{"id":350,"date":"2025-08-01T13:07:05","date_gmt":"2025-08-01T13:07:05","guid":{"rendered":"https:\/\/yourhealthdaybook.com\/?p=350"},"modified":"2025-08-01T13:07:05","modified_gmt":"2025-08-01T13:07:05","slug":"siren-call-of-daylight-saving-must-be-resisted-scientists-say","status":"publish","type":"post","link":"https:\/\/yourhealthdaybook.com\/?p=350","title":{"rendered":"Siren call of daylight saving must be resisted, scientists say"},"content":{"rendered":"

The clock, not the steam engine, is the key machine of the modern industrial age.
\n<\/em>\u2014Lewis Mumford, 1934<\/em><\/p>\n

Forget long, languid summer evenings \u2014 they\u2019re not worth the cost.<\/p>\n

Forget the annual \u201cspring forward,\u201d which we curse for how tired it leaves us but welcome for the promise of warmth and light.<\/p>\n

And, please, forget the U.S. Senate\u2019s unanimous vote<\/a> to make daylight saving time permanent. Though politicians think we want it and many of us think we\u2019ll love it, sleep scientists assure us we won\u2019t. It\u2019s been tried before. The results have been disastrous, and we\u2019ve always switched back.<\/p>\n

In fact, researchers say, if there\u2019s a year-round time to try, it is not daylight saving but standard time \u2014 that harbinger of winter, afternoon sunsets, and heavy coats \u2014 that should get the nod.<\/p>\n

\u201cThey had a 50 percent chance and they chose the wrong one,\u201d Charles Czeisler, the Frank Baldino Jr., Ph.D., Professor of Sleep Medicine at Harvard Medical School and Brigham and Women\u2019s Hospital, said of the Senate\u2019s vote.<\/p>\n

Everyone knows that the shift to daylight saving in March is rough. Studies show reduced alertness and a 6 percent increase in fatal traffic accidents the following week. There is also a more lasting increase in heart attacks, strokes, and suicide, according to a 2020 position paper by the American Academy of Sleep Medicine. The shift also undoes the positive effects of changes to school start times that let high schoolers start later, after research showed they benefitted from the extra sleep.<\/p>\n

Recent research has identified another argument for sticking with standard time year-round: cancer risk. The cancer-time connection surfaced more than a decade ago, when studies showed that night workers had higher rates of the disease, an effect disconnected from workplace carcinogens. In 2017, investigators from Harvard, Brigham and Women\u2019s Hospital, and the National Cancer Institute revealed that rates of breast, lung, stomach, and other cancers rose among those who lived farther west across a time zone. In 2018, a research team including Harvard scientists looked specifically at the connection between time zones and liver cancer, showing a similar rise in cases the farther west a patient lived.<\/p>\n

\u201cWe are affected by light in ways we don\u2019t think about\u201d<\/div>\n
\u2014 Charles Czeisler, professor of sleep medicine<\/div>\n

The exact connection between time and cancer is an area of active investigation, but Czeisler said the fact that the cancers involved are hormone-sensitive points to hormone dysregulation caused by our messed-up and misaligned schedules. A leading area of interest is melatonin.<\/p>\n

Melatonin is \u201cthe marker of biological night,\u201d according to Matthew Weaver, a Harvard instructor in medicine and one of the liver cancer researchers, because its levels rise and fall in a predictable 24-hour cycle. Morning light is particularly important for resetting our circadian rhythms to align with the 24-hour day. Avoiding light in the evening is also important and would become more difficult with permanent daylight saving, Weaver said, because exposure to light suppresses melatonin and delays bedtimes.<\/p>\n

<\/strong>But that\u2019s not all. Melatonin, it turns out, has anti-tumor properties, Czeisler said, making it a potential key player in the time-cancer connection.<\/p>\n

The underlying issue, researchers say, is misalignment of three clocks. The body\u2019s internal clock, or circadian rhythm, which is marked by rising and falling melatonin, changes in body temperature and cortisol levels, and other physiological characteristics, synchronizes each day with the rising and setting of the sun\u2019s clock. Gumming up the works is a third clock \u2014 the social clock \u2014 which tells us when to get up, when school starts, when work starts, when to wind down for the evening, and when to close our eyes. Standard time does a decent job aligning all three clocks, while daylight saving shifts everyone an hour out of alignment.<\/p>\n

