Infections caused about one new cancer in eight in 2024, IARC estimates, and it says most could already be prevented

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Each with its own sources. None of these is a link to the story above.

1. 02

   Fewer US teens feel sad or hopeless

   The US Centers for Disease Control and Prevention (CDC) has surveyed US high school students every two years since 1991. [11] In 2025, 33% reported persistent feelings of sadness or hopelessness in the past year, down from a peak of 42% in 2021. [11][13] The share who seriously considered suicide fell from 22% to 14%, and the share who made a plan fell from 18% to 12%. [12] Girls reported this sadness far more often than boys, 43% against 24%. [13]

   Girls43%

   Boys24%

   Why it matters — With the questions unchanged, the share of persistently sad or hopeless students since 2015 went 30%, 31%, 37%, 42%, 40% and 33%. [12][13] So the fall since 2021 is real, and 2025 is still above 2015. [13] A psychologist told the New York Times that suicidal thinking is now lower than in 2019. [11]

2. 03

   175,000 letters, and 97% were copies

   When the US Food and Drug Administration (FDA) proposed banning menthol cigarettes in 2022, it received 175,000 public comments in three months. [17] Researchers at Rutgers, a US university, found that 97% were form letters, copies of the same text, opposing the ban. [17] Only 2% were unique. [17] Nearly half used the wording of campaigns run by Altria and Reynolds American, the makers of Marlboro Menthol and Newport. [17] The Biden administration postponed the ban in April 2024, citing the response, and it was scrapped in 2025. [17]

   97 of 100

   form letters in every 100 comments

   Why it matters — About 80% of Black smokers in the US use menthols, and Black smokers die of smoking-linked illness at higher rates. [17] After Canada banned menthol cigarettes, daily menthol smokers were 8 percentage points more likely to quit than other daily smokers, a 2022 study found. [18]

3. 04

   WHO widens the choice of contraception

   On 23 September the WHO published new guidelines on contraception, including three methods not in its guidance before. [15][16] Combined contraceptive pills can now be taken for up to six months in a row, or continuously for a year, as an alternative to the usual cycles. [15] Implants can stay in for up to five years, and a pill called mifepristone, taken within five days of sex, is added as emergency contraception. [15] The WHO advised countries not to add contraceptive pills containing quinestrol to their programmes, citing limited evidence and reports of serious side effects. [15]

   Why it matters — An estimated 164 million women who want to avoid pregnancy use no contraception, the WHO says. [15] It also set out, for the first time, what a future male contraceptive should offer. [15] More than 75% of couples in a WHO survey said they would be willing to use one. [15]

4. 05

   Metals in Maui residents, 18 months on

   University of Hawaii researchers tested the urine of 1,400 adults on Maui. [9] The tests ran up to a year and a half after the August 2023 wildfires, which destroyed the town of Lahaina and killed more than 100 people. [9] Antimony was nearly 40 times higher than in US national data, manganese 3.8 times, barium 2.3 times and arsenic 2.2 times. [9] People with more metal in their bodies did worse on breathing tests. [9] The study was published on 28 September in PNAS, a US science journal. [9]

   Antimony40 x

   Manganese3.8 x

   Barium2.3 x

   Arsenic2.2 x

   Why it matters — The researchers say the metals may have come from burned buildings, cars and electronics, rather than only burned plants. [9] They cannot say exactly how much came from the fire, because there is no comparable data from before it. [9] The study hopes to collect data for a decade after the fire. [10]

5. 06

   One US teen in four sleeps eight hours

   The same CDC report found that about one US high school student in four slept at least eight hours on a school night in 2025, fewer than in 2015. [14] About one in four was active for an hour a day, and that share also fell over the ten years. [14] More students ate fruit and vegetables daily than in 2023, and more played on a sports team. [14][12] About one in three used social media every hour or more. [14]

   Why it matters — This year's report led with diet, sleep and screen time, priorities of US Health Secretary Robert F. Kennedy Jr. [12] It left out teen vaping, sex and violence, which past reports covered, although the survey still collected that data. [12]

6. 07

   Donor hearts took on their new body's age

   A team including Jesse Poganik, who studies ageing at Harvard, grafted extra hearts between young, middle-aged and old mice, then read age-linked chemical tags on the hearts' DNA. [7] Young hearts in old mice aged faster, and old hearts in young mice looked biologically younger. [7][8] Tissue samples from the hearts of 11 people at a Boston hospital, whose donors were much older or younger than them, showed the same pattern. [7] The work is a preprint, not yet checked by other scientists. [7]

