Team McCallum

R&D for Lifetime of Life

Walking v diabetes+.

Dr Terry Dwyer and colleagues have found that walking cuts the risk of diabetes in a study of 600 adults in Tasmania. While the team focussed on diabetes, the results suggest a protective effect against metabolic syndrome and cardiovascular disease.

Roughly 600 adults aged around 50 in 2000 were tracked for 5 years.  At the start, most were overweight or obese and as a whole, the group gained weight over the period.

The volunteers were fitted with pedometers for 2 days in 2000. One finding was that those with higher daily step counts at this start time ended with a better body mass index (BMI), better waist to hip ratio and better insulin sensitivity, compared to those less active.

After 5 years, the group wore pedometers for another 2 days. As a whole, the group gained weight and became less active.  However, one third stayed active or increased their steps in the period, and again these were the ones with better measures on BMI, waist-hip ratio and insulin sensitivity.

The following figures are for those walking 10,000 steps, which is about 5 miles or 8km.

For a person of average height, weight dropped was just under 3kg, or about 6lbs. This corresponds to a BMI reduction of 0.83kg/metre squared. Insulin sensitivity increased by about 12%, with men doing slightly better than women.

These results are all ‘dose-dependent’. In other words, walking less still resulted in some improvements.

When the researchers factored in BMI, the differences between those active and those not disappeared, so the team attributed the improvement to a cut in body fat.

The researchers were looking at diabetes, and the improvement in insulin sensitivity would result in a considerably reduced risk of the disease.

The figures also strongly suggest there would be an improvement in other diseases linked to BMI and larger waists, including high blood pressure, metabolic syndrome, cardiovascular disease and more.

The impact on the waist is interesting, since fat stored around the waist is linked to adiposopathy (sick fat), and this study suggests that walking is a way to burn ‘sick’ fat preferentially to ‘healthy’ fat, reducing the waist to hip ratio.

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January 17, 2011 Posted by | Accelerometer, Activity, Adiposopathy - sick fat, Aging, BMI - body mass index, CVD - cardiovascular disease, Diabetes, Exercise, High blood pressure, Metabolic syndrome, Success, Waist circumference, Walking, Weight management | Leave a comment

Udiet: the battlefield.

2010 was stuffed with debate over the reasons why people in developed countries are getting heavier.

 The most simplistic explanations focussed on overeating, or inactivity, or both. HFCS (high fructose corn syrup) also came in for a beating. The problem with this is that Europe imports very little HFCS, but countries in Europe are reporting more and more problems associated with obesity.

 www.obesitymyths.com comes up with a much larger range of interesting possibilities. But in 2005, the New York Times linked this site to sponsorship from fast food producers such as Coca-Cola and McDonald’s, in this article.

Two reputable groups of scientists published work where they found that the mantra of ‘eat less and exercise more’ doesn’t cover all of the potential reasons.

 A government group in the UK called Foresight was asked to predict what will happen there over time, based on best evidence, and building in realistic assumptions. In order to do so, they had to scour published research to identify the drivers of obesity and build a very detailed model of which drivers are most important. Written in simple English, this is probably the best explanation there is of the obesity epidemic.

The full report is available as a free PDF download here. However, at over 160 pages, it won’t be everyone’s cup of tea.

The second group of scientists published a summary of obesity drivers in November 2009. Again, this is available free using this link.

Their findings outline the battlefield for the Udiet.

1. Overeating, particularly re heavily marketed energy dense foods.

2. Underactivity, again with an organisation driver behind it.

3. Infection caused by bacteria and viruses.

4. Epigenetics, whereby prenatal and early postnatal exposure to the environment alters how genes are expressed without changing the genes. For example, babies born very underweight at birth who are incubated and fed rich diets to catch up weight have a higher risk of obesity and associated issues later in life.

5. Increasing maternal age. Animal studies have shown that babies born to older mothers are fatter than those born to younger mothers.

6. BMI breeding effect. Studies have found that those with a body mass index somewhat above average are producing slightly more children, on average, than the rest of the population, causing the population BMI to increase over time.

