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Your chronological age might not yield the answer. CU-Boulder researchers are studying ways to reverse arterial aging, linked to the leading cause of mortality in America. I spent 12 weeks in a clinical study of a carbohydrate that might reverse arterial aging. Here’s what I learned…

The treadmill spins faster and tilts higher. What was a light, flat jog is now a hard uphill run. My legs are faltering. Arms are flailing. It’s not flattering.

My breathing veers toward gasping. But my nose is pinched closed, and each breath is taken and measured via a tube in my mouth. A spiderweb of wires stuck on my torso tracks my heart rate, which hits 196 beats per minute.

This—both mind and body concur—is a fine time to stop.

I am completing the second of two VO2 max tests, which measure maximal aerobic capacity. I’d done the first test in spring, the second after 12 weeks of a University of Colorado Boulder research study to determine the arterial benefits of a natural carbohydrate called trehalose.

I am 52 years old. I get regular invitations from the AARP, and my arteries are stiffer and do not dilate as well as they did at age 22. That stiffness matters, because declining arterial health—often caused by endothelial dysfunction—is linked to cardiovascular disease.

Heart disease causes about one in four deaths annually and is the leading cause of mortality in the nation, the U.S. Centers for Disease Control and Prevention reports. Most heart-disease deaths occur in people over 65, a demographic group that is expected to balloon.

In 2010, 40 million Americans were 65 or older. By 2050, that number is expected to be 89 million. The portion of the U.S. population over 65 is expected to rise from 13 percent to 20 percent, reports the U.S. Department of Health and Human Services.

Let’s face it. Despite our best efforts, some people are not going to exercise or improve their diet, but they may benefit from alternative strategies.

Lowering heart-disease risk in older people could save health-care resources and improve quality of life for millions.

Those entering middle age need not abandon all hope. Older adults can slow the decline of arterial function with good lifestyle choices: exercising more, losing weight, eating well and ingesting less salt.

But habits persist. People forgo exercise and good nutrition regardless of how persuasively public-health campaigns preach. That’s one reason researchers, including those at CU-Boulder, investigate alternatives.

How to maintain arterial health?

The  at CU-Boulder researches a host of ways to slow or reverse arterial aging in middle-aged and older adults. The lab, directed by Douglas R. Seals, professor of distinction of integrative physiology, conducts clinical tests on the arterial benefits of Vitamin D, oral sodium nitrite, curcumin (the active ingredient in turmeric) and trehalose.

Seals emphasizes the benefits and limitations of good lifestyle choices. “Let’s face it. Despite our best efforts, some people are not going to exercise or improve their diet, but they may benefit from alternative strategies.”

I figure I need no “alternative strategy.” I spend more than 200 hours a year vigorously exercising, and I’m vegan. I have low cholesterol numbers, low risk for heart disease, and probably low risk for aneurysm and stroke, which claimed my dad and granddad.

I volunteered to participate in the trehalose study for two reasons: curiosity and a desire to support science that could help people.

Trehalose is a nutraceutical: a food or non-synthetic food supplement with purported health benefits. The carbohydrate, found in mushrooms and other sources, has a unique chemical structure and might improve arterial health.

Studies in mice have shown that trehalose can protect against age-related neurological diseases and extend longevity.  

In addition, the Integrative Physiology of Aging Laboratory has shown that in old mice, trehalose restores arterial elasticity and endothelial function to levels observed in young animals. 

This was the first step in the translational-research approach employed by the laboratory, in which compelling therapies are first studied in animals and then examined in humans.

Good arterial health depends on proper functioning of the lining of blood-vessel walls—the endothelium. Good endothelial function relies in part on the ability of cells to eliminate damaged proteins and dysfunctional mitochondria. This shedding of damaged cellular components is called autophagy.

“It’s a kind of a way for cells to clean house,” says Rachelle Kaplon, a doctoral candidate in integrative physiology and the principal investigator of the trehalose study.

Trehalose is a nutraceutical: a food or non-synthetic food supplement with purported health benefits. The carbohydrate, found in mushrooms and other sources, has a unique chemical structure and may improve arterial health.

With age, autophagy becomes less efficient. That decline contributes to age-related vascular oxidative stress and inflammation, precursors to heart diseases including stroke, peripheral artery disease and atherosclerosis. Volunteers are still participating in the trehalose study, which should be completed by next spring.

Research participants like me consume 100 grams of carbohydrate dissolved in water each day for 12 weeks. This is a double-blind experiment, so neither Kaplon nor participants knows whether the carbohydrate being ingested is trehalose or maltose, the placebo.

