Researchers warn planned C-section births — the most common surgery in the US — can increase risk of childhood cancers
After studying the health of nearly 2.5 million children, members of the Swedish Karolinska Institutet found an increased risk of developing acute lymphoblastic leukemia during these events – and not in similar emergency 'C-section' procedures.
They're still working to understand why this is the case, but have identified possible factors that could help to explain. The researchers noted that babies in planned C-sections are not stressed or exposed to vaginal bacteria, as during emergency C-sections. Doctors perform a C-section when the health of the baby is at risk or when a vaginal delivery isn't possible or safe.
'C-sections are an important and often life-saving part of obstetric care. We don't want mothers to feel anxious about medically indicated C-sections. But when this result is combined with other study results showing that the risk of later asthma, allergies or type 1 diabetes increases in children born by planned C-section, there is reason to discuss C-sections that are not medically indicated," researcher Christina-Evmorfia Kampitsi said in a statement.
Kampitsi and her team found that of the nearly 376,000 children born in by C-section Sweden between 1982 to 1989 and 1999 to 2015, nearly 1,500 later developed leukaemia. The risk of acute lymphoblastic leukemia was 21 percent higher in children born by planned C-section compared with children born vaginally.
Furthermore, the risk of developing the most common form of acute lymphoblastic leukemia, known as B-cell acute lymphoblastic leukemia, was 29 percent higher in those born by planned C-section. The increased cancer risk was more pronounced in boys than in girls, and in the early years of a child's life.
Acute lymphoblastic leukemia is a type of blood and bone marrow cancer, and the most common type of cancer in children. It's also unclear what causes the DNA mutations that can lead to the cancer, but treatments result in a good chance for a cure, according to the Mayo Clinic. The American Cancer Society estimates there will be 6,100 new cases and 1,400 deaths this year due to the cancer in both U.S. children and adults.
The researchers emphasized that the risk of developing these cancers remains low, regardless of the mode of delivery.
The excess risk associated with planned C-sections corresponds to approximately one case of B-cell acute lymphoblastic leukemia annually, they said.
C-sections have become increasingly common in the U.S., accounting for about one in three births, according to Centers for Disease Control and Prevention data. Notably, maternal mortality has been rising in the U.S. in recent years, with as many as 84 percent of pregnancy-related deaths believed to be preventable, according to Yale Medicine.
There are 1.2 million C-sections performed every year, making it the 'most common major surgery performed in the United States,' according to Dr. Cindy Celnik, the chief medical officer of The Woman's Hospital of Texas.
"Fortunately, acute lymphoblastic leukemia is rare,' added Kampitsi. 'This means that many C-deliveries are needed to obtain a statistically significant result, and it is difficult to obtain such a large sample in a Swedish registry study. However, the results are close to significant, are in line with what previous studies have shown, and remain when we adjust for other relevant factors, which still makes them relevant.'
Kampitsi was the lead author of the findings, which were published on Friday in The International Journal of Cancer.