7. Assortitative mating is taking place. This hypothesis is that those with higher BMI prefer partners of similar kind, and due to the genetic effect, this leads to even heavier children. A wide range of population studies support this idea.

8. Sleep debt is happening, and leads to increased eating, increased fat deposition and lowered activity. Research shows metabolic changes occur to support this, and also leads to higher risk of diabetes and heart disease. For example, one study shows that getting one and a half hours less sleep than ideal over a two week period results in a diabetic-like profile for glucose and insulin.

9. Endocrine disruptors interfere with estrogen and androgen signalling, and have been building up in the human environment for some time.  These have been found to be involved in obesity in animals and in humans.

10. Commonly used medicines are known to contribute to weight gain. These include medicines for diabetes, high blood pressure, steroids, contraceptives, and anti-histamines.

11. Artificial ambient temperature. The hotter your environment, the less energy you burn keeping warm. The UK home went from 13 centigrade in 1970 to 18 centigrade by 2000. US homes went from 18 centigrade in 1923 to nearly 25 centigrade in 1986.

12. Mothers input. The state of the mother’s glucose and insulin handling systems directly affect the number of fat cells and the fat cell content of the baby.

13. Reduction in smoking rate. The scientists considered this so well documented they excluded it from their list.

14. Altered US demographics. A 2006 article along the same lines had found that alterations in the US population were increasing the races which tend toward higher BMI, therefore  increasing the average BMI of the nation.

The aim of the scientists’ report was not to remove the first two reasons from focus, but to show that the battlefield is considerably more complex than simply food and exercise.

These 14 points are not comprehensive. For example, other researchers have found that altering the circadian rhythm, by staying up late in artificial light and not synchronising your body clock to early morning light, is also a risk factor for weight gain. Also, breastfeeding v formula milk wasn’t mentioned, although formula milk is associated with higher risk of obesity.

January 9, 2011 Posted by | Activity, BMI - body mass index, Breastfeeding, Child Health, CVD - cardiovascular disease, Diabetes, Environment, Epigenetics, Exercise, HFCS - high-fructose corn syrup, High blood pressure, Obesity, Pregnancy, Pregnancy, Success, Thermogenesis, UK, United States, Weight management | Leave a comment

How smart is your dog?

John W Pilley and Alliston K Reid decided they would like to find out how much a dog can learn, given extensive training over a long period. The dog in question was a border collie called Chaser. Pilley and Reid couldn’t find Chaser’s limit after 3 years, when the dog could remember the names of over a thousand different objects and was still learning new ones.

The 1,022 objects were toys that Chaser used, each with a different name. However, Chaser also understood verbs, so the dog could combine the correct object with what was supposed to be done with that toy.

Further, Chaser understood a few groups. For example, there were objects that collectively could be referred to as balls, while others fell into the frisbee group.

Finally, Chaser could remember, at least for a short while, that a particular toy was excluded from the group to which it apparently belonged. For example, a particular ball was not to be counted as a ball. This remembering for a short time then forgetting is displayed by children when they learn.

As noted, Pilley and Reid did not find Chaser’s limit. They simply stopped trying to find it after the 3 years was up.

The other point of interest is that these things were toys to Chaser – fun, enjoyment, a real incentive to learn, and this be the main carry over message for humans.

But the next time you talk to your dog just be aware that the dog may understand more than you think.

January 9, 2011 Posted by | Activity, Brain, Exercise, Fun, Health, Language, Learning, Nature, Psychology, Success | Leave a comment

Preventing falls in older adults.

The US Preventive Services Task Force is reviewing its recommendations on primary care and preventing falls in the elderly. A team of scientists has analysed extensive research studies to conclude that vitamin D supplements and exercise are the top treatments.

The report in the Annals of Internal Medicine shows that the team evaluated nearly 3,500 published studies to identify good quality randomised control trials that related to primary care interventions for falls in elderly adults living in the community. Amongst other results, they ended up with 16 studies relating to exercise and 9 relating to vitamin D.

The exercise trials included gait, balance, or functional training, typically along with strength, resistance, or general exercise.

The exercise studies averaged a 13% reduction in the risk of falls, while the vitamin D trials averaged a 17% reduction.

