Tuesday, February 1, 2011

Bread Matters

The impact of Folic Acid Fortification in Australia

Just over a year after the introduction of mandatory folic acid fortification in wheat flour for bread making, Australian researchers have set out to determine the impact it has had on the blood folate levels of Australians.

Research suggests an adequate intake of folate pre conception can reduce the incidence of neural tube defects in newborn infants. This has lead to the introduction of government sponsored health promotion campaigns encouraging women of child-bearing age to supplement with folic acid. In 1995, voluntary fortification was introduced and successfully increased the populations’ blood folate levels, and resulted in a reduction in neural tube defects between 1996 and 2006. In September 2009, fortification of 2-3mg of folic acid per kg of wheat flour for bread making was mandated under Standard 2.1.1 of the Food Standards Code, resulting in 0.135mg of folic acid per 100g of bread (approx 2-3 slices), or around half the recommended dietary intake (RDI) of folate. Note: the RDI is higher for woman of childbearing age.
 
Over 20,000 blood samples were used for the study between April 2009 and April 2010, as well as April 2007 and April 2008 (used as baseline). These samples tested for serum and red blood cell (RBC) folate levels in diagnostic pathology labs.

Between April 2009 and April 2010 the prevalence of low serum folate levels decreased by 77% (from 9.3% to 2.1%) and the prevalence of low RBC folate levels decreased by 85% (from 3.4% to 0.5%). The even better news is that while concerns were originally raised that women of child-bearing age may not be huge consumers of bread, the prevalence of low RBC folate levels amongst women of child-bearing age (15-50) was reduced to only one sample from 609 samples tested (0.16%). There was also a 31% increase in mean serum folate and a 22% increase in mean RBC folate levels for the samples tested.

It’s important to note the samples are not necessarily representative of the whole Australian population as they were obtained unexpectedly from those for whom a blood folate test was requested for the investigation of a possible folate deficiency, and are therefore likely to be biased towards low folate levels. Another limitation is that different patients were studied pre and during the mandatory fortification period and both samples would have included blood samples from those patients with coeliac disease or others on wheat free diets. Lastly, the authors stated they do not know the number of patients that might have already been taking a folate supplement.

Although no evaluation has been made to date on the impact of mandatory folic acid fortification of wheat flour for bread making on the incidence of neural tube defects, the results of this study are somewhat impressive in relation to the reduction of folate deficiency in the Australian population.

Already one of the leading sources of fibre in the diets of Australians, low in fat, a source of protein, thiamin, niacin and folic acid, there are plenty of reasons to enjoy the goodness of bread!

Reference:

Brown et al. The impact of mandatory fortification of flour with folic acid on the blood folate levels of an Australian Population. MJA (2011) 194: 65-67

Food or Physical Activity?

Picking sides in the energy balance equation

As the holidays draw to a close and children start heading back to school its is vital to get yourself and the kids back into the school routine, organising after school sport, switching computer game time with homework time, limiting TV time, and producing quick, easy and healthy family dinners at the table.

With unpleasant stats on childhood obesity and the fact many families are becoming increasingly squeezed for time it’s worth entering the debate on what is more effective - food intake or physical activity?

We know the stats are unpleasant with one in four children overweight or obese in Australia. But with our busy lifestyles and often not enough hours in the day, Dietitian’s are often asked, what is the easiest way to help kids maintain a healthy weight? One of the main causes of obesity is energy imbalance, with epidemiological studies indicating that children’s habitual energy expenditure has declined and their energy intake has increased. However, the underlying cause cannot be related to just one factor. A combination of everything that makes tasty, tempting, energy dense, nutrient-lacking food items easily available, convenient, cheap and marketable is one major contributor, along with every technological advance that results in us doing less physical work; washing machines, dryers, mix masters, cars and the endless list continues all which makes us more prone to excessive energy intake and inadequate physical activity than any previous generation.

The science suggests that there is little evidence dietary composition or macronutrient distribution has a meaningful influence on weight management independent of energy intake. However, it has been established that diet can affect satiety and is likely to influence weight indirectly by affecting the quantity of kilojoules eaten.

A recent review of the research completed in the US set out to understand the relative importance of overconsumption and physical inactivity to excess weight gain. The researchers found that there is wide variation in data quality and in the accuracy of measures of energy intake, and based on the available evidence there was no consensus on whether overconsumption or physical inactivity was the main driver for weight gain among US children and teens.

Despite this conclusion, intervention studies usually report that dietary modifications can be effective at weight loss on their own, whereas exercise based interventions do not, although a combination of the two works better than either on its own. From a practical perspective it is important to think about the most efficient ways to lose weight, and whilst we always, and will continue to recommend physical activity which has powerful influences on weight and health, we have to accept the challenge of getting an increasingly sedentary generation to participate in physical activity, all which could be undone by an unhealthy food or drink choice.

If you think about the 1000kJ a child might burn during 1 hour of bike riding per day and then consider the 2500kJ++ in a Happy Meal that takes less than 5 mins to eat, it’s easy to understand how hard it is becoming to maintain a healthy weight. This example emphasises the challenge we will continue to face unless we improve the quantity and quality of children’s diets. A study just published has found that that detailed representation of fast food and soft drink brands (developed via experience and advertising) has higher scores on an ‘added flavour’ sugar/fat/salt liking palate, fundamentally changing children's taste palates to increase their liking of highly processed and less nutritious foods. The researchers concluded early food-related behaviours are important and if we want to intervene we need to start when children are young.

Back to school lunch box tips
  • Pat wet ingredients dry with a paper towel and layer lettuce between wet ingredients and bread to prevent moisture from spreading. Prepare sandwiches as close to lunchtime as possible to ensure freshness.
  • Older students might go for something a little more gourmet. Tempt teen tastebuds with roast vegies on Turkish bread or a wholemeal wrap. 
  • If the kids keep throwing out their crusts, beat them to it. Try using breads with no crust, such as wraps or Turkish bread. Alternatively, cut the crust of regular bread and use the left over crusts to make croutons or breadcrumbs.
  • Wholegrain dinner rolls with healthy fillings can be used instead of larger bread rolls for younger kids. Cutting sliced bread into different shapes or creating a face by adding a grape cut in half for the eyes, a piece of carrot for the nose and a capsicum mouth can make lunches fun.
  • Get kids involved with a best filling competition or a naming competition for sandwiches. Encourage the school canteen to have a reduced price or a meal deal with a free apple or yoghurt.
  • Introduce wholegrain breads into the kids’ diet with ‘zebra’ sandwiches by using one slice of wholegrain and one white slice. Wholegrain crispbreads and rice cakes are a good alternative for kids who don’t like bread.
References:

Katz DL. Unfattening our children: Forks over feet. International Journal of Obesity (2011) 35, 33-37.
 Bleich SN et al. Relative contribution of energy intake and energy expenditure to childhood obesity: a review of the literature and directions for future research. International Journal of Obesity (2011) 35, 1-15.
 Cornwell TB et al. Alternative thinking about starting points of obesity. Development of child taste preferences. Appetite (2011) Published online ahead of print.