Scientists find cancer-linked chemicals in popular hair extensions

By Sola Charles 

A new investigation  has found dozens of potentially harmful chemicals in widely sold hair extensions, including those made from human hair. The findings represent the most detailed chemical review so far of this largely unregulated beauty product category. 

Researchers say the results add strong evidence that hair extensions may pose health risks, particularly for black women, who use these products at much higher rates.

The study published in the American Chemical Society journal Environment & Health comes at a time of growing concern about the long term health effects of hair extensions. 

More than 70 percent of black women report wearing hair extensions at least once in the past year, compared with fewer than 10 percent of women from other racial and ethnic groups. Extensions are often worn for cultural expression, personal style, and convenience.

"While prior reports have found some chemicals of concern in hair extensions, there's still much we don't know about their overall chemical makeup. We wanted to get a better picture of the extent of the problem. This is an industry that has long overlooked the health of black women, who should not have to choose between cultural expression, convenience, and their health," says lead author Dr. Elissia Franklin, a research scientist at Silent Spring Institute.

Hair extensions are produced from synthetic fibers or bio-based materials, including human hair. Manufacturers frequently treat these fibers with chemicals to make them flame resistant, waterproof, or antimicrobial.

"Yet, companies rarely disclose the chemicals used to achieve these properties, leaving consumers in the dark about the health risks from prolonged wear," says Franklin. 

Because the fibers rest directly against the scalp and neck, wearers may experience extended skin contact. When extensions are heated during styling, they can also release chemicals into the air that users may inhale.

To better understand what these products contain, Franklin purchased 43 popular hair extension brands from online retailers and local beauty supply stores. The team grouped the products by fiber type, synthetic (mostly plastic polymers) or bio-based (including human, banana or silk), and documented the claims listed on their packaging. 

Among the synthetic products, 19 claimed to be flame retardant, three were labeled water resistant, nine advertised heat resistance, and three promoted "green" claims such as "no PVC" or "non-toxic."

Researchers then applied a method known as non-targeted analysis to search for a broad array of chemicals, including substances not typically screened in consumer goods. 

Using two-dimensional gas chromatography with high-resolution mass spectrometry, they detected more than 900 chemical signatures, representing both known and previously unidentified compounds. Machine-learning tools compared those signatures with an extensive chemical database, allowing the team to identify 169 chemicals spanning nine major structural classes.

The testing uncovered numerous substances associated with cancer, hormone disruption, developmental harm, and immune system effects. These included flame retardants, phthalates, pesticides, styrene, tetrachloroethane, and organotins.

All but two of the 43 samples contained hazardous chemicals. The only two without detected hazards were labeled as "non-toxic" or "toxic-free."

A total of 48 identified chemicals appear on major hazard lists, including 12 listed under California's Proposition 65 for causing cancer, birth defects, or reproductive harm. Four different flame retardants were detected in both synthetic and bio-based products.

No less than 17 chemicals connected to breast cancer were found in 36 samples, including compounds known to disrupt hormones in ways that may increase risk. Nearly 10 percent of products contained toxic organotins, in some cases at levels exceeding health-based limits set in the European Union, where these chemicals are regulated.

"We were especially surprised to find organotins. These are commonly used as heat stabilizers in PVC and have been linked with skin irritation, which is a common complaint among hair extension users." 

Organotins have also been linked with cancer and hormone disruption. The global hair extension market is projected to surpass $14 billion by 2028, with the United States leading in global imports. Given the size of the market and the chemicals detected, 

Franklin argues that more oversight is needed. "These findings make clear that stronger oversight is urgently needed to protect consumers and push companies to invest in making safer products," she says.

Why 1 in 3 early-stage kidney cancer patients show no symptoms

By Sola Charles 

The UK's leading kidney cancer charity has warned that 'highly restrictive' health guidelines mean a fifth of patients are getting diagnosed at the most advanced stage of the disease.

New data from Kidney Cancer UK found that one in five kidney cancer patients are being diagnosed at stage 4, when life expectancy past five years drops significantly.

In Kidney Cancer UK's 12th annual patient survey, the report found that approximately three-quarters of people diagnosed with stage 3 kidney cancer survive for at least five years.

