Medicinal cannabis is linked to long-term benefits in health-related quality of life

 

Patients prescribed medicinal cannabis in Australia maintained improvements in overall health-related quality of life (HRQL), fatigue, and sleep disturbance across a one-year period, according to a study published April 2, 2025, in the open-access journal PLOS One by Margaret-Ann Tait from The University of Sydney, Australia, and colleagues. Anxiety, depression, insomnia, and pain also improved over time for those with corresponding health conditions.

Research into the therapeutic benefits of medicinal cannabis has increased since the discovery of the analgesic properties in cannabis plant compounds. In 2016, advocacy groups lobbied the Australian government to bring about legislation changes that allow patients who were not responding to conventional treatment to access medicinal cannabis with a prescription from clinicians. More than one million new patients in Australia have received medicinal cannabis prescriptions for more than 200 health conditions.

A multicenter prospective study called the QUEST initiative (QUality of life Evaluation STudy) recruited adult patients with any chronic health condition newly prescribed medicinal cannabis oil between November 2020 and December 2021. Tait and colleagues gathered 12-month follow-up data to determine if previously reported improvements at three months would be maintained long-term. Of 2744 consenting participants who completed baseline assessments, 2353 also completed at least one follow-up questionnaire and were included in analyses, with completion rates declining to 778/2353 (38%) at 12 months. Participants with clinician-diagnosed conditions completed questionnaires covering condition-specific symptoms, and HRQL, which encompasses physical, emotional, social, and cognitive function, as well as bodily discomfort.

The researchers found that short-term improvements in overall HRQL reported at three months were maintained over a 12-month period in patients prescribed medicinal cannabis in Australia. People with chronic health conditions reported improvements in fatigue, pain, and sleep. Patients with anxiety, depression, insomnia, or chronic pain diagnoses also showed improvements in condition-specific symptoms over 12 months. Patients treated for generalized anxiety, chronic pain, insomnia, and PTSD all showed improvements in HRQL. Participants with movement disorders had improved HRQL but no significant improvements in upper extremity function scores.  

The study was large enough to assess patients across a wide range of chronic conditions and socio-demographics in a real-world setting. However, without a control group, it was not possible to confidently attribute changes over time to medicinal cannabis.

Despite this limitation, the results suggest that prescribing medicinal cannabis to patients with chronic health conditions may improve pain, fatigue, insomnia, anxiety, and depression and overall HRQL. The findings also suggest that any improvements would be apparent quickly and maintained long-term. According to the authors, the results from this study contribute to the emerging evidence base to inform decision making both in clinical practice and at the policy level.

The authors add: “This is promising news for patients who are not responding to conventional medicines for these conditions." 

The freely available article in PLOS One: https://plos.io/4bIvkNp

Awareness grows of cancer risk from alcohol consumption, survey finds

 

– Public awareness of the link between drinking alcohol and an elevated risk of cancer has grown since last fall, with more than half of Americans now saying that regularly consuming alcohol increases your chances of later developing cancer, according to a survey by the Annenberg Public Policy Center (APPC) of the University of Pennsylvania.

In the survey, conducted Jan. 30-Feb. 10, 2025, with over 1,700 U.S. adults, 56% say the regular consumption of alcohol increases your chances of later developing cancer, up from 40% in an Annenberg survey in September 2024. The percentage of those who say alcohol consumption has no effect on your chances of later developing cancer fell to 16% from 20% in September 2024, and fewer are not sure how alcohol consumption affects cancer risks (26%, down from 40%).

The survey was fielded less than a month after U.S. Surgeon General Dr. Vivek Murthy’s advisory on alcohol and cancer risk on Jan. 3, 2025. It called for updated warning labels on alcoholic beverage containers to indicate that drinking alcohol carries an increased risk for at least seven types of cancer, including breast, colon, and liver cancer.

The Surgeon General’s warning, which was widely covered in the news media, was not the only report issued on alcohol and cancer in recent months, but the survey found it was the only one to gain significant public awareness. Of the people who say they had “read or heard about” one or more recent reports on the impact of alcohol on health, nearly 3 in 10 (29%) say they would be less likely to accept an alcoholic drink on a social occasion if one is offered to them.