Kaplon does note that trehalose is a relatively easy pill to swallow. “Unlike a lot of pharmaceutical drugs that might be able to target this process,  trehalose is a very safe compound used widely in food manufacturing.”

Weight gain is possible, of course. Research subjects are asked to keep their weight and physical activity stable. That means reducing the number of calories you get from regular sources

The Integrative Physiology of Aging Lab hopes its work may help aging adults maintain healthy lifestyles as long as possible. Kaplon calls this a “meaningful increase in lifespan,” one with, say, less time in a nursing home and more physical and cognitive ability into older adulthood.

Subjects: healthy but not off the charts

Before joining the experiment, which is being conducted on people over 50, I had to qualify. I passed a cognitive-function test (correctly answering questions like “what year is it?” and demonstrating a functioning short-term memory).

Eligible volunteers must show some level of vascular dysfunction. Despite my efforts to live well, I lack the arteries of a 22-year-old. That might seem predictable. It isn’t.

Researchers also tested my blood pressure, blood composition and physical fitness. From an arterial function perspective, I had to be healthy, but not too healthy.

Eligible volunteers must show some level of vascular dysfunction. Despite my efforts to live well, I lack the arteries of a 22-year-old. That might seem predictable. It isn’t.

More than 100 people over 50 have signed the consent form for the study, but about a quarter of them show no age-associated vascular dysfunction, Kaplon says.

“We get people who are really physically active or just have a pretty healthy lifestyle who have really well-preserved vascular function”—with the arteries of 20-year-olds.

Those candidates do not qualify for the experiment.

“We don’t feel it’s ethical to put people through all of the testing if there’s nothing that we can do to improve their blood-vessel function,” Kaplon observes.

But there is unpredictable variation. The lab sees sedentary, sometimes-overweight candidates who have “great vascular function.”

And there are very active people like me who have diminished vascular function. Genetics, stress, sleep patterns and other factors can take a toll.

Tests, carbs and more tests

Once a subject qualifies for the study, researchers take “baseline” measurements of maximal oxygen uptake and arterial function. These tests are repeated at the end of the 12-week period, to determine what change, if any, researchers see in vascular function and aerobic fitness.

The testing is conducted in CU-Boulder’s Clinical Translational Research Center, the only such center in the country not on a medical campus.

The VO2 max tests, perhaps more dramatic than the arterial function tests, showed my maximal oxygen intake to be 50 milliliters per kilogram of body weight per minute at the beginning of the study.

A VO2 max of 50 is good for a Baby Boomer. A fifty-something with a VO2 max of 35 is average, and one scoring less than 26 is considered to have “very poor” uptake.

By contrast, in their peak, Olympic marathon champ and Boulder running legend Frank Shorter recorded a VO2 max of 71, and Tour de France champ Greg LeMond clocked a 92.5.

The arterial function tests yielded more-precise data. Generally, greater dilation indicates healthier vasculature.

With my arms in inflatable cuffs, researchers test the function of the endothelial layer of arteries by infusing four substances: acetylcholine, which increases arterial dilation; sodium nitroprusside, another substance that increases dilation; a nitric oxide synthase inhibitor, a drug that blocks vasodilation; and vitamin C, an antioxidant.

Acetylcholine acts on the endothelial layer of arteries to cause vasodilation (primarily through endothelial release of nitric oxide). As such, this is a measure of endothelium-dependent dilation, Kaplon notes.

At the beginning of the study, my arteries responded minimally to acetylcholine: My response was about 16 percent of what is seen in people’s 20s.

If researchers see impaired dilation—such as mine—it could reflect one of two things. It could be that the signals that need to be sent from the endothelium aren’t being sent. Or it could be that the smooth muscle cells aren’t functioning well and aren’t responding to the signals they’re receiving.

My smooth muscle cells performed well, the tests showed.

The tests showed that acetylcholine injected with vitamin C evoked much more dilation. This indicates that my reduced vascular dilation is due in part to oxidative stress—which may further indicate that I have faltering autophagy.

Bummer.

At the time of the study, I did not know whether I was in the placebo (control) group or the trehalose (experimental) group. Now, I know which group I was in but can’t divulge it publicly. Kaplon must remain “blinded” as she completes her analysis of the results.

Meanwhile, it is heartening to observe the work of Kaplon, Seals and their colleagues.

I know full well the bell tolls for me. Research like this might delay its toll on thee.

For more information about the Integrative Physiology of Aging Laboratory, click .

Clint Talbott is director of communications and external relations for the College of Arts and Sciences.