In 2013, two years after he was diagnosed with the earliest signs of dementia, Don Reynolds sat down with his attorney and filled out his advance health care directive, the legal document that lets loved ones and health care providers know his wishes for treatment as the end of life approaches.

The retired social worker, now 82, designated his 80-year-old wife, Ruth, as his agent in making health care decisions should he not be able to speak for himself. Further, he specified: “If the extension of my life would result in a mere biological existence devoid of cognitive function and with no reasonable hope for normal functioning, then I do not desire any form of life-sustaining procedure, including nutrition and hydration, unless necessary for my comfort or the alleviation of pain.”

Sitting with Ruth in their home on a winding, wooded street in Sacramento, Don considers those words. Over time, his dementia has deepened into a diagnosis of mild Alzheimer’s disease, and Ruth says she’s noticed worsening symptoms, including confusion, changed sleep patterns and trouble finding his way through the house they’ve lived in for decades.

But he remains a thoughtful man who methodically enters questions and observations in a spiral notebook so he can ponder them later with a men’s group from his church. What does it mean to Don now, as the mists of Alzheimer’s gather, to consider forgoing sustenance when his cognitive function wanes?

“I would want to know what kind of situation it is,” he said. “When the spoon is being extended, there’s a certain grey area there.”

That grey area presents a puzzle that medical, ethical and legal experts are only beginning to piece together. Advance directives and Physician Orders for Life Sustaining Treatment forms routinely instruct health care agents to withhold artificial nutrition and hydration — feeding tubes and intravenous drips — at the end of life.

But can people who are cognitively intact today decide to put into place directives stating that, if they ever develop advanced Alzheimer’s disease in the future, they want to go without food and water? Can someone forbid their future caregivers and nursing home aides from extending that spoon, as Don Reynolds puts it, if Alzheimer’s strips them of their selves?

The issue has taken on increased urgency as 76 million baby boomers across the country hope to plan better for their own final years after watching their parents’ decline and as Alzheimer’s, the fatal and incurable neurodegenerative disease that already affects 5.2 million Americans, is projected to triple its reach by 2050.

In a recent Marist Institute poll, 44 percent of Americans cited Alzheimer’s as the disease they fear the most — above cancer and heart disease. And for people who are already 65 and older, that figure soars to almost 60 percent.

Estate planning experts and health care professionals say it remains rare to find directives that instruct caregivers against hand-feeding in the case of advanced Alzheimer’s.

In a recent Marist Institute poll, 44 percent of Americans cited Alzheimer’s as the disease they fear the most — above cancer and heart disease. And for people who are already 65 and older, that figure soars to almost 60 percent.

“Generally, when people get to the point of having advanced dementia, something else happens with them to cause them to pass away,” says Heather Chubb, a Gold River estate planning attorney. “The issue is very, very sticky. If I had somebody who’s slipping away, who doesn’t recognize anyone any more even though he’s physically healthy, could I then use the advance directive to tell the facility not to feed him? I have not seen this explored from a legal standpoint.”

Not in California, at least. Wisconsin state law forbids families and institutions from intentionally not feeding an aging, demented patient even when his or her directive requests that. New York, Minnesota and New Hampshire say no, too. An ongoing case in Canada has found that a British Columbia woman with advanced Alzheimer’s must continue to be spoon fed despite her requests in her living will to the contrary. And medical ethicists have weighed in on whether the cessation of hand-feeding a deeply demented patient amounts to starvation or a humane right-to-die strategy.

While the debate quietly gathers steam, it still tends to be an afterthought to the more politically charged and emotional Death with Dignity campaigns, which were given new visibility with the widely publicised death last year of Brittany Maynard, a brain cancer victim in her early 30s.

The End of Life Option Act, as the current Death with Dignity effort in the California legislature is known, would apply only to patients whose cognitive function remains intact. The same is true for right-to-die advocacy across the country: The five states that have laws on their books allowing patients to choose assisted suicide also mandate that those patients have capacity to decide.

Similarly, Voluntarily Stopping Eating and Drinking (VSED) directives were long ago recognized by the U.S. Supreme Court as legal for any patient who is competent to make that decision. Choice hinges on competency, but people with advanced Alzheimer’s disease may not be able to speak or even remember who they are. They may no longer have the capacity to make their wishes known.

