Wednesday, July 23, 2025

The Lancet Public Health:  Aiming for 7,000 daily steps can reduce risk of chronic diseases, cognitive decline, and death, finds new study

The Lancet

A comprehensive new study analysing data from over 160,000 adults finds that walking approximately 7,000 steps per day is associated with reductions in the risk of several serious health outcomes, including all-cause mortality (47% reduction), cardiovascular disease (25% reduction), cancer (6% reduction), type 2 diabetes (14% reduction), dementia (38% reduction), depression (22% reduction), and falls (28% reduction).* Unlike earlier studies that mainly focused on heart health or overall death rates, this research, published in The Lancet Public Health journal, is the first to comprehensively examine how taking more steps per day can reduce the risk of several different health outcomes.

The study also revealed that even modest step counts (around 4,000 steps per day) are linked to better health compared to very low activity (around 2,000 steps per day). For some conditions, such as heart disease, health benefits continued to increase beyond 7,000 steps, but for most conditions, the benefits tended to level off. The authors highlight that 7,000 steps per day may be a more realistic target than the current unofficial target of 10,000 steps per day, particularly for those who are less active, suggesting that this target can still provide significant improvements in health.

The systematic review included 57 studies, of which 31 studies were included in meta-analyses, providing the most comprehensive evidence to date of the association between the number of daily steps and a wide range of health outcomes. The authors caution that the evidence for health benefits for most conditions, such as cancer and dementia, is supported by a small number of studies, meaning there is a low level of certainty for those results, and many of the studies included did not account for some confounding factors, like age or frailty, that could bias the findings.

The authors say that their study underscores the value of using daily step counts as a straightforward way to measure physical activity. They suggest these results could help shape future public health guidelines and recommendations, encouraging more people to track their steps as a practical way to improve their health.

Journal

The Lancet Public Health

DOI

10.1016/S2468-2667(25)00164-1

Method of Research

Systematic review

Subject of Research

People

Article Title

Daily steps and health outcomes in adults: a systematic review and dose-response meta-analysis

Article Publication Date

23-Jul-2025

Rethink the 10,000 a day step goal, study suggests

Walking 7000 steps a day can lower the risk of an early death by up to 47 percent

University of Sydney

Walking 7000 steps a day can lower the risk of an early death by up to 47 percent
Health benefits increased with every 1000-step increment up until 7000 steps, at which point the benefits began to taper off

A major new study led by the University of Sydney suggests that walking 7000 steps a day offers similar health benefits across several outcomes as walking 10,000.

Led by Professor Melody Ding from the School of Public Health, the study was published in The Lancet Public Healthand analysed data from 57 studies from 2014 to 2025 that were conducted in more than ten countries including Australia, USA, UK and Japan.

The largest and most comprehensive review to date, the researchers examined the impact that different daily step counts have on the chance of dying from cardiovascular disease and cancer, and developing diseases such as cancer, type 2 diabetes, dementia and depression. Professor Melody Ding says the findings offer a more achievable benchmark for people who struggle to meet traditional exercise guidelines.

“Aiming for 7000 steps is a realistic goal based on our findings, which assessed health outcomes in a range of areas that hadn’t been looked at before,” said Professor Ding.

“However, for those who cannot yet achieve 7000 steps a day, even small increases in step counts, such as increasing from 2000 to 4000 steps a day, are associated with significant health gain.

“We know daily step count is linked to living longer, but we now also have evidence that walking at least 7000 steps a day can significantly improve eight major health outcomes - including reducing risk of cardiovascular disease, dementia and depressive symptoms.”

Health benefits at different step counts

The researchers looked at studies in which participants wore step counting devices, such as pedometers, accelerometers and fitness trackers, to track their daily step counts. Starting at 2000 steps, experts compared the health outcomes of people walking more steps a day at 1000 step increments to see whether there was any difference in the risk of early death or other major diseases.

When compared with 2000 steps a day, researchers found that:

Walking 7000 steps a day reduced the risk of death by 47 percent, which was almost identical to the benefit seen at walking 10,000 steps per day.
Dementia risk dropped by 38 percent from walking 7000 steps a day, with only a 7 percent extra reduction at 10,000 steps.
Risk of type 2 diabetes fell by 22 percent from walking 10,000 steps a day and reduced to 27 percent at 12,000 steps.
Significant health improvements were seen when people increased their average daily steps from 2000 to between 5000 and 7000 steps.

“For people who are already active, 10,000 steps a day is great,” said Dr Katherine Owen, co-author and chief analyst of the study from the School of Public Health. “But beyond 7000 steps, the extra benefits for most of the health outcomes we looked at were modest.”

