Many people assume that latex and memory foam are one and the same. This common misconception leads to all sorts of confusion during the mattress buying process.
They are, in fact, as similar as chalk and cheese. Or a better comparison might be as football and cricket – true, both are team sports (and latex and memory foam both make mattresses) but they are of a fundamentally different character. I am a cricket fan myself, but that is not to say that the millions of football supporters around the world have got it wrong. The same holds true of memory foam and latex mattresses – both make a good mattress; both are loved by many people the world over.
In many ways trying to compare latex and memory foam is unfair. They are simply different. However, when buying a new mattress and choosing between them it is best to go armed with as much information as possible and fully aware of the pros and cons of each.
This article is here to provide you with the knowledge you will need to make the right choice for you.
The differences between latex and memory foam mattresses originate in the materials they are made from
Memory foam is, as the name suggests, a foam. Foam is a man-made, petroleum based product called polyurethane. Memory foam is a technologically-advanced, high-density polyurethane that has a visco-elastic quality. Memory foam is essentially created through a chemical process and is a type of plastic. To create memory foam, polyeurethane gets infused with various agents such as gel, copper, granite and synthetic chemicals.
Latex can also be produced synthetically and if produced in this way it is also petroleum based. This article concentrates, however, on natural latex – a very different thing indeed.
Natural latex is, as the name suggests, given to us by nature – it is the milky white substance, biological name Fiscus elastica, taken from the rubber tree through a process called ‘tapping’. Over 99% of the world’s natural latex is tapped from the Hevea brasiliensis tree which originally came from Brazil but in the early 20th Century was introduced to the Far East; notably Malaysia, Indonesia, Burma, Cambodia and China. By the 1920’s latex had come to be known regionally as “the white gold”. Today, most natural rubber still comes from the Far East where the trees are grown on large rubber plantations. Tapping the tree for latex does not harm the tree and latex is a wholly organic biodegradable material.
In short – a foam mattress and latex mattress are different predominantly because one is a chemical product and the other is natural and organic. A chemical product will feel and behave in ways which are entirely different to the ways in which a natural product will feel and behave. Spending a night on a memory foam mattress is therefore different to a night asleep on a latex mattress.
Furthermore, for consumers who are concerned about their environmental footprint, latex is undoubtedly the most environmentally friendly mattress material on the planet.
Further differences in the finished mattress stem from the processes used in its creation.
Memory foam is, as described above, a man-made product. Polyeurethane can, in and of itself, be produced to be hard or soft, rigid or flexible and be used for a broad range of end products from toys to trainers, aeroplane wings to automobile parts. Essentially, the final characteristic of the product depends upon the manufacturing process. Memory foam had its beginnings in a science lab in England in the 1930’s. In the 1960’s NASA developed the product further and utilised it to protect pilots during crashes.
And here’s the science bit: To create memory foam the various chemical agents that will react with each other are mixed together and ‘beaten’ in to a froth. The froth is then poured into a mould and within the mould a chemical reaction occurs (an exothermic reaction). In order to make the mattress flexible and soft (rather than hard or rigid) a gas is infused in to the polymer. It is then cooled and reheated.
This manufacturing process creates, within the memory foam, billions of spherical shaped cells which soften in reaction to body heat and once soft move away from the pressure of the body as it lies on the mattress. The end result of the manufacturing process is therefore a product that has the specific and recognisable ‘indentation’ properties of memory foam and that make this kind of mattress feel different to all other mattress types.
Latex, as described above, comes from the tree as a finished product in its own right. In 1000BC Indians living in Central and South America learned how to make waterproof clothes and shoes using the latex from the rubber tree. They called the rubber trees “cahuchu” (crying wood) and this is why the French still call rubber caoutchouc today. By itself, however, unprocessed rubber is not much good as a mattress.
There are two processes generally used in the production of latex mattresses; the Dunlop method used since 1929 and the Talalay method developed in the 1940’s. Neither are particularly ‘science-y’ but are more akin to baking a cake. Each method produces a latex mattress with a slightly different feel; with a Talalay mattress being slightly softer but less durable than a Dunlop.
