Dementia and Genetics
Dementia, a principal term describing a decline in cognitive functions due to various underlying conditions, manifests through memory loss, confusion, and mood fluctuations. These symptoms impact the everyday activities and well-being of individuals. While age is a significant factor in its prevalence (approximately one in three individuals aged 85 or older experiences some form of dementia), it’s important to note that dementia isn’t an expected outcome of ageing and doesn’t impact everyone.
Genetic variants are crucial to understanding the risk of dementia in families. Among the various types of dementia, specific forms, such as familial Alzheimer’s disease (FAD) and familial frontotemporal dementia (FTD), have a hereditary basis.
Yet, the impact of these variants isn’t solely determined by genetics. Their interaction with environmental and social factors also contributes significantly. This intricate relationship emphasises the need for assessments, including genetic testing. By exploring the complex interconnection between genetics, environmental factors, and the development of dementia, a deeper understanding of this condition can be gained, and proactive steps toward the better health of individuals can be taken.
Familial Dementia
In familial dementia, the origins of dementia can be attributed to inherited genetic changes. These changes, often referred to as faulty genes, are the reason for initiating familial dementia. In dominant inheritance scenarios, a single copy of the changed gene from either parent is enough to trigger the condition. In contrast, in recessive inheritance, changes from both parents are requisite for its development. Typically manifesting between the ages of 30 to 65, most forms of familial dementia fall under the category of early-onset dementia.
Familial Alzheimer’s disease stands out as a rare form of familial dementia. This form accounts for less than 1% of Alzheimer’s cases. A changed gene, such as presenilin 1, presenilin 2, or the amyloid precursor protein gene (APP), increases the likelihood of developing Alzheimer’s, typically in one’s 40s or 50s. In addition, conditions like familial frontotemporal dementia and certain types of familial vascular dementia also arise from single-gene changes, emphasising the complex connection between genetics and the diverse spectrum of dementia subtypes. Furthermore, individuals with Down’s syndrome face an increased risk of dementia due to an extra copy of chromosome 21, potentially leading to an accumulation of amyloid plaques associated with Alzheimer’s disease.
For cases of familial dementia, genetic testing proves particularly valuable. It has emerged as a vital tool for assessing an individual’s predisposition to dementia, especially if a family member is diagnosed. However, testing can induce emotional distress and anxiety. Pre-testing counselling is often recommended to help individuals navigate the potential emotional impact.
How Is Dementia Passed Genetically?
Dementia’s genetic foundations happen from changes within genes constructed from DNA molecules. The human genetic material is packaged into chromosomes, with 22 pairs of chromosomes and two X chromosomes (in women) or one X and one Y chromosome (in men). Each chromosome comprises thousands of genes, functioning as blueprints for various aspects of an individual. Among the genetic contributors to dementia risk is the Apolipoprotein E gene, carried on chromosome 19. Its presence increases the vulnerability to various forms of dementia, with the risk escalating as the number of gene copies increases.
Genetic changes can influence the development of different conditions. Some genes directly cause those conditions, while others, called risk factor genes, increase the probability of developing a condition. Dementia’s genetic influence operates through two primary avenues: single-gene and complex or multiple-gene diseases. Single-gene diseases happen from alterations in a specific gene, often resulting in severe but rare conditions. These conditions can be directly inherited, passing from parent to child.
In contrast, complex conditions, like most forms of dementia, develop due to the influence of multiple factors, including environmental factors, lifestyle choices, and genetic risk variants. In rare cases, dementia arises from single-gene diseases, particularly frontotemporal dementia. In such instances, genetic counselling and testing can offer valuable insights and support individuals and their families.
How Likely Are You to Get Dementia if Your Parent Has It?
The likelihood of developing dementia when your parent has been diagnosed varies based on the type of dementia and its genetic basis. Alzheimer’s disease, which accounts for a significant portion of dementia cases, occurs relatively frequently in older individuals, regardless of family history. For instance, familial Alzheimer’s disease accounts for less than 1% of all dementia cases, where the inherited gene increases the risk of early-onset Alzheimer’s, typically appearing in one’s 40s or 50s. However, frontotemporal dementia is hereditary in 40% to 50% of cases, while Lewy body dementia exhibits limited genetic influence, with only around 10% of cases being hereditary.
Genetic testing is helpful in families with a history of dementia, allowing them to identify members at risk of developing dementia. Learning about a genetic predisposition can assist some individuals in planning for the future and making informed lifestyle decisions. However, some individuals may choose not to see if they carry a gene associated with dementia.