“Our data suggest that the Surgeon General’s synthesis of the science showing that alcohol consumption increases one’s risk of cancer got traction,” said Kathleen Hall Jamieson, director of the Annenberg Public Policy Center. “The Surgeon General’s impact is a reminder that what health officials communicate about science can affect behavior.”

Reports on alcohol consumption and health

Nearly half of our survey respondents (48%) say they had “read or heard about” one or more reports on the impact of alcohol on health. In a separate question, 46% of those who say they were exposed to at least one report say the report they knew about was the Surgeon General’s, though 44% were unsure which report they had encountered.

In its own report in December 2024, the National Academies of Sciences, Engineering, and Medicine (NASEM) reviewed the scientific evidence on the relationship between moderate alcohol consumption and health impacts, including mortality, cancer, weight, and cardiovascular disease. While this report noted the connection between moderate alcohol consumption and a higher risk of breast cancer, it listed positive and negative findings about alcohol consumption and various other health conditions. Another federal report from U.S. health agencies, led by the Substance Abuse and Mental Health Services Administration, on Jan. 14, 2025, found that even moderate drinking carried health risks, including liver disease, cancer, and injuries.

The survey found that very few among the public say they knew of those other reports.

After noting that moderate alcohol use is defined as one drink a day for women and up to two drinks a day for men, the survey asked those who had seen or heard of only one report what it says about moderate alcohol use. Nearly half of those individuals (47%) say that, according to the report, moderate alcohol use “has harmful effects” and a quarter (25%) say it has some harmful and some positive health effects. One in 5 (20%) were not sure what the report says.

Did the reports have an effect?

The respondents who knew of at least one report on alcohol and health were asked if “anything that you have heard or read about the report(s)” made you more or less likely to accept a drink if one is offered on a social occasion, or if it had no effect. As noted above, nearly 1 in 3 (29%) say they would be less likely to accept an alcoholic drink if one is offered. But 61% say the report(s) would have no effect on whether they would accept an alcoholic drink. A very small group (9%) say they would be more likely to accept a drink.

Among the small group who report that something they heard or read about the report(s) made them more likely to accept a drink on a social occasion, most (73%) say they also would be more likely to accept a second drink if one is offered. About 1 in 5 (22%) say they’d be less likely to accept a second drink if offered.

APPC’s Annenberg Science and Public Health knowledge survey

The survey data come from the 23rd wave of a nationally representative panel of 1,716 U.S. adults conducted for the Annenberg Public Policy Center by SSRS, an independent market research company. Most have been empaneled since April 2021. To account for attrition, small replenishment samples have been added over time using a random probability sampling design.  The most recent replenishment, in September 2024, added 360 respondents to the sample. This wave of the Annenberg Science and Public Health Knowledge (ASAPH) survey was fielded Jan. 30-Feb. 10, 2025. The margin of sampling error (MOE) is ± 3.4 percentage points at the 95% confidence level. All figures are rounded to the nearest whole number and may not add to 100%. Combined subcategories may not add to totals in the topline and text due to rounding.

Download the topline and the methods report.

The policy center has been tracking the American public’s knowledge, beliefs, and behaviors regarding vaccination, Covid-19, flu, RSV, and other consequential health issues through this survey panel for four years. In addition to Jamieson, APPC’s team on the survey includes research analysts Laura A. Gibson and Shawn Patterson Jr., Patrick E. Jamieson, director of the Annenberg Health and Risk Communication Institute, and Ken Winneg, managing director of survey research.

