Yet another great BBC Horizon production presented by Michael Moseley. This time Dr Moseley is on a quest to find out more about personality. In part fueled by a desire to cure 20 years of chronic insomnia and to find out whether he can change his self-confessed pessimistic outlook on life. As a qualified doctor and BBC presenter I guess his pessimism hasn’t served him too badly so far!
In the 70s, Oxford Ohio was the seat of an interesting social experiment. People over 50 years old were questioned and followed over several years to learn more about aging. Professor Becca Levy (Yale University) analysed the data and found that it was in fact attitude that determined longevity. People with positive beliefs about aging live an average of 7.5 years longer than those with negative beliefs. They put it into context by noting that curing cancer would only add 3-4 years life expectancy.
One of the most important personality traits is whether we’re optimistic or pessimistic. Being pessimistic, anxious and neurotic affects our reaction to the world but how can we objectively measure this? Well, it’s been found that these traits lead to an increased activity of the right frontal cortex compared to the left. To measure this, Dr Moseley visited Professor Elaine Fox (University of Essex). It turned out he had 3 times more activity on the right than the left. His pessimism was confirmed! In addition, Prof Fox had him take a test to check his reaction time to dots on a screen. The dots were either preceded by an angry face or a happy face. His reaction time was a lot shorter when the dots were preceded by an angry face. Possibly because he had a habit of focusing more on the negative than the positive.
At MIT Professor Rosalind Picard asked him to wear a wristband whilst they had a chat. The wristband measured his skin temperature and electrical conductivity which are both affected by the autonomic nervous system and so gave a good indication of his emotional state. Dr Moseley’s baseline levels were high, suggesting heightened arousal, even though he felt relaxed. That’s because intriguingly, the body tells us about a change in state before the mind realises.
So now he had evidence indicating he was pessimistic and possibly a little anxious. What could he do about it? Professor Fox suggested using Cognitive Bias Modification (CBM). He simply had to look at screen shots of mainly unhappy faces and spot the one happy face…repeatedly. In theory this decreases the unconscious negative bias by breaking the habit of looking for the negative. Evidence has shown that it helps combat anxiety but not depression. Dr Moseley confided in being self- absorbed, worrying about the past, stressing about the future and as a result being unable to savour the present. So he decided to use CBM 3x/week for about 7 weeks.
His next encounter was with Andy Puddicombe, a former Buddhist monk, who now teaches mindfulness meditation. He said that 10-20 mins of meditation a day would be enough to make a psychological and physiological difference. MRI studies of meditators have shown they have increased grey matter in areas that regulate emotion and increased activity in the left prefrontal cortex which is a centre for positive emotions. The meditation he was taught consisted of focusing on breathing. With training, the mind wanders less down negative habitual routes. So in addition to his CBM training, Dr Moseley decided to do 7 weeks of daily mindfulness meditation.
How does our personality come about? Is it nature or nurture? Professor Tim Spector (King’s College London) has studied identical twins for over 20 years. He believes that 40-50% of personality is based on genetics. His study of discordant twins has revealed that genes can change through life! This is the fascinating field of epigenetics. Genes can be switched on or off by stressful life events. If they can change in one direction they can change in the other, which means we can regain control of our genes!
Professor Michael Meaney’s (McGill University) studies on mice have demonstrated that the effect of good maternal care (more contact, licking) protects rats from anxiety by modifying genes and these changes are transmitted through generations. The hippocampus controls stress, emotion and memory. Better mothering increases glucocorticoid receptors in this part of the brain.
After 7 weeks of CBM and mindfulness meditation Dr Moseley confessed he was sleeping better than he had in the last 10 years! He repeated the tests and measurements with professor Fox and found that he now had less than 2 times more activity in the right frontal cortex than the left. The activity in the right frontal cortex was half of what it previously was. His reaction time was now better when preceded by a happy face than an angry face, which suggested he may be noticing more of the positive in his daily life.
