A new study suggests that older women who consume coffee daily may have a lower risk of dementia.

The findings found that higher caffeine consumption in older women was associated with reduced risk of developing dementia or cognitive impairment.

According to a recent research, among a group of older women, self-reported caffeine consumption was associated with a 36 per cent reduction in the risk of incident dementia over 10 years of follow-up.

This level is equivalent to two to three cups of coffee per day, five to six cups of black tea or seven to eight cans of cola.

"The mounting evidence of caffeine consumption as a potentially protective factor against cognitive impairment is exciting given that caffeine is also an easily modifiable dietary factor with very few contraindications," said study's lead author Ira Driscoll.

Driscoll added, "What is unique about this study is that we had an unprecedented opportunity to examine the relationships between caffeine intake and dementia incidence in a large and well-defined, prospectively studied cohort of women".

For the study, Driscoll and her team used data from 6,467 community-dwelling, postmenopausal women aged 65 and older who reported some level of caffeine consumption.

Intake was estimated from questions about coffee, tea, and cola beverage intake, including frequency and serving size.

In 10 years or less of follow-up with annual assessments of cognitive function, 388 of these women received a diagnosis of probable dementia or some form of global cognitive impairment.

Those who consumed above the median amount of caffeine from this group (with an average intake of 261 mg per day) were diagnosed at a lower rate than those who fell below the median (with an average intake of 64 mg per day).

The researchers adjusted for risk factors such as hormone therapy, age, race, education, body mass index, sleep quality, depression, hypertension, prior cardiovascular disease, diabetes, smoking and alcohol consumption.

The findings were published in the Journals of Gerontology Series, A Biological Sciences and Medical Sciences.