Other approaches such as vision correction, medication assessment, home-hazard modification, and behavioral counseling weren’t found to be effective in reducing falls.

December 23, 2010 Posted by | Aging, Exercise, Health, Success, Vitamin D | Leave a comment

Preventing Alzheimer’s?

Earlier in 2010 TeamMcCallum published research showing that beetroot juice lowered high blood pressure. The mechanism was that beetroot is rich in nitrate, bacteria on the tongue convert this to nitrite, which in turn gets converted to nitric oxide. The nitric oxide dilates blood vessels and so lowers blood pressure.

Now Dr Zvonimir S Katusic and team from the Mayo Clinic in Rochester, Minnesota, have researched the apparent risk link between cardiovascular disease (CVD) and Alzheimer’s. The study involved looking at the function of the lining of blood vessels (endothelium) in the brain.

First, the team inhibited the generation of nitric oxide by the vessels. This triggered a series of events that led to increased production of the amyloid precursor protein (APP), and an enzyme that normally cuts APP up so it can be disposed of. This increase in production/disposal led to an increase in the production of beta-amyloid plaque, one of the two major things seen in Alzheimer’s.

They checked the result in mice bred to be deficient in production of nitric oxide. These mice are insulin-resistant and have high blood pressure. The results were the same – more APP, more enzyme to chop it up, and more beta-amyloid plaque production.

According to one of the team “On the cardiovascular side we’ve known for some time that preservation of healthy endothelium is critical to prevent major cardiovascular events. Now it seems this may have important implications for cognitive impairment.”

Risk factors for CVD (high cholesterol, diabetes, high blood pressure, smoking, sedentary lifestyle and aging) have all been associated with inability of the endothelium to produce enough nitric oxide. Now they are linked by this research to Alzheimer’s.

This explains the protective effect of, say, exercise. And beetroot juice too!

December 4, 2010 Posted by | Aging, Alzheimer's, Cholesterol, Cognitive decline, CVD - cardiovascular disease, Exercise, High blood pressure, Obesity, Smoking, Success | 1 Comment

Exercise v diabetes.

Dr Timothy S Church reported in the Journal of the American Medical Association that a combination of resistance and aerobic exercise of around 140 minutes per week was successful in improving a key marker in type 2 diabetics already on medication.

262 sedentary men and women, average age 56, were randomly allocated to one of – a control group (no exercise), resistance training, aerobic training, and combined resistance and aerobic training.

The resistance training group exercised 3 times a week. The aerobic group did enough exercise to burn 12 kcal per kilo of bodyweight per week. The combined group did aerobics to expend 10 kcal per kilo per week plus 2 sessions of resistance training, which totalled around 140 minutes. This is fairly close to 2008 guidelines of 150 minutes of exercise per week.

The program ran for 9 months, and medicine continued to be used as prescribed by a physician.

Compared to controls, the other groups decreased waist circumference by around and inch. The resistance training group lost 3.1 lbs of fat, while the combination group lost 3.7 lbs of fat (both retaining lean tissue unchanged).

The key outcome measure was glycated hemoglobin (HbA1C). This is a measure of the long term average level of blood sugar.

While the resistance-only and aerobics-only groups had lower values of HbA1C than controls, these were not great enough to be statistically significant, so these forms of exercise on their own don’t have enough impact.

For the combined exercise group, the cut in HbA1C compared to controls was big enough to be significant. This supports the 2008 guidelines, that a mix of both at around 150 minutes per week is beneficial.

During the study, the control group increased its use of diabetic medicines, while in the combined exercise group the use of medication to treat diabetes dropped.

November 26, 2010 Posted by | Diabetes, Exercise, Success, Waist circumference, Weight management | Leave a comment

What you should know about SICK fat.

The International Journal of Clinical Practice is running a special section in its December issue covering male health. Dr Harold E Bays, Dr Joseph M Gonzalez-Campoy, and Dr Alan B Schorr, 3 experts in metabolic syndrome and related conditions, have written a reference summary on the topic.

It is called “What men should know about metabolic syndrome, adiposopathy and ‘sick fat’, but it also covers women. So it’s really a summary of adiposopathy, where ‘adiposo’ means fat, and ‘pathy’ means sick or diseased, hence SICK FAT.