But for those diagnosed at stage 4, when the cancer has spread to other organs, five-year survival falls significantly to around 10–15 per cent. 

New data from Kidney Cancer UK found that one in five kidney cancer patients are being diagnosed at stage 4, the most advanced stage of the disease

People born in 1990 are up to three times more likely to develop the disease than those born in the 1950s - a trend doctors say is partly driven by rising obesity and high blood pressure.   

One of the biggest challenges with kidney cancer is that early-stage disease (stages one and two) is almost entirely symptom-free. As a result, there are often no warning signs to indicate cancer is present unless investigations are carried out for an unrelated reason.

When looking at the time from first feeling unwell and seeking medical advice to receiving a diagnosis, the survey results show that almost a third of patients waited more than three months.

In the period before referral for diagnosis, more than one in four patients are initially diagnosed with a different condition, adding to the overall time it takes for a diagnosis to be made.

The survey also found that in patients diagnosed at stages 1-3, the most common symptoms reported were pain in the back/flank/side, blood in urine and fatigue. However, notably, 29 per cent reported no symptoms at all.

In patients diagnosed at stage 4, the most common symptoms reported were pain in the back/flank/side, fatigue, blood in urine and weight loss. Of these patients, 15 per cent still reported no symptoms at all.

While the survey reveals the high percentage of kidney cancer patients diagnosed at stage 4, it also reveals that over a quarter are diagnosed at stage 3. The charity is calling for a clear and government-funded research strategy to develop a simple, inexpensive test for use in primary care. Currently, there is no simple blood test or easy method of early detection. 

Prof. Grant Stewart, Professor of Surgical Oncology at the University of Cambridge and Consultant Urologist at Addenbrooke's Hospital, Cambridge, says: “The finding that just over 20 per cent of patients are now being diagnosed with stage 4 kidney cancer represents a concerning year-on-year increase.”

Men suffer critical heart disease earlier than women – Study

By Sola Charles 

Heart disease risk begins to climb for men in their mid-30s, years before it rises for women, a decades-long study tracking people from young adulthood has uncovered.

From the study titled "Sex Differences in Age of Onset of Premature Cardiovascular Disease and Subtypes: The Coronary Artery Risk Development in Young Adults Study," men reached a 5 percent risk of cardiovascular disease roughly seven years earlier than women, revealing a clear and early gap in heart health.

The study was published in the Journal of The American Heart Association. The research team analysed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. The project enrolled more than 5,100 Black and white adults between ages 18 and 30 in the mid-1980s and followed them through 2020.

Because participants were healthy at the start, the researchers were able to identify when cardiovascular disease risk first began to separate between men and women. Men reached a 5 percent rate of cardiovascular disease, defined broadly to include heart attack, stroke and heart failure, about seven years earlier than women (50.5 versus 57.5 years).

Coronary heart disease accounted for most of this difference, driving the earlier rise in risk among men. Heart disease risk looked similar for men and women until about age 35, when men's risk began to increase more quickly.

According to the long-term study led by Northwestern Medicine, based on more than 30 years of follow-up, the findings suggest that heart disease screening and prevention may need to begin earlier in adulthood, especially for men.

"That timing may seem early, but heart disease develops over decades, with early markers detectable in young adulthood," said study senior author Alexa Freedman, assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine.

"Screening at an earlier age can help identify risk factors sooner, enabling preventive strategies that reduce long-term risk."

Previous research has long shown that men tend to develop heart disease earlier than women. Over time, however, common risk factors such as smoking, high blood pressure and diabetes have become more alike between the sexes. Because of this, researchers expected the difference in heart disease timing to shrink. Instead, the gap remained. That result was unexpected, Freedman said.

To better explain why these differences continue, Freedman and her colleagues say researchers need to look beyond standard measures like cholesterol and blood pressure and consider a wider range of biological and social influences.

Most of this difference was due to coronary heart disease. Men reached a 2 percent incidence of coronary heart disease more than 10 years earlier than women. Stroke rates were similar for both sexes, and differences in heart failure appeared later in life. 

