A century ago, pediatricians began prescribing for children with intractable seizures the “keto diet,” which they also used to treat diabetes in children and adults. The low-carbohydrate, high-fat meals were designed to induce a near hypoglycemic state, forcing the body to use ketones for fuel instead of glucose.
The strategy fell out of favor after the discovery of insulin in the 1920s and the development of better antiseizure medications. The global market for the ketogenic diet topped $11 billion in 2022.
Is it just a fad, or has the public – and science – caught up with the 100-year-old approach?
Although scientists still don’t know why the ketogenic diet was effective for controlling seizures, they have documented the effectiveness of ketogenic diets for the treatment of diabetes and metabolic syndrome. An extensive body of literature has documented their use in athletes, but less is known regarding conditions such as heart disease and dementia.
Although the data are promising, much of the research has been conducted with mice or has come from trials of short-term use in humans. But recently, the National Institutes of Health awarded a $3.5 million federal grant for a double-blind, randomized, placebo-controlled clinical trial to understand the effects of the long-term use of ketone ester supplementation on frailty. Developed 20 years ago, ketone esters are precursor molecules that the body quickly breaks down into ketone bodies when carbohydrates aren’t available.
“We’ve learned so much recently about how ketone bodies interact with aging biology,” John Newman, MD, PhD, of the Buck Institute for Research on Aging in Novato, Calif., and the study’s principal investigator, said in an interview. “And we’re only just starting to translate that out of the laboratory and into human studies to see how we can take advantage of ketone bodies to improve people’s health.”
Researchers from the Ohio State University and the University of Connecticut will also participate in the TAKEOFF (Targeting Aging With Ketone Ester in Older Adults for Function in Frailty) trial, which seeks to recruit a total of 180 people across the three sites.
Dr. Newman, assistant professor at the Buck Institute and associate professor in the division of geriatrics at the University of California, San Francisco, said
One of the common things that happen during aging is that tissues – such as of the heart, brain, and muscle – lose the ability to metabolize glucose effectively. Over time, resistance to insulin can develop.
Researchers can map out areas of the brain affected by Alzheimer’s disease, for example, by assessing where patients’ glucose uptake drops. In heart failure, the heart has difficulty obtaining enough energy from glucose and instead burns fats and ketone bodies.
How might ketones affect frailty in the elderly?
As a practicing geriatrician, Dr. Newman measures frailty by evaluating patients’ strength, endurance, and how they react to stresses. He and his colleagues believe certain molecular and cellular changes may make patients more likely to fall, to recover more slowly from surgery, or to lose mobility.
The main hypothesis of the TAKEOFF study is “that if you target these fundamental mechanisms of aging, you would be able to impact many different diseases of aging across different organ systems.”
Dr. Newman and Brianna Stubbs, DPhil, lead translational scientist at the Buck Institute, are still finishing up the BIKE (Buck Institute Ketone Ester) pilot study, which was the first double-blind, randomized, placebo-controlled study to evaluate the use of ketone ester supplements in adults older than 65 years. “The BIKE study is 12 weeks long. That’s actually the longest that anyone has studied ketone ester supplements in humans,” Dr. Stubbs said. The results will help them firm up the protocol for the TAKEOFF trial, which will likely treat patients for up to 24 weeks.
The primary outcome measure at all three study sites will be leg press strength. Researchers will also assess a variety of secondary outcomes that cover geriatric and cognitive function – measures such as gait speed and walking endurance, cognitive tests, and quality of life. And at the Buck, Dr. Newman and Dr. Stubbs will be evaluating the use of biomarkers that are often available in clinical labs – insulin, C-reactive protein, cystatin, and natriuretic peptide tests – for use as outcome measures that are responsive to treatment interventions and that can be used to track outcomes in future research on aging.
To achieve the goal of looking broadly at different organ systems likely to be affected by ketogenic supplements, they have assembled a team of coinvestigators with wide-ranging expertise in ketone and aging research.
Jeff Volek, PhD, professor in the department of human sciences at the Ohio State University, in Columbus, has contributed extensively to the literature on the use of ketogenic diets and supplements in a variety of populations, such as endurance athletes and patients with insulin resistance or diabetes.
Dr. Volek has demonstrated that ketones can have an anticatabolic effect on muscle tissue. “They could help offset some of the muscle loss with aging, which would in turn improve their physical functioning and ability to do daily activities,” he said.
The anti-inflammatory property of ketones may provide another benefit to older people. They can reduce oxidative stress, which is considered one of the chief pathologic mechanisms responsible for conditions such as heart disease, Alzheimer’s disease, asthma, and arthritis.
In addition to the main study outcomes, Dr. Volek’s lab will study muscle physiology by performing biopsies at baseline and after consumption of ketogenic supplements to assess metabolic changes in muscle cells as they consume energy. Study participants will also undergo MRIs to detect subtle changes in muscle size before and after treatment.