When we see an 80-year-old female athlete tearing down the track toward the finish line, a business owner putting in a full day at a job he loves at 90, or a 75-year-old volunteering her time as a surrogate grandparent, most of us think, “yes, that’s how I want to age.” We envision an active, passionate, and satisfying life, not just a long life.
Fortunately, our individual desire to remain vigorous in later life jibes with a rising social imperative to keep more seniors free of the chronic diseases we associate with aging. It’s been called the “Silver Tsunami,” referring to the increasing number of people entering their senior years, who could potentially strain healthcare resources.
“The current approach—which is to do nothing until you get sick and then keep you alive in a sick state—is costing a fortune, and it’s questionable whether it’s really improving quality of life that much,” said Brian Kennedy, PhD, CEO and President of the Buck Institute for Research on Aging in Novato.
That’s one reason scientists are now studying not just lifespan (how many years you live), but healthspan (the number of years you live without age-related illness). We’re lucky to have some world-renowned researchers delving into the biology of aging at the Buck Institute. They’re working diligently with yeast, worms, flies, mice and humans as they test different approaches to achieving a longer healthspan.
Particularly promising in in the field of healthspan research is rapamycin, a drug that is prescribed to suppress immune response and prevent organ rejection in kidney transplant patients. “The reason we got excited about rapamycin is that it has the clearest effect on aging,” Dr. Kennedy said. “This drug extends life span in mice by 30 percent–that’s a big, big number–bigger than any other drug I know of. Imagine if it had the same effect in humans; that’s like 20 extra years of healthspan.”
Like all drugs, however, rapamycin does have side effects, potentially leaving those taking the drug open to a greater risk of opportunistic infections. “One of the things we [at the Buck Institute] are trying to do is to find versions of rapamycin that have the same effi cacy but have fewer side effects,” noted Dr. Kennedy. “The immune suppression is a complicated story. There are also metabolic consequences of this drug we don’t like, such as dyslipidemia (having an abnormal amount of cholesterol or fats in the blood) and hyperglycemia (high blood sugar).”
Another drug under evaluation by researchers in the field of geroscience is metformin, used in treating people with Type 2 diabetes, which has fewer and less severe side effects than rapamycin. A study of diabetes patients taking metformin versus patients without diabetes being treated in the same doctors’ offi ces showed that the patients taking the metformin actually had a lower mortality rate.
Dr. Kennedy explained, “What that suggests is that metformin is protecting against diabetes, but it’s also protecting against a lot of the other diseases of aging at the same time, probably because it’s impacting the primary aging pathways. Now there is a big movement to get the FDA to approve a clinical trial that looks at healthspan with metformin.”
Dale Bredesen, MD, of the Buck Institute is exploring lifestyle interventions and nutritional supplements as a way to reverse mild cognitive impairment. An internationally known researcher in the area of Alzheimer’s disease, Dr. Bredesen has compiled a list of approximately 20 risk factors—including poor diet, lack of exercise, and vitamin D deficiency—for the neurodegenerative disease.
“The question was, if you take people with mild cognitive impairment, and you compare them to people in the same age group that don’t have the impairment, are more of these categories abnormal in these MCI patients? And the answer was yes,” said Dr. Kennedy.
Dr. Bredesen customized the therapy for each person studied, based on individual parameters deemed to be in the abnormal range. “There hasn’t been a full-scale trial, but Dale has worked with a lot of people now, and it’s pretty amazing how much they improve in function if you correct these things,” commented Dr. Kennedy.
According to results reported for the therapy: “Nine of the 10 [subjects studied] displayed subjective or objective improvement in cognition beginning within three to six months, with the one failure being a patient with very late stage AD [Alzheimer’s disease].”
Long-term caloric restriction, calling for consistently consuming 20 to 40 percent fewer calories than the norm, is another lifestyle approach known to retard the ravages of aging. It hasn’t gained a large popular following, however, due to the discipline required to maintain the strict dietary regimen. Dr. Kennedy said studies show that periodic fasting may provide the same benefits as prolonged calorie restriction, without inducing the same feelings of privation.
Even more realistic for the general population might be just a commitment to eating a healthier diet, according to Dr. Kennedy. “For 95 percent of the population, you don’t even need to talk about dietary restriction. We need to talk about a sustainable diet that gives you a caloric intake that is reasonable and incorporates the healthy foods into your lifestyle,” he said. “The positive, healthy impact of that— forget dietary restriction—would be huge.”
While the results of healthspan studies are encouraging, there still remains a healthcare industry heavily invested in treating disease rather than preventing it. “What we really need is a change in mindset to say, we should stop thinking about aging as this unmodifiable, inevitable process,” concludes Dr. Kennedy. “If we can keep people healthy, then they stay functional, they have low healthcare costs, they’re contributing to society, and they’ll have a high-quality life. But…any time you’re trying to change the way the world thinks about health, it’s a big challenge.”