Researchers have discovered that being treated for one age-related disease may actually be protective for another age-related disease. Those having received common treatments for rheumatoid arthritis have been found to have a significantly lower rate of dementia, according to a recent study.

The type of drug intervention used was a key factor. The category of drugs referred to as classical disease-modifying antirheumatic drugs (DMARDs) were shown to be correlated to a lower incidence of dementia.

The lead author of the study, Andy Judge, M.D., from the Oxford NIHR Biomedical Research Centre and Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences at the University of Oxford, investigated the impact of common drug treatments using a UK Clinical Practice Research Datalink information database.

The researchers identified those over the age of 18 who had a diagnosis of rheumatoid arthritis from the years 1995 through 2011. They looked at the 3,876 who used DMARDs and the 1,938 who did not, along with other factors.

The DMARDs include drug treatments such as such as methotrexate, sulphasalazine, hydroxychloroquine and leflunomide, low-dose prednisolone and their combinations. While all contributed to lower dementia rates, methotrexate had the most significance.

With an estimated 1.3 million Americans having rheumatoid arthritis and 1 percent of the world population also having it, the numbers of those potentially taking medications to treat the disease is staggering. If there is an additional benefit of reduced cognitive impairment with aging, the gains over costs maybe worth looking at.

There are an estimated 5.5 million Americans with Alzheimer's-related dementia, 5.3 million being over the age of 65 and 200,00 under the age of 65. Alzheimer's disease and other related dementias were estimated to have cost $579 billion in 2017. The disease expenses average over $287,000 for the final five years of life.

Rheumatoid arthritis can also be costly. Medications can account for the vast majority of expenses. The amount spent on medications may be as high as $9.3 billion in the year 2020. One of the reasons is that some categories of drugs are costlier.

The DMARDs, however, are relatively inexpensive. Most patients spend between $1,500 and $2.000 yearly. Compare that to biologics, which can range from $1,300 to $3,000 per month. While outcome and quality of life should take priority, given the advantage of probable reductions of impaired cognitive functioning with DMARDs, these drugs may be the better alternative.

The observations during the study became apparent at approximately three years, and the significance of the finding remained after years of followup. A shortcoming, though, was the lack of validation for the individual cases of dementia through the data source. But a strength was using a matched population.

The conclusions — that there is a 40 percent reduction of risk for dementia in general, and a 50 percent reduction specific to methotrexate certainly warrants further study. And the news for those suffering from arthritis is positive.