Editors' Note: This article is part of the Patheos Public Square on the Faith and Aging. Read other perspectives here.

If you like to count your blessings, here's one to add to your list: if you're an American, your chances for living a long life have never been better. If you had been born in the U.S. one hundred years ago, however, the story of your life could have been written on far fewer pages. In 1916, the average American man lived 49.6 years and the average American woman lived 54.3 years.

Fast forward to the present. In 2016 Americans are living, on average, nearly eighty years. Of those who've already reached their 65th birthday, one in four will live past age ninety, and one in ten will live past ninety-five. This dramatic increase in longevity is largely due to advances in public health that occurred during the past century: vaccinations, sanitation, recognition of tobacco as a health hazard, safer food, safer highways, and safer workplaces.

Even more fascinating is how many people are on track to live longer. Those born during the baby boom era (1946-1964) began turning sixty-five in 2011. By 2050, there will be 83.7 million Americans age sixty-five or older. More Americans than ever before will be living longer than ever before. This looming, unprecedented increase in the older adult population has been dubbed the "silver tsunami."

At first glance, this population shift seems to be good news (e.g., we're all probably going to live longer). But it's also laden with sobering, not-so-good news. The downside has to do with other factors that will collide with the increase in older adults. Two of the biggest concerns are interrelated:

Overall, older Americans are not exactly a picture of health. Three out of four have multiple chronic illnesses such as diabetes. More than 40 percent are obese and most are sedentary. Obesity is linked to cancer, heart disease, and stroke. A sedentary (physically inactive) lifestyle negatively impacts blood pressure, blood sugar, and cholesterol, paving the way for heart disease.

Consider that even now, well before the full impact of the "silver tsunami" is realized, a whopping 86 percent of our nation's health expenditures already go to treat chronic conditions.

Compromised health may be a pathway to Alzheimer's disease. There is strong evidence that physical activity and good management of conditions such as diabetes, obesity, and high blood pressure reduces the risk of cognitive decline and perhaps dementia. Since most older adults are overweight or obese, most don't exercise, and most have at least one chronic condition, the typical older American may be on track for cognitive decline, and possibly Alzheimer's disease.

Currently, 5.4 million people have Alzheimer's disease (AD). If a cure is not found by 2050, by then at least 13.8 million Americans will have AD, with other estimates as high as 16 million. The greatest risk factor for AD is advancing age, and AD usually begins after age 65. Thus, the Alzheimer's epidemic is inseparably entwined with America's spike in aging.

If a real tsunami were headed for American shores, we would mobilize with urgency, taking every precaution to protect our lives, property, and national interests. We should not take the "silver tsunami" any less seriously.