A recent, large (n=72,269) 8-year prospective* observational study of adults aged 40-79 has found an association between irregular sleep and major cardiovascular events.

*this means they started the study at a given point, and measured what happened for the next eight years—as opposed to a retrospective study, which would look at what had happened during the previous 8 years.

As to what qualifies as major cardiovascular events, they counted:

• Heart attack
• Cardiac arrest
• Stroke
• Cardiovascular death (any)

Irregular sleep, meanwhile, was defined per a bell curve of participants. Based on a sleep regularity index (SRI) score, those with a score of 87 or more were on the “regular” side of the curve, and those with a score of 72 or lower were on the “irregular” side of the curve.

What they found is that irregular sleep is associated with major cardiovascular events, regardless of the actual amount of sleep that people got. So in other words, you could be sleeping 9 hours per day, but if it’s a different 9 hours each day, your cardiovascular risk will still be higher.

How much higher?

• For those in the middle of the curve (so, moderate irregularity), it was 8% higher than those on the “regular” side.
• For those on the “irregular” side of the curve, it was 26% higher than those on the “regular” side.

All of the above is after taking into account confounding variables such as age, physical activity levels, discretionary screen time, fruit, vegetable, and coffee intake, alcohol consumption, smoking, mental health issues, medication use, and shift work. Which is quite something, given that shift work is a very common reason for irregular sleep schedules in a lot of people.

Limitations

While, as noted above, they did their best to account for a lot of things, this was an observational study, not an interventional study or a randomized controlled trial, and as such, it cannot truly establish cause and effect.

For example, an observational study in the 90s found that the sport most strongly associated with longevity was polo. For any unfamiliar, it’s a game played on horseback with mallets and balls. Why was this game so much better than, say, swimming? And the answer is most likely that polo is played almost entirely by very rich people. It wasn’t the sport that enhanced longevity—it was the wealth.

So similarly here, it could be for example that people who are predisposed to heart conditions, are prone to having irregular schedules. We won’t know for sure until we have interventional studies (and we probably can’t get RCTs for this, for practical reasons).

Still, it seems likely that the association is indeed causal, in which case, having a regular sleep schedule if at all possible seems like a very good way to look after one’s health.

You can read more about the study here:

Irregular sleep may elevate risk of major cardiovascular events

Practical take-away

This study strongly suggests that sleep regularity is even more important than sleep duration.

This means that there is extra reason to not sleep in past one’s normal getting-up time, even if one had a less restful night.

That’s the end of sleep that’s the most important in practical terms, too, because we can control our getting-up time, whereas we can’t really control our going-to-sleep time, because it’s perfectly possible to just lie there awake.

So, controlling the getting-up time is really the key to the whole thing. See also:

Calculate (And Enjoy) The Perfect Night’s Sleep

And for scope, you might enjoy reading:

Morning Larks vs Night Owls: How Much Can We Control Our Sleep Schedule?

Enjoy!

How to keep your teeth young

The association between aging and teeth is so well-established that it’s entered popular idiom, “too long in the tooth”, and when it comes to visual representations, false teeth are well-associated with old age.

And yet, avoiding such outcomes does not get anywhere near so much attention as, say, avoiding wrinkles or hair loss.

At 10almonds, we’ve covered general dental health before, in a three-part series:

1. Toothpastes & Mouthwashes: Which Help And Which Harm?
2. Flossing, Better (And Easier!)
3. Less Common Oral Hygiene Options

Today, we’re going to be looking specifically at keeping our teeth young. What if you have lost your teeth already? Well, gum health remains important, and it’s foundational for everyone, so…

Look after your gums first and last

Hollywood’s most “perfect” whites would be nothing without the gums holding them in place. So, set aside the cosmetic whitening products that often harm gums (anything containing bleach / hydrogen peroxide, is generally a bad idea), andinstead focus on your gums.

As for avoiding gum disease (periodontitis)?

❝In conclusion, periodontitis might enhance the association of biological aging with all-cause mortality in middle-aged and older adults.

Hence, maintaining and enhancing periodontal health is expected to become an intervention to slow aging and extend life span.❞

Source: Does Periodontitis Affect the Association of Biological Aging with Mortality?

Ways to look after gum health include the obvious “floss” and “brush often” and “use fluoride toothpaste”, along with other options we covered in our “Less Common Oral Hygiene Options” article above.

Also important: don’t smoke. It is bad for everything, and this is no exception.

We expect we probably don’t have many subscribers who smoke, but if you do, please consider making quitting a priority.

See also: Smoking, Gum Disease, and Tooth Loss

Consider supplementing with collagen

Everyone’s all about the calcium and vitamin D for bones (and teeth), but a large part of the mass of both is actually collagen. And unlike calcium, which most people not living in a food desert get plenty of, or vitamin D, which is one of the most popular supplements around, collagen is something that gets depleted as we get older. We’ve written about its importance for bones:

We Are Such Stuff As Fish Are Made Of—Collagen’s benefits are more than skin deep

And as for its role in combatting gum disease and tooth loss:

Nanoscale Dynamics of Streptococcal Adhesion to AGE-Modified Collagen

By the way, that “AGE” there isn’t about chronological age; it’s about advanced glycation end-products. Those are also something you can and should avoid:

Are You Eating AGEs?

A different kind of “spit and polish”

We imagine you have the “polishing” part in hand; that’s tooth-brushing, of course. But spit?

Saliva is hugely important for our oral health, but it’s not something most of us think about a lot. For example, you might not have known (or might have known but not thought much about) that many common medications affect our saliva, including many blood pressure medications and antidepressants:

Impact of ageing and drug consumption on oral health

Because there are so many possibilities, this is the kind of thing to check with your pharmacist or doctor about. But as a rule, if you take a medication whose side-effects include “dry mouth”, this might be you.

Here’s a really useful (academic) article that covers what drugs cause this, how to diagnose it, and what can be done about it:

Hyposalivation in Elderly Patients

If something’s difficult, find a way to make it easier

Sometimes, as we get older, some things that used to be easy, aren’t. We can lose strength, coordination, manual dexterity, memory, attention, and more. Obviously, we try not to, and do what we can to keep ourselves in good health.

But, if you do have some disability that makes for example brushing and/or flossing difficult to do consistently and/or well, consider talking to your doctor to see if there are assistive devices that can help, or some other kind of support that could allow you to do what you need to.

See also: Improving oral hygiene for better cognitive health: Interrelationships of oral hygiene habits, oral health status, and cognitive function in older adults

There’s never any shame in getting help if we need it.

Take care!