See other Annenberg health knowledge surveys:

• Raw milk and bird flu: With bird flu in raw milk, many still do not know risks of consuming it (March 14, 2025)
• Firearm safety: Over 1 in 3 adults in households with guns do not store all in locked locations (March 11, 2025)
• Low-dose aspirin: Nearly half of adults mistakenly think benefits of daily aspirin outweigh risks (Feb. 3, 2025)
• Vaccination mandates: Most Americans favor school vaccination requirements, but support is rising for opt-out options (Jan. 28, 2025)
• The RSV vaccine & vaccine hesitancy: Greater acceptance of RSV vaccine seen as vaccine hesitancy appears to have plateaued (Dec. 23, 2024)

The Annenberg Public Policy Center was established in 1993 to educate the public and policy makers about communication’s role in advancing public understanding of political, science, and health issues at the local, sta

Weight training protects older people’s brains against dementia

 The benefits of weight training are many: it promotes gains in strength and muscle mass, reduces body fat, and contributes to well-being and mental health. And now a study carried out at the State University of Campinas (UNICAMP), in the state of São Paulo, Brazil, has demonstrated another important effect: it protects the brains of older people against dementia. The results were published in the journal GeroScience.

The study involved 44 people with mild cognitive impairment – an intermediate clinical condition between normal aging and Alzheimer’s disease in which cognitive decline is greater than expected for age, indicating a higher risk of dementia. The results showed that strength training not only improved memory performance but also altered brain anatomy.

After six months of twice-weekly weight training, the participants showed protection against atrophy in the hippocampus and precuneus – brain areas associated with Alzheimer’s disease – as well as improvements in parameters that reflect the health of neurons (white matter integrity).

“We already knew that there would be physical improvement. Cognitive improvement was also imagined, but we wanted to see the effect of weight training on the brains of older people with mild cognitive impairment. The study showed that, fortunately, weight training is a strong ally against dementia, even for people who are already at high risk of developing it,” says Isadora Ribeiro, a FAPESP doctoral fellowship recipient at UNICAMP’s School of Medical Sciences (FCM) and first author of the article.

The work was carried out within the framework of the Brazilian Institute for Neuroscience and Neurotechnology (BRAINN) – a FAPESP Research, Innovation and Dissemination Center (RIDC) – and is the first to demonstrate what happens to the integrity of the white matter of individuals with mild cognitive impairment after weight training.

“As well as neuropsychological tests, we also performed MRI scans at the beginning and end of the study. These results are very important because they indicate the need to include more physical educators in the public health system at the primary health care level since increased muscle strength is associated with a reduced risk of dementia. It’s a less complex and cheaper treatment that can protect people from serious diseases,” comments Marcio Balthazar, BRAINN researcher and study supervisor.

“For example, the new anti-amyloid drugs approved in the United States indicated for the treatment of dementia and for people with mild cognitive impairment, cost around USD 30,000 a year. That’s a very high cost. These non-pharmacological measures, as we’ve shown is the case with weight training, are effective, not only in preventing dementia but also in improving mild cognitive impairment,” the researcher adds.

Protocol

The research participants were divided into two groups: half underwent a resistance exercise program with weight training sessions twice a week, at moderate to high intensity and with progressive loads; the other half did not exercise during the study period and were part of the so-called control group.

In the analyses carried out at the end of the intervention, the volunteers who practiced weight training had better performance in verbal episodic memory, improved integrity of neurons and areas related to Alzheimer’s disease protected from atrophy, while the control group showed a worsening of brain parameters.

“A characteristic of people with mild cognitive impairment is that they have volume loss in some brain regions associated with the development of Alzheimer’s. But in the group that did strength training, the right side of the hippocampus and precuneus were protected from atrophy. This result justifies the importance of regular weight training, especially for older people,” Ribeiro highlights.

The researcher believes that a longer period of training could lead to even more positive results than those reported in the study. “All the individuals in the bodybuilding group showed improvements in memory and brain anatomy. However, five of them reached the end of the study without a clinical diagnosis of mild cognitive impairment, such was their improvement. This leads us to imagine that longer training sessions, lasting three years, for example, could reverse this diagnosis or delay any kind of dementia progression. It’s certainly something to be hopeful about and something that needs to be studied in the future,” Ribeiro argues.

According to the researchers, weight training can protect the brain against dementia on two fronts: by stimulating the production of neural growth factor (an important protein for the growth, maintenance and survival of neurons) and by promoting global disinflammation in the body.

“Any physical exercise, whether weight training or aerobic activity, is known to increase levels of a chemical involved in brain cell growth. It can also mobilize anti-inflammatory T-cells. This is key. After all, the more pro-inflammatory protein that is released in the body, the greater the chance of developing dementia, accelerating the neurodegenerative process and forming dysfunctional proteins that eventually kill neurons,” Balthazar explains.

