This week the World Health Organization (WHO) released new guidelines recommending people switch the regular salt they use at home for substitutes containing less sodium.

But what exactly are these salt alternatives? And why is the WHO recommending this? Let’s take a look.

A new solution to an old problem

Advice to eat less salt (sodium chloride) is not new. It has been part of international and Australian guidelines for decades. This is because evidence clearly shows the sodium in salt can harm our health when we eat too much of it.

Excess sodium increases the risk of high blood pressure, which affects millions of Australians (around one in three adults). High blood pressure (hypertension) in turn increases the risk of heart disease, stroke and kidney disease, among other conditions.

The WHO estimates 1.9 million deaths globally each year can be attributed to eating too much salt.

The WHO recommends consuming no more than 2g of sodium daily. However people eat on average more than double this, around 4.3g a day.

In 2013, WHO member states committed to reducing population sodium intake by 30% by 2025. But cutting salt intake has proved very hard. Most countries, including Australia, will not meet the WHO’s goal for reducing sodium intake by 2025. The WHO has since set the same target for 2030.

The difficulty is that eating less salt means accepting a less salty taste. It also requires changes to established ways of preparing food. This has proved too much to ask of people making food at home, and too much for the food industry.

Enter potassium-enriched salt

The main lower-sodium salt substitute is called potassium-enriched salt. This is salt where some of the sodium chloride has been replaced with potassium chloride.

Potassium is an essential mineral, playing a key role in all the body’s functions. The high potassium content of fresh fruit and vegetables is one of the main reasons they’re so good for you. While people are eating more sodium than they should, many don’t get enough potassium.

The WHO recommends a daily potassium intake of 3.5g, but on the whole, people in most countries consume significantly less than this.

Potassium-enriched salt benefits our health by cutting the amount of sodium we consume, and increasing the amount of potassium in our diets. Both help to lower blood pressure.

Switching regular salt for potassium-enriched salt has been shown to reduce the risk of heart disease, stroke and premature death in large trials around the world.

Modelling studies have projected that population-wide switches to potassium-enriched salt use would prevent hundreds of thousands of deaths from cardiovascular disease (such as heart attack and stroke) each year in China and India alone.

The key advantage of switching rather than cutting salt intake is that potassium-enriched salt can be used as a direct one-for-one swap for regular salt. It looks the same, works for seasoning and in recipes, and most people don’t notice any important difference in taste.

In the largest trial of potassium-enriched salt to date, more than 90% of people were still using the product after five years.

Making the switch: some challenges

If fully implemented, this could be one of the most consequential pieces of advice the WHO has ever provided.

Millions of strokes and heart attacks could be prevented worldwide each year with a simple switch to the way we prepare foods. But there are some obstacles to overcome before we get to this point.

First, it will be important to balance the benefits and the risks. For example, people with advanced kidney disease don’t handle potassium well and so these products are not suitable for them. This is only a small proportion of the population, but we need to ensure potassium-enriched salt products are labelled with appropriate warnings.

A key challenge will be making potassium-enriched salt more affordable and accessible. Potassium chloride is more expensive to produce than sodium chloride, and at present, potassium-enriched salt is mostly sold as a niche health product at a premium price.

If you’re looking for it, salt substitutes may also be called low-sodium salt, potassium salt, heart salt, mineral salt, or sodium-reduced salt.

A review published in 2021 found low sodium salts were marketed in only 47 countries, mostly high-income ones. Prices ranged from the same as regular salt to almost 15 times higher.

An expanded supply chain that produces much more food-grade potassium chloride will be needed to enable wider availability of the product. And we’ll need to see potassium-enriched salt on the shelves next to regular salt so it’s easy for people to find.

In countries like Australia, about 80% of the salt we eat comes from processed foods. The WHO guideline falls short by not explicitly prioritising a switch for the salt used in food manufacturing.

Stakeholders working with government to encourage food industry uptake will be essential for maximising the health benefits.

Xiaoyue (Luna) Xu, Scientia Lecturer, School of Population Health, UNSW Sydney and Bruce Neal, Executive Director, George Institute Australia, George Institute for Global Health

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Extreme heat is increasingly common in Australia and around the world and besides making us uncomfortable, it can harm our health. For example, exposure to extreme heat can exacerbate existing medical conditions, or cause problems such as heat stroke.

Due to a combination of physiology and behaviour, children are potentially more vulnerable to severe heat-related illness such as heat stroke or heat exhaustion.

But these are not the only heat-related health issues children might experience on a very hot day. In a new study, we looked at emergency department (ED) visits and unplanned hospital admissions among children in New South Wales on heatwave days.

We found a significant increase in children attending hospital compared to milder days – with a range of health issues.

