Guidelines Dietary - Eat For Health

Bone healthEvidence suggesting an association between a low sodium diet and markers of bone health in postmenopausalwomen is inconclusive (Evidence Report, Section 13.3).3.2.3 How limiting intake of foods and drinks containing added salt may improvehealth outcomesSodium and other electrolytes are needed to maintain extracellular volume and serum osmolality. There arevarious systems and hormones that influence sodium balance including the renin-angiotensin-aldosteronehormone system, the sympathetic nervous system, atrial natriuretic peptide, the kallikrein-kinin system,various intrarenal mechanisms, and other factors that regulate renal and medullary blood flow. 8Future data may lead to a refined understanding of the underlying mechanisms. For example, the ratio of sodium topotassium may influence blood pressure more strongly than the amount of sodium alone 742-744 and reducing sodiumintake may be particularly important for overweight people with certain conditions. 745 The Dietary Guidelines forAmericans, 2010 comment that the effects of higher sodium intake can be countered if potassium intake isalso higher and note that potassium intake in the US is lower than desirable. 1983.2.4 Practical considerations: Limit intake of foods and drinks containing added saltThere has been a shift in the language on this issue. The first edition of the dietary guidelines included therecommendation to ‘Eat less salt’. 750 The second edition revised this to ‘Choose low salt foods and use saltsparingly’. 751 The third edition advised Australians to ‘Choose foods low in salt’. 36 In these Guidelines, it isrecognised that any reduction in dietary sodium will reduce blood pressure in those with normal levels ofblood pressure, reduce risk of developing hypertension and also reduce blood pressure in those with elevatedblood pressure.The NRV Document recommends an intake of sodium in the range 460–920mg/day for adults to cover the essentialrequirement. Current advice in Australia is for dietary sodium intake to be preferably less than 1,600mg/day for adultsor no higher than the set Upper Level (UL) of 2,300mg/day. 8 Among those with high sodium intake, reduction insodium intake would reduce blood pressure even if specific targets were not achieved.Diets that are consistent with the Guidelines will help to limit sodium intake. Fresh, unprocessed or minimallyprocessed foods such as fresh vegetables (including legumes/beans) and fruit, frozen or tinned vegetables(including legumes/beans) and fruit with no added salt, meats, fish and milk are generally lower in sodium.Some breads and cereal products and cheeses have higher levels of salt and make a significant contribution tosodium intake, although there is considerable variation between products and brands. However, these foodsprovide other important health benefits outlined in relevant sections of the Guidelines. The public should not avoidthese foods, but should be encouraged to check food labels and select lower-sodium products in these categories.Some foods are labelled ‘low sodium/salt’ if the food contains no more than 120mg of sodium per 100g. 752Not all foods that meet this criterion carry a ‘low sodium’ claim.Guideline 3Because salt is 40% sodium, avoiding discretionary salt in cooking or at the dinner table will also reduce sodiumintake (the set UL of 2,300mg/day is approximately equal to 6g of table salt). In the 1995 National NutritionSurvey, 62% of the population aged 2 years and older reported always or usually adding salt at the table or duringcooking. 45 Since 1995, Asian-style cooking has become increasingly popular in Australia and many Asian-stylesauces such as soy, oyster and fish sauces are particularly high in sodium. Lower sodium options of these foodsshould be chosen, recognising that they may still have high sodium content. Salt substitutes or ‘lite’ salts thatreplace some sodium chloride with potassium chloride can provide a salt taste with lower levels of sodium.Herbs, spices, garlic, lemon juice and vinegars can also be used to season foods without adding salt.Iodine deficiency previously existed in Australia and has re-emerged in recent years. Iodised salt is one way toincrease iodine intake. Since 2009, it has been mandatory for any salt used in commercial bread baking to beiodised (organic bread is exempt from this requirement). 753 Milk and dairy foods are an important source ofiodine in Australia.Pregnant and breastfeeding womenAdvice to limit the intake of sodium for the general population is also applicable to pregnant and breastfeedingwomen. 754Limit intake of foods containing saturated fat, added salt, added sugars and alcoholNational Health and Medical Research Council75