In the Dunlop method the natural latex is interfered with as little as possible making it the most environmentally friendly mattress-production process. The thick rubber sap is ‘whipped’ into a foamy substance, placed in to a mould and steam-baked in an oven causing it to solidify. After a washing cycle it is cut in to blocks and air-dried. The Talalay method has two further steps; after being placed in to the mould a vacuum is created by sucking out all the air, the latex is then flash-frozen before being flash heated (vulcanised).
Whichever process is used the end result is a distinctive latex mattress feel which provides recognisable benefits to the sleeper. This is because during the manufacturing process numerous pincoil holes form in the latex creating an open-cell structure. It is this structure, combined with the properties of the natural latex itself, that is responsible for the specific and recognisable properties that make a latex mattress wholly different to all other mattress types; namely its springy resilience, the manner in which it ‘cups’ the sleeping body, its breathability and hypoallergenic qualities.
In short – the processes used in the manufacture of memory foam differ to the processes used in the manufacture of a natural latex mattress. The end product of the two manufacturing processes is two mattresses that ‘work’ in different ways.
Result: Differing sleep experiences
Firstly, there are some similarities between a memory foam and a latex mattress. These similarities afford both latex and memory foam similar positives characteristics.
The first similarity is that they each provide excellent lumbar support; they will both support the sleeper’s spine in its proper and neutral alignment no matter which sleeping position is preferred. This is an important thing to look for in any mattress as improper or little support can cause tension, back ache and ultimately back problems over the long term.
The second similarity is that both memory foam and latex mattresses excel at relieving pressure on joints and soft tissue (aiding circulation of blood and oxygen around the body).
However, the latex mattress and memory foam mattress differ in the way that they provide support and relieve pressure and this causes the one mattress to feel very different to the other; as is explored below.
There are significant differences between memory foam and latex mattresses in three key areas:
Memory foam has a spongy or pudding-like feel. As the cells in a memory foam mattress are warmed by body heat they move and this allows the memory foam to contour exactly to the shape of the sleeper’s body. It has been described to feel as if you are sleeping “in the bed” rather than on it. Many sleepers enjoy this and describe it as cosy. For others, it feels claustrophobic. Objectively, there is certainly an enveloping feeling which occurs as the bed moulds itself to the body.
Alongside the moulding of the bed around the sleeper there can also develop a feeling of being ‘stuck’ in the bed. This results from the fact that once the sleeper moves, the cells that have been heated and have shifted take time to restore themselves to their neutral position. The imprint left in the mattress will only slowly restore itself. This can make it difficult for the sleeper to roll over and find a new position.
Latex, on the other hand, creates a more solid mattress with a springier feel. The latex mattress adjusts to ‘cup’ the sleeper’s body by the cell structure compressing where pressure (weight) is applied. As the top layer of latex is created with larger cylindrical holes it feels soft to the touch whilst the core of the latex (the inner layer) has smaller holes so it is firmer. The feeling of sleeping on a latex mattress has been described as a feeling of lightness. Furthermore, as a result of the natural latex bounce, when the sleeper moves there is an especially fast recovery time as the mattress restores itself. This makes it a particularly responsive mattress.
Memory foam, by its very nature, requires heat to work in order to provide pressure relief and comfort to the sleeper. However, the heat-retention property of memory foam is perhaps its most fundamental flaw as a mattress material.
Not only does the memory foam react to the heat from the sleeper’s body, the fact that 100% of the body is in full contact with the mattress prevents air from circulating around the sleeper thus trapping the heat. Polyurethane also has no inherent mechanism that allows air to circulate through the mattress itself.
A memory foam mattress can therefore make the sleeper uncomfortably warm. It is a sleeping surface that can cause sweating and hamper sleep in hotter climates.
Memory foam mattress producers are well aware of the heat problem associated with their mattresses and have tried to combat this; with various levels of success and at additional cost to the consumer. Some memory foam mattresses have additional layers of cooling gel applied, some have holes bored through the mattress to allow for air circulation. Essentially, however the memory foam maker is trying to mimic the natural cooling properties of the latex mattress.
