Chloe Lambert meets the man combining mainstream medicine treatments with fasting and forest bathing.
Dr Andreas Michalsen was a successful young cardiologist at one of Berlin's busiest hospitals. He specialised in emergency and critical care medicine, publishing respected papers on heart failure. A glittering career lay ahead, but he was already growing disillusioned.
Michalsen felt the world was entering a "crisis in medicine", fuelled by stress, poor diets and sedentary lifestyles, which his profession was ultimately treating with a sticking plaster: "I was doing a lot of expensive and painful interventions, which the data told me would not lead, in the end, to a real, significant improvement in health," he recalls.
To the derision of his colleagues, he decided to train in natural medicine. Today, as professor of clinical naturopathy at Berlin's Immanuel Hospital and the Charite, the largest university hospital in Europe, he applies his dual training to thousands of patients with a wide range of diseases. Alongside surgery, chemotherapy and modern pharmaceuticals, patients at the Charite receive acupuncture, forest bathing and therapeutic fasting. And as interest in alternative medicine grows, so do the waiting lists.
Alongside his reputation for natural medicine, Michalsen, whose book The Natural Prescription was a number one bestseller when released in Germany in 2017, is considered a world leader in fasting. Believing it to be far more than a weight-loss method, he prescribes it for conditions ranging from diabetes to migraines to arthritis. He is even investigating whether fasting may aid the treatment and prevention of cancer, having shown that patients who undergo a short fast before chemotherapy tolerate it better. His theory is that when temporarily deprived of energy, cells may enter "a state of hibernation... which can protect them like a shield from external attacks".
Regardless of your weight, Michalsen says fasting - by regularly cutting out breakfast or dinner - is one of the best things a person can do to delay ageing and protect themselves against disease.
"There is now a body of research that underlines that periods of restricted eating are a recovery for the body. Stem cell production, hormone regulation, our metabolic systems - they all recover when we introduce this technique into our life."
It's also, he says, an excellent way to break the bad habits so many of us have fallen into, such as snacking and constant overeating, and to rediscover what hunger is.
In his book, Dr Michalsen makes a passionate case for mainstream and complementary medicine working in synergy rather than opposition. Not only is this how more and more patients want to be treated, he says - it's also the only way we'll meet the challenge of increasing life expectancy in the developed world.
"Conventional medicine is very successful in treating acute diseases like heart attacks or trauma," he says.
"But about 60 to 80 per cent of the medical burden is now caused by chronic disease - osteoarthritis, diabetes, hypertension - and here it is not as successful.
"It leads to escalating costs, escalating use of medication, and it's no solution for the patient.
"What we are doing in Berlin is reintegrating [complementary treatment] into the system."
As ageing populations place more pressure on hospitals and concerns grow over the overuse of medications such as statins, calls for a more holistic approach to health are increasing. In December, MPs in the All-Party Parliamentary Group for Integrated Healthcare published a report warning that chronic illnesses could cripple the UK's National Health Service unless the service began to embrace more natural alternatives.
Meanwhile, ancient practices such as yoga and meditation are soaring in popularity, along with an increased appetite for healthy diets: recently, the BBC news presenter Jane Hill, 50, said that regular exercise and a diet rich in broccoli had helped her to recover after breast cancer.
"I have, as it happens, done all the right things for about 25 years," she said.
"When I told some of my friends I had been diagnosed with breast cancer, I used a lot of black humour - what was the point of eating all that broccoli for 25 years? How ridiculous - I don't even like broccoli.
"But, oh my goodness, I hadn't realised the difference it would make going into such a big operation."
She said a nurse who checked her post-operative scars was amazed by how quickly they had healed "and she said that's about going into [an operation] in pretty good shape so I'm very glad I ate all that broccoli".
Michalsen still believes passionately in the power of conventional medicine; his past medical life in cardiology has seen to that. He stresses that alternative therapies are, for the majority, given as an addition to, rather than a replacement for mainstream treatments - and that his team continues to apply the rigorous, data-based approach they were taught to use in their training.
"There isn't much money for funding research in this field, but for all the treatments we apply we expect that they have at least some early data, a sound theory behind them, and they must be safe."
He is all too aware that many alternative therapists do not follow such standards, advocating dangerous and unproven "cures" and leading vulnerable patients to become paranoid about mainstream medicine.
"The main problem is that complementary medicine is not integrated into academic, university medicine, so a lot of treatments are proposed which are not scientifically sound.
"We do a lot of research, and if we see in our medical application that a treatment is not working, we don't use it anymore."
The answer to the problem of quack cures and anti-vaxxers, he says, is greater respect and co-operation between alternative and mainstream doctors.
"People have an interest in natural medicine, but when they go to their doctor they are told it's rubbish, so they don't feel heard and may develop strange ideas, for example about vaccinations.
"When cancer patients come to us, for example, and say, 'I don't want chemotherapy, it's toxic', we tell them: 'It's good for you, please do it.' As it's us saying it, they do. They see there's no opposition, there's a balance."
Above all, he believes doctors need to listen more, to negotiate with patients and offer an individualised treatment plan.
"Take high blood pressure. I say to patients, we have wonderful, highly effective medications and there's no problem if you're taking two or three of them. But we can also do a periodic fasting treatment and you can change to a plant-based diet, which will probably have the effect of one or two of the drugs, so you can cut down on them. But you have to do it. You have to decide."
Some of the practices explored in Michalsen's book are eyebrow-raising: he praises herbal remedies, bloodletting and cupping, for example, and makes the case for placebo healing.
He acknowledges there is much more work to do to establish the true value of these practices but says he is optimistic that many of the alternative treatments he is studying will find their way into the mainstream doctor's toolkit.
"We need to understand that there is a way to improve health, without MRIs, without surgery, without medication - with natural biology." The path to 21st-century medicine, he believes, begins with doctors denouncing their prejudices and "listening to each other".
• The Natural Prescription by Andreas Michalsen (RRP £16.99).
Dr Michalsen's prescription for good health
Michalsen recommends either a fast of about five days once or twice a year, or regular time-restricted eating - omitting dinner or breakfast so that you don't eat anything for at least 14 hours. In general, he says, we should only eat when truly hungry and abstain from snacks. Anyone considering trying it for the first time should seek medical supervision, he adds.
Michalsen points to research which shows just 90 seconds spent looking at a green, natural landscape has a significant stress-reducing effect.
Yoga and tai chi
Though any form of regular exercise is excellent for health, he says yoga is particularly beneficial for stress reduction - reducing blood pressure - and is a natural way to treat back pain and neck pain.
A plant-based diet
Eat as little fast food as possible and follow a diet rich in berries, fruits and vegetables, especially leafy greens, nuts and seeds, whole grains, beans, peas and lentils and spices.
A daily cold shower - turning the temperature to cold at the end of your regular warm shower for one to two minutes - boosts immunity and aids sleep. "It's hard at the beginning but it gets easier and increases your vitality very nicely," says Michalsen.