Team McCallum

R&D for Lifetime of Life

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.

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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

Eating well?

Two stories published today illustrate the difference between how well people think they eat and how well they really eat.

In Ecuador, Dr Simin Nikbin Meydani examined the diet and health of 350 men and women aged 65+ living in 3 poor neighbourhoods around the capital, Quito. Despite being poor, these people seemed to be eating well, with 33% of the men overweight and 55% of the women overweight.

In reality, their diet was heavily based on white rice, potatoes, sugar and white bread. Foods to provide micronutrients, such as chicken, legumes, fruit and vegetables, were sparse.

Using standard definitions, the team found that 19% of the men and 81% of the women had metabolic syndrome. High levels of C-reactive protein, a marker associated with cardiovascular disease risk, were found in 50% of the population. By analysing diet components, the team was able to tie risk of metabolic syndrome to under-consumption of vitamin C and vitamin E in this population.

The research was published in Public Health Nutrition.

Meanwhile, in the US, a survey of over 1,200 people found that many thought they were eating better than they really were.

53% thought their diet was somewhat healthy, 32% thought very healthy and 6% thought extremely healthy.

However, only 30% ate their 5 portions of fruit and vegetables a day, only half watched how many sweets they ate and 43% drank at least one can of sugar-sweetened beverage each day.

Of those who said they were at a healthy weight, 30% were clinically in the overweight range, and 35% were obese.

While 81% claimed to be active, the average amount of time spent moderately active was one hour, with a large chunk clocking up 5 hours per day sitting down.

The study was conducted by Consumer Reports.

January 4, 2011 Posted by | Activity, CVD - cardiovascular disease, Diet, Fruit, Gender, Health, Metabolic syndrome, Obesity, Soft drinks, Success, Sugar, United States, Vegetables, Vitamin C - ascorbic acid, Vitamin E, Weight management | Leave a comment

Preventing newborn flu.

Advice on both sides of the Atlantic is that pregnant mothers are an at-risk group that should get the flu vaccine. Now a second study has confirmed that mums-to-be who get the jab pass on the benefits to a second key group. where neither the US or the UK recommends vaccination. New-borns under 6 months have 90% less chance of catching flu if mum had the jab when pregnant.

Dr Marietta Vazquez looked at hospital admissions for flu in babies under 12 months old, from the period 200 to 2009, in Yale-New Haven hospital in north east US. These were each matched carefully with two controls who did not catch influenza.

On this comparison, where mother got inoculated against influenza while pregnant, baby had a 92% less risk of being admitted to hospital with flu. This protection only showed up in those under 6 months.

This finding is in line with an earlier study on the subject. Then, testing babies’ blood for antibodies showed better levels for those whose mother was vaccinated, at birth and at 3 months, while at 6 months the levels were similar to babies of non-inoculated mothers.

The US recommends inoculation of babies from the age of 6 months on. The UK does not.

December 21, 2010 Posted by | Influenza, Pregnancy, Success, UK, United States, Vaccine | Leave a comment

Influenza season imminent.

The US Centers for Disease Control and Prevention (CDC) has warned that the flu season is nearly here. The start of the flu season is when 12% of samples sent to the CDC test positive for flu, and currently the rate is just below this at 10.7%.

Other information released by the CDC suggests that those who have not had this season’s vaccine would be wise to do so quickly.

In the south east of the US, positive tests rates are running higher. Georgia has the highest, at 20%. The impact is particularly great in school-age children.

There are 3 different components in the flu vaccine, and the CDC released information on what it turning up in the tests, and how this matches the vaccine.

A minority of cases are of the pandemic H1N1 2009 type. The vaccine contains a component for this type.

The majority are for testing positive for B type virus and for an A type H3N1. The current vaccine has a B type component that matches the B type found, as did the vaccine in the 2009 season.

However, the H3N1 type in circulation does not match the H3N1 component of the 2009 vaccine. So anyone immunised last year is not protected against the H3N1 strain now in circulation. However, the current vaccine does protect against this H3N1 strain.

In summary, the 2010 vaccine protects against all 3 types in circulation, while the 2009 vaccine fails to protect against one of the majority strains being found now. Hence the need to get this year’s vaccine.

Although the information released by the CDC applies to the US, the circulating flu strains are typically the same throughout the northern hemisphere, and the vaccine used in Europe has the same 3 components as those used in the US. So a 2010 shot makes good sense for Europeans too.

December 5, 2010 Posted by | CDC - Centers for Disease Control and Prevention, Child Health, Health, Influenza, Success, United States, Vaccine | Leave a comment

Vitamin D in high-risk seniors.

