Welcome to Straight Talk on Health. I’m your host Dr. Chet Zelasko. Straight Talk on Health is a joint production with WGVU in Grand Rapids MI. I examine the practical application of health information. Nutrition. Exercise. Diet. Supplementation. I look at the science behind them, and let you know whether it’s something to consider or not. You can check out other things that I do on my website Drchet.com and sign up for my free emails.
This past weekend, the clocks moved ahead one hour in most states here in the U.S.and other countries around the world. This seems to impact some people more than others; our bodies are more sensitive to the effects of changing sleep patterns than we think.I’ve examined this issue off and on over the years and I wanted to check the research to see if there were any updates. Let’s take a look at what we know and what we’ve found out.
In a 2008 study, Swedish researchers found that when the clocks are turned ahead one hour in the spring, the number of heart attacks increase on the following Monday and stay elevated above the mean for the rest of that week. This was confirmed in a 2020 study that examined the same question in a larger population of Swedish and U.S. citizens. There doesn’t appear to be any changes there.
What about the opposite situation? In the fall after the clocks are turned back, the number of heart attacks goes below the mean for the following week. One hour—that’s all we’re talking about, and it has a profound effect for about 1% of the population. Does one percent sound like no big deal? That’s over 3.3 million people who could be impacted in the US alone in the weeks after the clock change.
Is there a solution to this? The simplest solution would be to try going to bed a few minutes earlier every night leading up to the time change. That could help. But let’s take a look at a couple clock-changing solutions. Why do this?
We’ve become so obsessed with sleep, even our watches can track the amount of quality sleep we get. We went to bed at our usual time and for most of us in the U.S., we woke up one hour earlier than planned because the clocks have moved forward. As someone who adapts to sleep changes well, I empathize with those who don’t. So here are a couple of research-based solutions I’ve found, one societal and one personal.
Researchers from Stanford undertook a very complicated theoretical study. By using county solar light patterns, time policy, and health data with circadian models, they calculated the relationship of those variable conditions and diseases. Let’s just say this would be impossible without the number crunching ability of today’s computers.
What they found was that a shift to Standard Time year-round would decrease the occurrence of stroke and obesity. A permanent shift to Daylight Savings Time would also decrease the occurrence of stroke and obesity as well, although not to the same extent. It should be noted that the impact was dependent on both latitude and longitude of people within the time zone. The further north in latitude, the more pronounced was the potential impact.
How big of an impact? With Standard Time it could potentially reduce the risk of obesity by 0.78% and the risk of stroke by 0.09%. Not a big deal? Based on the current population of the US, that could mean a reduction of the cases of obesity by 2.6 million cases and 300,000 cases of stroke per year. While this is an emotional as well as political land mine for many proponents and opponents of time changes, this is still one variable that deserves consideration. The solution is to find common ground, pick one position and stick with it for at least a decade to see what, if any, health changes occur.
Another approach is taking a nap, time change or not. Getting some additional sleep, even as little as a 20-minute nap, can be beneficial. Researchers in Greece found that people who took a nap in the afternoon had a lower rate of death from cardiovascular disease (CVD). How much lower? 37%!
I don’t always take an afternoon nap because my schedule is too variable than it used to be. Wrangling an 11 year old to and from school at specific times combined with other activities sometime messes with my napping intentions. I can also tell you that it can take 19 minutes of the time I allow for my nap to actually get to sleep. But when that alarm rings at 25 minutes, I feel refreshed and ready to go.
This napping approach was confirmed by a study published last month suggesting that naps under 30 minutes reduced CVD outcomes—however, naps longer than 60 minutes increased the risk of CVD events. Speculation was that long naps interfered with nighttime sleep patterns.
We all look for an easy way to reduce our risk of heart attacks. Sometimes, the simplest solution is the correct one, and you can’t get much simpler than sleep. It can be challenging to fit in a nap during the day, but if you can do it, it may help you to be more effective in what you’re doing and lower your risk of cardiovascular disease and possibly other diseases as well. Did I also mention that focus and alertness was also increased after taking a short nap? As for a permanent switch to Standard Time for more early sunlight? That will be open for debate for years. All we can do is what we ourselves can control.
Here are a couple of quick observations for you. Paula and I watch a variety of cooking shows, probably too many. However, that’s where I’ve really learned some things that have punched up the flavors in the foods I cook. I’ve talked about fish sauce—the ultimate umami and salt sauce. Just don’t smell it because it’s made from fermented seafood. Be careful on the amount you add to what you’re cooking because a couple of splashes are probably enough. One more thing: make sure you cook the soup, stew, or the vegetables you’re braising long enough for the fish sauce to cook thoroughly. If you do, there is no fishy taste at all. I use it with beef or pork but not chicken.
What has always left me wondering about some of the cooking shows are all the chefs who will make crudo’s or ceviche. Essentially, the techniques use raw fish that are either served immediately—that’s the crudo—or marinated in lime or lemon juice that supposedly cook the fish or shrimp. After watching both technique for years, I decided to check out my major concern: does the method of cooking actually kill the parasites in either method?
In a word: no. Raw fish is raw fish and a little olive oil and herbs may enhance the flavor but that’s it. The lime or lemon juice may kill a specific strain of bacteria in a ceviche but will not kill other parasites in seafood. The only way to know whether the parasites are killed is to store it at -4 degrees F or colder for at least 7 days. I know some chefs buy the freshest fish virtually right off the boat. No way I’m eating that fish. Everyone else can eat the crudo’s and ceviche’s but unless it’s cooked to the correct temp, I’m not eating it. That’s the story behind fine dining and raw fish.
One final thing. If you’ve ever used a walk-run approach to running instead of running continuously, the designer of that technique, Jeff Galloway, recently died at 79 years old. He was an Olympian n the 10k but more importantly, he spent his life training and coaching every day runners to be able to do more. Using that technique, I shaved over 15 minutes of an 18.3 mile race I ran every year in Canada. Walking for just 30 seconds every mile improved my finishing time that much. He was truly someone who gave of himself to every runner he met—including me as I met him personally decades ago. He will be missed.
That’s all the time I have for this episode. If you like this podcast, please hit the share button and tell your friends and colleagues about it. Until next time, this is Dr. Chet Zelasko saying health is a choice. Choose wisely today and every day.
References:
1. https://doi.org/10.1073/pnas.2508293122
2. Arch Intern Med. 2007 Feb 12;167(3):296-301.doi: 10.1001/archinte.167.3.296
3. Pub Health Rev. 2026. doi: 10.3389/phrs.2026.1609013.