To assess these issues, the volunteers’ levels of irisin and BDNF (brain-derived neurotrophic factor) – substances whose synthesis is stimulated by muscle contraction and which are associated with neural protection and synaptic plasticity – were measured. The results are currently being analyzed.

“It’s a continuation of this study in which we’ll try to better understand how these factors are related to changes in brain anatomy. We believe that it’s a set of anti-inflammatory and neuroprotective factors that lead to these changes,” Ribeiro predicts.

Low LDL cholesterol levels linked to reduced risk of dementia

 

People with low levels of low-density lipoprotein cholesterol (LDL-C) in their blood have a lower risk of dementia, including lower risk of Alzheimer’s disease related dementia, shows a study published online today in the Journal of Neurology Neurosurgery & Psychiatry. 

Use of statins conveyed an additional protective effect for people with low LDL-C, specifically those with blood levels less than 1.8 mmol/L (<70 mg/dL), reducing their risk of dementia even further.

However, reducing LDL-C to very low levels below 0.8 mmol/L (<30mg/dL) did not reduce dementia risk further.

The benefits of low LDL-C levels to protect against cardiovascular events is well recognised, but the relationship between LDL-C levels and dementia has been less clear, particularly the cut-off for LDL-C below which there is no further benefit for reducing risk of cognitive decline.

To address this, the authors accessed data collected by 11 university hospitals on adult outpatients with no previous diagnosis of dementia followed for at least 180 days after LDL-C testing. They identified 192,213 people with LDL-C levels less than 1.8 mmol/L (<70mg/dL) and 379,006 patients with LDL-C levels more than 3.4 mmol/L (>130mg/dL), and matched individuals in each group into 108,980 matched pairs.

Analysis of subsequent diagnoses of dementia showed that LDL-C levels below 1.8 mmol/L (<70mg/dL) were associated with a 26% reduction in the risk of all-cause dementia and a 28% reduction in the risk of Alzheimer’s disease related dementia, compared with LDL-C levels above 3.4 mmol/L (>130mg/dL).

The protective effect against cognitive decline lessened at lower LDL-C levels and eventually disappeared entirely. At LDL-C levels below 1.4 mmol/L (<55mg/dL), there was an 18% risk reduction for both all cause dementia and Alzheimer’s disease related dementia compared with LDL-C levels above 3.4 mmol/L (>130mg/dL), and when LDL-C levels fell below 0.8 mmol/L (<30mg/dL) the risk reductions disappeared.

Statin use conferred additional protection against dementia in the presence of low LDL-C levels. Among people with LDL-C levels below 1.8 mmol/L (<70mg/dL), statin use was associated with a 13% reduction in all cause dementia risk and a 12% decrease in risk of Alzheimer’s disease related dementia compared with non-users.

This is an observational study, and as such, no firm conclusions can be drawn about cause and effect. The authors also acknowledge that the study has some limitations including the potential for unmeasured confounding factors because of its retrospective design, possible underreporting of dementia cases due to variations in diagnostic accuracy between hospitals, and the focus on baseline LDL-C levels when lipid profiles could change over time.

Nevertheless, the authors conclude: “Low LDL-C levels (<70 mg/dL (<1.8 mmol/L)) are significantly associated with a reduced risk of dementia, including Alzheimer’s disease related dementia, with statin therapy providing additional protective effects.”

They add: “These findings underscore the crucial role of managing LDL-C in lowering dementia risk.”

Western diet causes inflammation

 A switch of just two weeks from a traditional African diet to a Western diet causes inflammation, reduces the immune response to pathogens, and activates processes associated with lifestyle diseases. Conversely, an African diet rich in vegetables, fiber, and fermented foods has positive effects. This study, published in Nature Medicine, highlights the significant impact of diet on the immune system and metabolism.

Lifestyle diseases such as cardiovascular diseases, diabetes, and chronic inflammatory conditions are surging across Africa, posing a growing challenge to healthcare systems throughout the continent. Increasing economic development, urbanization and wider availability of processed foods have accelerated the adoption of Western eating habits in Africa. To understand the health consequences of this shift, researchers from Radboud university medical center and KCMC University in Tanzania have studied the effects of such dietary changes on health.

