Doing housework could cut your risk of developing dementia, according to a new study

Frequent exercise - including doing the housework - can lower the risk of dementia, according to new research.

Dementia is the seventh leading cause of death worldwide, affecting an estimated 55 million people, according to the World Health Organization (WHO). It says there are around 10 million new cases each year. Alzheimer’s disease is the most common form of dementia, contributing to around two-thirds of cases.

A growing body of evidence suggests that keeping physically active from middle age may help maintain cognitive capacity and ward off dementia. Exactly which activities and their intensity prevent dementia most effectively remains unknown. However, new research published in the Neurology scientific journal found that frequent exercise, including performing household chores, lowered dementia risk. Daily visits to and from family and friends also played a role.

The study analyzed healthcare data from just over half a million participants. They were an average of 56 years old and were monitored for an average of 10 years, with slightly more females than males taking part. Genetic risk factors for developing dementia, as well as any family history of the condition, were taken into account.

During the study period, 5,185 participants developed dementia. These tended to be older males who had a history of hypertension or hyperlipidaemia (higher levels of certain fats in the blood). They also tended to have a lower socio-economic status and a higher body mass index. Those who took most frequent exercise had a 35% lower risk of dementia, according to Medical News Today. Those who engaged in regular housework had a 21% lower risk, and daily interaction with friends and family reduced the risk by 15%.

The researchers concluded that physical as well as mental activity protected against dementia regardless of genetic risk or any family history of the condition. However, they also said going to pubs or social clubs and watching TV seemed to be linked to a higher risk of developing the disease - but didn’t elaborate on why this could be.

The study says that there are several possible explanations as to why physical activity could reduce dementia risk. Regular aerobic exercise may improve blood flow to the brain, which could reduce cognitive decline that comes with ageing. Exercise also has antioxidant effects which could delay damage to the brain. The researchers also noted that physical activity can indirectly influence other modifiable factors for cognitive function including obesity, hypertension, insulin resistance, depression and cardiovascular fitness.

The researchers say the results of mental activity patterns among participants in the study reinforce the benefits of social contact with family and friends. They say that a lack of social activity might directly result in cognitive inactivity or faster cognitive decline. This, they say, could also indirectly influence functions of the brain through increasing the risk of cardiovascular disease and depression.

Dr Dorina Cadar, a Senior Lecturer in cognitive epidemiology and dementia at the University of Sussex, told Medical News Today that social interaction is key to psychological wellbeing and mental resilience: “There is evidence showing that lacking social connections can damage a person's health as much as smoking 15 cigarettes a day. Social isolation and loneliness present one of the most significant health and social care challenges of the 21st century, increasing one’s risk of dying by almost 30%. Half a million older people in the [United Kingdom] do not see or speak to anyone for more than six days a week. That has tremendous consequences on individual mental health and subsequent dementia risk,” she explained.

In a separate study, scientists in the US say they have been able to boost people’s memory by using weak electrical currents to stimulate parts of the brain. Findings published by a team at Boston University suggest the technique could help people with conditions such as Alzheimer’s disease. Known as transcranial alternating current stimulation (tACS), the non-invasive method delivers electrical currents through electrodes placed on the scalp.

The experiment on 150 people aged over the age of 65 used word memorization tasks and resulted in both long- and short-term memory improvement - in some cases for a month. “Those who had the lowest levels of general cognitive function before the study experienced the largest memory improvements,” reports Nature.

It remains unclear whether the technique could be used in other memory tasks, or if improvements could last for longer than a month, but the team says it plans to explore this in future studies.

Dementia has significant implications in terms of medical and social care costs. The WHO estimates that in 2019 the total cost of dementia worldwide was $1.3 trillion dollars. It says these costs are expected to surpass $2.8 trillion by 2030 as the number of dementia sufferers and associated costs increase.

Davos Alzheimer’s Collaborative is led by the World Economic Forum and The Global CEO Initiative on Alzheimer’s Disease. It’s investing $700 million over six years into drug development and healthcare diagnostics. It’s also building a cohort of a million people living with Alzheimer’s, giving researchers worldwide access to real-world data.