Another great programme from BBC Horizon presented by Dr Moseley. He starts off the programme by following the oldest man to complete the London marathon…a 101 yr old sikh who is healthy and takes no medication…the typical 65 yr old european takes 6 pills a day! The centenarian attributes his good health to his diet and more specifically his small portion size…about half of a normal adult”s.
This is not the first time that caloric restriction has been linked to longevity. In the 1930s, during the great depression in the US, although there were widespread food shortages…surprisingly life expectancy increased by 6 years. During the same period scientists at Cornell University found that animals on restricted diets lived longer.
Dr Moseley had a keen personal interest in the subject because of the threat of disease due to elevated blood sugar and cholesterol. He traveled the US speaking to the most eminent specialists in the field in a quest for a solution to his health problems. His first port of call was Professor Luigi Fontana from Washington University and Salerno Schools of Medicine. Prof Fontana advised a diet low in calories but high in nutrients and introduced Dr Moseley to Joe. Joe was in his 50s and had been on 1900 kcal/day for about 10 years. His body fat was 11.5% whereas Dr Moseley”s, also in his 50s, had a body fat % of about 27. Although the benefits were clear, Dr Moseley wanted to understand the mechanism in the hope of being able to draw the benefits without having to do any of the hard work! This is one of the reasons I like his programmes…his attitude is typical of the average european (or american)…we want results quickly, with as little effort as possible…sound familiar?
He then met up with Professor Valter Longo at the University of Southern California. Prof Longo showed him a special mouse…about half the size of a normal mouse…but incredibly it had a lifespan that was 40% longer…the equivalent of 120 human casino jameshallison years! The mouse had been genetically modified to have low levels of the a growth hormone called Insulin-like Growth Factor 1 (IGF1). IGF1 is thought to be the link between calorie restriction and longevity. There are about 350 people worldwide who have genetically inherited low levels of IGF1. Their condition is named Laron syndrome and although some of them smoke and eat what they want, amazingly they don”t get diabetes or cancer! Low levels of IGF1 seem to increase cell repair and decrease cell division (which probably accounts for their extremely small stature).
Protein has been found to increase our metabolism and put us in “go-go” mode but the downside is that it decreases cell repair. Three things can help decrease levels of IGF1: decreasing calorie intake, decreasing protein intake and lastly, the most effective way…is by fasting. Fasting can dramatically reduces levels of blood glucose and IGF1 within as little as 24 hrs. Obviously fasting can be dangerous and should only be undertaken if in good health and under close medical supervision. So Dr Moseley decided to give it a go for 3.5 days. He only allowed himself water, black tea and a 50 kcal soup each day. As expected, his blood sugar decreased significantly and his IGF1 levels halved. Unfortunately, the effects are only temporary and one would need to decrease protein intake and fast every couple of months to maintain changes…not for Dr Moseley, so he continued his search…
Dr Krista Varady from the University of Illinois at Chicago had a much more palatable proposition…eat as much of whatever you want on one day and eat a reduced amount of whatever you want the following day…feed day, fast day, feed day, fast day, etc. It”s called Alternate Day Fasting (ADF). On the fast days women are advised to eat 400-500 kcal and men 500-600 kcal. Preliminary trials with overweight subjects are showing promising results including weight loss, lower levels of bad cholesterol and fats in blood and decreased blood pressure.
Lastly, Dr Moseley paid a visit to Dr Mark Mattsen from the National Institute on Aging in Baltimore. He has conducted animal experiments on intermittent fasting and has found that it postpones the development of Alzheimer”s and senile dementia like diseases. Sporadic bouts of hunger seem to trigger the growth of new neurones! In evolutionary terms, this would have provided a survival advantage in times of famine. Intermittent fasting has better effects on the brain than daily calorie restriction. Dr Mattsen suggested alternating 5 days of normal eating with 2 days of fasting. So Dr Moseley gave it a go for 5 weeks. On the normal days her took in around 200 kcal and on the fast days he ate about 600 kcal. Please bear in mind that normal calorie intake is based on sex, height, weight and activity. The results were extremely impressive. He managed to lose 1 stone and decrease his body fat from 27% to 19%! His blood sugar levels decreased to within normal limits, his IGF1 levels halved, his total cholesterol decreased and his good cholesterol increased. I assume that although he could have eaten whatever he wanted, he was sensible about it.
