Research over the years has suggested intermittent fasting has the potential to improve our health and reduce the likelihood of developing cancer.

So what should we make of a new study in mice suggesting fasting increases the risk of cancer?

What is intermittent fasting?

Intermittent fasting means switching between times of eating and not eating. Unlike traditional diets that focus on what to eat, this approach focuses on when to eat.

There are lots of commonly used intermittent fasting schedules. The 16/8 plan means you only eat within an eight-hour window, then fast for the remaining 16 hours. Another popular option is the 5:2 diet, where you eat normally for five days then restrict calories for two days.

In Australia, poor diet contributes to 7% of all cases of disease, including coronary heart disease, stroke, type 2 diabetes, and cancers of the bowel and lung. Globally, poor diet is linked to 22% of deaths in adults over the age of 25.

Intermittent fasting has gained a lot of attention in recent years for its potential health benefits. Fasting influences metabolism, which is how your body processes food and energy. It can affect how the body absorbs nutrients from food and burns energy from sugar and fat.

What did the new study find?

The new study, published in Nature, found when mice ate again after fasting, their gut stem cells, which help repair the intestine, became more active. The stem cells were better at regenerating compared with those of mice who were either totally fasting or eating normally.

This suggests the body might be better at healing itself when eating after fasting.

However, this could also have a downside. If there are genetic mutations present, the burst of stem cell-driven regeneration after eating again might make it easier for cancer to develop.

Polyamines – small molecules important for cell growth – drive this regeneration after refeeding. These polyamines can be produced by the body, influenced by diet, or come from gut bacteria.

The findings suggest that while fasting and refeeding can improve stem cell function and regeneration, there might be a tradeoff with an increased risk of cancer, especially if fasting and refeeding cycles are repeated over time.

While this has been shown in mice, the link between intermittent fasting and cancer risk in humans is more complicated and not yet fully understood.

What has other research found?

Studies in animals have found intermittent fasting can help with weight loss, improve blood pressure and blood sugar levels, and subsequently reduce the risks of diabetes and heart disease.

Research in humans suggests intermittent fasting can reduce body weight, improve metabolic health, reduce inflammation, and enhance cellular repair processes, which remove damaged cells that could potentially turn cancerous.

However, other studies warn that the benefits of intermittent fasting are the same as what can be achieved through calorie restriction, and that there isn’t enough evidence to confirm it reduces cancer risk in humans.

What about in people with cancer?

In studies of people who have cancer, fasting has been reported to protect against the side effects of chemotherapy and improve the effectiveness of cancer treatments, while decreasing damage to healthy cells.

Prolonged fasting in some patients who have cancer has been shown to be safe and may potentially be able to decrease tumour growth.

On the other hand, some experts advise caution. Studies in mice show intermittent fasting could weaken the immune system and make the body less able to fight infection, potentially leading to worse health outcomes in people who are unwell. However, there is currently no evidence that fasting increases the risk of bacterial infections in humans.

So is it OK to try intermittent fasting?

The current view on intermittent fasting is that it can be beneficial, but experts agree more research is needed. Short-term benefits such as weight loss and better overall health are well supported. But we don’t fully understand the long-term effects, especially when it comes to cancer risk and other immune-related issues.

Since there are many different methods of intermittent fasting and people react to them differently, it’s hard to give advice that works for everyone. And because most people who participated in the studies were overweight, or had diabetes or other health problems, we don’t know how the results apply to the broader population.

For healthy people, intermittent fasting is generally considered safe. But it’s not suitable for everyone, particularly those with certain medical conditions, pregnant or breastfeeding women, and people with a history of eating disorders. So consult your health-care provider before starting any fasting program.

Amali Cooray, PhD Candidate in Genetic Engineering and Cancer, WEHI (Walter and Eliza Hall Institute of Medical Research)

This article is republished from The Conversation under a Creative Commons license. Read the original article.

While many people maintain positive emotional wellbeing as they age, around half of older Australians living in residential aged care have significant levels of depression. Symptoms such as low mood, lack of interest or pleasure in life and difficulty sleeping are common.

Rates of depression in aged care appear to be increasing, and without adequate treatment, symptoms can be enduring and significantly impair older adults’ quality of life.