"This was still a relatively young sample -- everyone was under 65 at last follow-up -- and stroke and heart failure tend to develop later in life," Freedman explained.

One of the most notable findings was when the risk gap began. Men and women had similar cardiovascular risk through their early 30s. Around age 35, men's risk increased more quickly and remained higher through midlife.

Many heart disease prevention and screening efforts focus on adults older than 40. 

The new results suggest this approach may miss an important early window for action.

"Our findings suggest that encouraging preventive care visits among young men could be an important opportunity to improve heart health and lower cardiovascular disease risk," Freedman said.

Late bedtimes linked to higher heart disease risk

By Sola  Charles 

People who naturally stay up late may be putting their hearts under added strain as they age.

A large study tracking more than 300,000 adults found that middle-aged and older night owls had poorer overall heart health and a higher risk of heart attack and stroke than those who were active earlier in the day, with the effect especially pronounced in women. 

Much of this elevated risk appeared to stem from lifestyle factors common among evening types, including smoking and inadequate sleep.

Adults in midlife and older age who tend to be most active in the evening, especially women, showed poorer overall heart health than those without a strong preference for mornings or evenings, based on research.

Common habits among night owls, including lower-quality diets, too little sleep, and higher rates of smoking, that help explain why their cardiovascular health scores were lower.

Researchers say the findings point to a clear opportunity, since improving daily habits such as sleep, diet, and smoking cessation could help night owls reduce their risk of heart attack and stroke.

Adults in middle age and later life who tend to be more active in the evening were found to have worse cardiovascular health than those who are active earlier in the day.

The association appeared to be stronger among women, according to the new research published in the Journal of the American Heart Association, an open-access, peer-reviewed journal of the American Heart Association.

The findings suggest that when people are most active during the day may play an important role in long-term heart health.

Researchers examined health data from more than 300,000 adults (average age of about 57 years) enrolled in the UK Biobank. The analysis focused on chronotypes, which describe a person's natural preference for sleep and wake timing, and how those preferences relate to cardiovascular health.

Participants were grouped based on their self-identified daily patterns. About 8 percent described themselves as "definitely evening people," meaning they typically went to bed very late (up till 2 a.m.) and reached peak activity later in the day. 

Around 24 percent reported being "definitely morning people," who tended to wake up earlier, go to bed earlier (for example 9 p.m.), and be most active earlier in the day. 

The remaining 67 percent were categorised as having an "intermediate" chronotype if they were unsure or said they were neither clearly a morning nor evening person.

Cardiovascular health looks at behaviours and health factors known to support heart health, including eating a healthy diet, staying physically active, not smoking, and getting good-quality sleep. It also includes maintaining healthy levels of body weight, cholesterol, blood sugar, and blood pressure.

The researchers identified several notable patterns when comparing chronotype groups: Compared with people in the intermediate category, those classified as "evening people," often called night owls, were 79 percent more likely to have an overall poor cardiovascular health score.

Night owls also had a 16 percent higher risk of experiencing a heart attack or stroke during a median follow-up period of about 14 years.

The link between evening chronotype and lower heart health scores was stronger among women than among men.

Much of the increased heart disease risk seen in evening types were linked to lifestyle habits, particularly nicotine use and insufficient sleep.

In contrast, "morning people," also known as early birds, showed a 5 percent lower prevalence of poor cardiovascular health scores compared with individuals without a strong morning or evening preference.

"'Evening people' often experience circadian misalignment, meaning their internal body clock may not match the natural day-to-night light cycle or their typical daily schedules," said lead study author Sina Kianersi, a research fellow in the division of sleep and circadian disorders at Brigham and Women's Hospital and Harvard Medical School, both in Boston. 

"Evening people may be more likely to have behaviors that can affect cardiovascular health, such as poorer diet quality, smoking and inadequate or irregular sleep.

"These findings show that the higher heart disease risks among evening types are partly due to modifiable behaviors such as smoking and sleep. Therefore, evening types have options to improve their cardiovascular health. Evening types aren't inherently less healthy, but they face challenges that make it particularly important for them to maintain a healthy lifestyle."