   Why it matters — Doctors usually prefer donors under 45. [7] The US did 4,636 heart transplants in 2024, and hundreds of people around the world still die each year waiting for one. [7] Poganik says some ageing is probably irreversible, and an outside expert says these measures of age are still experimental. [7][8]

7. 08

   US thalidomide survivors ask to be counted

   In the early 1960s a US drug company, William S. Merrell, handed out thousands of unlabelled doses of thalidomide, a sedative, without FDA approval. [20] An FDA reviewer, Frances Oldham Kelsey, kept it off general sale, but some pregnant women were given it for morning sickness. [20] Some of their babies were born with shortened limbs, and many doctors did not tell the mothers or write it down. [20] The FDA recognises 17 US survivors. [20] One author estimates about 100. [20]

   17FDA's formal count

   vsvs

   about 100One author's estimate

   Why it matters — Survivors are asking the US Congress to recognise them and pay each $150,000. [20] Many were told by doctors they could not be survivors, because the United States had supposedly escaped the drug. [20] They say their health is getting worse as they age. [20]

8. 09

   A garlic-honey remedy can grow botulism

   Some TikTok videos, with hundreds of thousands of likes, promote garlic fermented in honey as a natural antibiotic for flu season. [19] Health Canada, the country's national health body, warned that fermenting garlic in raw honey at room temperature can carry a risk of botulism. [19] Honey alone is too dry for germs to grow, but bacteria in the honey can draw water from the garlic and begin to multiply. [19] They grow best with little oxygen, and their toxin can stop the diaphragm, the muscle that drives breathing. [19]

   Why it matters — Botulism is rare: the CDC recorded 243 confirmed and 30 probable US cases in 2021, and 181 of them were babies. [19] Raw honey is not given to babies under one year old because of the botulism risk. [19]

9. 10

   20.6 million new cancers in one year

   IARC and the American Cancer Society estimated in July that 20.6 million people were diagnosed with cancer in 2024, and 9.8 million died of it. [21] The count covers 34 cancer types in 186 countries. [21] Lung cancer was the most common, with about 2.6 million new cases, followed by breast, bowel, prostate and stomach cancer. [21] Lung cancer also caused the most deaths, about 1.9 million. [21]

   Why it matters — The figures mean about one person in five develops cancer in their lifetime. [21] New cases are expected to reach 34.4 million a year by 2050, 67% more than in 2024. [21]

10. 11

    Reynolds sells fruit vapes the FDA never cleared

    Reynolds American, owned by British American Tobacco, is selling Vuse Pro vapes in peach, berry, watermelon and fresh mint in Ohio and other states, STAT reported on 8 September. [22] The FDA has not authorised them. [22] In May the agency said it would not act against unauthorised fruit-flavoured vapes whose makers had applications pending and had sent data on the risk to young people. [22] Only 48 e-cigarettes have ever been authorised. [22]

    Why it matters — The FDA's new policy came about a week after Reynolds American gave $5 million to a super PAC, a political fundraising group, backing President Trump, STAT reported. [22] Reynolds says the sales follow state rules and come with ID checks and purchase limits. [22]

11. 12

    WHO's main contraception guides updated

    In November 2025 the WHO launched the sixth edition of its Medical Eligibility Criteria, the guide that tells health workers which contraceptive is safe for which person. [24] A fourth edition of its guide on how to use each method came with it. [24] Under the new editions, progestogen-only hormone injections can be offered straight after childbirth, and emergency contraception can be repeated within one cycle. [24] Hormonal methods can also be used safely by women taking PrEP, medicine that prevents HIV infection. [24]

    Why it matters — Countries in all six WHO regions use these guides to write their own rules. [23] New evidence on progestogen-only methods, including injections, found no harm to breastfeeding or to babies, even when started within six weeks of birth. [23]

12. 13

    A second survey shows fewer depressed US teens

    A May 2026 analysis by KFF, a US health policy research group, found 15% of Americans aged 12 to 17 had a major depressive episode in 2024. [25] That means at least two weeks of low mood or lost interest, with several other symptoms. [25] The share was 21% in 2021. [25] About 19% reported moderate to severe anxiety, and 7.8% had a drug or alcohol use disorder, down from 9.2% in 2021. [25]

