Around 47 million people around the world are living with dementia, with 4.1 million of them in India, according to a new report, which also found that nearly half of all people with dementia globally will live in Asia by 2050.

Dementia is a general term for a decline in mental ability severe enough to interfere with daily life. Memory loss is an example. Alzheimer's is the most common type of dementia. Dementia is not a specific disease. It's an overall term that describes a wide range of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person's ability to perform everyday activities. Alzheimer's disease accounts for 60 to 80 percent of the Dementia cases worldwide.

Globally, there is a rise in the population of the elderly people with the generation of baby boomers having entered the age of 60 years. Old age is commonly associated with disorders such as high blood pressure and heart diseases. Along with these problems, it also leads to the slowing of the brain functions. Memory lapse is the most common brain dysfunction that people notice and are aware of. However, the attribution of memory lapse to old age commonly masks the onset of a disease called dementia.

India houses the second most number of individuals suffering from dementia with an estimated 4.1 million people suffering from it as per the ‘Dementia India’ report published by the Alzheimer’s and Related Disorders Society of India. This is expected to double by 2035. Maharashtra and Uttar Pradesh alone are expected to house more than 5,00,000 patients by 2026.

Scientists have found that losing the sense of smell is an early sign that a person is at the risk of development of dementia later in life. If you can't smell peppermint, fish, orange, rose and leather it could be an accurate early warning sign of dementia, according to a new study. The study entitled ‘Olfactory Dysfunction Predicts Subsequent Dementia in Older US Adults’, was published in the latest issue of the Journal of the American Geriatrics Society.

From their study, the researchers noted that elderly people who could not differentiate well between smells were at a greater risk of future cognitive decline. In their study, 20 percent of the individuals who had a bad sense of smell were twice as likely to get dementia within five years of the study. They write that going by these results, the sense of smell could be used as an early diagnostic marker for dementia.

A study conducted at Colombia University Medical Center, compared how well a declining sense of smell can predict cognitive decline, by comparing it to a well-established marker of Alzheimer’s disease – amyloid protein in the brain. The researchers used the UPSIT score to rate sense of smell and brain imaging or spinal fluid analysis to determine the level of brain amyloid protein in 84 people.

At follow-up periods of either two or four years, 67% of participants showed signs of memory decline. While the amount of brain amyloid present, but not odour identification, predicted memory decline, those with an impaired sense of smell were three times more likely to have memory problems.

This simple smell test could provide a quick and inexpensive way to identify those who are already at substantial risk. Although the test simply marks someone for closer attention, it could help find people who are at risk. Then the person can be enrolled in early-stage prevention trials.