The researchers are working with the Australian government to use the evidence from this study to inform future updates to physical activity guidelines.

“Our research helps to shift the focus from perfection to progress. Even small increases in daily movement can lead to meaningful health improvements,” said Professor Ding.

Experts are calling for future studies to explore how step goals should vary based on age, health status and region, and to include diverse populations and longer-term data to strengthen the evidence. Professor Ding says this kind of detail is rare and will be useful for health practitioners when tailoring advice for patients.

-ENDS-

Journal

The Lancet Public Health

DOI

10.1016/S2468-2667(25)00164-1

Method of Research

Systematic review

Subject of Research

People

Article Title

Daily steps and health outcomes in adults: a systematic review and dose-response meta-analysis

Article Publication Date

23-Jul-2025

Grassland changes put endangered parrot at greater risk

University of Adelaide

Golden-shouldered parrot credit Peter Valentine — image:
The endangered golden-shouldered parrot is abandoning areas of grassland it usually nests in because woody plants are encroaching upon its preferred vegetation.
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Credit: Peter Valentine

The endangered golden-shouldered parrot, a technicolour species native to Far North Queensland’s Cape York Peninsula, is abandoning areas of grassland it usually nests in because woody plants are encroaching upon its preferred vegetation.

Dr Gabriel Crowley, from the University of Adelaide, assessed the fate of 555 golden-shouldered parrot eggs from 108 nests monitored on Artemis Station by its owner, Susan Shephard, and Charles Darwin University researcher, Professor Stephen Garnett.

They discovered that the spread of woody plants increased the probability of predation, and reduced nest success and survival of nesting adults.

“The golden-shouldered parrot prefers to nest in areas of low woody-vegetation density, mainly along grassy drainage depressions,” says Dr Crowley, whose research was published in the journal PLOS One.

“We observed that they abandoned areas where woody plant encroachment was most advanced, which means it should be considered as a potential threatening process and managed accordingly.”

Grasslands are the world's most threatened terrestrial ecosystem, with vast areas disappearing because of the spread of urban and industrial development.

Maintaining remnant grasslands in good condition is therefore essential for the conservation of grassland-dependent species, such as the golden-shouldered parrot.

“In our study, nest success decreased as the density of trees around the nest increased,” says Dr Crowley.

“Most losses could be attributed to predation, with the numbers of both adults and chicks taken increasing with tree density.

“This effect was most pronounced for butcherbirds, which perch in nearby trees waiting for the birds to emerge from the nest. The parrots are therefore most likely to fledge successfully in open grasslands, where they are safe from woodland predators.”

Dr Crowley’s three decades of research has shown that the grasslands of Cape York Peninsula have been disappearing under woody plants since cattle grazing replaced management by First Nations Peoples.

“On Cape York Peninsula, grazing has reduced fuel loads and the frequency of fires needed to keep woody plant encroachment at bay,” Dr Crowley says.

While this study focused on the plight of the Cape York Peninsula’s golden-shouldered parrot, Dr Crowley says it is indicative of a problem seen around the world.

“Similar processes may explain the decline of grassland birds across the globe, including from African savannas and North American prairies,” says Dr Crowley.

“Grassland loss is also an issue in South Australia, where urban and industrial development, grazing and rabbits are the main threats. However, fire management is also an essential tool for maintaining the open structure of these systems.

“It is therefore important that we recognise that while uncontrolled wildfires can have a devastating effect on the environment, when used properly, fire has an important role in maintaining the health of many ecosystems.”

NOTE: For more on this research, see Dr Crowley’s article published in The Conversation.

The University of Adelaide and the University of South Australia are joining forces to become Australia’s new major university – Adelaide University. Building on the strengths, legacies and resources of two leading universities, Adelaide University will deliver globally relevant research at scale, innovative, industry-informed teaching and an outstanding student experience. Adelaide University will open its doors in January 2026. Find out more on the Adelaide University website.

DOI

10.1371/journal.pone.0327543

Women politicians judged more harshly than men, research finds

Cambridge University Press

When women political candidates deviate from expectations or the views of their party, they are judged far more harshly than men by voters, a new study in Politics & Gender, published on behalf of the American Political Science Association by Cambridge University Press, reveals.

The research also found that voters begin campaigns with greater uncertainty about women candidates than about men, leading them to scrutinise women candidates to a greater extent when forming opinions of them.