Hashtags

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
6 hours ago
- Yahoo
TikTokers are obsessed with ‘fibermaxxing'. Here's what the experts say
Break out the chia pudding! The social media trend known as 'fibermaxxing' wants you to add more fiber to your daily diet. TikTok users tout the health benefits of including simple foods packed with the carbohydrate, including the relieving effects in the bathroom. Some TikTokers point to the recent rise in rates of colon cancer in young people, and note that eating fiber can help reduce the risk. To 'fibermaxx,' they're eating more chia seeds in their yogurt bowls, making meals with more beans, and taking supplements. While nutritionists are largely supportive of the trend, they have a few caveats. 'More isn't always better,' Mascha Davis, a registered dietician nutritionist and the owner of Nomadista Nutrition, told Health this week. 'Many people don't get enough fiber, but it's just important to be thoughtful about how you're doing it so that it's not too much too fast,' Kate Mintz, a registered dietitian at U.C.L.A. Health, also recently told The New York Times. Fiber is often used to fight constipation, helping stools to pass easier. 'Even if you suffer from constipation, increasing fiber all at once could make the situation worse before you get cleared out,' Jennifer House, a dietitian and founder of First Step Nutrition, also explained to Health. Getting too much fiber could lead to a bloated and uncomfortable experience, according to the Mayo Clinic. People need to be careful and methodical, and talking to a physician can help to determine what's a right amount, on a case by case basis. What's more, when people with autoimmune conditions such as Crohn's disease see symptoms flare up, they may need to eat less fiber to help manage symptoms. After stomach or intestinal surgery, doctors may also instruct you to keep a lower fiber diet that lets your digestive system heal. Before a colonoscopy the advice may be similar, helping to clear out the large intestine to ensure a successful procedure. But in general, Americans aren't getting enough fiber - more than 90 percent of women and 97 percent of men do not meet the recommended daily intakes. Total dietary fiber intake should be 25 to 30 grams a day from food, and not supplements, according to UCSF Health. Currently, dietary fiber intakes among American adults average about only 15 grams a day. Fiber is good for your gut, heart, and brain, and may also slash the risk of type 2 diabetes and heart disease. The Mayo Clinic recommends adding fiber to the diet slowly over a few weeks, letting the natural bacteria in your digestive system adjust to the change. Staying hydrated is also crucial and fiber works best when it absorbs water. So, what can you eat to fiber to the max? The next time you're at the grocery store, pick up some popcorn, beans, cereal, apples, oranges, peas, cauliflower, or carrots. Raspberries are a particularly fiber-rich fruit, packed with eight grams. "If you're going to have a cookie, have an oatmeal cookie," Joanne Slavin, a professor of food science and nutrition at the University of Minnesota, told the American Heart Association. "It doesn't take large amounts of fiber to have a real effect.'


CNET
7 hours ago
- CNET
With Trends Like 'Japanese Walking,' Is Walking Actually Exercise? We Asked Personal Trainers
You've heard of "hot girl walks," but what about "Japanese walking"? It's also known as interval walking training, and The Washington Post reports that even though this technique is now going viral on TikTok, Japanese walking came about after a 2007, Japan-based study concluded that high-intensity interval walking training may help protect against age-related decreases in muscle strength and peak oxygen uptake as well as increases in blood pressure. A more recent, July 2025 study found that prefrail and frail older adults who increased their walking cadence by 14 steps per minute had a 10% increase in the odds of improvement during a 6-minute walk test, which represents an advancement in mobility, function or endurance. With these positive study outcomes, you may be wondering: Does walking count as exercise? To find out, we asked personal trainers. Is walking exercise? Yes, walking is exercise, and experts across physical and mental health disciplines agree. Sergii Putsov, a certified personal trainer with a PhD in sports science, says, "Walking for just 30 minutes every day can lower your risk of severe cardiovascular disease and dementia." April Crowe, a licensed clinical social worker at Paramount Wellness Retreat, adds that "walking in natural environments also boosts cognitive function and creativity, thereby providing a unique kind of therapy." Does walking do more than build your heart's strength? As it turns out, yes. The Mayo Clinic has identified additional health benefits of walking. According to the medical center, walking can improve muscle endurance, boost energy, lower blood pressure, strengthen bones and support the immune system. You can see benefits both outdoors and on a treadmill. Walking alone can also change the shape of your body. In 2017, the Journal of Physical Activity and Health did a meta-analysis of 22 clinical trials related to walking and health. The results revealed that brisk walking reduced waist circumference, fat mass and body fat percentage to a "clinically significant" degree in men and women under age 50 living with obesity. It can also lead to overall weight loss. So, that "hot girl walk" you take could cause noticeable changes to your body if you stick to it. Is walking enough exercise on its own? Walking can certainly be combined with other activities as part of a circuit. You can also walk as a warm-up for jogging or cycling. Walking on its own can deliver results and may have fewer negative impacts on your body than other high-impact sports. Gregor Parella, also a CPT, says of walking for walking's sake: "It is much better than jogging because jogging can put undue pressure on your ankles, especially if you're heavily built. On the other hand, brisk walking is one of the best exercises because it tones up your leg and calf muscles without the