\u201cDaylight saving time is like living in the wrong time zone: If you\u2019re in Boston, you go to sleep on Chicago time,\u201d said Elizabeth Klerman, a professor of neurology at Harvard Medical School and Massachusetts General Hospital who has co-authored time-cancer research. \u201cIf you already need an alarm clock to wake up in the morning, why make it worse?\u201d<\/p>\n

Scientists have explored various wrinkles in our disjointed solar, biological, and social times, Klerman said. One study looked at countries whose cultures are noted for eating dinner late and found that their time zone \u2014 the social clock \u2014 was misaligned by an hour from the solar clock, offering a reason for their late-night hunger. Another study examined so-called \u201cmorning\u201d and \u201cevening\u201d people, sending them on a camping expedition during which they were all exposed to the sun\u2019s bright light all day instead of an office\u2019s dim illumination. Everyone\u2019s bedtime, including that of the night owls, shifted earlier.<\/p>\n

Electric lights are part of the problem. They\u2019re bright enough to keep us awake and make us more productive in the evenings, but they\u2019re not bright enough to retune our body clocks. Artificial light provides somewhere between 100 and 200 lux \u2014 a measure of brightness related to a candle\u2019s flame \u2014 but if you were to step outside even on a cloudy day, your body would be bathed in 10,000 lux or more, Czeisler said. On a clear day, you can experience 100,000 lux, a blast of light that reaches people indoors.<\/p>\n

\u201cWe are affected by light in ways we don\u2019t think about,\u201d Czeisler said. \u201cHumans like to control their environment. We live in buildings where we control the temperature. We want to be able to decide when we do things, when we sleep, when we wake. But we are not as far removed from nature as we might like to think.\u201d<\/p>\n

Some people compare daylight saving time with jet lag, but Czeisler said that the comparison doesn\u2019t hold up. Jet lag\u2019s fleeting grogginess fades as our bodies adjust to the local clock in a one-time shift. When we change the clocks to daylight saving time, our bodies are caught in misalignment between solar and social time until clocks \u201cfall back\u201d to standard.<\/p>\n

If the Senate\u2019s shift to year-round daylight saving time is approved in the House and signed by the president, we\u2019ll be trying something that\u2019s been tried before, expecting a different result. The move was made during World War II and again in the 1970s during an oil embargo. The consequences have included an increase in schoolchildren killed by cars from January to April, a time of the year already plagued by late sunrises.<\/p>\n

\u201cIt\u2019s been tried before,\u201d Czeisler said. \u201cPeople go screaming back.\u201d<\/p>\n\n","protected":false},"excerpt":{"rendered":"

The clock, not the steam engine, is the key machine of the modern industrial age. \u2014Lewis Mumford, 1934 Forget long, languid summer evenings \u2014 they\u2019re not worth the cost. Forget the annual \u201cspring forward,\u201d which we curse for how tired it leaves us but welcome for the promise of warmth and light. And, please, forget …<\/p>\n","protected":false},"author":1,"featured_media":351,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"loftocean_post_primary_category":0,"loftocean_post_format_gallery":"","loftocean_post_format_gallery_ids":"","loftocean_post_format_gallery_urls":"","loftocean_post_format_video_id":0,"loftocean_post_format_video_url":"","loftocean_post_format_video_type":"","loftocean_post_format_video":"","loftocean_post_format_audio_type":"","loftocean_post_format_audio_url":"","loftocean_post_format_audio_id":0,"loftocean_post_format_audio":"","loftocean-featured-post":"","loftocean-like-count":0,"loftocean-view-count":394,"tinysalt_single_post_intro_label":"","tinysalt_single_post_intro_description":"","tinysalt_hide_post_featured_image":"","tinysalt_post_featured_media_position":"","tinysalt_single_site_header_source":"","tinysalt_single_custom_site_header":"0","tinysalt_single_custom_sticky_site_header":"0","tinysalt_single_custom_sticky_site_header_style":"sticky-scroll-up","tinysalt_single_site_footer_source":"","tinysalt_single_custom_site_footer":"0","footnotes":""},"categories":[6],"tags":[],"class_list":["post-350","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-staying-healthy"],"_links":{"self":[{"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=\/wp\/v2\/posts\/350","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=350"}],"version-history":[{"count":0,"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=\/wp\/v2\/posts\/350\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=\/wp\/v2\/media\/351"}],"wp:attachment":[{"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=350"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=350"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yourhealthdaybook.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=350"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}