The simulated experiment behind the findings

These findings emerged from a computer-based experiment simulating a congressional campaign and election. The researchers asked participants – 1,700 adult Americans – to learn about fictitious general election candidates, evaluate them, and “vote” for the candidate of their choice. The researchers varied whether the candidate in the voter’s own party was a man or a woman, and whether they were associated with certain ‘transgressions’ designed to push participants away from their preferred party’s candidate.

The experiment introduced participants to two fictitious candidates – one Democrat and one Republican – running for a congressional office. The in-party candidate was presented as either a man or a woman; gender was conveyed via names (James/Jamie Anderson for Republicans and Patrick/Patricia Martin for Democrats), pronouns, and photographs. The out-party candidate always appeared as a moderate, white man. Along with information about the two candidates’ policies and how closely these aligned with their party’s views, the researchers offered participants basic demographic and background information about candidates, including a description of their family, a positive newspaper editorial, their work experience, political experience, social philosophy – and eventually even an article about a fake scandal.

In conditions where the candidate’s policies aligned with those of their party, and where the scandals were the candidates’ only transgressions, the scandals generally played a minimal role. Partisans who saw their in-party candidate caught viewing pornography, laughing at a person who is homeless, or tearing up a copy of the US Constitution, did not significantly decrease their evaluations or likelihood of voting for those in-party candidates, regardless of if they were a man or woman. Only the “embezzle” scandal produced significant decreases, but those were nearly identical for candidates of both genders.

When policy positions were incongruent with expectations, however, more striking
differences emerged. For example, men were permitted to deviate with their policy stances with no penalty, but the 11-point drop in preference for the woman candidate who did the same was nearly equivalent to the decrease for either candidate when policy-congruent but involved in the most severe “embezzle” scandal.

Men get a head start

Lead researcher Dr Tessa Ditonto, Associate Professor in Gender and Politics at Durham University, explained the biases underpinning this uneven playing field.

“Men, who still are by far the majority of office holders in the United States, seem to benefit from a default assumption that they will turn out as expected, based upon predispositions,” Ditonto said.

“By contrast, women candidates can expect to need an active campaign amid an electorate that starts out uncertain that women candidates are necessarily good party representatives. Voters are open to learning this but need to see this confirmed before they are convinced.

“Women candidates must work harder to provide the necessary information to voters so that even co-partisans can be assured that she aligns well with the party’s platform. Without reinforcing information, voters remain somewhat sceptical and unsure of women candidates, and even partisan voters are willing to examine their other options.”

Revelations about the ‘tipping point’ and other findings

The researchers found a “tipping point” at which partisans – people who expect to prefer their party’s candidates’ issue stances and personal characteristics – become likelier to vote against their preferred party’s candidate. This tipping point arrives when the amount or nature of negative information about an in-party candidate becomes so overwhelming that partisan voters begin to disengage.

“The challenge is that any sort of candidate attribute that deviates from expectations about what a typical candidate of a particular party ‘should’ look like, pushes people closer to making that switch,” Ditonto said.

“And that tipping point arrives more quickly when women politicians are involved, because they’re being held to narrower and higher standards while also being scrutinised more.”

Voters also expect women candidates to adhere to their party’s platform, while giving greater latitude to men to “go maverick”. For men, deviating from the party’s typical stances can be perceived as bold leadership, while for women it is considered a sign of disloyalty.

Similarly, women officeholders in the US Congress are evaluated more strongly on their party-line votes than their male colleagues. Women seeking elected office, it would seem, are expected to be team-players rather than innovators.

Journal

Politics & Gender

DOI

10.1017/S1743923X25100159

Method of Research

Experimental study

Subject of Research

People

Article Title

The Gendered Risks of Violating Expectations and the Importance of Information for Women Candidates

Article Publication Date

23-Jul-2025

LAHB: A bioplastic that may solve marine plastic pollution problem

An environment-friendly plastic lost over 80% of its mass after 13 months underwater real-time deep-sea conditions

Shinshu University

The LAHB samples deployed in the deep-sea using Shinkai 6500 — image:
Researchers submerged LAHB films at a depth of 855 m near Hatsushima Island to test real-world deep-sea biodegradation. After 13 months, the LAHB plastic lost over 80% of its mass, showing its potential as a safer alternative to conventional plastics that persist in marine ecosystems.
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Credit: Japan Agency for Marine-Earth Science and Technology (JAMSTEC)

Researchers have demonstrated a new eco-friendly plastic that decomposes in deep ocean conditions. In a deep-sea experiment, the microbially synthesized poly(d-lactate-co-3-hydroxybutyrate) (LAHB) biodegraded, while conventional plastics such as a representative bio-based polylactide (PLA) persisted. Submerged 855 meters underwater, LAHB films lost over 80% of their mass after 13 months as microbial biofilms actively broke down the material. This real-world test establishes LAHB as a safer biodegradable plastic, supporting global efforts to reduce marine plastic waste.