same pressure on joints. Even walking at a slow pace is better than being stationary at home, but a faster pace will also hasten the health benefits. A 2019 study in Atherosclerosis found that "walking pace was inversely associated with the risk of death and development of cardiovascular disease" in male physicians with an average age of 67.8. In other words, the faster you walk, the lower your risk of death and cardiovascular disease. Regarding how long you should walk, the US Department of Health and Human Services recommends at least 150 minutes of moderate-intensity physical activity each week, or 30 minutes a day for five days, for substantial health benefits. This can include walking briskly at 2.5 mph to 4 mph. Walking at a slow or leisurely pace (2 mph or less) is considered a light-intensity activity, which is likely to produce some health benefits compared to sedentary behavior, but not as many benefits as walking health benefits of walking There are many health benefits to walking. Not only can the activity lower cortisol levels, like all forms of exercise, and give you some fresh air, but you may see various tangible improvements in the following health indicators: Better sleep. Low-impact physical activity can lead to more fitful sleep. One small 2020 study published in Sleep Health found that increasing daily steps led to better quality sleep, especially among women. Low-impact physical activity can lead to more fitful sleep. One small 2020 study published in Sleep Health found that increasing daily steps led to better quality sleep, especially among women. Lower risk of type 2 diabetes. According to the American Diabetes Association, walking at least 30 minutes per day could help you stave off type 2 diabetes. Increasing your daily step count may keep your glucose levels in check. According to the American Diabetes Association, walking at least 30 minutes per day could help you stave off type 2 diabetes. Increasing your daily step count may keep your glucose levels in check. Lower blood pressure. A 2022 study from the American Family Physician reported that a regular walking schedule with moderate intensity can lower systolic blood pressure, diastolic blood pressure and heart rate. A 2022 study from the American Family Physician reported that a regular walking schedule with moderate intensity can lower systolic blood pressure, diastolic blood pressure and heart rate. Improved balance. Remaining steady on your feet is increasingly important for your health as you age. Harvard Health Publishing states that walking builds lower body strength, which improves balance. Remaining steady on your feet is increasingly important for your health as you age. Harvard Health Publishing states that walking builds lower body strength, which improves balance. Lower risk of cancer. Walking may even reduce your risk of some cancers. A 2013 study out of Cancer Epidemiology, Biomarkers & Prevention found that postmenopausal women who walked at least seven hours per week had a 14% lower risk of getting breast cancer than women who walked three hours or less every week. Ways to take your walking to the next level If you hit a plateau with your walking routine, you can add some intensity to your walk without having to jog or switch activities. Making your walk more rigorous could increase the number of calories burned by giving your body a new challenge. Ways to up the ante on your daily walk include: Increase the time of your walk. If you're currently walking 30 minutes a day, add more time in 10- or 15-minute intervals. Putsov recommends walking at least 45 minutes a day if your goal is weight loss. If you're currently walking 30 minutes a day, add more time in 10- or 15-minute intervals. Putsov recommends walking at least 45 minutes a day if your goal is weight loss. Increase your speed. You can also add more intensity by picking up speed. Free fitness workout apps with GPS enabled, including Nike Run Club, can help you track distance and time to calculate your pace. You can also add more intensity by picking up speed. Free fitness workout apps with GPS enabled, including Nike Run Club, can help you track distance and time to calculate your pace. Wear wrist or ankle weights. Tying on weights like Bala Bangles Tying on weights like Alternate your pace. Both CPTs we spoke to recommended walking intervals to make walking more challenging. Try walking for five minutes at a regular pace, then five minutes of speed walking, and so on. Both CPTs we spoke to recommended walking intervals to make walking more challenging. Try walking for five minutes at a regular pace, then five minutes of speed walking, and so on. Add an incline to your route. Are you walking on a flat surface for most of your route? Find a hill to increase the difficulty of your trek. You may also want to add retro-walking (walking backward) up an incline. Getty Images How to stay motivated while walking It's easy to get excited about a new workout routine initially, and it's just as natural to get bored or frustrated when you stop seeing major results. You may find music and podcasts helpful because they make time appear to pass more quickly. Just make sure that these sounds are background noise so that you can still be aware of your environment and those around you. Crowe also recommends setting clear, achievable goals. She says it can help to remind yourself about how far you've come, explaining, "Recording all achievements made during walks, whether through mobile apps or personal journals, will act as a reminder," which can push you harder next time. If going it alone is making it harder to stay on track, try walking with a partner or seeing if there is a walking club in your area. Parella says a walking buddy can increase your sense of accountability and make the experience more fun. You may also try new scenery to stay motivated during a walk. Getting some sun will increase your vitamin D intake, which may improve your mood. Walking safety tips Before you hit the sidewalk on your daily walk or hot girl walk, be sure you're well-equipped for the task. While a neighborhood or lakeside stroll may seem harmless, you still want to set yourself up for a safe return.
