on the nutrition facts panel of the US food label.
One of the rationales behind the US moving to this type of labelling is that it would provide consistency to global food labels, in particular for international firms working in these different geographical zones.
Britain's TV advertising watchdog, Ofcom, has concluded there is no need for tighter regulations on advertising of food products to children. Research showed television advertising does have a modest direct effect, but the significance was small compared to other factors.
However, as childhood obesity levels continue to rise, food manufacturers will need to play a part in tackling the problem.
In December 2003, the British government asked the regulator to assess whether increasing levels of food and drink advertising to kids had a major impact on children's health. The six-month investigation took the form of more than 2,000 interviews with children, parents, teachers and nutritionists to explore why children choose the food they do, how food promotion influences this, and the key messages children take from television advertising.
In addition, Ofcom asked an independent expert - Professor Sonia Livingstone of the London School of Economics - to conduct a full review of relevant academic research, and analysed data from other studies, including details of family eating habits drawn from a panel of 11,000 people, including more than 2,000 children.
The watchdog also analysed audience research data to assess children's television viewing habits, and analysed data on the food advertising market, including the size of the market, advertising spending and details of the range of creative approaches used in television advertising of food products.
While Ofcom's research showed that television advertising does indeed have a modest direct effect on children's food consumption, but that the significance of this is small when compared to other factors potentially linked to childhood obesity such as exercise, trends in family eating habits inside and outside the home, parents' demographics, school policy, public understanding of nutrition, food labelling and other forms of food promotion.
"On that basis, Ofcom has concluded that a total ban on such advertising would be both ineffective and disproportionate in its wider impact," the regulator said in a statement.
The UK's food watchdog is keeping a close eye on emerging research for the chemical acrylamide, a potential carcinogen discovered in crisps and French fries two years ago and which ignited a raft of new research to assess its risk to the consumer.
At a recent meeting of the Working Party on Chemical Contaminants in Food (WPCC) the Food Standards Agency (FSA) reported there are approximately 150 on-going acrylamide projects worldwide, with the majority of work concentrating on potatoes and cereals.
But the FSA is looking to fund research 'to fill some of the gaps', including looking at acrylamide in the UK diet and acrylamide formation in domestically prepared food.
In April 2002, this potentially harmful chemical came to the attention of the food industry when scientists at the Swedish Food Administration first reported unexpectedly high levels of acrylamide in carbohydrate-rich foods, including crisps, chips and some breads. Since then, acrylamide has been found in a range of cooked and heat-processed foods in other countries, including the Netherlands, Norway, Switzerland, the UK and the US.
And later in 2002, breakthrough research led by Professor Don Mottram at the University of Reading looked at how the chemical could be formed.
Mottram's team suspected it could be created by a reaction between an amino acid called asparagine, which occurs naturally in relatively high levels in potatoes and other cereals, and sugar.
Tests confirmed that when the amino acid is heated, it does react with sugar to create acrylamide, a process called the Maillard reaction. This occurs at temperatures above 100°C (212°F). Their findings were published in Nature 419, 448-449 (2002).
These two key studies propelled the food industry to find out more. In particular, the industry is looking at ways to reduce acrylamide levels by moderating the processing conditions - investigating, for example, certain potato varieties and the impact they can have on the chemical's formation.
The UN-backed World Health Organisation (WHO) is also co-ordinating scientists on acrylamide research projects across the world and the European Commission and the European Food Safety Authority (EFSA) have developed a database to summarise research activities in the EU.
Wheat bran antioxidants: link to cancer prevention (back to contents)
Preliminary findings of collaborative research conducted at Kansas State University and Wichita State University suggest that the antioxidant components of wheat may help prevent colorectal cancer tumours.
The research focuses on a class of antioxidants found in wheat bran that appear to block the formation of mutagenic compounds. This effect is in addition to the benefits derived from consuming higher fibre content from the bran. The initial study indicated that diets containing the same level of wheat bran, but different levels of antioxidants, had a dramatically different capacity to suppress tumour development.
Ron Madl, researcher at Kansas State University (KSU), said eating "a couple of slices of whole wheat toast each day or adding some wheat bran when shaping a hamburger may be all that it takes to lessen the risks of colorectal cancer".
"Findings in the study are encouraging and researchers are now continuing the studies using other animal model systems to test whether these components of wheat can suppress mammary and prostate cancer development," he said.
A complementary research project, led by Dr George Wang at KSUs college of Human Ecology, is focusing on the anti-tumour capabilities associated with the lignan in wheat bran and is observing similar effects: higher antioxidant activity, higher lignan content and more cancer suppression.
"While we have known that whole wheat-based foods are an important part of a balanced diet, this research suggests that the bran antioxidants may play an even more important role in protecting consumers from cancer," Ron Madl said.
He concluded that more work is needed to understand why some wheat varieties are more effective than others, thereby enabling wheat breeders to enhance this attribute for future variety releases.
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