Lifestyle diseases

Seventy-seven healthy men from Tanzania, both urban and rural residents, participated in the study. Some participants who traditionally ate an African diet switched to a Western diet for two weeks, while others who ate a Western diet adopted a traditional African diet. A third group consumed a fermented banana drink daily. As a control, ten participants maintained their usual diet. The researchers comprehensively analyzed the function of the immune system, blood inflammation markers, and metabolic processes at baseline, after the two-week intervention, and again four weeks later.

Participants who switched to a Western diet exhibited an increase in inflammatory proteins in their blood, alongside activation of biological processes linked to lifestyle diseases. Their immune cells also responded less effectively to pathogens. Meanwhile, those who switched to a traditional African diet or consumed the fermented drink showed a reduction in inflammatory markers. Some of these effects persisted even four weeks later, indicating that short-term dietary changes can have long-lasting effects.

Insights from Africa

This is the first study to comprehensively map the health effects of a traditional African diet. 'Previous research has focused on other traditional diets, such as the Japanese or Mediterranean diet', says internist Quirijn de Mast from Radboudumc. 'However, there is just as much to learn from traditional African diets, especially now, as lifestyles in many African regions are rapidly changing and lifestyle diseases are increasing. Africa's rich diversity in traditional diets offers unique opportunities to gain valuable insights into how food influences health.'

De Mast finds it remarkable how significant the effects of diet are, even after just two weeks. 'The African diet includes plenty of vegetables, fruits, beans, whole grains, and fermented foods. Our study highlights the benefits of these traditional food products for inflammation and metabolic processes in the body. At the same time, we show how harmful an unhealthy Western diet can be. It typically consists of processed and high-calorie foods, such as French fries and white bread, with excessive salt, refined sugars, and saturated fats. Inflammation is at the root of many chronic conditions, which makes this study highly relevant for Western countries as well.'

Daily physical activity, even at light intensities, linked to lower cancer risk

What: In a prospective cohort study of more than 85,000 adults in the United Kingdom, researchers at the National Institutes of Health (NIH) and University of Oxford found that individuals who engaged in light- and moderate-to-vigorous-intensity daily physical activity had a lower risk of cancer than individuals who were more sedentary. The findings, published March 26, 2025, in British Journal of Sports Medicine, are among the first to evaluate the cancer risk reduction associated with light-intensity activities such as doing errands and performing household chores.

Previous studies have shown an inverse association between physical activity and cancer risk, but most of these studies relied on self-reported questionnaires, which may not accurately capture the intensity of different activities. Earlier studies that used objective measures were focused on higher-intensity physical activity. In the new study, led by researchers from NIH’s National Cancer Institute, participants in the UK Biobank study (median age of 63) wore wrist accelerometers that tracked total daily activity, activity intensity, and daily step count over a period of one week. The researchers then looked at the relationship between the daily averages and incidence of 13 cancer types, including breast and colorectal cancer, previously associated with physical activity. 

After a mean follow-up of 5.8 years, 2,633 participants had been diagnosed with one of the 13 cancer types. Individuals with the highest total amount of daily physical activity had a 26% lower risk of developing cancer than individuals who had the lowest amount of daily physical activity. The researchers also explored the impact of replacing daily sedentary time with light- and moderate-to-vigorous-intensity physical activity and found that this shift was associated with a reduced risk of cancer. The associations between physical activity and cancer risk remained even after researchers adjusted for demographic factors, lifestyle factors, body mass index (BMI), and other health conditions. 

Higher daily step count, but not the pace of the steps (step intensity), was also associated with a lower risk of cancer. Compared with cancer risk in those taking 5,000 steps per day, cancer risk was 11% lower for those taking 7,000 steps per day and 16% lower for those taking 9,000 steps per day. Beyond 9,000 steps, the risk reduction plateaued. The researchers suggested that less physically active individuals may lower their cancer risk by incorporating more walking, at any pace, into their daily routine. 