Despite the growing popularity of bio-based plastics, plastic pollution remains one of the world’s most pressing environmental issues. According to the OECD’s Global Plastics Outlook (2022), about 353 million metric tons of plastic waste were produced globally in 2019, with nearly 1.7 million metric tons flowing directly into aquatic ecosystems. Much of this waste becomes trapped in large rotating ocean currents, known as gyres, forming the infamous “garbage patches” found in the Pacific, Atlantic, and Indian Oceans.

To tackle this, researchers have been searching for plastics that can be degraded more reliably in deep-sea environments. One promising candidate is poly(d-lactate-co-3-hydroxybutyrate) or LAHB, a lactate-based polyester biosynthesized using engineered Escherichia coli. So far, LAHB has shown strong potential as a biodegradable polymer that breaks down in river water and shallow seawater.

Now, in a study made available online on July 1, 2025, and published in Volume 240 of the journal Polymer Degradation and Stability on October 1, 2025, researchers from Japan have shown for the first time that LAHB can also get biodegraded under deep-sea conditions, where low temperatures, high pressure, and too limited nutrients make breakdown of plastic extremely difficult. The study was led by Professor Seiichi Taguchi at the Institute for Aqua Regeneration, Shinshu University, Japan, together with Dr. Shun'ichi Ishii from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Japan and Professor Ken-ichi Kasuya from Gunma University Center for Food Science and Wellness, Japan.

“Our study demonstrates for the first time that LAHB, a microbial lactate-based polyester, undergoes active biodegradation and complete mineralization even on the deep-sea floor, where conventional PLA remains completely non-degradable,” explains Prof. Taguchi.

The research team submerged two types of LAHB films—one containing about 6% lactic acid (P6LAHB) and another with 13% lactic acid (P13LAHB)—alongside a conventional PLA film for comparison. The samples were submerged at a depth of 855 meters near Hatsushima Island, where deep-sea conditions, cold temperatures (3.6 °C), high salinity, and low dissolved oxygen levels make it hard for microbes to degrade plastic.

After 7 and 13 months of immersion, the LAHB films revealed clear signs of biodegradation under deep-sea conditions. The P13LAHB film lost 30.9% of its weight after 7 months and over 82% after 13 months. The P6LAHB film showed similar trends. By contrast, the PLA film showed no measurable weight loss or visible degradation during the same period, underscoring its resistance to microbial degradation. The surfaces of the LAHB films had developed cracks and were covered by biofilms made up of oval- and rod-shaped microbes, indicating that deep-sea microorganisms were colonizing and decomposing the LAHB plastic. The PLA film, however, remained completely free of biofilm.

To understand how the plastic decomposes, the researchers analyzed the plastisphere, the microbial community that formed on the plastic’s surface. They found that different microbial groups played distinct roles. Dominant Gammaproteobacterial genera, including Colwellia, Pseudoteredinibacter, Agarilytica, and UBA7957, produced specialized enzymes known as extracellular poly[3-hydroxybutyrate (3HB)] depolymerases. These enzymes break down long polymer chains into smaller fragments like dimers and trimers. Certain species, such as UBA7959, also produce oligomer hydrolases (like PhaZ2) that further cleave these fragments, splitting 3HB–3HB or 3HB–LA dimers into their monomers.

Once the polymers are broken down into these simpler building blocks, other microbes, including various Alpha-proteobacteria and Desulfobacterota, continue the process by consuming the monomers like 3HB and lactate. Working together, these microbial communities ultimately convert the plastic into carbon dioxide, water, and other harmless compounds that ideally return to the marine ecosystem.

The findings of this study fill a critical gap in our understanding of how bio-based plastics degrade in remote marine environments. Its proven biodegradability makes it a promising option for creating safer, more biodegradable materials.

“This research addresses one of the most critical limitations of current bioplastics—their lack of biodegradability in marine environments. By showing that LAHB can decompose and mineralize even in deep-sea conditions, the study provides a pathway for safer alternatives to conventional plastics and supports the transition to a circular bioeconomy,” says Prof. Taguchi.

# # # # # # # # # #

About Shinshu University

Shinshu University is a national university founded in 1949 and located nestling under the Japanese Alps in Nagano known for its stunning natural landscapes.

Shinshu University was selected for the Forming Japan’s Peak Research Universities (J-PEAKS) Program by the Japanese government. This initiative seeks to promote the formation of university consortia that will enhance research capabilities across Japan.

