Alzheimer's disease and other forms of dementia currently affect about 4 million people living in the United States and about 15,000 residents of Hawai'i. By the year 2050, that number is projected to more than triple, to 14 million in the U.S. and almost 50,000 in Hawai'i.

Are we doing enough to protect ourselves, as a society and as individuals, against this rapidly rising tide of dementia, or are we ignoring a silent yet impending epidemic? Our research at the Pacific Health Research Institute is providing some ideas about how we can move forward.

As everyone knows, dementia is related to aging. It is characterized by problems with memory and thinking. About one in 10 Americans past the age of 65 suffers from dementia, and almost half the population over 85 is affected. As the elder age bracket is the fastest growing segment of our population, the need to address this epidemic becomes urgent.

The cost of dementia to the U.S. economy is already staggering. It is estimated that we spend more than $100 billion every year caring for those currently afflicted, accounting for medical expenses and the lost productivity of patients and family caregivers. By 2050, those costs will be more than $350 billion annually.

A large portion of these costs are for nursing home care and other specialized facilities. Hawai'i's culture favors keeping aging family members at home, and while this has obvious advantages for patients, it is costly in terms of additional stress for family caregivers and lost income.

Even with the cultural preference for home care, there is still a shortage of available nursing home beds for patients with dementia in Hawai'i. In fact, Hawai'i currently has only about 24 nursing home beds per 1,000 residents over 65 years old, compared to the national average of 43. This shortage will skyrocket as our population ages.

What can we do? For one, we need to rethink our healthcare strategies for taking care of the growing population of our elders. More resources should be allocated to plan for efficient and cost effective senior care facilities. Hawai'i must develop and support more programs that provide care for dementia patients within the community. Health insurance that covers long-term care expenses should be made available at a reasonable cost.

In addition, health research I have been involved with may provide new directions. The Honolulu Asia Aging Study (HAAS) is a long-standing scientific collaboration between the Pacific Health Research Institute and Kuakini Medical Center, and an outgrowth of the renowned Honolulu Heart Program. This project has tracked a cohort of more than 8,000 Japanese-American men who have generously participated in health studies focused on cardiovascular disease and now diseases of aging. The youngest member of the cohort is now 87, the oldest 106. We have made several surprising discoveries about dementia and we have findings that provide encouraging news about lifestyle changes that may reduce the risk of dementia.

The HAAS study and other studies around the world have reported that increased levels of exercise may decrease the incidence of dementia. While the exact reasons for this are unclear, regular exercise improves circulation and stimulates blood flow to the brain. Exercise has also been shown to decrease the risk of stroke, and we know that small strokes, otherwise undetectable, are positively correlated with dementia.

High blood pressure or hypertension is another important risk factor for dementia. Data from HAAS now show that hypertension can also be associated with Alzheimer's changes in the brain and that effectively treating hypertension offers protection against dementia.

Head trauma, particularly in early or mid-life, may also be associated with dementia. Wearing a helmet when taking part in any activity with head-trauma risk, such as biking, skateboarding, and motorcycle or horseback riding, will also likely reduce the risk of dementia.

The HAAS studies also demonstrate that most cases of dementia are caused not by a single disease such as Alzheimer's, but by a combination of factors. It is unlikely that we will discover a single "magic bullet" to prevent or cure dementia. But we can take a more holistic approach to dealing with this impending epidemic — better healthcare strategies, lifestyle changes, and more research to help uncover additional risk factors and determine better treatments.

We cannot stop dementia yet. But if we focus on improving healthcare delivery for our elderly and continue our research into the causes of this silent epidemic, we will certainly be able to improve our outlook for the future.

Helen Petrovitch is chairwoman of the Department of Research, Pacific Health Research Institute. She wrote this commentary for The Advertiser.