Dr Moseley ended the programme by saying that it was “the most interesting journey that I”ve ever been on…and I”ve never said that before”.
Last year BBC Horizon created a documentary entitled ‘The Secret World of Pain‘. I watched it on YouTube a week ago, thought it was really well put together and so decided to share the most salient points.
Pain is one of our most ancient survival mechanisms and it protects and alerts us to danger. The SCN9A gene is responsible for regulating electrical signals that send pain sensation to the brain. Certain rare genetic disorders can prevent people from feeling pain…these unfortunate people are much more susceptible to burns and other injuries…this underlines just how crucial the sensation of pain is to us.
Pain can alert us to injury or potential injury, but why doesn’t it reflect the extent of injury…and why is it so subjective? There are a couple of possible reasons for this. Key experiences in early life have been found to be as important to pain perception as genetics. Early life is crucial for the formation of pain pathways which are shaped in response to touch. For example, premature babies are exposed to a lot more painful procedures and this alters the normal development of their pain pathways…the overdevelopment of pain pathways makes them hypersensitive and much more likely to experience pain in the future.
Pain and pleasure are both perceptions…psychological constructs…and so environment, context, decision-making, attention, distraction, motivation, emotion, etc can change how signals are processed and hence influence pain. There is a limit to how much information the brain can process at any one time…focussing attention on something pleasant (distraction) decreases the brain’s ability to process pain signals.
Subjects in an experiment were shown a triangle and exposed to a low temperature which they rated as 3/10 on a pain scale…this was repeated several times…they were then shown a square and exposed to a high temperature which they rated as 7/10 on a pain scale…this was repeated several times…they were then shown the square but exposed to the low temperature instead…surprisingly they rated the pain as 5/10. The researchers concluded that anxiety had affected their sensation of pain. I would add that expectation and conditioning may also have played a part.
Chronic pain is pain that persists long after an injury has healed…and therefore serves no purpose. It affects 1 in 5 people and is one of the biggest medical health problems. It can become an enormous burden on the brain and leads to chemical and structural changes. MRI scanning has revealed that people with chronic pain have less grey matter in the pre-frontal cortex. The answer to chronic pain may lie in reversing these changes. Encouragingly, electromagnetic impulses to the brain cortex have helped to normalise changes and to decrease pain, albeit temporarily. Research into this sort of treatment is extremely promising but still in its infancy.
Last month BBC Horizon ran a programme entitled “The Truth About Exercise”. In it Dr Michael Mosley travelled the country speaking to an assortment of Exercise Scientists. One of the first points made was that it takes a lot of exercise to burn calories. In fact, the example provided was that to burn off a cappuccino, a blueberry muffin and a banana, one would have to jog around a track for about 55 mins! Therefore, to stand any chance of losing weight, we must control what we eat.
Fortunately, exercise can have benefits even when no weight is lost. One of the benefits mentioned was the production of an enzyme that helps redistribute fat in the body and sends it to the muscles where it’s burned. This helps reduce the chance of getting atherosclerosis and possibly death from cardiovascular disease. Other health factors that can be improved are insulin sensitivity and the body’s maximum oxygen consumption (VO2 max). Insulin sensitivity is important because it means that blood glucose levels can decrease more rapidly thereby requiring less secretion of insulin by the pancreas. This reduces the likelihood of developing Type 2 diabetes. As for VO2 max, it’s been found to be a good marker of health and longevity.
