Monday, February 1, 2010

Wholegrains and hypertension

Food manufacturers reduce sodium in food supply

Most people know wholegrains are better for you. Along with lowering your risk of cardiovascular disease, type 2 diabetes, obesity and some cancers; latest research has established that wholegrains can also help to lower your risk of and reduce hypertension (high blood pressure) potentially decreasing the need for medication.

Hypertension is defined as a systolic blood pressure of 140mmHg or higher or a diastolic blood pressure of 90mmHg or higher. A leading risk factor for heart disease, hypertension tends to develop with age and is estimated to affect over 2 million Australians. High dietary sodium intake is just one of the many major risk factors for hypertension together with physical inactivity, smoking, overweight or obesity and alcohol consumption.

In a US study of almost 30,000 female health professionals, those who ate more than 4 servings of wholegrains (equivalent to 4 slices of wholegrain bread) had a 23% lower risk of hypertension compared to those who ate virtually no wholegrains. Even those who ate smaller amounts of wholegrains (equivalent to 1 slice of wholegrain bread) had a 7% reduced risk.

The Health Professionals Follow Up Study of over 50,000 US males found a similar association, with those eating the most wholegrains having nearly a 20% reduction in risk of hypertension compared to those eating the least wholegrains. This inverse association between wholegrain intake and risk of hypertension was evident independent of sodium intake. This finding is important since grain-based foods such as bread and breakfast cereals are coming under increasing 'fire' from health professionals for their contribution to sodium intakes.

Eating less sodium doesn't mean cutting out foods like bread and breakfast cereal. National dietary surveys in both adults and children show that grain-based foods are important sources of essential macro and micro- nutrients to the diets of Australians, even though they contribute to sodium intake. In the recent National Children's Nutrition & Physical Activity Survey, as much as half of the total sodium intake from grain-based foods came from less desirable products like biscuits, cakes and takeaway option, highlighting the importance of strategies to reduce sodium contribution from non-core foods.

Choosing healthier grain-based food options can help lower the amount of sodium we eat. Australian research published this year by Webster and colleagues found cereals and cereal products, particularly breakfast cereals, cereal bars, pasta and noodles, to be amongst the lowest sodium foods. Processed meats, sauces and spreads were the highest in sodium.

Many large manufacturers of popular grain-based foods in Australia have reduced the sodium content of their products over the past decade or more by an average of 25% in the quest to further reduce sodium content of foods available within the Australian food supply. Manufacturers are committed to continue long-term sodium reduction efforts slowly and safely where technically feasible, to maintain consumer acceptability and taste expectations, so grain-based foods can continue to be enjoyed every day by Australians of all ages.

Go Grains Health & Nutrition 2009

1. Webster et al, A systematic survey of the sodium contents of processed foods, AJCN, 2010
2. Flint et al, Whole grains and incident hypertension in men, AJCN, 2009
3. Wang et al, Whole- and refined grain intakes and the risk of hypertension in women, AJCN, 2007

Diet affects academic performance

Children with healthier diets do better in school

But yet another study of school students has demonstrated an association between overall diet quality and academic performance. There was a significant association between eating a variety of nutritious foods in the correct amounts and academic performance. Poor diet with too much fat and sugar and too little fruit, vegetables and wholegrains, is recognised as the primary contributor to overweight and obesity in school children, with undernourished school children shown to have decreased attention and academic performance compared to those well nourished.

Healthy eating habits adopted early in childhood and maintained through adolescence and adulthood will benefit academic performance, and improve long term health potentially reducing the risk of developing chronic diseases, such as obesity, diabetes and cardiovascular disease.

With school holidays over, it is back to the ritual of the school year and lunchbox preparation. The lunchbox makes up a large proportion of the food eaten daily by school children and therefore should include a variety of nutritious foods as recommended by dietary guidelines. A healthy diet should include at least four serves of grain-based foods each day (including breads, rice, pasta and noodles), vegetables and legumes, fruit, dairy products, meat, fish and poultry products.

Providing children with quality, variety and adequate nutrition will fuel them with energy to keep them physically active and mentally alert for school activities throughout the day.

Lunch box ideas

Fruit: fresh or tinned fruit. Cut up and easy to eat whole fruit is more appealing. Dried fruit is high in sugar so should be provided occasionally.

Vegetables: cherry tomatoes and vegetable sticks such as carrot, cucumber, celery and capsicum, make great snacks or sandwich fillings. Include dips such as yoghurt, avocado, hummus, eggplant or any homemade dips (a better alternative as they have less salt and fat).

Dairy Food: fruit yoghurts, milk drinks which can be frozen overnight, mini packaged cheeses or cheese sticks. Low fat and low salt crackers accompaniments are a healthier alternative to pre-packaged ones.

Breads: include variety; multi-grain breads, wholemeal pitas and wholegrain rolls are loaded with essential vitamins and minerals and are a great source of healthy carbohydrates - providing children with energy for physical activity, healthy growth and good brain function. Half white and half wholemeal sandwiches are a great way to introduce fussy eaters to wholegrains. Try crispbreads and fruit loaf or buns, foccacias, muffins, crumpets, rice cakes and homemade pizza. Avoid chips and savoury biscuits as these tend to be high in salt and fat.

Water: is the best and first choice for hydration, and especially important in the warmer months.

Sandwich Fillings: variety adds interest. Include vegemite, various spreads, cheese, lean meat, chicken, tuna, salmon, egg, baked beans, avocado, tomato, lettuce, rocket, hummus, grated carrot, sliced cucumber and snow pea sprouts.

What to Look Out For

Lunch Box Safety: ensure foods are appetising and do not become warm or soggy after several hours. Pack food in insulated containers. Lunch boxes should be kept cool to ensure they are safe. Pack a frozen water bottle or ice brick with the lunch. Perishable items should be packed between the cold items.

Nuts: many schools have a nut free policy due to the incidence of allergy. Consult with your school if nuts or nut spreads are an option to include in the lunchbox.

Salt: is listed on the nutrition panel as sodium. Foods with less than 120mg per 100g are low in salt, while foods with more than 500mg are high in salt.

Fat: look for low fat and low saturated fat options.

1. Florence et al. Diet and Academic Performance. J Sch Health. 2008;78:209-215
2. Evans et al. A cross-sectional survey of children's packed lunches in the UK: food and nutrient -based results. J Epidemiol Community Health. 2009;0:1-7.