Sugar substitute sucralose increased feelings of hunger

 Compared to sugar, consuming sucralose—a widely used sugar substitute—increases activity in the hypothalamus, a brain region that regulates appetite and body weight, according to a new USC study. Sucralose also changes how the hypothalamus communicates with other brain regions, including those involved in motivation. The study was just published in the journal Nature Metabolism.

About 40% of Americans regularly consume sugar substitutes, usually as a way to reduce calories or sugar intake. “But are these substances actually helpful for regulating body weight? What happens in the body and brain when we consume then, and do the effects differ from one person to the next?” said the study’s corresponding author, Kathleen Alanna Page, MD, director of the USC Diabetes and Obesity Research Institute and co-chief of the Division of Endocrinology and Diabetes at the Keck School of Medicine of USC.

Page and her colleagues designed a randomized experiment to test how sucralose changes brain activity, hormone levels and hunger. Earlier research—mostly done with animal models and large population studies—has hinted at a link between calorie-free sweeteners and obesity, but has not directly shown how these substances affect hunger in humans. 

With funding from the National Institutes of Health, the researchers tested how 75 participants responded after consuming water, a drink sweetened with sucralose or a drink sweetened with regular sugar. They collected functional magnetic resonance imaging (fMRI) brain scans, blood samples and hunger ratings before and after participants consumed the drink. Sucralose increased hunger and activity in the hypothalamus, especially in people with obesity. It also changed the way the hypothalamus communicated with other brain regions. Unlike sugar, sucralose did not increase blood levels of certain hormones that create a feeling of fullness.

The findings show how sucralose confuses the brain by providing a sweet taste without the expected caloric energy, said Page, who is also an associate professor of medicine at the Keck School of Medicine. This “mismatch” could even trigger changes in cravings and eating behavior down the line.

“If your body is expecting a calorie because of the sweetness, but doesn’t get the calorie it’s expecting, that could change the way the brain is primed to crave those substances over time,” she said.

An altered brain response

The study included 75 participants, about evenly split between male and female and weight status (healthy weight, overweight or obese). On three separate visits, each participant was tested with sucralose, sugar or water, allowing the researchers to look for differences both within and between individuals.

At each visit, researchers collected baseline brain scans and blood samples. They also asked participants to rate how hungry they were. Next, participants consumed 300 ml of water, a sugar-sweetened drink or a drink sweetened with sucralose. Researchers then collected follow-up brain scans, blood samples and hunger ratings several times during the next two hours.

Compared to drinking sugar, drinking sucralose increased brain activity in the hypothalamus and increased feelings of hunger. Compared to drinking water, sucralose increased hypothalamic activity, but did not change feelings of hunger. Those effects were strongest in people with obesity.

The researchers also used fMRI scans to study functional connectivity, which shows how regions of the brain communicate with one another. Consuming sucralose led to increased connectivity between the hypothalamus and several brain areas involved with motivation and sensory processing—including the anterior cingulate cortex, which plays a role in decision-making. Those findings suggest that sucralose could impact cravings or eating behavior, Page said.

As expected, consuming sugar led to increases in blood sugar and the hormones that regulate it, including insulin and glucagon-like peptide 1 (GLP-1). Drinking sucralose, on the other hand, had no effect on those hormones.

“The body uses these hormones to tell the brain you’ve consumed calories, in order to decrease hunger,” Page said. “Sucralose did not have that effect—and the differences in hormone responses to sucralose compared to sugar were even more pronounced in participants with obesity.”

Age, sex and long-term effects

While the study answers key questions about how the brain and body respond to sucralose, it raises several others. Do the observed changes in brain and hormone activity have long-term effects? Longitudinal studies that measure body weight and eating behavior are needed to help clarify the link.

Page and her colleagues also observed differences by sex: female participants showed greater changes in brain activity than did male participants, suggesting that sucralose may affect the sexes differently.

The researchers have now begun a follow-up study that explores how calorie-free sweeteners affect the brains of children and adolescents, who consume more sugar and sugar substitutes than any other age group.

“Are these substances leading to changes in the developing brains of children who are at risk for obesity? The brain is vulnerable during this time, so it could be a critical opportunity to intervene,” Page said.