The International Osteoporosis Foundation (IOF) has responded to the recent publication by the Institute of Medicine (IOM) that recommended vitamin D levels. The IOF recommends levels 50% higher for high-risk seniors.

The IOF actually published its own finding for seniors in April 2010. In this, the IOF focussed on research into vitamin D in those aged 60 plus, relating to the impact on falls and fractures.

High-risk seniors are considered to be those in this age range who are also one or more of – obese, suffering from osteoporosis, limited in sun exposure (such as those in institutions or homebound), absorb vitamin D poorly, or are from populations suffering from low vitamin D levels, such as the Middle East and South East Asia.

The IOF recommends that blood levels of vitamin D are first established, then a formula used to calculate the supplements required, then blood levels are tested after 3 months for adequacy.

The IOF position paper showed that supplementation of vitamin D increased lower body strength in seniors and cut falls by 20%. There was also a cut of 20% in fractures. In both of these, supplementation below the amounts recommended by the IOF did not produce these benefits. The IOF did not recommend higher levels because no research has been carried out at higher levels.

The IOM recommends a blood level of 20 ng/ml (50 nmol/L). The IOF recommends a blood level of 30 ng/ml (75 nmol/L) for high-risk seniors as this is where the research found the benefits.

Supplementation at 10 micrograms/day (400 IU/day) produced no improvement. For this reason, the IOF recommended that high-risk seniors should take 800-1,000 IU/day, noting that this is well below the 4,000 IU/day toxic limit published by the IOM.

December 3, 2010 Posted by | Activity, Aging, Health, Obesity, Osteoporosis, Success, United States, Vitamin D | 1 Comment

Vitamin D v metabolic syndrome.

Researchers from the University of California Davis Medical Center found that patients with metabolic syndrome (but otherwise healthy) were much more likely to have insufficient vitamin D in their blood than controls without metabolic syndrome.  The patients came from around Sacramento, a part of northern California with plenty of sun, making the results more surprising.

Dr Ishwarlal Jialal and team compared 44 patients who had metabolic syndrome, but without diabetes or cardiovascular disease (CVD), against 37 healthy controls matched for age and gender.

The Institute of Medicine (IOM) has very recently published recommended levels of calcium and vitamin D, and based on best evidence, worked on a level of 20ng/ml of vitamin D in the blood as sufficient.

Dr Jialal found that 8% of controls had insufficient vitamin D at the IOM level, but in the metabolic syndrome group it was 30%.

The average value of vitamin D in blood in the metabolic syndrome group was found to be 23.1ng/ml, which suggests the IOM recommended level of 20 ng/ml may be too low. In the control group, it averaged 27.8ng/ml.

Dr Jialal also found there was no difference in levels in winter and summer, which reinforces the finding that in northern California, normal activity in sunlight is not enough to generate adequate vitamin D levels. This contrasts with southern California, where research has shown there in no difference in vitamin D between those with and without metabolic syndrome, while in Florida (even farther south) diabetics do not tend to have low vitamin D.

Sacramento is about 39 degrees north. As most of Europe is at or north of this, it would put most Europeans at risk, unless they are out in the sun more than this US sample, or getting it from food sources.

Metabolic syndrome is a risk factor for diabetes, CVD and stroke.

December 2, 2010 Posted by | Activity, CVD - cardiovascular disease, Diabetes, Health, IOM - Institute of Medcine, Metabolic syndrome, Stroke, Success, United States, Vitamin D | Leave a comment

Calcium and vitamin D by IOM.

The Institute of Medicine (IOM) was asked by US and Canadian health authorities to conduct an independent, evidence based review of the dietary requirements for calcium and vitamin D.

Overall, the committee concludes that the majority of Americans and Canadians are receiving adequate amounts of both calcium and vitamin D. Further, there is emerging evidence that too much of these nutrients may be harmful.”

Prof A Catherine Ross chaired the committee conducting this update, the first since 1997. The team reviewed over 1,000 studies on vitamin D and calcium and took further evidence from experts.

The review covered all health outcomes,  including cancer, cardiovascular disease, high blood pressure, diabetes, metabolic syndrome, falls, immune response, neuropsychological functioning, physical performance, preeclampsia, and reproductive outcomes. It found that only in relation to bone health are the results unequivocal, and based its recommendations on this.

The committee noted that studies appearing in the media re population levels of deficiency are using arbitrary levels that have not been established by a central authority, and so have little validity.

Based on available data, the committee found almost all individuals get sufficient vitamin D when their blood levels are at or above 20 nanograms per milliliter as it is measured in the US, or 50 nanomoles per liter as measured in Canada.

Also, the committee considered that few people are getting their vitamin D from sunlight, and based their recommendations on this.

