Relaxation techniques may help lower high blood pressure—at least in the short term—but the longer term effects are unclear, finds a pooled data analysis of the existing research published in the open access journal BMJ Medicine.

And the risk of bias in the existing body of research means that further, more rigorously designed and longer studies are needed to confirm whether these techniques have a constructive role in the treatment of high blood pressure, conclude the researchers.

High blood pressure affects around a third of 30-79 year olds and is one of the leading attributable causes of deaths in both men and women, note the researchers. While drugs are available to treat the condition, adherence to them is poor, generating interest in alternative approaches, such as relaxation techniques, to reduce one of the major risk factors for high blood pressure—high stress levels. But it’s far from clear which of these methods, which can include breath control, mindfulness, yoga, Tai Chi, and biofeedback, among others, might be most effective.

To build on the evidence base, the researchers scoured research databases for studies, published in English up to February 2024 that looked at the potential impact of relaxation techniques on high blood pressure (140/90 mm Hg and above) and elevated blood pressure (120/80 mm Hg and above). They included 182 studies, 166 of which looked at high blood pressure, and 16 of which looked at elevated blood pressure (pre-hypertension).

Where possible, the researchers deployed network meta analysis, a statistical technique used to simultaneously compare the effects of several different ‘treatments’.

The pooled results of 54 studies showed that most relaxation techniques seemed to lower both systolic and diastolic blood pressure for people with high blood pressure after 3 or fewer months. The most commonly included interventions were breath control (13 studies), yoga/tai chi (11), biofeedback (8), progressive muscle relaxation (7), and music (7).

Compared with no intervention, breath control achieved a reduction of 6.65 mm Hg in systolic blood pressure (the first and higher number in a blood pressure reading), meditation a drop of 7.71 mm Hg, meditative movement, such as tai chi and yoga, a drop of 9.58 mm Hg, and mindfulness a drop of 9.90 mm Hg.

Music was also associated with a fall of 6.61 mm Hg, progressive muscle relaxation with a fall of 7.46 mm Hg, and psychotherapy with a reduction of 9.83 mm Hg. Combined techniques were associated with a drop of 6.78 mm Hg in blood pressure. 

There was no statistical evidence of effectiveness for any technique after 3 to 12 months and the certainty of the evidence was very low. The most commonly included techniques at this timepoint were biofeedback (7 studies), yoga/tai chi (4), and progressive muscle relaxation (4).

Very few studies included long term follow up of 12 months or more, and of the 3 included in the network analysis, the results showed that compared with no treatment autogenic (self directed) training might lower both systolic and diastolic blood pressure, but the certainty of the evidence was low. 

There was no statistical evidence of effectiveness for other treatments assessed at this time point, including biofeedback, progressive muscle relaxation, and techniques involving a combined approach.

Limited data were available for elevated blood pressure: only two studies compared relaxation techniques with no treatment/usual care and the effects on systolic blood pressure were small. 

The researchers note that the descriptions of relaxation interventions were sometimes incomplete or sparse, there were few data on costs and cost effectiveness, and most of the included studies didn’t report information on the risk of cardiovascular disease/events/deaths. 

But they suggest: “The results of our systematic review and network meta-analysis indicate that relaxation or stress management techniques might result in meaningful reductions in blood pressure at up to three months of follow-up.” 

But they caution: “Uncertainty exists about this effect, however, because of the risk of bias in the primary studies, the potential for publication bias in this area, and imprecision in the effect estimates, meaning that the observed changes in blood pressure might be too small to affect cardiovascular or cerebrovascular outcomes.” 

And they add: “Hypertension is a chronic condition, likely to require long term drug treatments or behavioural changes. As such, interventions that are used for a brief period, or provide only short term benefits, are unlikely to be clinically useful. 

“Too few studies exist, however, to assess whether the beneficial effects of relaxation are maintained when the techniques are practised for longer than three months. Future studies must clearly report whether participants were still using relaxation methods at the time of the outcome assessment, with details on adherence to the relaxation schedule. These factors might strongly influence the effectiveness of the different relaxation and stress management techniques.” 

New research from the University of Sydney has revealed poor oral health is significantly associated with higher instances of migraines, abdominal and body pain in women. 

Published in Frontiers in Pain Research, the world-first study identified specific oral microbes correlated with certain pain conditions, suggesting a potential relationship between the oral microbiome and the nervous system.   

The findings highlight the importance of good oral health to potentially mitigate pain and improve overall wellbeing, prompting further exploration into the role of oral microbiota in chronic unexplained pain conditions. This includes fibromyalgia, a condition experienced by 67 percent of the study participants. 

“This is the first study to investigate oral health, oral microbiota and pain commonly experienced in women with fibromyalgia, with our study showing a clear and significant association between poor oral health and pain,” said lead investigator Associate Professor Joanna Harnett from the Faculty of Medicine and Health. 

“Our findings are particularly important to fibromyalgia which, despite being a common rheumatological condition, is often underrecognised,” said first author and PhD candidate in the Faculty of Medicine and HealthSharon Erdrich.  

“Fibromyalgia is a chronic condition characterised by widespread musculoskeletal pain, and headaches including headaches, as well as fatigue, sleep disturbances, and cognitive problems.” 

The research examined associations between self-reported oral health, the oral microbiome, and various pain presentations in a group of New Zealand women with and without fibromyalgia.   

Oral health was assessed using the WHO oral health questionnaire and evaluated against body pain, headaches, migraines, and abdominal pain using validated instruments, including the Short-form 36 (which measures quality of life), the International Headache Society headache survey and the functional bowel disorder severity index. Strong associations were evident between oral health scores and pain and each of these were associated with specific microbes found in the mouth, which were assessed using advanced genomic technology.   

Participants with the poorest oral health were more likely to suffer from higher pain scores: 60 percent were more likely to experience moderate to severe body pain, and 49 percent were more likely to experience migraine headaches. Lower oral health was a statistically significant predictor of frequent and chronic migraine. 

Four oral microbial species from the Dialister, Fusobacterium, Parvimonas and Solobacterium genera were significantly associated with pain after age, BMI and added dietary sugars were considered.   

A weak but significant inverse correlation with diet quality and oral health was also found, though the researchers note this has yet to be investigated in detail. 

The Australian Dental Association recommends regular oral hygiene appointments and dental health checks, in addition to twice daily teeth brushing and flossing. 

There is growing recognition in medicine that what happens in one part of the body can ripple through others. That idea is now being explored in a surprising place: the mouth. A new review by an international group of researchers has examined the mounting evidence linking periodontal disease—commonly known as gum disease—to chronic liver conditions, including cirrhosis, metabolic dysfunction-associated steatotic liver disease (MASLD), and alcohol-related liver disease. Though the mouth and liver are separated by both distance and function, the paper makes a compelling case that these two systems are more connected than we thought.

Gum disease, especially in its more advanced form known as periodontitis, is a chronic inflammatory condition caused by bacterial infections in the tissues that support the teeth. It is one of the most common diseases worldwide, and its severity tends to increase with age, smoking, alcohol use, and poor access to dental care. For patients already struggling with liver disease—many of whom share these same risk factors—oral health often takes a back seat.

But ignoring the mouth could be a mistake. The review lays out multiple ways that periodontitis may aggravate liver disease. The first is via the “oral-gut-liver axis,” a term researchers use to describe the complex interplay between oral bacteria, the gut microbiome, and liver function. Pathogenic bacteria from the mouth can be swallowed or enter the bloodstream during everyday activities like chewing and brushing. Once in the gut, these microbes may alter the composition of the intestinal microbiome, leading to dysbiosis and increased gut permeability—also known as a “leaky gut.” This can allow bacterial products such as endotoxins to reach the liver, triggering inflammation and fibrogenesis.

Animal models offer further support for this theory. Studies have shown that oral administration of specific periodontal pathogens, such as Porphyromonas gingivalis, can exacerbate liver steatosis and inflammation in mice with pre-existing metabolic disease. These microbes, or their byproducts, have even been found in liver tissue, suggesting that translocation from the mouth to the liver is biologically plausible.

The immune system also plays a central role in this interaction. Chronic periodontal inflammation leads to the release of pro-inflammatory cytokines like TNF-alpha and IL-6, which have long been implicated in the progression of liver disease. Additionally, the review highlights the involvement of Th17 cells—a type of immune cell activated by oral pathogens that may migrate to the liver and worsen metabolic dysfunction. Together, these pathways form a vicious cycle: liver disease impairs oral health, while oral inflammation accelerates liver damage.

The clinical data, while still developing, supports this association. Patients with cirrhosis consistently show worse oral health than the general population, with higher rates of gingival overgrowth, attachment loss, and bone loss. The prevalence of periodontitis among patients awaiting liver transplantation can be as high as 72 percent. Studies have also found links between severe periodontal disease and increased mortality in cirrhosis patients.

For those with MASLD, the most common form of chronic liver disease, the evidence is also compelling. Population-level studies have found that people with advanced periodontitis are significantly more likely to have MASLD, even after adjusting for shared risk factors like obesity and diabetes. And in a small trial, periodontal treatment led to a short-term improvement in liver enzyme levels—a tantalizing hint that oral health interventions could influence liver function.

That said, the review authors caution that the research is still at an early stage. Much of the clinical data comes from observational studies, which cannot definitively prove cause and effect. There is also the challenge of disentangling shared lifestyle and socioeconomic factors that affect both oral and liver health. Still, the biological plausibility, consistency of findings, and preliminary interventional data make a strong case for paying more attention to the teeth and gums of patients with liver disease.

The review ends with a call for multidisciplinary collaboration. Gastroenterologists and hepatologists, who typically manage liver disease, may not think to ask about oral health or refer patients for dental care. Yet the data suggest they should. Similarly, dental professionals may not be aware of how their work could influence liver outcomes. Closer cooperation between these specialties could lead to earlier detection and better care.

Until more definitive evidence is available, one message is clear: brushing, flossing, and regular dental visits might be more important than we ever realized, especially for those living with chronic liver conditions. In the meantime, researchers are calling for larger, high-quality trials to test whether treating gum disease can slow liver disease progression or reduce complications. If the connection holds, the humble toothbrush could become an unexpected tool in the fight against liver failure.