Yahoo
a day ago
- Yahoo
A Fartlek Isn't Just a Funny Word. Here's How These Running Workouts Can Make You Fitter, Faster.
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." IF THE WORD "fartlek" makes you giggle, you're not alone. But there's nothing funny about how this style of training can help runners—especially beginners—level up to faster speeds. The idea of running "fast" can feel overwhelming when you're still figuring out how to make running a consistent practice. The whole principle behind this training approach is to take the pressure off by making it less push, more play. Fartlek means "speed play" in Swedish, says Tucker Grose, a USATF-certified run coach in Denver, CO. And that's exactly what it is: a fun, no-pressure way to add short bursts of faster running into your routine. That loose approach is what makes fartlek workouts so effective. When you're not worried about a set pace or distance (or obsessing over what your watch is telling you), you can zero in on how your body really feels at any given moment and start to recognize when it's time to push through or ease off. And that's the kind of training that's going to help you run stronger for longer. What Fartlek Workouts Mean for Runners Running can sometimes feel like a negotiation between your brain and your body. If you've ever picked up the pace to catch a walk signal or challenged yourself to run to the next mailbox, tree, or lightpost before taking a walk break, congrats: You've already done a fartlek. "A fartlek workout is usually an unstructured workout of various speeds and distance and intensity," says Matthew Meyer, an RRCA-certified run coach and certified personal trainer in Boulder, Colorado. If that sounds ambiguous, that's kind of the point. "It's so informal because it's teaching you how to gauge feeling and effort." A fartlek workout is a type of interval training, in that you're mixing up your pace during a run by alternating between harder efforts and easier recoveries. But while interval workouts are generally tightly structured with the goal of hitting specific paces for set distances or time splits to elicit certain training adaptations, fartlek workouts are looser and more effort-based. You don't need to be on a track and you don't need a fancy running watch—you just need to run on feel. That's what makes fartleks such a beginner-friendly place to start with speedwork. But these workouts aren't just for novices. Fartleks are also a great way for experienced runners to ease back into harder efforts after time off, and they're often used at the beginning of a training cycle to reintroduce speed without the physical stress of going from 0 to 100. The Benefits of Fartlek Workouts for Runners Fartlek workouts are unstructured, so they teach you to run by effort. This is a skill every runner needs to avoid overtraining or underperforming. Most runners are actually pretty bad at self-pacing for optimal returns; one small study found recreational runners were, on average, 14 percent slower when they externally regulated their pace (i.e., stuck to a strict time per mile plan) than when they ran based on their physiological capabilities (using Vo2 or heart rate to determine effort—in other words, when they ran by feel). In a race, that could mean you're not going as fast as you potentially could if you stick to strict pace splits, leaving time on the table. "The main benefit [of a fartlek] is just getting to learn how you feel at different effort levels," says Grose. To gauge effort during running, coaches often recommend runners to rank their rate of perceived exertion (RPE) on a scale of 1 to 10, with one being at rest and 10 being all-out. It's a subjective measurement that can be tough to pin down when you start, but you will get better with practice and experience. "Some people have a pretty good internal thermometer for that but some people have zero, and when you tell those people to run at an effort level of 6 out of 10, they're like, what does that even mean?" says Meyer. "That's definitely a vocabulary we learn over time." You can't get more in tune with your body without figuring out where your limits are, and "the unstructured nature of fartlek training allows for that kind of experimentation," says Grose. By varying your pace and effort, Meyer says you're also training the aerobic and anaerobic systems. Think of it like shifting gears: The former is lower intensity and builds your endurance so you can run longer; the latter is higher intensity, which will help you run faster even during slower, longer efforts. The methodology seems to work: Runners who did fartlek workouts for 12 weeks significantly improved their cardiovascular endurance and speed endurance during a small study published in the International Journal of Physiology, Nutrition and Physical Education. How You Can Use Fartlek Workouts Before you start mixing in speed play, you should be consistently and comfortable running two to three times per week. That way, your body has a solid foundation from which you can start dialing up the intensity. Since fartlek workouts are based on feel, keep your surroundings in mind. "I think one of the best ways to approach a fartlek workout is to really let the terrain and how you feel dictate how you move at different speeds," says Grose. If you're in a hilly park, you'll naturally have to work harder against the incline—but when you hit the downhill, you can ease off the effort while still moving quickly. On flat terrain, suggests Meyer, you can use visual cues, like mailboxes or light poles, as markers, speeding up between the first two and slowing down between the next two. You can also use your music: Run easy during each verse, then pick up the pace when the chorus hits. Because these workouts are so unstructured, it's totally up to you to figure out how hard you should be running. "The intent is to be able to do these intervals more than once, so the hope is that you're not burying yourself in each interval," says Grose. "You're getting to the point where you're breathing heavily, you're feeling a little fatigued, maybe you're starting to slow down, and then you take a break to recover so you can do that again." Your recoveries can be as long as you need—especially in the beginning. "In the beginning, walk breaks can be really helpful," says Grose. "Then, as you get more and more comfortable with the style of workout, you can play around with jogging during those recovery intervals." Remember: You're not trying to empty the tank during a fartlek workout. You're just trying to get a better sense of what efforts you can hold for certain durations. 3 Fartlek Running Workouts for Better Training Fartleks are meant to be unstructured, but if you're new to the concept, a little guidance can go a long way. Each of these workouts gives you just enough structure to follow while still letting you run based on feel. Make sure to start each session with a five- to 20-minute brisk walk or easy jog to warm up, and finish with a similar cooldown. 1:00 On / 1:00 Off Fartlek "This is a favorite of mine for checking in to see where your body's at," says Meyer. "It's a great one to start with, and to return to through a training cycle to see how things have changed." It's also super scalable: You can start with as few as five reps (just five minutes of work), and add more reps over time as your stamina increases. How to do it: 1:00 at a 7 out of 10 effort 1:00 at a 3 out of 10 effort Repeat 10 times Ladder Fartlek Workout "This one teaches us how we feel at six minutes of intensity versus one minute of intensity," says Meyer. "The only rule is to start at a moderate enough effort that you can get faster as the intervals get shorter." The challenge is pacing the long intervals smartly enough that you can still hit the gas towards the end of the workout. How to do it: 6:00 at a 5 out of 10 effort 5:00 at a 6 out of 10 effort 4:00 at a 7 out of 10 effort 3:00 at a 8 out of 10 effort 2:00 at an 9 out of 10 effort 1:00 at a 10 out of 10 effort Recover for 1:00 at a 3 out of 10 effort between each interval Hill + Tempo Fartlek Workout "Hills are a great way to develop speed and power and work on form," says Grose. "This workout builds up fatigue on the legs, and then you have to hang out at a comfortably hard effort to let the body process some of the waste product you accumulated during the hill sprints." That's going to help you feel stronger at the end of a longer run or race. How to do it: 8 x 0:30 uphill at an 8 out of 10 effort Walk down at a 3 out of 10 effort 2 x 6:00 on flat ground at a 6 to 7 out of 10 effort Walk or jog for 3:00 at a 3 to 4 effort in between You Might Also Like The Best Hair Growth Shampoos for Men to Buy Now 25 Vegetables That Are Surprising Sources of Protein