But only a minority of aged care residents with depression receive services specific to the condition. Less than 3% of Australian aged care residents access Medicare-subsidised mental health services, such as consultations with a psychologist or psychiatrist, each year.

Instead, residents are typically prescribed a medication by their GP to manage their mental health, which they often take for several months or years. A recent study found six in ten Australian aged care residents take antidepressants.

While antidepressant medications may help many people, we lack robust evidence on whether they work for aged care residents with depression. Researchers have described “serious limitations of the current standard of care” in reference to the widespread use of antidepressants to treat frail older people with depression.

Given this, we wanted to find out whether psychological therapies can help manage depression in this group. These treatments address factors contributing to people’s distress and provide them with skills to manage their symptoms and improve their day-to-day lives. But to date researchers, care providers and policy makers haven’t had clear information about their effectiveness for treating depression among older people in residential aged care.

The good news is the evidence we published today suggests psychological therapies may be an effective approach for people living in aged care.

We reviewed the evidence

Our research team searched for randomised controlled trials published over the past 40 years that were designed to test the effectiveness of psychological therapies for depression among aged care residents 65 and over. We identified 19 trials from seven countries, including Australia, involving a total of 873 aged care residents with significant symptoms of depression.

The studies tested several different kinds of psychological therapies, which we classified as cognitive behavioural therapy (CBT), behaviour therapy or reminiscence therapy.

CBT involves teaching practical skills to help people re-frame negative thoughts and beliefs, while behaviour therapy aims to modify behaviour patterns by encouraging people with depression to engage in pleasurable and rewarding activities. Reminiscence therapy supports older people to reflect on positive or shared memories, and helps them find meaning in their life history.

The therapies were delivered by a range of professionals, including psychologists, social workers, occupational therapists and trainee therapists.

In these studies, psychological therapies were compared to a control group where the older people did not receive psychological therapy. In most studies, this was “usual care” – the care typically provided to aged care residents, which may include access to antidepressants, scheduled activities and help with day-to-day tasks.

In some studies psychological therapy was compared to a situation where the older people received extra social contact, such as visits from a volunteer or joining in a discussion group.

What we found

Our results showed psychological therapies may be effective in reducing symptoms of depression for older people in residential aged care, compared with usual care, with effects lasting up to six months. While we didn’t see the same effect beyond six months, only two of the studies in our review followed people for this length of time, so the data was limited.

Our findings suggest these therapies may also improve quality of life and psychological wellbeing.

Psychological therapies mostly included between two and ten sessions, so the interventions were relatively brief. This is positive in terms of the potential feasibility of delivering psychological therapies at scale. The three different therapy types all appeared to be effective, compared to usual care.

However, we found psychological therapy may not be more effective than extra social contact in reducing symptoms of depression. Older people commonly feel bored, lonely and socially isolated in aged care. The activities on offer are often inadequate to meet their needs for stimulation and interest. So identifying ways to increase meaningful engagement day-to-day could improve the mental health and wellbeing of older people in aged care.

Some limitations

Many of the studies we found were of relatively poor quality, because of small sample sizes and potential risk of bias, for example. So we need more high-quality research to increase our confidence in the findings.

Many of the studies we reviewed were also old, and important gaps remain. For example, we are yet to understand the effectiveness of psychological therapies for people from diverse cultural or linguistic backgrounds.

Separately, we need better research to evaluate the effectiveness of antidepressants among aged care residents.

What needs to happen now?

Depression should not be considered a “normal” experience at this (or any other) stage of life, and those experiencing symptoms should have equal access to a range of effective treatments. The royal commission into aged care highlighted that Australians living in aged care don’t receive enough mental health support and called for this issue to be addressed.

While there have been some efforts to provide psychological services in residential aged care, the unmet need remains very high, and much more must be done.

The focus now needs to shift to how to implement psychological therapies in aged care, by increasing the competencies of the aged care workforce, training the next generation of psychologists to work in this setting, and funding these programs in a cost-effective way.

Tanya Davison, Adjunct professor, Health & Ageing Research Group, Swinburne University of Technology and Sunil Bhar, Professor of Clinical Psychology, Swinburne University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.