Our motto, "Powered by Nature - strengthening our network with society and applying nature to create innovative solutions for a better tomorrow" reflects the mission of fostering promising creative professionals and deepening the collaborative relationship with local communities, which leads to our contribution to regional development by innovation in various fields. We’re working on providing solutions for building a sustainable society through interdisciplinary research fields: material science (carbon, fiber and composites), biomedical science (for intractable diseases and preventive medicine) and mountain science, and aiming to boost research and innovation capability through collaborative projects with distinguished researchers from the world. For more information visit https://www.shinshu-u.ac.jp/english/ or follow us on X (Twitter) @ShinshuUni for our latest news.

Journal

Polymer Degradation and Stability

DOI

10.1016/j.polymdegradstab.2025.111527

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Unveiling deep-sea biodegradation of microbially produced lactate-based polyester (LAHB) via plastisphere metagenomics and metatranscriptomics

Article Publication Date

21-Jul-2025

COI Statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Spanish and Italian scientists design sustainable and more resistant asphalt using cigarette butts

University of Granada

image:
alternative for recycling cigarette butts (from any type of cigarette, but especially electronic cigarettes, as they contain a higher amount of usable fibre) as an additive in road construction.
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Credit: University Of Granada

Researchers from the Building Engineering Laboratory (LabIC.UGR) are collaborating with the University of Bologna (Italy) on the design and evaluation of the resistance of asphalt made from pellets of this waste, in a project co-funded by the Chinese government

Since the advent of filter cigarettes, cigarette butts have become a predominant form of waste, with projections indicating that around 9 trillion will be generated worldwide in 2025. This poses a serious environmental problem, as many of them are improperly disposed of in natural environments, beaches, forests, waterways, etc.

Since the advent of filter cigarettes, cigarette butts have become a predominant form of waste, with projections indicating that around 9 trillion will be generated annually by 2025. In addition, since the emergence of low-nicotine e-cigarettes, the consumption and production of this waste has been on the rise (especially among young people aged 14 to 30). Much of this waste poses a serious environmental problem, as it is improperly disposed of in natural environments, beaches, forests, aquatic environments, etc., and has an extremely slow degradation rate.

An innovative collaborative research project between the University of Granada (UGR) and the University of Bologna (Italy), co-funded by the Chinese government, proposes an alternative for recycling cigarette butts (from any type of cigarette, but especially electronic cigarettes, as they contain a higher amount of usable fibre) as an additive in road construction. The research carried out has demonstrated the feasibility of incorporating this waste to improve the crack resistance of road pavements and the reuse of higher rates of recycled material.

The Department of Civil, Chemical, Environmental and Materials Engineering at the University of Bologna designed and manufactured different types of pellets from cigarette butts. To do this, the end of the cigarette butt (composed of organic ash) was discarded, while the rest (almost all of the weight, consisting of cellulose fibres and PLA plastic) was crushed and mixed with a Fischer-Tropsch-type wax (which acts as a binder) and subjected to a process of pressing, heating and cold cutting to produce the pellets.

Subsequently, the Building Engineering Laboratory (LabIC.UGR) was responsible for evaluating the resistance of asphalts manufactured with 40% of their weight coming from recycled material from deteriorated roads and pellets from electronic cigarette butts. LabIC.UGR, directed by professors Mª Carmen Rubio Gámez and Fernando Moreno Navarro, is one of the university’s unique laboratories and a world leader in the development of sustainable asphalt materials.

During the manufacture of asphalt, when the pellets come into contact with the hot bitumen, the wax melts and releases the recycled cellulose and plastic fibres from the cigarette butts. These fibres act as a reinforcement within the asphalt matrix, increasing its resistance to cracking, but also as a binder, allowing its content to be increased, making the material more ductile and flexible. In addition, the presence of waxes would make it possible to modify the viscosity of the bitumen and reduce the manufacturing temperature of the mixture, thereby reducing energy consumption and pollutant emissions.

The results of the tests carried out at LabIC.UGR have shown that the use of these pellets would allow the manufacture of asphalts with high recycled material content that offer better resistance to cracking under traffic loads and thermal shrinkage than conventional asphalts. Among the tests carried out, the UGR-FACT® method for the structural and durability study of the material, patented by the University of Granada, stands out.

Journal

Construction and Building Materials

DOI

10.1016/j.conbuildmat.2025.141832

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Use of Engineered Pellets Containing E-Cigarette Butts and a Recycling Agent for Stone Mastic Asphalt Mixtures Incorporating Recycled Asphalt

Article Publication Date

21-Jul-2025