Daijiworld Media Network – New Delhi

New Delhi, Aug 21: People who do not have high blood pressure or diabetes and do not smoke may live nearly 13 years longer without developing dementia compared to those with all three risk factors, according to a long-term study conducted in the United States.

The study, based on the US-based Atherosclerosis Risk in Communities (ARIC) Study, followed 12,409 adults for a median period of 26.3 years. Researchers examined three major vascular risk factors during midlife — hypertension, diabetes and current smoking.

The findings showed that the number of these risk factors was linked to the length of time people remained free from dementia.

Participants without any of the three risk factors were estimated to live an average of 30.1 years without dementia from the age of 55. In comparison, those with all three risk factors had an average dementia-free period of 17.5 years.

People with one risk factor had about 26.3 dementia-free years from age 55, while those with two risk factors had around 21 years.

The likelihood of developing dementia also increased significantly with a greater number of vascular risk factors. Compared with participants who had none, those with all three had a 2.69-fold higher risk of developing dementia. Their risk of dying without dementia was also 5.61 times higher.

The impact became more pronounced with advancing age. Among people with all three risk factors, the estimated risk of developing dementia increased from 23 per cent at age 55 to 37 per cent at age 75. By age 85, only 7 per cent remained dementia-free, compared with 35 per cent among those who had none of the three risk factors.

The findings highlight the importance of addressing vascular health during midlife, as high blood pressure, diabetes and smoking are potentially modifiable risk factors.

The study also comes amid growing international focus on dementia prevention. Updated global guidelines from the World Health Organization have stated that up to 45 per cent of dementia cases could potentially be prevented or delayed by addressing modifiable risk factors.

The recommendations include controlling high blood pressure and diabetes, quitting smoking and remaining physically active. Reducing exposure to air pollution has also been identified as an important preventive measure.

The researchers said the findings reinforce the potential long-term benefits of managing cardiovascular and metabolic health earlier in life.