As a result, withholding sustenance from them can amount to committing elder abuse or manslaughter, says Dr. Stanley Terman, founder of Caring Advocates, a Southern California organization that helps people put into place a range of end-of-life documents that include VSED.

Still, he said, “We do not lose the right to determine what happens to our body just because you lose your competence.”

Instead of VSED for dementia patients, he advocates what he calls natural dying, which he said requires four separate physician orders: The first specifies the withdrawal of hand-feeding and drinking. Next, caregivers must make food and water available  so the patient can feed himself if he’s capable. The third order requests the cessation of all other medical treatments that would prolong life, including dialysis and cardiopulmonary resuscitation. A final order puts abundant comfort care into place.

A less detailed “dementia provision” offered by Compassion & Choices, one of the groups backing California’s Death with Dignity measure, allows people to add language to their directives saying they don’t want to be fed or given fluids under certain advanced dementia conditions, including the inability to recognize family.

In the absence of established law, experts worry that the public’s overwhelming fear of Alzheimer’s disease could cause confusion and misunderstandings.

“Not all dementia is progressive dementia where you know things will get worse month after month,” says Dr. Michael McCloud, a UC Davis Medical Center gerontologist and founder of the acclaimed Mini Medical School series on aging. “You can have a single stroke that puts you in dementia, and over time, you may develop some build-back. There can be progress.

“The other component is not understanding that in the natural course of Alzheimer’s, you’ll lose insight and memory of having said that you don’t want food or water. The person you’ve become may very much want to be alive. The potential is there to create more rather than less suffering in the late stages of dementia.”

For any patient at the end of life, feeding can be complicated. Families, who have long equated food with love, want to nurture their loved one as long as they can: It often feels right to spoon feed a dying relative. But experts say that when the body starts to shut down during the dying process, people can’t process food and hydration, and forcing them to eat can cause unnecessary suffering.

Similarly, people in the final stages of Alzheimer’s disease lose the ability not only to feed themselves but to swallow.

“But people in early-stage dementia still find meaning in life,” says Judy Thomas, an attorney and the chief executive officer of the Sacramento-based palliative care advocacy group Coalition for Compassionate Care of California, which takes no stand on right-to-die measures.

“The human spirit has a lot of resilience. We’re healthy people looking at people with dementia and judging their life,” she says. “I don’t think we can totally anticipate what that life is.”

That’s what Elizabeth Edgerly, the Alzheimer’s Association of Northern California’s chief program officer, told the staff of a Bay Area nursing facility that called her in to consult with its review committee a few years ago. Family members were urging nursing aides not to offer food to their relative with late-stage Alzheimer’s disease — but when aides held up a spoon and smacked their lips, the patient would eat.

“I think it’s a slippery slope,” says Edgerly, who doesn’t know the outcome of that case. “Should we do something invasive to keep this person alive? That’s an easier topic for advance directives to cover. When the directive says, ‘I don’t want to eat or drink,’ that’s more difficult. It’s frightening to do that as an acceptable way to plan for end of life. And it falls on someone else to do that as your proxy.”

In two decades as a skilled nursing administrator, Betsy Donovan says she’s never seen that situation. Now, as Eskaton’s chief operating officer, she oversees the Sacramento region senior living organization’s 14 skilled nursing and assisted living centers.

“We would follow whatever the directive states,” she says. “But even in hospice, at what point does that provision become active? It’s very individual, and it’s up to the physician and the patient.”

Or perhaps the patient’s family.

Ruth Reynolds watches her husband, Don, fade from Alzheimer’s disease day after day. He gets distracted easily now. Although he has loved to follow the Sacramento Kings on TV, lately he has a hard time watching the games: He can’t keep up with the fast-paced action on court. It doesn’t make sense to him any more.

She put her own advance healthcare directive into place at the same time Don did, and their wishes are similar. And so the two of them wait for whatever comes next, as his dementia gradually but steadily increases.

“I can see the ethical debate,” Ruth says. “If I was cognitively severely impaired and I wasn’t responding to people any more, maybe I’d just want to go.”

Her husband was listening carefully, considering her words.

“Yeah,” he says. “Maybe.”