In recent years, research has identified additional evidence-based risk factors for dementia that should be considered in addition to those already known. These three additional factors are:
Risk Factor 10 – Alcohol Consumption
Excessive alcohol consumption can increase the risk of dementia by impairing brain function, accelerating the breakdown of brain cells and promoting inflammation. Alcohol dependence and regular heavy drinking in particular can lead to an increased likelihood of dementia. Alcohol is a neurotoxin, and those who consume it in excessive amounts increase their risk of developing dementia in the medium to long term by 20 percent. Some renowned studies even estimate the risk at 39 percent. In addition, the risk of high blood pressure, diabetes, atrial fibrillation and heart failure increases. The World Health Organisation (WHO) defines excessive consumption for men as 60 grams of pure alcohol, which corresponds to about 1.5 litres of beer or a bottle of wine. Women should be even more careful: The recommended limit is 40 grams, which is reached with one litre of beer or half a bottle of wine. It used to be believed that regular alcohol consumption in small amounts – like the famous evening glass of red wine – was beneficial to health. However, this assumption is now controversial.
Risk Factor 11 – Craniocerebral Trauma
Craniocerebral injuries, especially those that occur repeatedly, can increase the risk of dementia. Craniocerebral injuries can cause swelling and inflammation in the brain, impairing cognitive function and increasing the risk of neurodegenerative diseases such as Alzheimer’s disease. Traumatic brain injuries are injuries to the skull bone that can lead to impaired brain function due to brain swelling and bleeding. Falls, traffic accidents and sports injuries are common causes. Symptoms vary depending on the severity of the trauma. The German Society for Neurointensive and Emergency Medicine (DGNI) states that about 270,000 people in Germany need medical treatment for head injuries every year. In recent years, researchers have increasingly identified traumatic brain injury as a risk factor for dementia. The authors of the Lancet study estimate that 3.4 percent of all dementia cases are due to traumatic brain injury. If such trauma is accompanied by unconsciousness, the risk may even quadruple.
Risk Factor 12 – Air Pollution
Particulate matter and other pollutants in the air can impair brain function and lead to inflammation, which is associated with an increased risk of dementia. Long-term exposure to poor air quality can lead to brain cell damage and impaired cognitive function. The Lancet study identifies environmental pollution as another risk factor for dementia. Particulate matter and nitrogen oxides in particular have harmful effects on the brain. It was previously believed that the blood-brain barrier protected the brain from harmful external attacks. However, particulate matter (tiny droplets and solid particles filled with toxins) can enter the brain directly through the olfactory bulb when inhaled through the nose, bypassing the blood-brain barrier. According to current data, the risk increase for dementia in polluted regions such as large cities and industrial areas is about ten percent. However, with about 75 percent of the world’s population living in such conditions, 2.3 percent of all dementia cases are attributed to air pollution. This underscores the importance of environmental protection and clean air for brain health and dementia prevention.
What about heavy metal pollution and resulting dementia diseases?
The role of heavy metal exposures and their influence on dementia risk is not yet fully understood and was not considered in the 12 risk factors study. Nevertheless, there is evidence of the neurotoxic effect of some heavy metals such as aluminium, which can lead to memory impairment and changes in nerve cells. The discussion about aluminium and its possible role in the development of dementia has been going on for decades and continues to be studied. Although aluminium has no essential function in the brain, it tends to accumulate there and trigger inflammatory reactions. Other metals such as iron, zinc or copper are necessary for the brain in certain amounts. However, excessive accumulation of these metals can be harmful. For example, excess iron can cause oxidative stress, which can lead to neurodegeneration. Further research is needed to better understand the link between heavy metal exposures and dementia risk and to develop possible preventive measures.