How to Avoid Dementia if it Runs in Your Family?
Reducing the risk of dementia, especially when it runs in the family, involves adopting a combination of healthy lifestyle choices and proactive health management. While genetics can play a role, there are many controllable factors that can contribute to the risk of developing dementia. Here are some key strategies to consider:
Physical Activity: Regular physical activity is a powerful tool to lower the risk of dementia. Both aerobic activities like walking, swimming, and cycling, as well as strength-building exercises, contribute to overall brain health.
Healthy Diet: Eating a balanced and nutritious diet can reduce dementia risk. Emphasise fruits, vegetables, whole grains, lean meats, seafood, and healthy fats while limiting processed meats, sugars, and refined grains.
Avoid Smoking and Alcohol Consumption: Reducing or quitting smoking is crucial in reducing the risk of dementia. Reducing alcohol consumption is also recommended to lower the risk of developing dementia, so keep your alcohol intake within recommended limits.
Mental and Social Activities: Engaging in mentally stimulating activities like puzzles, learning new skills, reading, and socialising can help build cognitive resilience.
Control Health Conditions: Managing health conditions such as high blood pressure, diabetes, and high cholesterol can significantly reduce the risk of dementia.
Healthy Weight Management: Maintaining a healthy weight through a balanced diet and exercise benefits brain health and overall well-being.
Adequate Sleep: Prioritise getting seven to eight hours of quality sleep each night to support mental and physical well-being.
Limit Stress: Managing stress through relaxation techniques, mindfulness, and healthy coping mechanisms can positively impact overall brain health.
Stay Hydrated: Drink enough water throughout the day to support overall health and cognitive function.
Stay Mentally and Socially Active: Engage in lifelong learning, socialising, and staying mentally active to keep your brain engaged and healthy.
Even if an individual has a genetic predisposition, adopting a healthy lifestyle can significantly reduce the risk of developing dementia. To make informed choices, individuals must receive professional guidance and consider undergoing regular health check-ups to monitor their overall well-being.
Promoting Brain Health and Risk Reduction
Promoting brain health and reducing the risk of dementia is crucial, and scientific understanding of the various factors contributing to cognitive decline is always increasing. Protecting the head from traumatic brain injuries (TBIs) is a crucial step, as TBIs can trigger processes in the brain that lead to Alzheimer’s disease. Wearing protective headgear during activities with a higher risk of head injury, such as cycling, horse-riding, or engaging in certain sports, is recommended.
Research shows that maintaining cardiovascular health is closely linked to brain health. Conditions like high blood pressure, high cholesterol, and diabetes, when left untreated, can impact the blood vessels in the brain and contribute to cognitive challenges. However, treating these conditions through lifestyle changes and medical interventions can significantly reduce the risk of dementia. Following a brain-healthy diet can support cognitive function and help combat cognitive decline. Regular exercise is another essential aspect of maintaining brain health since it improves blood circulation to the brain, nourishing it with essential nutrients and oxygen.
Staying socially active and managing stress are additional strategies to protect brain health. Engaging in hobbies, volunteering, and maintaining social connections can boost mood and foster cognitive resilience. Mindfulness, relaxation techniques, and maintaining healthy sleep habits also contribute to brain health. While all dementia risk factors can’t be controlled, promoting brain health through lifestyle choices offers a promising path to improve cognitive well-being and improve the quality of life of individuals.
Leaf Complex Care Support People Struggling with Dementia
Leaf Complex Care offers comprehensive support for individuals facing the challenges of dementia, focusing on improving quality of life and providing specialised care.
One of the specialised services we provide is live-in dementia care, which allows individuals to receive personalised support and companionship within the comfort of their own homes. This approach enables individuals to maintain familiar surroundings and routines, immensely benefiting their mental health. The live-in care service is designed to provide round-the-clock assistance with daily activities, medication management, emotional support, and engagement in cognitive and recreational activities tailored to each individual’s needs.
We understand that every individual’s experience with dementia is unique, and care plans are tailored to meet each individual’s specific requirements. By placing the individual at the centre of their care, Leaf Complex Care creates a nurturing and empowering environment that helps individuals maintain their dignity, independence, and self-esteem.
Leaf Complex Care operates across the UK, with offices in Bristol, Slough, Somerset, and Birmingham and is committed to providing high-quality dementia care to individuals and their families.
If you or your loved one is facing challenges with dementia and needing support, Leaf Complex Care is here to help. Contact us today.