    Why it matters — This is a different national survey from the CDC's, and it also shows a fall since 2021. [25][13] KFF notes that federal money for school mental health services was disrupted under the second Trump administration. [25]

13. 14

    Blood proteins give each organ an age

    Researchers estimated the biological age of 11 organs in 11,757 people from a US community heart study, using proteins in their blood. [26] Older organ ages went with the diseases of that organ, even after allowing for a person's real age. [26] For every five years a person's heart looked older, their risk of heart disease was about 16% higher. [26] The study was published in December 2025 in JCI Insight, a medical journal. [26]

    Why it matters — The group whose organs all looked older had higher risks of cancer, heart failure, kidney failure and death. [26] Today's transplant study found a heart's biological age can shift in a new body. [7]

14. 15

    Burning houses add pollution nobody counts

    A study in Nature Communications in December 2025 built an inventory of pollution from buildings burned in wildfires across the lower 48 US states from 2000 to 2020. [27] National pollution records do not count these emissions. [27] The 20 most destructive fires produced 68% of all the carbon monoxide from burned buildings. [27] In several states, burning buildings released more of some toxic gases, such as hydrochloric acid, than all human-made sources combined. [27]

    Why it matters — Destructive building fires were more likely in fire weather and in forested, built-up areas. [27] The study names the 2023 Lahaina fire, which destroyed more than 2,000 buildings, as a recent fire of this kind. [27]

15. 16

    Lead dust in Los Angeles homes after the fires

    After the Palisades and Eaton fires in Los Angeles in January 2025, researchers tested the air and surfaces in 19 homes before people moved back. [28] Metals in the air were below health limits. [28] But wipe samples found metals on surfaces in many homes, and lead on window sills and entry floors went above US Environmental Protection Agency dust limits in several. [28] The study was published in December 2025. [28]

    Why it matters — Homes near the fire, without air purifiers, cleaned with ordinary vacuums, or with windows open during the fire had more dust in the air. [28] The authors say surfaces can hold fire pollution even two months after the fire. [28]

16. 17

    Menthol sales fell fast after 2021

    A study of US convenience-store sales, published in January 2026, found cigarette sales fell from 9.23 billion packs in 2016 to 5.61 billion in 2024. [29] Menthol cigarettes fell slowly until 2021, then by about 15% a year from 2021 to 2024. [29] The cheapest, deep-discount brands were the only group to grow, and their prices fell. [29]

    Why it matters — Menthol sales were falling fast even though the US ban proposed in 2022 never took effect. [29][17] The authors call for research on whether the growing cheap brands change who smokes. [29]

17. 18

    What US schools take from pupils: vapes

    Since November 2023, US school staff have uploaded photos of nicotine products taken from pupils to a Rutgers University project. [30] By the end of September 2025 they had sent 1,535 images showing 9,589 products, its 2025 report says. [30] Of those, 99.1% were e-cigarettes, mostly disposable, and over 99% of flavoured products were not tobacco-flavoured, most often fruit. [30] Nicotine pouches were 0.4%. [30]

    Why it matters — The most common brand was Geek Bar, at about a quarter of products. [30] The project says school confiscations give an early view of which brands young people are getting. [30]

18. 19

    A DNA mark on cancers after transplants

    People who receive a donated organ or stem cells get cancer more often, which is usually put down to drugs that weaken the immune system and let cancer-causing viruses in. [31] A team including researchers at Brigham and Women's Hospital in Boston studied the DNA of 41,874 cancers. [31] In tumours from 13 transplant patients they found a new pattern of DNA changes, unlike those caused by tobacco or faulty DNA repair. [31] It was published in January 2026. [31]

    Why it matters — The team names a strong candidate: ganciclovir, an antiviral drug many transplant patients take against cytomegalovirus, a common virus, though the exact mechanism is not settled. [31] Their estimate that about 10% of tumours after transplant carry it is uncertain, they say. [31]

