Can we cure dementia before it even starts?
The future of preventive medicine may depend on the continued health of Leroy Hood’s brain. In a decades-long career, he’s achieved momentous strides in decoding the molecular-level workings of the human body and revealing possible early indicators of disease. The goal, he told me, is to diagnose chronic diseases early — before people develop symptoms. “Suppose you didn’t have to get cancer or diabetes, or you didn’t have to get heart disease,” he said.
His goal looks a lot like the promise Elizabeth Holmes made about predicting and preventing disease. She never got anywhere near those big claims before her company collapsed and she was convicted of fraud. She’s scheduled to report to prison tomorrow.
While she was in a race against her own unrealistic promises to investors, Mr Hood is in a very different kind of race — against his own ageing and genetic predispositions. He knows, thanks to technology he helped develop, that he carries a genetic variant called APOE4, which puts him, along with about a quarter of the population, at high risk of developing late onset Alzheimer’s Disease. And for him, it’s late. He’s 84. He says he needs about eight more years to finish what he’s started.
On his side are a smart plan and discipline. Each day, he eats right, puts himself through a series of brain exercises and performs 150 push-ups and 100 sit-ups. (There’s evidence that physical exercise is protective against dementia.)
Wellness experts have long wanted medical tests to work like the ghost of Christmas future — revealing the scenarios that will unfold if you don’t change your ways. Holmes’ grandiose promises so often relied on painting just that kind of picture. But it can be impossible, as a consumer, to know if a test and preventive treatment saved your life, or if the test was bunk. Mr Hood wants to put wellness on a firm scientific footing, backed with data and rigorous studies.
If anyone has the background to do it, Mr Hood does, as one of the founders of a field called systems biology. It applies rigorous standards to the messiest, most unpredictable and complex aspects of the human body.
When I pointed out the similarity to Holmes’ promises, he agreed. “She wove this story that was utterly compelling,” he said. “I think it’s far more difficult than she ever imagined, but it will be done.”
Making predictive wellness reliable and scientific will take reams of data not just on the genome but the epigenome, proteome, microbiome (and a few other -omes). It would also require a better understanding of the complex ways these all affect each other. That’s something Mr Hood shaped the field of system’s biology to handle — to make sense of the ways genes are affected by other genes, and the way these systems of genes work in concert with other systems, including environmental factors and the microbiome — that zoo of symbiotic bacteria that resides in your body.
He’s laid out what he’s learned so far in a book, released last month — The Age of Scientific Wellness, co-authored with research collaborator Nathan Price. Price is currently chief scientific officer at a company called Thorne HealthTech, which uses microbiome composition and other biological data to offer personalised health guidance.
The authors describe what they learned from subjecting 108 volunteers — called the Pioneer 100 — through almost every conceivable kind of test. Then, through a company called Arivale, they gathered similar data from 5,000 customers, who received estimates of their biological ages and personalised plans to turn them back compared to their chronological ages. On average, they wrote, women gained back 1.5 years and men, 0.8 years. The company folded in 2019 for financial reasons, but like a navigation app, each customer added data and predictive power. The scientific mission ploughed forward.
The book is where I learned how Hood and his family were affected by the APOE4 gene. His wife had the same genetic variant and died from Alzheimer’s. By the time she was 67, her symptoms had escalated beyond what might be ascribed to ordinary forgetfulness.
Mr Hood and his wife each carried the highrisk gene. Their daughter didn’t inherit it, but their son did, giving him a 60% to 70% chance of developing the disease by his mid-60s. Exercise is known to reduce risk, and his son is an ultramarathoner, said Mr Hood. Some 30% of people with his genetic profile don’t get dementia, and he could easily be one of them. And maybe scientific wellness will find other ways to mitigate the risk.
Genes aren’t destiny. Scientists continue to be surprised by people whose genes defy their simplistic understanding. Some people whose genes show they should develop a certain illness are fine, and others who should be fine get sick. Hood believes that despite the complexity, human health can be much more predictable and controllable than it is now. The payoff for an overburdened medical sector could be enormous.
Mr Hood’s story highlights the need not only to develop more accurate medical tests, but to learn more about interpreting the results — a nuance that always seemed to elude Elizabeth Holmes. An accurate but simplistic, clumsy interpretation of an APOE4 gene could devastate some people. Nobody knows why Mr Hood is going strong at 84 — whether it’s some misbehaviour gene, or his behaviour — his diet, brain exercises and push-ups. But if he has his way, we’ll all find out.