Many people are drinking less sugary soft drink than in the past. This is a great win for public health, given the recognised risks of diets high in sugar-sweetened drinks.

But over time, intake of diet soft drinks has grown. In fact, it’s so high that these products are now regularly detected in wastewater.

So what does the research say about how your health is affected in the long term if you drink them often?

What makes diet soft drinks sweet?

The World Health Organization (WHO) advises people “reduce their daily intake of free sugars to less than 10% of their total energy intake. A further reduction to below 5% or roughly 25 grams (six teaspoons) per day would provide additional health benefits.”

But most regular soft drinks contain a lot of sugar. A regular 335 millilitre can of original Coca-Cola contains at least seven teaspoons of added sugar.

Diet soft drinks are designed to taste similar to regular soft drinks but without the sugar. Instead of sugar, diet soft drinks contain artificial or natural sweeteners. The artificial sweeteners include aspartame, saccharin and sucralose. The natural sweeteners include stevia and monk fruit extract, which come from plant sources.

Many artificial sweeteners are much sweeter than sugar so less is needed to provide the same burst of sweetness.

Diet soft drinks are marketed as healthier alternatives to regular soft drinks, particularly for people who want to reduce their sugar intake or manage their weight.

But while surveys of Australian adults and adolescents show most people understand the benefits of reducing their sugar intake, they often aren’t as aware about how diet drinks may affect health more broadly.

What does the research say about aspartame?

The artificial sweeteners in soft drinks are considered safe for consumption by food authorities, including in the US and Australia. However, some researchers have raised concern about the long-term risks of consumption.

People who drink diet soft drinks regularly and often are more likely to develop certain metabolic conditions (such as diabetes and heart disease) than those who don’t drink diet soft drinks.

The link was found even after accounting for other dietary and lifestyle factors (such as physical activity).

In 2023, the WHO announced reports had found aspartame – the main sweetener used in diet soft drinks – was “possibly carcinogenic to humans” (carcinogenic means cancer-causing).

Importantly though, the report noted there is not enough current scientific evidence to be truly confident aspartame may increase the risk of cancer and emphasised it’s safe to consume occasionally.

Will diet soft drinks help manage weight?

Despite the word “diet” in the name, diet soft drinks are not strongly linked with weight management.

In 2022, the WHO conducted a systematic review (where researchers look at all available evidence on a topic) on whether the use of artificial sweeteners is beneficial for weight management.

Overall, the randomised controlled trials they looked at suggested slightly more weight loss in people who used artificial sweeteners.

But the observational studies (where no intervention occurs and participants are monitored over time) found people who consume high amounts of artificial sweeteners tended to have an increased risk of higher body mass index and a 76% increased likelihood of having obesity.

In other words, artificial sweeteners may not directly help manage weight over the long term. This resulted in the WHO advising artificial sweeteners should not be used to manage weight.

Studies in animals have suggested consuming high levels of artificial sweeteners can signal to the brain it is being starved of fuel, which can lead to more eating. However, the evidence for this happening in humans is still unproven.

What about inflammation and dental issues?

There is some early evidence artificial sweeteners may irritate the lining of the digestive system, causing inflammation and increasing the likelihood of diarrhoea, constipation, bloating and other symptoms often associated with irritable bowel syndrome. However, this study noted more research is needed.

High amounts of diet soft drinks have also been linked with liver disease, which is based on inflammation.

The consumption of diet soft drinks is also associated with dental erosion.

Many soft drinks contain phosphoric and citric acid, which can damage your tooth enamel and contribute to dental erosion.

Moderation is key

As with many aspects of nutrition, moderation is key with diet soft drinks.

Drinking diet soft drinks occasionally is unlikely to harm your health, but frequent or excessive intake may increase health risks in the longer term.

Plain water, infused water, sparkling water, herbal teas or milks remain the best options for hydration.

Lauren Ball, Professor of Community Health and Wellbeing, The University of Queensland and Emily Burch, Accredited Practising Dietitian and Lecturer, Southern Cross University

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

What’s the difference? is a new editorial product that explains the similarities and differences between commonly confused health and medical terms, and why they matter.

Changes in thinking and memory as we age can occur for a variety of reasons. These changes are not always cause for concern. But when they begin to disrupt daily life, it could indicate the first signs of dementia.