19. 20

    Mental illness and liver cancer in US veterans

    A UCLA study, published in 2025, followed 221,712 US veterans with cirrhosis, a badly scarred liver, from 2000 to 2021. [32] About 80% had hepatitis C, and 61% had a mental health condition, most often alcohol or drug use disorders. [32] Veterans with mental health conditions had a higher risk of liver cancer, even after allowing for age and hepatitis C treatment. [32]

    Why it matters — The authors think these conditions may stop people getting their hepatitis C cured. [32] The senior author, Jihane Benhammou, says curing hepatitis C alone is not enough to protect them. [32]

20. 21

    WHO narrows its teen pregnancy guideline

    The WHO has updated its 2011 guideline on preventing early pregnancy among adolescents in low- and middle-income countries, its authors wrote in November 2025. [33] Girls aged 15 to 19 in those countries have about 21 million pregnancies a year, half of them unintended. [33] The update focuses on two aims: preventing child marriage and helping married girls, and getting more adolescents to start and keep using contraception. [33]

    Why it matters — Worldwide, births to 15- to 19-year-olds fell from 64.5 per 1,000 in 2000 to 42.5 in 2021. [33] Rates are highest among girls with less schooling or less money, and the update puts more weight on groups left out of that progress. [33]

21. 22

    Chemicals in volunteer firefighters' blood

    PFAS are human-made chemicals found in the blood of nearly all US residents, and some are linked to certain cancers. [34] A study published in June 2026 measured 12 of them in the blood of 550 volunteer firefighters in nine US states. [34] Volunteers make up 65% of the US fire service. [34] Firefighters can meet PFAS in firefighting foam, in smoke and in their protective gear. [34]

    Why it matters — Levels tracked people's age, sex, region and health more strongly than their firefighting work. [34] The authors say that points to exposure from their wider communities, not only from the job. [34]

22. 23

    Wood smoke left a mark on airway cells

    Researchers at the California National Primate Research Center, part of the University of California, Davis, exposed airway lining cells from laboratory primates to wood smoke again and again. [35] The smoke changed which genes the cells switched on, including genes for inflammation and cell death. [35] Many of the changes were still there a week after the smoke stopped. [35] The study was published in November 2025. [35]

    Why it matters — Under the microscope, the tissue looked normal. [35] So the smoke changed the cells in ways a microscope did not show. [35]

23. 24

    Short sleep and sad teens, year by year

    A study published in November 2025 compared CDC survey results for US high school students from 2013 to 2023. [36] In the survey years when teens slept less on average, more of them reported symptoms of depression, and the link was strong. [36] The authors say this does not show that short sleep causes depression. [36] Sleep loss affects over 70% of US adolescents, they write. [36]

    Why it matters — The CDC's 2025 results broke the pattern for now: sadness fell while the share of students sleeping eight hours did not change. [13][14]

24. 25

    Active teens, lower suicide risk, small effects

    A study published in September 2025 used the CDC's 2023 survey of 15,734 US high school students. [37] Students who were more physically active had slightly lower suicide risk and lower risk of drug and alcohol use. [37] Much of that link ran through better mental health, and some through sleep and diet. [37] The measured effects were small. [37]

    Why it matters — The CDC's 2025 report found that fewer students were active for an hour a day than in 2015. [14]

25. 26

    In India, richer women use more reversible contraception

    A study published in August 2025 used India's National Family Health Survey of 2019 to 2021 to compare contraception by wealth. [38] Among the poorest fifth of women, 37.8% used no contraception, against 30.6% of the richest fifth. [38] Use of modern methods that can be stopped rose from 15.9% among the poorest to 25.0% among the richest. [38] Sterilisation was most common in the middle wealth group, at 42.6%. [38]

    Why it matters — Southern and western India relied more on sterilisation, and the northeast on methods that can be stopped. [38] The gaps by wealth held after allowing for other social factors, the authors found. [38]

26. 27

    Was the first heart donor brain-dead?

    The first human heart transplant was done by Christiaan Barnard in South Africa in 1967, using the heart of Denise Darvall, who had been hurt in a car crash. [39] A history paper published in November 2025 argues she was almost certainly not brain-dead by today's standards. [39] It also cites a claim by Barnard's brother Marius that her heart was stopped with a potassium injection, a claim he later withdrew. [39]

    Why it matters — Her case set the example for taking organs from brain-dead patients, the paper says. [39] It was written by one author, Zoltan Sutto, from records of the time, and published in The Linacre Quarterly. [39]