Latest Science Review: Rapid aging in mid 40s and early 60s

We review the latest science behind popular health and wellness headlines.

The Headlines:

Humans age at two key points in their life, study finds (CNN)

Scientists find humans age dramatically in two bursts - at 44, then 60 (The Guardian)

Study finds bursts of rapid aging at 44 and 60 (The Hill)

The Research:

Article: Nonlinear dynamics of multi-omics profiles during human aging

Published online: August 14, 2024

Publication: Nature Aging

The Key Conclusion

Humans age at a biomolecular level in two waves—in the mid 40s and in the early 60s. The key biomolecular changes fall into the categories below.

Mid 40s

• Skin/Muscle

• Caffeine Metabolism

• Cardiovascular Disease

• Lipid Metabolism

• Alcohol Metabolism

Early 60s

• Skin/Muscle

• Caffeine Metabolism

• Cardiovascular Disease

• Immune

• Kidney Function

• Carbohydrate Metabolism

3 common sense questions to help you assess the trust level of research conclusions.

1. What is the journal the research was published in?

2. Who are the scientists?

3. What is the study design?

What about this research?

1. What is the journal the research was published in?

   The journal is Nature Aging, which is part of the umbrella of Nature publications which is a highly selective journal. This is a positive for this research.

2. Who are the scientists?

   The scientists have been doing research work at Stanford Medicine, which is a reputable institution. In addition, you can take a look at their past publications—in terms of the volume of their peer-reviewed work and the number of times that their previous work has been cited by others. If there is a high number of citations that means their work is at least higher quality and other scientists are mentioning it in their own research. Look for any mentions of disclosures of conflicts of interest in the primary article—either funding sources or personal affiliations with industry, like for-profit companies. They have a high volume of past reputable work and no disclosures which is positive for this research.

3. What is the study design?

   STUDY SIZE

   They studied 108 participants, which is a red flag. This is a fairly small number especially when you think about the types of characteristics that they're cutting this pool of 108 by. For example. they are cutting down the pool of 108 participants by sex (50/50 split), age (25yo-75yo), and ethnic background. As a result, there is a limitation on how broad the conclusions can be. For example, you shouldn’t interpret all humans of all ethnic groups go through 2 waves of aging. And there is a limitation on the specificity of the conclusions. For example, for yourself personally you shouldn’t ascribe too much meaning to specific ages like 44yo or 60yo that’s mentioned in some of the headlines, instead you should think of it as a range—the mid 40s and early 60s. Even with the limitations on broadness and specificity, this research is valuable from a directional standpoint and can inform future research which is really important and something they bring up in the discussion section of the article. There was another research study that was done at Stanford University back in 2019 covering the same topic of aging and in that study they primarily were using protein samples in the blood as opposed to the much more diverse set of data samples here—blood, stool, skin. That study covered over 4,200 participants which is a much more robust size and they came up with similar results—rapid aging at certain time points. This adds to the trust level for these research conclusions

   RECRUITMENT CRITERIA

   This research focused on healthy people as defined by prior to onset of any disease, like cardiovascular disease, insulin resistance, etc. Disease onset can increase with age. So by excluding this, the scientists can get a truer picture of what biomolecular changes are happening via natural course of aging independent of disease onset. This is a positive of the research. However, they only evaluated disease onset at initial recruitment so some participants may have developed a disease. But given that the max duration of a participant in the study was 1.7 years, which is short for longitudinal data collection, it is not as likely, but still possible.

   DATA TYPES

   Another limitation of the study design is that they only collected biological samples and no behavioral data. For the conclusions on alcohol metabolism, it is difficult to fully tease apart how much that impaired metabolism might be tied to higher alcohol consumption in mid life or natural degradation of certain pathways. So this is something to keep in mind when interpreting the results and applications for yourself.

Given the limitations in the study design, how should you interpret the research conclusions?

Use this research to reflect on your own body and start conversations with your doctor.

For those nearing their mid 40s:

• Reflect on any muscular skeletal changes you are experiencing and discuss with your doctor.

• Discuss your overall cardiovascular disease risk with your doctor including any changes in your lipid profile.

• Look at ways to add a combination of cardio and strength training to your current lifestyle.

• Reflect on your consumption of alcohol and caffeine. How do you feel when you consume these beverages? Think about several hours after consumption as well as well as a longer time horizon like 12-24 hours after consumption.

At Well∙ish, we believe in helping people stay healthy for as long as possible so they can enjoy the full life that they have built! It was exciting to see Michael Synder (senior researcher of the article that we are reviewing) share a similar sentiment:

“I’m a big believer that we should try to adjust our lifestyles while we’re still healthy.”