Another term that can crop up when we’re talking about dementia is Alzheimer’s disease, or Alzheimer’s for short.

So what’s the difference?

What is dementia?

Dementia is an umbrella term used to describe a range of syndromes that result in changes in memory, thinking and/or behaviour due to degeneration in the brain.

To meet the criteria for dementia these changes must be sufficiently pronounced to interfere with usual activities and are present in at least two different aspects of thinking or memory.

For example, someone might have trouble remembering to pay bills and become lost in previously familiar areas.

It’s less-well known that dementia can also occur in children. This is due to progressive brain damage associated with more than 100 rare genetic disorders. This can result in similar cognitive changes as we see in adults.

So what’s Alzheimer’s then?

Alzheimer’s is the most common type of dementia, accounting for about 60-80% of cases.

So it’s not surprising many people use the terms dementia and Alzheimer’s interchangeably.

Changes in memory are the most common sign of Alzheimer’s and it’s what the public most often associates with it. For instance, someone with Alzheimer’s may have trouble recalling recent events or keeping track of what day or month it is.

We still don’t know exactly what causes Alzheimer’s. However, we do know it is associated with a build-up in the brain of two types of protein called amyloid-β and tau.

While we all have some amyloid-β, when too much builds up in the brain it clumps together, forming plaques in the spaces between cells. These plaques cause damage (inflammation) to surrounding brain cells and leads to disruption in tau. Tau forms part of the structure of brain cells but in Alzheimer’s tau proteins become “tangled”. This is toxic to the cells, causing them to die. A feedback loop is then thought to occur, triggering production of more amyloid-β and more abnormal tau, perpetuating damage to brain cells.

Alzheimer’s can also occur with other forms of dementia, such as vascular dementia. This combination is the most common example of a mixed dementia.

Vascular dementia

The second most common type of dementia is vascular dementia. This results from disrupted blood flow to the brain.

Because the changes in blood flow can occur throughout the brain, signs of vascular dementia can be more varied than the memory changes typically seen in Alzheimer’s.

For example, vascular dementia may present as general confusion, slowed thinking, or difficulty organising thoughts and actions.

Your risk of vascular dementia is greater if you have heart disease or high blood pressure.

Frontotemporal dementia

Some people may not realise that dementia can also affect behaviour and/or language. We see this in different forms of frontotemporal dementia.

The behavioural variant of frontotemporal dementia is the second most common form (after Alzheimer’s disease) of younger onset dementia (dementia in people under 65).

People living with this may have difficulties in interpreting and appropriately responding to social situations. For example, they may make uncharacteristically rude or offensive comments or invade people’s personal space.

Semantic dementia is also a type of frontotemporal dementia and results in difficulty with understanding the meaning of words and naming everyday objects.

Dementia with Lewy bodies

Dementia with Lewy bodies results from dysregulation of a different type of protein known as α-synuclein. We often see this in people with Parkinson’s disease.

So people with this type of dementia may have altered movement, such as a stooped posture, shuffling walk, and changes in handwriting. Other symptoms include changes in alertness, visual hallucinations and significant disruption to sleep.

Do I have dementia and if so, which type?

If you or someone close to you is concerned, the first thing to do is to speak to your GP. They will likely ask you some questions about your medical history and what changes you have noticed.

Sometimes it might not be clear if you have dementia when you first speak to your doctor. They may suggest you watch for changes or they may refer you to a specialist for further tests.

There is no single test to clearly show if you have dementia, or the type of dementia. A diagnosis comes after multiple tests, including brain scans, tests of memory and thinking, and consideration of how these changes impact your daily life.

Not knowing what is happening can be a challenging time so it is important to speak to someone about how you are feeling or to reach out to support services.

Dementia is diverse

As well as the different forms of dementia, everyone experiences dementia in different ways. For example, the speed dementia progresses varies a lot from person to person. Some people will continue to live well with dementia for some time while others may decline more quickly.

There is still significant stigma surrounding dementia. So by learning more about the various types of dementia and understanding differences in how dementia progresses we can all do our part to create a more dementia-friendly community.

The National Dementia Helpline (1800 100 500) provides information and support for people living with dementia and their carers. To learn more about dementia, you can take this free online course.

Nikki-Anne Wilson, Postdoctoral Research Fellow, Neuroscience Research Australia (NeuRA), UNSW Sydney

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