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.

Today’s news coverage reports potentially unsafe levels of “forever chemicals” detected in drinking water supplies around Australia. These include human-made chemicals: perfluorooctane sulfonate (known as PFOS) and perflurooctanic acid (PFOA). They are classed under the broader category of per- and polyfluoroalkyl substances or PFAS chemicals.

The contaminants found in our drinking water are the same ones United States authorities warn can cause cancer over a long period of time, with reports warning there is “no safe level of exposure”.

In April, the US Environmental Protection Agency (USEPA) sent shock waves through the water industry around the world when it announced stricter advice on safe levels of PFOS/PFOA in drinking water. This reduced limits considered safe in supplies to zero and gave the water industry five years to meet legally enforceable limits of 4 parts per trillion.

So, should the same limits be enforced here in Australia? And how worried should we be that the drinking in many parts of Australia would fail the new US standards?

What are the health risks?

Medical knowledge about the human health effects of PFOS/PFOA is still emerging. An important factor is the bioaccumulation of these chemicals in different organs in the body over time.

Increased exposure of people to these chemicals has been associated with several adverse health effects. These include higher cholesterol, lower birth weights, modified immune responses, kidney and testicular cancer.

It has been very difficult to accurately track and measure effects of different levels of PFAS exposure on people. People may be exposed to PFAS chemicals in their everyday life through waterproofing of clothes, non-stick cookware coatings or through food and drinking water. PFAS can also be in pesticides, paints and cosmetics.

The International Agency for Research on Cancer (on behalf of the World Health Organization) regards PFOA as being carcinogenic to humans and PFOS as possibly carcinogenic to humans.

Our guidelines

Australian drinking water supplies are assessed against national water quality standards. These Australian Drinking Water Guidelines are continuously reviewed by industry and health experts that scan the international literature and update them accordingly.

All city and town water supplies across Australia are subject to a wide range of physical and chemical water tests. The results are compared to Australian water guidelines.

Some tests relate to human health considerations, such as levels of lead or bacteria. Others relate to “aesthetic” considerations, such as the appearance or taste of water. Most water authorities across Australia make water quality information and compliance with Australian guidelines freely available.

What about Australian PFOS and PFOA standards?

These chemicals can enter our drinking water system from many potential sources, such as via their use in fire-fighting foams or pesticides.

According to the Australian Drinking Water Guidelines, PFOS should not exceed 0.07 micrograms per litre in drinking water. And PFOA should not exceed 0.56 micrograms per litre. One microgram is equivalent to one part per billion.

The concentration of these chemicals in water is incredibly small. And much of the advice on their concentration is provided in different units. Sometimes in micrograms or nannograms. The USEPA uses parts per trillion.

In parts per trillion (ppt) the Australian Guidelines for PFOS is 70 ppt and PFOA is 560 ppt. The USEPA’s new maximum contaminant levels (enforceable levels) are 4 ppt for both PFOS and also PFOA. Previous news reports have pointed out Australian guidelines for these chemicals in drinking water are up to 140 times higher than the USEPA permits.

Yikes! That seems like a lot

Today’s news report cites PFOS and PFOA water tests done at many different water supplies across Australia. Some water samples did not detect either chemicals. But most did, with the highest PFOS concentration 15.1–15.6 parts per trillion from Glenunga, South Australia. The highest PFOA concentration was reported from a small water supply in western Sydney, where it was detected at 5.17–9.66 parts per trillion.

Australia and the US are not alone. This is an enormous global problem.

One of the obvious challenges for the Australian water industry is that current water treatment processes may not be effective at removing PFOS or PFOA. The Australian Drinking Water Guidelines provide this advice:

Standard water treatment technologies including coagulation followed by physical separation, aeration, chemical oxidation, UV irradiation, and disinfection have little or no effect on PFOS or PFOA concentrations.

Filtering with activated carbon and reverse osmosis may remove many PFAS chemicals. But no treatment systems appear to be completely effective at their removal.

Removing these contaminants might be particularly difficult for small regional water supplies already struggling to maintain their water infrastructure. The NSW Auditor General criticised the planning for, and funding of, town water infrastructure in regional NSW back in 2020.

Where to from here?

The Australian water industry likely has little choice but to follow the US lead and address PFOS/PFAS contamination in drinking water. Along with lower thresholds, the US committed US$1 billion to water infrastructure to improve detection and water treatment. They will also now require:

Public water systems must monitor for these PFAS and have three years to complete initial monitoring (by 2027) […]

As today’s report notes, it is very difficult to find any recent data on PFOS and PFOA in Australian drinking water supplies. Australian regulators should also require ongoing and widespread monitoring of our major city and regional water supplies for these “forever chemicals”.

The bottom line for drinking tap water is to keep watching this space. Buying bottled water might not be effective (2021 US research detected PFAS in 39 out of 100 bottled waters). The USEPA suggests people can reduce PFAS exposure with measures including avoiding fish from contaminated waters and considering home filtration systems.

Correction: this article previously listed the maximum Australian Drinking Water Guidelines PFOA level as 0.056 micrograms per litre. The figure has been updated to show the correct level of 0.56 micrograms per litre.

Ian A. Wright, Associate Professor in Environmental Science, Western Sydney University

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