Why are children more vulnerable in the heat?

Sweating is the main way we lose heat from our bodies and cool down.

Children have a greater skin surface area to body mass ratio, which can be an advantage for sweating – they can lose more heat through evaporation for a given body mass. But this also means children can lose fluids and electrolytes faster through sweating, theoretically making them more susceptible to dehydration.

Meanwhile, younger children, particularly babies, can’t sweat as much as older children and adults. This means they can’t cool down as effectively.

Children in general also tend to engage in more outdoor physical activity, which might see them more exposed to very hot temperatures.

Further, children may be less in-tune to the signals their body is giving them that they’re overheating, such as excessive sweating or red skin. So they might not stop and cool down when they need to. Young children especially may not recognise the early signs of heat stress or be able to express discomfort.

Our study

We wanted to examine children’s exposure to extreme heat stress and the associated risks to their health.

We measured extreme heat as “heatwave days”, at least two consecutive days with a daily maximum temperature above the 95th percentile for the relevant area on a universal thermal climate index. This ranged from 27°C to 45°C depending on the area.

We assessed health outcomes by looking at ED visits and unplanned hospital admissions among children aged 0–18 years from NSW between 2000 and 2020. This totalled around 8.2 million ED visits and 1.4 million hospital admissions.

We found hospital admissions for heat-related illness were 104% more likely on heatwave days compared to non-heatwave days, and ED visits were 78% more likely. Heat-related illness includes a spectrum of disorders from minor conditions such as dehydration to life-threatening conditions such as heat stroke.

But heat-related illness wasn’t the only condition that increased on heatwave days. There was also an increase in childhood infections, particularly infectious enteritis possibly related to food poisoning (up 6% for ED visits and 17% for hospital admissions), ear infections (up 30% for ED visits and 3% for hospital admissions), and skin and soft tissue infections (up 6% for ED visits and 4% for hospital admissions).

We know many infectious diseases are highly seasonal. Some, like the flu, peak in winter. But heat and humidity increase the risk of certain infections caused by bacterial, viral and fungal pathogens.

For example, warmer weather and higher humidity can increase the survival of bacteria, such as Salmonella, on foods, which increases the risk of food poisoning.

Hot weather can also increase the risk of ear infections. Children may be at greater risk during hot weather because they often swim or play at the beach or pool. Water can stay in the ear after swimming and a moist environment in the ear canal can cause growth of pathogens leading to ear infections.

Which children are most vulnerable?

During heatwaves, we found infants aged under one were at increased risk of ED visits and hospital admission for any reason compared to older children. This is not surprising, because babies can’t regulate their body temperature effectively and are reliant on their caregivers to keep them cool.

Our study also found children from the most disadvantaged areas were more vulnerable to heat-related illness on heatwave days. Although we don’t know exactly why, we hypothesised families from poorer areas might have limited access to air-conditioning and could be more likely to live in hotter neighbourhoods.

Keeping kids cool: tips for parents

The highest levels of heat exposure on hot days for young children is usually when they’re taken outside in prams and strollers. To protect their children from direct sunlight, parents often instinctively cover their stroller with a cloth such as a muslin.

However, a recent study from our group showed this actually increases temperatures inside a stroller to as much as 3–4˚C higher than outside.

But if the cloth is wet with water, and a small fan is used to circulate the air close to the child, stroller temperatures can be 4–5˚C lower than outside. Wetting the cloth every 15–20 minutes (for example, with a spray bottle) maintains the cooling effect.

When young children are not in a stroller, and for older children, there are a few things to consider to keep them cool and safe.

Remember temperatures reported on weather forecasts are measured in the shade, and temperatures in the sun can be up to 15˚C higher. So sticking to the shade as much as possible is important.

Exercise generates heat inside the body, so activities should be shortened, or rescheduled to cooler times of the day.

Sunscreen and hats are important when outdoors, but neither are especially effective for keeping cool. Spraying water on the child’s skin – not just the face but arms, legs and even the torso if possible – can help. Wetting their hats is another idea.

Proper hydration on hot days is also essential. Regular water breaks, including offering water before, during and after activity, is important. Offering foods with high water content such as watermelon and orange can help with hydration too.

Wen-Qiang He, Research Fellow in Biostatistics and Epidemiology, Faculty of Medicine and Health, University of Sydney; James Smallcombe, Post-doctoral Research Associate, Faculty of Medicine and Health, University of Sydney; Natasha Nassar, Professor of Paediatric and Perinatal Epidemiology and Chair in Translational Childhood Medicine, University of Sydney, and Ollie Jay, Professor of Heat & Health; Director of Heat & Health Research Incubator; Director of Thermal Ergonomics Laboratory, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.