Carrying the Weight of Dementia: Genetics, risk and prevention

Our GPs regularly see the impact dementia can have, not only on patients, but on entire families. While some forms of dementia are strongly linked to genetics, growing evidence also shows that lifestyle and vascular health can play an important role in reducing the risk of more common types of dementia.

 

Here, Dr Vicky Carre explores the different causes of dementia, the latest developments in treatment and prevention, and the remarkable story of Jordan Adams, who is currently running 33 marathons in 33 days in memory of his mother, who died from frontotemporal dementia.

At this year's London Marathon, 31-year-old Jordan Adams stood out even among the usual incredible array of fancy dress and charity runners. He completed the 26.2 miles carrying a full-sized fridge - a standard white appliance weighing roughly 25 kilograms -strapped to his back.

And this marked the start of an even more demanding undertaking: 33 marathons in 33 consecutive days. After London, the fridge was transported to Ireland, his late mother Geraldine’s home nation, where Jordan is now running 32 further marathons across the country. By the time you read this, he will be around day 12 - deep into a physically punishing schedule that would be difficult enough without the added weight.

A family shaped by frontotemporal dementia

Jordan’s mother was diagnosed with frontotemporal dementia (FTD) at the age of 47 and died five years later. FTD is a relatively rare form of dementia, but one that disproportionately affects people under 65. FTD has a strong genetic component with around 30% of cases caused by inherited genetic mutations. In these families, the pattern is stark: each child has a 50% chance of inheriting the mutation which will almost inevitably then lead to the disease.

This raises complex ethical and emotional questions around genetic testing for diseases in which we currently have no cure. Some choose to know; others prefer uncertainty. There is no right answer - only what an individual feels able to carry.

Jordan and his younger brother Cian have both tested positive for the mutation associated with their mother’s illness. Their sister, Kennedy, tested negative - meaning she has not inherited the gene and will not face the same risk. For Jordan and Cian, the situation is very different.

 

What is frontotemporal dementia?

Frontotemporal dementia accounts for around 5–10% of dementia cases but is one of the leading causes of young-onset dementia.

The disease affects the frontal and temporal lobes of the brain - areas responsible for judgement, emotional regulation, and communication. Unlike Alzheimer’s disease, which typically begins with memory problems, FTD often presents with changes in behaviour, personality, or language. People may become disinhibited, lose empathy, act out of character, or develop progressive speech difficulties.

The bigger picture: common causes of dementia

Although FTD is important, it is relatively uncommon. Most dementia cases fall into a few major categories.

Alzheimer’s disease

Alzheimer’s disease accounts for around two-thirds of dementia cases. It typically begins with memory impairment and progresses gradually over time. It is associated with the build-up of abnormal proteins (amyloid and tau) in the brain.

Vascular dementia

Vascular dementia is the second most common cause and results from reduced blood flow to the brain, often due to stroke or long-term damage to the walls of the brain’s blood vessels. This damage usually results from the effects of high blood pressure, diabetes, smoking, and high cholesterol.

Lewy body dementia

Lewy body dementia is another important subtype. It can present with fluctuations in attention, visual hallucinations, and Parkinson’s-like movement symptoms. It is caused by abnormal deposits of another type of protein (alpha-synuclein) in the brain cells.

What we find in practice is that many patients - particularly in older age - have a mixture of these processes causing their dementia.

Treatment: still limited, but evolving

There is currently no cure for frontotemporal dementia and no treatment proven to slow its progression. Management focuses on symptom control and support.

For Alzheimer’s disease, some medications can modestly improve symptoms. More recently, there has been growing interest in treatments that directly target the underlying disease process. Antibody therapies designed to remove the abnormal amyloid and tau proteins from the brain are beginning to emerge, offering cautious optimism that disease progression may be slowed in selected patients.

Looking further ahead, gene-based therapies are an area of intense interest. For inherited conditions such as FTD, where a specific mutation is known, there is real hope that future treatments may be able to modify or silence these genes.

Prevention: where evidence is strongest

For individuals like Jordan and his brother, who carry a genetic mutation linked to FTD, there is currently no proven way to prevent the disease. However, this is not the case for most dementia.

A substantial proportion of dementia risk - particularly Alzheimer’s and vascular dementia - is linked to modifiable factors. Addressing these can reduce risk or delay onset:

• Cardiovascular health: controlling blood pressure, cholesterol, and diabetes and avoiding smoking helps to keep the brain’s blood vessel walls in good condition

• Physical activity: regular exercise supports brain and vascular health by encouraging good blood flow and boosting neurotransmitters in the brain that promote the health of brain cells

• Alcohol: avoid alcohol which is directly toxic to brain cells

• Diet and weight: maintain a healthy, balanced diet full of antioxidants to nourish the brain cells – best achieved by eating lots of fruits, vegetables, nuts and legumes

• Cognitive and social activity; learning new skills, reading, engaging with your community, playing games and solving puzzles have all been proven to make a difference – use it or lose it!

  
  

There is also increasing awareness of medication-related risk. Drugs with “anticholinergic effects” (some of the more old-fashioned antihistamines, bladder medications and antidepressants), sedative medications and strong painkillers have been associated with increased risk of cognitive decline when used long term. These medications are often necessary, but they should be reviewed periodically - so talk to your GP to make sure any regular medication you take is providing overall benefit.

The future for dementia

Jordan Adams’ challenge is physically extreme, but its purpose is straightforward. His family’s experience highlights a form of dementia where risk is largely determined by genetics - something modern medicine cannot yet prevent.

For most of us though, dementia risk is not fixed. There is good evidence that addressing lifestyle factors can really make a difference to reduce or delay the onset of the more common forms of dementia.

At the same time, research is moving forward with great pace. Treatments that target the abnormal proteins seen in Alzheimer’s disease, along with the longer-term prospect of gene therapies, offer genuine hope, including for those with inherited conditions such as frontotemporal dementia.

Raising funds for this research is one of the objectives of Jordan’s challenge. If you want to follow Jordan’s progress through his 33 marathons - fridge and all - you can track the journey and find links to his fundraising page via @theftdbrothers on social media.