The article is free, and quite short, but it is fairly technical.

In simple English, the 3 doctors are suggesting that metabolic syndrome is a rather loose term covering a series of problems that lay people understand better in other terms – high blood pressure, blood fats that are wrong, blood sugar level wrong, type 2 diabetes and increased risk of cardivascular disease (CVD) and other illnesses.

The first key point is that fat is not an inactive store of calories. It has a wide range of hormonal functions essential for human health. So there is ‘good’ fat.

However, visceral fat (that stored around the organs inside the abdomen) can turn from healthy fat into sick fat (adiposopathy). Sick visceral fat does not look like or work like healthy visceral fat. When it turns sick, it churns out a range of inflammatory substances, increases blood pressure and unbalances a range of hormones.

It decreases testosterone levels in men and increases them in women, closing the gender gap. “One of the biochemical consequences of obesity is often a closer approximation of the genders with regard to sex hormone levels.”

There is a quick review of all the major treatments for metabolic syndrome diseases, ranging from exercise and good diet through all the major medications to bariatric surgery (stomach bypass or banding). This shows the impact on blood sugar levels, blood pressure and blood fat profiles work similarly across all.

The experts then discuss which path is wiser – treating the results of sick fat, or curing the sick fat. They concluded “An emerging concept is that the development of antiobesity agents must not only reduce fat mass (adiposity) but must also correct fat dysfunction (adiposopathy).”

They conclude that scientists have known about the disease-causing potential of fat for more than 50 years, but that it is only in the last 10 years that fat has been thought of as being a major active component in the human hormone system.  “Clinicians may find that: ‘A discussion as to how increasing body weight may cause their fat to becomesick,or how losing body weight may cause their fat to becomehealthier, might be better than discussing the diagnostic components defining themetabolic syndrome.’”

The only notable omissions from an excellent round-up are – why visceral fat turns sick in the first place – and – whether there is a smarter or faster way to cure sick fat than simply overall weight loss.

Our recent articles on fructose (in the form of pure fruit drinks) and sugar-sweetened beverages suggest that both dump in more fructose than the body can handle at one go. This suggests one trigger for making it sick, and one way to cure it faster, though this is unlikely to be the only cause/cure.

Click here for a full copy of the article by the 3 doctors.

November 15, 2010 Posted by | Adiposopathy - sick fat, CVD - cardiovascular disease, Diabetes, Diet, Exercise, Gastric banding, Health, HFCS - high-fructose corn syrup, High blood pressure, Metabolic syndrome, Obesity, Soft drinks, Success, Weight management | Leave a comment

Pay attention to be happy?

What’s the recipe for being happy? The media have recently reported that research shows when our minds wander we tend, on average, to be unhappy. So should we simply pay attention to improve our happiness? The same research shows the answer is most definitely not. And buried in the detail is what we should really do for more happiness.

According to Matthew A Killingsworth and Prof Daniel T Gilbert, both of Harvard University, as published in Science, “We developed a smartphone technology to sample people’s ongoing thoughts, feelings, and actions and found (i) that people are thinking about what is not happening almost as often as they are thinking about what is and (ii) found that doing so typically makes them unhappy.”

2,250 people took part. Their smart phone went off and they answered whether they were focussed, or if they weren’t, whether they were happy, neutral or sad. Plus they said what they were doing.

Just under half had minds-a-wandering when phoned. Out of 22 possible activity answers, 21 resulted in thinking of other things at least 30% of the time.

The only exception was sex. When people who were involved in sex were phoned – at least of those who actually answered the call – most were focussed on – sex.

Killingsworth and Gilbert concluded from another check they ran that mind wandering did indeed cause unhappiness, as we worked on more unhappy things than happy things. If so, it might make sense to pay attention to be happy, though the researchers recommended otherwise.

Here’s a quite different view that has been around for a while. It’s called creativity, or ‘flow‘. If you are being really inventive, really creative, having a much better time, or simply much more into the activity, what do you do when your smart phone goes off?

