This week, I’m sharing another collection of oldies-but-goodies—pieces from our newsletter archive that address a variety of topics of continued interest to our audience. Some provide additional context for recent or upcoming content; some address frequently asked questions; and some are simply worth repeating for anyone who might have missed them.
The world of biomedical science is constantly evolving, but in evaluating what has changed, we like to pause now and then to acknowledge information and ideas that have remained relevant despite the passage of time—a celebration of “aging well,” if you will.
With the lazy days of summer winding down, many of us—especially those with school-aged kids—find we have more stressors and demands on our time (and wallets) as we head into the fall and the looming holiday season. Under these circumstances, getting sufficient, high-quality sleep can be more challenging, prompting some to turn to melatonin supplements for a little extra help. But as we discussed in this newsletter from two years ago, such “natural” sleep aids drastically exceed the doses that the body naturally produces to promote sleep, and it’s possible that regular, long-term exposure to high concentrations of this sleep hormone may gradually impair endogenous production and/or reduce the brain’s sensitivity to melatonin signaling. While these supplements can help to mitigate certain acute disruptions to sleep schedules—such as when experiencing jet lag or after a single night with too much screen time—they should not be considered a long-term, everyday solution for sleep concerns. (For information on more sustainable strategies for improving sleep, check out my recent podcast with Dr. Ashley Mason.)
Age-related hearing loss is strongly associated with dementia, though debate continues as to whether this relationship may be causal or if hearing loss might merely be an early biomarker of deterioration in cognitive function. The ACHIEVE randomized trial, published in 2023, attempted to address this question by examining whether correcting hearing loss might slow or prevent cognitive decline, reporting no significant differences in cognitive trajectories between treated and untreated groups.1 Yet as we describe in this newsletter covering the study, a number of limitations in the study’s methodology and results meant that the door had not completely closed on the possibility that hearing loss might be directly detrimental to cognitive function. Indeed, in the time since we wrote this piece, several secondary analyses of ACHIEVE data have shown that the treatment group experienced significant improvements relative to controls in various outcomes, including communicative function,2 fall risk,3 and social network size.4 These outcomes could plausibly relate to certain aspects of cognitive or neurological health, but more importantly, even if they represent distinct effects, they underscore an inescapable conclusion: whether or not hearing loss contributes causally to cognitive decline (as I still suspect it does), correcting hearing deficits offers so many other benefits to overall health and well-being as to make it a no-brainer choice for anyone looking to enjoy a longer, happier life.
In putting together these “oldies-but-goodies” roundups, we primarily highlight newsletters that have remained fairly constant in their relevance since their original publication. But in the case of this piece from November 2023, we have a rare opportunity to draw fresh attention to concepts that continue to grow in significance with the passage of time—namely, the vast potential of artificial intelligence (AI) for improving evaluation of medical data and assessment of an individual’s health risks.
The study discussed in this newsletter focused on the use of AI to facilitate analysis of raw image data from body composition scans—a strategy which, when it came to predicting mortality, significantly outperformed the traditional, human-driven practice of analyzing a handful of numerical metrics extracted from the [much richer] images.5 But as exciting as this application may have been in 2023, it’s impossible to deny that the last two years have seen greater advances in AI’s analytical and reasoning capacities than most of us could have thought possible. So in revisiting the success of AI in this early domain and seeing how the technology has progressed since then, we can perhaps begin to conceptualize just how powerfully AI may yet reshape the capabilities of modern medicine (and countless other fields).
It’s no secret that nutrition is one of my least favorite topics, and the reason for this is two-fold: 1) the sheer volume of bad science published in this space is staggering, and 2) the fact that many tend to defend their diet with such cultish zeal that any hope for critical, fact-driven analysis is lost. These problems often go hand-in-hand—as appeared to be the case with the study and docuseries on which this newsletter was based.6
In a soon-to-be-released “Ask Me Anything” episode, I explain how to assess the relative merits and shortcomings of various diet patterns from a health perspective and how to determine which approach might be right for you as an individual. However, this type of critical evaluation is only possible if we first open our eyes to the pervasiveness of diet tribalism and the flawed research that is so often used to support any given camp’s sense of superiority over others. Thus, prior to the upcoming AMA, I recommend revisiting this newsletter, which was largely intended to illustrate how biased study designs and appeals to emotion can (and often are) used inappropriately to manipulate public perspectives on the role of diet in human health.
Earlier this year, we launched our first “topic guide”—a new way to engage with the volumes of content we create on key topics related to health and longevity. Each topic guide is available to premium subscribers and provides a curated set of clips and episodes to help build a foundation in a given subject of interest, derive actionable takeaways, and enhance understanding of how various guest perspectives and individual puzzle pieces fit together into a larger picture. With our second topic guide released this past week on the topic of zone 2 training, we’d like to take this opportunity to also re-share our inaugural topic guide on metabolic health.
For a list of all previous weekly emails, click here.
References
- Lin FR, Pike JR, Albert MS, et al. Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomised controlled trial. Lancet. 2023;402(10404):786-797. doi:10.1016/S0140-6736(23)01406-X
- Sanchez VA, Arnold ML, Garcia Morales EE, et al. Effect of hearing intervention on communicative function: A secondary analysis of the ACHIEVE randomized controlled trial. J Am Geriatr Soc. 2024;72(12):3784-3799. doi:10.1111/jgs.19185
- Goman AM, Tan N, Pike JR, et al. Effects of hearing intervention on falls in older adults: findings from a secondary analysis of the ACHIEVE randomised controlled trial. Lancet Public Health. 2025;10(6):e492-e502. doi:10.1016/S2468-2667(25)00088-X
- Reed NS, Chen J, Huang AR, et al. Hearing intervention, social isolation, and loneliness: A secondary analysis of the ACHIEVE randomized clinical trial. JAMA Intern Med. 2025;185(7):797-806. doi:10.1001/jamainternmed.2025.1140
- Glaser Y, Shepherd J, Leong L, et al. Deep learning predicts all-cause mortality from longitudinal total-body DXA imaging. Commun Med (Lond). 2022;2(1):102. doi:10.1038/s43856-022-00166-9
- Landry MJ, Ward CP, Cunanan KM, et al. Cardiometabolic effects of omnivorous vs vegan diets in identical twins: A randomized clinical trial. JAMA Netw Open. 2023;6(11):e2344457. doi:10.1001/jamanetworkopen.2023.44457
