One bag of crisps can contain almost 25 per cent of the maximum salt intake for a six-year-old child and over 10 per cent of an adult's intake - and some "reduced fat" crisps may be higher in salt and carbohydrates than a traditional bag.
Many crisps also contain monosodium glutamate (aka E621), the controversial flavour enhancer. We all know that crisps aren't exactly a health snack so it's good news that the supermarket shelves are packed with "healthier option" crisps, isn't it? Well, maybe.
One problem is that consumers concerned about calories, salt and saturated fat are faced with a wide choice of deep-fried potato slices: reduced fat, lower calorie, reduced salt and balanced-salt. The lack of one standard definition of terms such as "lower calorie" or "reduced salt" can be confusing.
Each brand's claims are made in comparison to its own-brand "ordinary" crisps, so Tayto's "33 per cent lower in fat" Treble Crunch crisps are lower in fat than its standard crisps - but they contain more saturated fat per 100g than M&S "reduced fat" crisps.
The Food Safety Authority recommends that a product making a "low salt" claim should contain at least 25 per cent less salt than the standard version.
"Healthier" crisps are big business: Tayto (which describes its Honest crisps as "nutritious snacks") has spent €1.2 million on marketing the new brand. The company has no plans to reduce salt or MSG in its standard crisps.
While most of us are aware of the health implications of salt - high blood pressure which can lead to stroke and heart attack - it can be difficult to know just how much we are consuming every day.
"A huge amount is hidden. There's salt in virtually every packaged food: cereals, bread, snacks, soups, sauces, salad dressings," says Margot Brennan of the Irish Nutrition and Dietetic Institute.
A quick look at most food labels shows the problem with assessing salt content: it's simply not listed (Marks & Spencer products are an exception). Instead, most manufacturers show the sodium content "because it's a smaller number", says Brennan. Unless you go shopping with a calculator (and have several hours to spare), you're not going to do the sums to convert sodium levels to salt - which is to multiply by 2.5. This may change since food labelling in the EU is currently under review and various agencies, including the Department of Health, favour listing salt rather than sodium content.
Although the amount of monosodium glutamate in crisps is small, the additive has been implicated in a wide range of health problems, according to a report commissioned by the US Food and Drug Administration. It concluded that an unknown percentage of the population may develop MSG symptom complex, a condition characterised by one or more of the following symptoms: burning sensation in the back of the neck, forearms and chest; numbness in the back of the neck; tingling, warmth and weakness in the face, temples, upper back, neck and arms; chest pain; headache; nausea; rapid heartbeat; and bronchospasm (difficulty breathing) in MSG-intolerant people with asthma.
"Crisps are not a very nutritious food and should not form part of the daily diet," says Janis Morrissey, dietician with the Irish Heart Foundation. "Gradually reduce the amount of salt you eat by choosing more fresh foods and eat savoury snacks such as crisps only as a treat."
This week is Irish Heart Week. Locall: 1850-364364. Event details: www.irishheart.ie
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