Perhaps you’ll just ignore it. Perhaps you’ll answer, and say you were really involved in what you were doing. After all, the activity that headed up this list was having sex. More people who reported having sex said their mind was on the job than for any other activity.

This research may show up something much simpler, and something much more important. Forget paying attention to scrape out a tiny little bit of extra happiness. Focus on sorting out the activities people were doing that caught their attention, and the ones where their minds wandered (to an even less happy place).

The 3 activities at the bottom the pile, where minds wandered the most, were resting, working, and using a home computer.

Out of the 22 activities surveyed, here are the top 3. Sex – exercise – having a chat.

Take your pick. It’s whatever you prefer most that will do you most good.

November 14, 2010 Posted by | Activity, Exercise, Health, Positive Psychology, Social networks, Success | Leave a comment

Yoga v walking for mood?

Dr Chris C Streeter of Boston University School of Medicine compared the effects of walking to yoga and the impact on mood in healthy people.

Previous research had shown that yoga increases a neurotransmitter, called GABA, in the brain. Increasing GABA is linked to less anxiety and depression, and cuts PTSD (post-traumatic stress disorder). Increasing levels of GABA is one approach used in medicines to treat these conditions.

The current study was designed to see if yoga’s known beneficial effects on mood were due to GABA effects, or simply due to exercising (which also improves mood, depression etc). So Dr Streeter tried to match the exercise content of walking with the exercise content of yoga, to see which would win.

Brain scans were used to check on activity in the thalamus. This is an area of the brain involved in mood, and it gets more active at higher levels of GABA.

This is where things went a bit different to what the research team thought would happen.

The yoga group showed a bigger improvement in mood than the walking group. And the yoga people appeared to show more activity in the thalamus, so more GABA. So far so good.

However, the number of people completing the study was small, and the improvement in GABA was not statistically significant. The groups also had a couple of key differences – the yoga group drank more alcohol, while the walking group exercised more when out of the yoga/walking comparison. Perhaps the walkers improved less because they were already getting lots of benefit from exercise.

Or could it be that the yoga group got certified instructors in lyengar yoga, while the walking group got to walk around the inside of gym for an hour per session?

The jury is out, but the research did turn up one key finding.

This study lasted 12 weeks and involved people new to yoga, and it produced about half the increase in GABA that previous studies with experienced practitioners had reported. So if you want to get the full mood benefits of yoga, you’re going to have to stick with it for a fair while.

November 13, 2010 Posted by | Activity, Anxiety, Brain, Depression, Exercise, PTSD, Success, Walking | Leave a comment

Exercise beats colds.

Prof David C Nieman has found that the way to avoid getting colds in the first place, and cut the severity of those you do catch, is moderate exercise. Thinking of yourself as fit also had the same effect, although this seems to be mainly an overlap with exercising regularly.

Nieman’s team followed 1,000 US adults, aged 18-85 for 12 weeks, half during autumn and half during winter.

People rated how fit they thought they were on a 10 point scale. They logged when they did moderate exercise, defined as 20 minutes or more at one time.  Frequency and severity of colds were also logged using a validated method.

The team then stripped out a number of factors to get at the fitness impact.  When they did this and compared those in the top third against those in the bottom third,  regular moderate exercise ( 5 days per week) cut the number of days with a cold by nearly half, while the severity was cut by around a third.  Perceived fitness overlapped with actual exercise and produced much the same result.

The authors suggested that regular moderate exercise might be periodically boosting the immune system. Since the boost is short-lived (a few hours), the ‘regular’ part is explained.

‘Moderate’, just enough to break into a sweat, is also important. Moderate exercise does not elevate stress hormones (which can suppress the immune system rather than boosting it), while hard exercise does boost stress levels.

These effects all dose-dependent. The more active people were, even at levels lower than above, the fewer days spent with a cold.

Plugging the other factors back in, the following all cut the risk of getting a cold – older age, medium or high fitness, lower education, being male, being married, having a higher body mass index and eating fruit. The biggest modifiable factor was still exercise.

November 2, 2010 Posted by | Activity, Aging, BMI - body mass index, Cold - common cold, David C Nieman, Diet, Exercise, Health, Success | Leave a comment