A full breakdown of the recommendations by age range and gender is at the IOM short report on calcium and vitamin D. Please note a number of special situations are omitted from this but are covered by the full 678 page report, so check with your physician.

Some subgroups—particularly those who are older and living in institutions or who have dark skin pigmentation—may be at increased risk for getting too little vitamin D.

National surveys in both the United States and Canada indicate that most people receive enough calcium, with the exception of girls ages 9-18, who often do not take in enough calcium. In contrast, postmenopausal women taking supplements may be getting too much calcium.

Too much calcium is linked with kidney stones, while too much vitamin D is linked to kidney and other tissue damage. The short report therefore gives 3 values for each group – the estimated average amount (enough for the average person), the recommended dietary allowance (the level at which nearly everyone gets enough) and the upper level intake (the level at which more will cause harm rather than good).

In conclusion, “the committee emphasizes that, with a few exceptions, all North Americans are receiving enough calcium and vitamin D. Higher levels have not been shown to confer greater benefits, and in fact, they have been linked to other health problems, challenging the concept that “more is better.””

November 30, 2010 Posted by | Aging, Calcium, Canada, Cancer, Child Health, Cognitive decline, CVD - cardiovascular disease, Diabetes, Gender, High blood pressure, IOM - Institute of Medcine, Metabolic syndrome, Success, United States, Vitamin D | Leave a comment

US whooping cough outbreak.

US health officials have just updated advice on immunisation against pertussis (whooping cough) based on a serious outbreak in California. And yesterday, health officials in Grant County, in the state of Washington, announced an outbreak has already killed one infant and infected a dozen others, saying it is on scale that cannot be treated as isolated incidents.  The county’s health officer, Dr Alexander Brzezny, said the county should prepare for more cases.

The Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC) completely revised its last recommendation (from 2006), based on the pertussis outbreak in California which has infected over 6,200 people and killed 10 infants.

Irrespective of how recently you may have had vaccination against tetanus and diptheria (a combined vaccination called Td), ACIP recommends immediate immunisation using a triple vaccine called Tdap, which protects against tetanus, diptheria and pertussis.

The two current vaccines are licensed for people aged 10 to 64, but ACIP considered the issue of vaccinating people outside these age ranges, with the intention of cutting the number of infected people who may come in contact with unprotected infants.

The full details are complex, depending on your age and whether you have already received some protection against pertussis. But a simple summary is that ACIP recommended vaccination with Tdap for those from 7 years up, with no upper limit for adults coming into contact with infants aged under 12 months.

People living in the US should check with their physician to see if they need to act on this.

October 31, 2010 Posted by | CDC - Centers for Disease Control and Prevention, Health, News, Success, United States, Vaccine, Whooping cough - pertussis | Leave a comment

Sugared drinks v diabetes.

Dr Frank B Hu and 5 colleagues in N America have found that sugar-sweetened drinks, even at a low level, are linked to an increased risk of type 2 diabetes and metabolic syndrome. This effect is independent of any impact the sweetened drinks have on weight or on total calorie consumption. Further, it kicks in at levels as low as 1 to 2 standard size drinks per day.

The research team combed medical literature for good quality studies, in order to combine them. They found 8 studies of sugar-sweetened drinks and type 2 diabetes, covering 311,000 people, and 3 studies for metabolic syndrome, covering nearly 20,000 people.

From these they calculated that 1 to 2 sweet drinks per day, compared to less than 1 per month, raised the risk of type 2 diabetes by 26% and metabolic syndrome by 20%. One drink was a standard 12 oz size in the US, which is slightly larger than the 330 ml size in Europe. They found the result was dose-dependent, so more soft drinks increased both risks.

They concluded “In addition to weight gain, higher consumption of sugar-sweetened beverages is associated with development of metabolic syndrome and type 2 diabetes.” 

The full research paper shows that the sweetening component has quite different effects depending on whether it is fructose, glucose or an artificial sweetener. However, in the form of an added sweetener at this magnitude all have undesirable health effects.

The paper also references other research to show that the preferred US sweetener, HFCS (high fructose corn syrup, a 55/45 mix of fructose and glucose) and the standard European sweetener (sucrose, a 50/50 mix of fructose to glucose) both increase the risk of metabolic syndrome and type 2 diabetes through not only weight gain but through other paths. These extra paths include increased dietary glycemic load leading to insulin resistance, beta-cell disruption and inflammation. Further problems are hypertension and an increase in visceral fat (bad fat).

These findings dovetail neatly with recent research that there are good carbs and bad carbs.That report is here.

As soft drinks increase visceral fat, and both increase the risk of type 2 diabetes, this may explain why US adults have larger waist sizes than their UK equivalents, and also twice the rate of diabetes. That report is here.

October 28, 2010 Posted by | Diabetes, