Physical activity in nature helps prevent several diseases, including depression and type 2 diabetes.

Physical activity in natural environments prevent almost 13,000 cases of non-communicable diseases a year in England and save treatment costs of more than £100m, new research from the University of Exeter has found
Physical activity in natural environments prevents almost 13,000 cases of non-communicable diseases a year in England and saves treatment costs of more than £100m, new research from the University of Exeter has found.


According to the World Health Organization (WHO) the most common non-communicable diseases – including heart disease, stroke, cancer, diabetes, and chronic lung disease – cause 74 percent of global mortality. Non communicable diseases, also known as chronic diseases, are not passed from person to person and deaths attributed to these diseases are increasing in most countries.
Physical inactivity is associated with a range of non-communicable diseases, including cardiovascular diseases, type-2 diabetes, cancers, and mental health outcomes. In their Global Status Report on Physical Activity 2022, the WHO estimated 500 million new cases will occur globally between 2020 and 2030 should physical activity remain at today’s levels, incurring more than £21b a year in treatment costs. Non-communicable diseases, also known as chronic diseases, are not passed from person to person, and deaths attributed to these diseases are increasing in most countries. Natural environments support recreational physical activity, with this new study focusing particularly on places such as beaches and coast, countryside, and open spaces in towns and cities like parks. Using data including a representative cross-sectional survey of the English population, researchers at the University of Exeter have estimated how many cases of six non-communicable diseases – major depressive disorder, type 2 diabetes, ischaemic heart disease, ischaemic stroke, colon cancer, and breast cancer – are prevented through nature-based recreational physical activity.
Speaking about the findings, published in Environment International, Dr James Grellier from the University of Exeter Medical School said: “We believe this is the first time an assessment like this has been conducted on a national scale, and we’ve almost certainly underestimated the true value of nature-based physical activity in terms of disease prevention. Although we have focused on six of the most common non-communicable diseases, several less common diseases can be prevented by physical activity, including other types of cancer and mental ill health. It’s important to note that our estimates represent annual costs. Since chronic diseases can affect people for many years, the overall value of physical activity at preventing each case is certainly much higher.”
Increasing population levels of physical activity is an increasingly important strategic goal for public health institutions globally. The WHO recommends that adults aged 18 to 64 do at least 150 to 300 minutes of moderate-intensity aerobic physical activity (or at least 75 to 150 minutes of vigorous-intensity aerobic physical activity) per week to maintain good health. However, 27.5 per cent of adults do not meet these recommendations globally.
In 2019, 22 million adults in England aged 16 years or older visited natural environments at least once a week. At reported volumes of nature-based physical activity, Exeter researchers estimate this prevented 12,763 cases of non-communicable diseases, creating annual healthcare savings of £108.7m.
Population-representative data from the Monitor of Engagement with the Natural Environment survey were used to estimate the weekly volume of nature-based recreational physical activity by adults in England in 2019. Researchers used epidemiological dose-response data to calculate incident cases of six non-communicable diseases prevented through nature-based physical activity and estimated associated savings using published healthcare costs, informal care, and productivity losses. It’s estimated that the healthcare cost of physical inactivity in England in 2019 is approximately £1b.
Dr James Grellier from the University of Exeter Medical School said: “For people without the access, desire, or confidence to participate in organised sports or fitness activities, nature-based physical activity is a far more widely available and informal option. We believe that our study should motivate decision-makers seeking to increase physical activity in the local population to invest in natural spaces, such as parks, to make it easier for people to be physically active.”

Low-intensity exercise linked to reduced depression

New research finds strong association between physical activity and better mental health
New research finds a strong association between physical activity and better mental health.
New research has found a significant association between participating in low to moderate-intensity exercise and reduced rates of depression.

 
Researchers from Anglia Ruskin University (ARU) conducted an umbrella review of studies worldwide to examine the potential of physical activity as a mental health intervention.
 
The analysis, published in the journal Neuroscience and Biobehavioural Reviews, found that physical activity reduced the risk of depression by 23% and anxiety by 26%. A particularly strong association was found between low and moderate physical activity, including gardening, golf and walking, and reduced risk of depression. However, this was not strongly observed for high-intensity exercise.

 
Physical activity was also significantly associated with a reduced risk of severe mental health conditions, including a reduction in psychosis/schizophrenia by 27%.
 
The results were consistent in both men and women and across different age groups and across the world.
 
“Preventing mental health complications effectively has emerged as a major challenge and an area of paramount importance in the realm of public health. These conditions can be complex and necessitate a multi-pronged approach to treatment, which may encompass pharmacological interventions, psychotherapy, and lifestyle changes.
 
“These effects of physical activity intensity on depression highlight the need for precise exercise guidelines. Moderate exercise can improve mental health through biochemical reactions, whereas high-intensity exercise may worsen stress-related responses in some individuals.
 
“Acknowledging differences in people’s response to exercise is vital for effective mental health strategies, suggesting any activity recommendations should be tailored for the individual.
 
“The fact that even low to moderate levels of physical activity can be beneficial for mental health is particularly important, given that these levels of activity may be more achievable for people who can make smaller lifestyle changes without feeling they need to commit to a high-intensity exercise programme.”

Weight training improves symptoms of anxiety and depression in old people, study confirms

Brazilian researchers analyzed more than 200 articles on the subject and identified the types of training most indicated for these cases.

Weight training can help reduce body fat and increase muscle strength and mass in older people, contributing to functional autonomy and avoiding falls and injury. Furthermore, recent studies have shown that it can also benefit the mental health of older people, especially those who suffer from anxiety and depression.

These benefits were confirmed by a study reported in the journal Psychiatry Research. The study involved a systematic review and meta-analysis of more than 200 articles. The analysis was conducted by Paolo Cunha, a postdoctoral fellow with a scholarship from FAPESP at the Albert Einstein Jewish-Brazilian Institute of Education and Research (IIEPAE) in São Paulo, Brazil. 

“Resistance training has been shown to be one of the most effective non-pharmacological strategies for healthy aging. It promotes countless health benefits, including improvements to mental health,” Cunha said.

The findings of the study are highly promising, he continued. Besides improvements to symptoms of anxiety and depression in the general population, weight training appears to have a more significant effect on people with a confirmed diagnosis of anxiety or depression disorder.

“Epidemiological studies have shown that the decrease in muscle strength and mass that occurs naturally as we age may be associated with an increase in mental health problems, given the existence of various physiological mechanisms that bring about functional and structural changes and that are controlled by the brain,” Cunha said.

Another important mental health benefit, he added, is that when weight training is done in a group, it contributes to more social interaction among those involved.

Recommended exercises

The investigation also pointed to the best ways of structuring one’s training to improve mental health. “How the training is done appears to influence the results achieved. The information obtained so far suggests that older people should ideally do weight training exercises three times a week, with three sets of each exercise and sessions that are not too long – six exercises would seem to be sufficient. Do less, but do it well: a short set produces better results. This is meaningful information, as we lack guidelines with specific recommendations for resistance training that focuses on mental health parameters,” Cunha said.

While there are many possible ways to prescribe resistance training programs designed to improve the health, autonomy and quality of life for older people, most result directly or indirectly in improvements to symptoms of anxiety and depression, regardless of the intensity and volume of the exercises involved, according to Edilson Cyrino, last author of the article and principal investigator for the study. He is a professor at the State University of Londrina (UEL) and coordinates the Active Aging Longitudinal Study, a project begun in 2012 to analyze the impact of resistance training on parameters relating to the health of older women.

Another point observed by the researchers was that the use of training machines and free weights appears to be more beneficial for mental health than exercises that involve elastic bands or calisthenics (using the weight of the person’s body), for example. 

“We don’t have statistics comparing the two kinds of training, but the analysis showed that resistance training with weights and other gear is more effective in terms of improving the mental health of older people, largely because the intensity and volume of the exercises can be more precisely controlled,” Cunha explained.

Keto diet improves severe mental illness says new research

A small clinical trial led by Stanford Medicine found that the metabolic effects of a ketogenic diet may help stabilize the brain.
A small clinical trial led by Stanford Medicine found that a ketogenic diet’s metabolic effects may help stabilize the brain.

For people living with serious mental illness like schizophrenia or bipolar disorder, standard treatment with antipsychotic medications can be a double-edged sword. While these drugs help regulate brain chemistry, they often cause metabolic side effects such as insulin resistance and obesity, which are distressing enough that many patients stop taking the medications.

Now, a pilot study led by Stanford Medicine researchers has found that a ketogenic diet not only restores metabolic health in these patients as they continue their medications, but it further improves their psychiatric conditions. The results,suggest that a dietary intervention can be a powerful aid in treating mental illness.

“It’s very promising and very encouraging that you can take back control of your illness in some way, aside from the usual standard of care,” said Shebani Sethi, MD, associate professor of psychiatry and behavioral sciences and the first author of the new paper.

The senior author of the paper is Laura Saslow, PhD, associate professor of health behavior and biological sciences at the University of Michigan.

Making the connection

Sethi, who is board certified in obesity and psychiatry, remembers when she first noticed the connection. As a medical student working in an obesity clinic, she saw a patient with treatment-resistant schizophrenia whose auditory hallucinations quieted on a ketogenic diet.

That prompted her to dig into the medical literature. There were only a few, decades-old case reports on using the ketogenic diet to treat schizophrenia, but there was a long track record of success in using ketogenic diets to treat epileptic seizures.

“The ketogenic diet has been proven to be effective for treatment-resistant epileptic seizures by reducing the excitability of neurons in the brain,” Sethi said. “We thought it would be worth exploring this treatment in psychiatric conditions.”

A few years later, Sethi coined the term metabolic psychiatry, a new field that approaches mental health from an energy conversion perspective.

Meat and vegetables

In the four-month pilot trial, Sethi’s team followed 21 adult participants who were diagnosed with schizophrenia or bipolar disorder, taking antipsychotic medications, and had a metabolic abnormality — such as weight gain, insulin resistance, hypertriglyceridemia, dyslipidemia or impaired glucose tolerance. The participants were instructed to follow a ketogenic diet, with approximately 10% of the calories from carbohydrates, 30% from protein and 60% from fat. They were not told to count calories.

“The focus of eating is on whole non-processed foods including protein and non-starchy vegetables, and not restricting fats,” said Sethi, who shared keto-friendly meal ideas with the participants. They were also given keto cookbooks and access to a health coach. 

The research team tracked how well the participants followed the diet through weekly measures of blood ketone levels. (Ketones are acids produced when the body breaks down fat — instead of glucose — for energy.) By the end of the trial, 14 patients had been fully adherent, six were semi-adherent and only one was non-adherent.

Feeling better

The participants underwent a variety of psychiatric and metabolic assessments throughout the trial.

Before the trial, 29% of the participants met the criteria for metabolic syndrome, defined as having at least three of five conditions: abdominal obesity, elevated triglycerides, low HDL cholesterol, elevated blood pressure and elevated fasting glucose levels. After four months on a ketogenic diet, none of the participants had metabolic syndrome.

On average, the participants lost 10% of their body weight; reduced their waist circumference by 11% percent; and had lower blood pressure, body mass index, triglycerides, blood sugar levels and insulin resistance.

“We’re seeing huge changes,” Sethi said. “Even if you’re on antipsychotic drugs, we can still reverse the obesity, the metabolic syndrome, the insulin resistance. I think that’s very encouraging for patients.”

The psychiatric benefits were also striking. On average, the participants improved 31% on a psychiatrist rating of mental illness known as the clinical global impressions scale, with three-quarters of the group showing clinically meaningful improvement. Overall, the participants also reported better sleep and greater life satisfaction.

“The participants reported improvements in their energy, sleep, mood and quality of life,” Sethi said. “They feel healthier and more hopeful.”

The researchers were impressed that most of the participants stuck with the diet. “We saw more benefit with the adherent group compared with the semi-adherent group, indicating a potential dose-response relationship,” Sethi said.

Alternative fuel for the brain

There is increasing evidence that psychiatric diseases such as schizophrenia and bipolar disorder stem from metabolic deficits in the brain, which affect the excitability of neurons, Sethi said.

The researchers hypothesize that just as a ketogenic diet improves the rest of the body’s metabolism, it also improves the brain’s metabolism.

“Anything that improves metabolic health in general is probably going to improve brain health anyway,” Sethi said. “But the ketogenic diet can provide ketones as an alternative fuel to glucose for a brain with energy dysfunction.”

Likely there are multiple mechanisms at work, she added, and the main purpose of the small pilot trial is to help researchers detect signals that will guide the design of larger, more robust studies.  

As a physician, Sethi cares for many patients with both serious mental illness and obesity or metabolic syndrome, but few studies have focused on this undertreated population.

She is founder and director of the metabolic psychiatry clinic at Stanford Medicine

“Many of my patients suffer from both illnesses, so my desire was to see if metabolic interventions could help them,” she said. “They are seeking more help. They are looking to just feel better.”

Walking, jogging, yoga and strength training ease depression

Even low intensity activities are beneficial, but the more vigorous the activity, the greater the benefits
Even low-intensity activities are beneficial, but the more vigorous the activity, the greater the benefits.

Walking or jogging, yoga and strength training seem to be the most effective exercises to ease depression, either alone or alongside established treatments such as psychotherapy and drugs, suggests an evidence review published by The BMJ today.

Even low-intensity activities such as walking or yoga are beneficial, but the results suggest that the more vigorous the activity, the greater the benefits are likely to be.

The authors stress that confidence in many of the findings remains low and more high-quality studies are needed, but they say these forms of exercise “could be considered alongside psychotherapy and drugs as core treatments for depression.”

The World Health Organization estimates that more than 300 million people worldwide have depression. Exercise is often recommended alongside psychotherapy and drugs, but treatment guidelines and previous evidence reviews disagree on how to prescribe exercise to treat depression best.

To address this uncertainty, researchers trawled databases looking for randomised trials that compared exercise as a treatment for depression with established treatments (eg, SSRI antidepressants, cognitive behavioural therapy), active controls (eg, usual care, placebo tablet), or untreated controls.



They found 218 relevant trials involving 14,170 participants with depression for analysis. Each trial was assessed for bias and the type, intensity and frequency of each exercise intervention was recorded.

Other potentially influential factors such as participants’ sex, age, baseline levels of depression, existing conditions, and differences between groups were also taken into account.

Compared with active controls, large reductions in depression were found for dance and moderate reductions for walking or jogging, yoga, strength training, mixed aerobic exercises and tai chi or qigong.

Moderate, clinically meaningful effects were also found when exercise was combined with SSRIs or aerobic exercise was combined with psychotherapy, suggesting that exercise could provide added benefit alongside these established treatments.

Although walking or jogging were effective for both men and women, strength training was more effective for women, and yoga or qigong was more effective for men. Yoga was also more effective among older adults, while strength training was more effective among younger people.

And while light physical activity such as walking and yoga still provided clinically meaningful effects, the benefits were greater for vigorous exercise such as running and interval training.

Exercise appeared equally effective for people with and without other health conditions and with different baseline levels of depression. Effects were also similar for individual and group exercise.

The authors acknowledge that the quality of evidence is low and very few trials monitored participants for one year or more. Many patients may also have physical, psychological, or social barriers to participation, they note.

Nevertheless, they suggest a combination of social interaction, mindfulness, and immersion in green spaces that may help explain the positive effects.

“Our findings support the inclusion of exercise as part of clinical practice guidelines for depression, particularly vigorous intensity exercise,” they say. “Health systems may want to provide these treatments as alternatives or adjuvants to other established interventions, while also attenuating risks to physical health associated with depression.”

“Primary care clinicians can now recommend exercise, psychotherapy, or antidepressants as standalone alternatives for adults with mild or moderate depression,” explains Juan Ángel Bellón at the University of Malaga in a linked editorial.

He points out that taking regular exercise can be challenging for people with depression and says studies using real world data are needed to evaluate physical activity programmes for people with depression.

He notes that the European Union has recently committed to promoting exercise across member states and urges health services and local and national administrations to “provide enough resources to make individualised and supervised exercise programmes accessible to the entire population.”