Next, Dr Mosley met Jamie Timmons, professor of ageing biology at Birmingham University, and was told how training for 7 mins 3 times a week could deliver many of the health and fitness benefits of hours of conventional exercise! The training is called High Intensity Training (HIT) and resembles interval training. Interval training has been around for a long time and has been used by athletes to increase cardiovascular efficiency and increase tolerance to the build-up of lactic acid. The HIT protocol used on the programme was done on a static bike and consisted of: 2 mins warm-up, 20 secs full-out, 2 mins gentle, 20 secs full-out, 2 mins gentle and 20 secs full-out. This added up to a whopping 7 mins and was done 3 times a week for 4 weeks. It’s thought that this type of exercise can appeal to those that are time poor and need to get it done quickly or simply don’t enjoy it and so want to get it over and done with swiftly…hmmmmmm? It’s at this point that I became curious about exactly how many people fell into this category…so I did a little survey among some of my clients.
First I asked them whether they did any exercise or took part in any sports. Amazingly 95% of them did!
I then asked them how many times a week they exercised or took part in sports. Again I was surprised…an average of 3.6 times a week. I started wondering whether they were trying to please or impress me? Apparently 80% of the population doesn’t exercise regularly!
Finally, I asked them why they exercised? This was the last curveball…the most popular answer was because they enjoyed it…it made them feel good! Other popular reasons were for fitness, health (hypertension, diabetes, back pain) and weight loss.
So unfortunately there didn’t seem to be any takers for HIT. The claims are that HIT can give around 24% improvement in insulin sensitivity and 10% increase in VO2 max. After 4 weeks Dr Moseley did in fact improve his insulin sensitivity by exactly 24% but had no change in his VO2 max. His inability to improve his VO2 max was put down to genetics. According to Timmons, research has shown that 20% of the population doesn’t respond to endurance training.
What do I think about the HIT programme? Well, it paints exercising as a chore, but as the survey showed, most people get more from exercise or sports than just an improved insulin sensitivity…they enjoy it, it makes them feel good…possibly because of the endorphin release or a sense of achievement or accomplishment, maybe even because of social interactions? The HIT programme didn’t place much emphasis on fitness but other HIT protocols have. Gibala’s studies have shown benefits but his protocol was longer and a lot more gruelling…definetly not for everyone. There are many components to fitness: endurance, strength, flexibility, speed, agility, etc and I suppose people in the survey were happy to focus on particular aspects of this.
My main issue with the HIT protocol is its intensity. Pedalling “hell for leather” without a warm-up (not one that can be recognised as one anyway!) seems like a recipe for disaster. As a physiotherapist, I was a little uneasy watching Dr Moseley bounce around on his bike whilst pedalling as hard as he could for 20 secs…he should have known better after pulling a hamstring earlier in the programme when trying to sprint without any earlier warm-up…who knows, he may have felt comfortable doing it because he was surrounded by scientists? Surely this is not something that should be recommended to the sedentary masses?
The main drive of the HIT protocol seemed to be on health (primarily insulin sensitivity) and I think there are better, safer and more convenient ways of achieving this. New research published in the journal Diabetes Care has concluded that after meals, regular short bouts of light-intensity or moderate-intensity walking lower glucose and insulin levels. The subjects were asked to walk around for 2 mins every 20 mins. The light intensity walking decreased blood glucose and insulin levels by 24% compared to uninterrupted sitting. That figure is exactly the same as the one achieved by Dr Moseley after the HIT protocol.
If you enjoy exercise or sport and are happy with the fitness you’re achieving, keep it up! If you don’t enjoy exercise or sport and are mainly doing it for health or weight loss, you’re unlikely to keep going very long. My advice would be to focus on increasing your movement through activities of daily living…this was also talked about on Horizon but it seemed to get much less attention than HIT…in my opinion it’s where the real revolution lies…check in next week to find out more…