Latex in direct contrast to memory foam is naturally breathable. The open-cell structure of the latex mattress allows for air to circulate freely throughout the mattress allowing for a cool sleeping surface. For this reason a latex mattress should always be used with a slatted bed base (so as not to cut off air supply from underneath). Latex does not require heat to work and as the sleeper is more loosely cupped by the mattress air can get to the sleeper’s body.
Memory foam is a plastic, created through a manufacturing process. There are many websites which discuss toxins and other potential problems created by synthetic chemicals. A good summary of some of the concerns which have been raised can be found at http://www.sleepjunkie.org/are-memory-foam-mattresses-safe/ . It is important to highlight that out of the many millions of consumers who have bought memory foam mattresses only a very small proportion seem to experience allergic type reactions and there is no specific research showing that memory foam is toxic or unsafe. Once the manufacturing process has been completed the chemical constituents of the polyurethane are chemically inert.
However, with memory foam there are some residual concerns that remain about ‘off-gassing’. This refers to the phenomenon of chemicals breaking down and dispersing in to the air. There is often a distinct chemical smell that accompanies the opening of a new memory foam mattress which may take a number of days or weeks to dispel. Independent mattress consumer research website Sleep Like the Dead reports that as many as 12% of memory foam mattress owners report significant off-gassing and some 2% return their mattresses as a result of this problem. Reports of headaches, nausea, eye and throat irritation, sweating, sleeplessness and asthma resulting from off-gassing are reported to occur in about 1.5% of sleepers.
Latex often has a rubbery smell when the mattress is brand new and it is fair to say that some consumers do not like this smell. However, there has been no research to suggest that there are any negative health implications accompanying the odour; which should disperse within a few days.
Many sleepers believe that the initial rubbery smell is well compensated for when taking into consideration the health benefits that they get by sleeping on a latex mattress each night. This is because latex is the only mattress material that has naturally hypoallergenic properties.
Because natural latex is an organic material; and because an open cell structure is formed when it is processed, a latex mattress is resistant to moisture and thus to the build-up of moulds and mildew. This quality is an important consideration for all sleepers living in humid climates but is particularly important for those who suffer from chest infections, asthma and allergies (wherever they may live). Furthermore, latex mattresses actually repel dust mites and dirt and other environmental irritants do not adhere to it. Thus a latex mattress provides a naturally hypoallergenic sleeping environment that is free of industrial chemicals and safe for all sleepers from children to the elderly.
In short – whilst latex and memory foam share similar positive characteristics and both provide excellent support and pressure relief; there are three significant areas in which a latex mattress could be said to out-perform its memory foam equivalent.
Having highlighted the three most significant areas in which latex and memory foam differ, it is also worth outlining a number of other areas for consideration when choosing between a memory foam and latex mattress.
Whole mattress/mattress topper: Whilst a natural latex mattress can be made from 100% latex (it will be latex all the way through from top to bottom), a memory foam mattress is in fact a type of hybrid mattress. Memory foam will only ever be used as the top layer, with standard polyurethane foam forming the mattress core.
Turning: A latex mattress can be turned whereas a memory foam mattress cannot (as a result of the memory foam only being on the top).
Durability: Both latex and memory foam mattresses have a good sleep-life. Overall, however latex mattresses can be expected to remain true and provide good sleep for longer.
Consistency of firmness: A latex mattress will be of the same firmness wherever in the world you may choose to take it. However, as memory foam reacts to heat, it is softer in warmer climes and firmer where it is cold. Thus a mattress purchased and suiting you perfectly in South East Asia may suddenly feel firmer and uncomfortable transported to Greenland.
Environmental impact: Finally, it is hard to ignore the research showing the impact our use of petrochemicals and over manufacture of plastics in particular are having on planet Earth. Research led by a team of scientists at Newcastle University highlights the harm plastic is doing, even in our deepest oceans. The desire to make ethical consumer choices and reduce your environmental footprint may lead some to sleep with a clearer conscience upon a latex mattress.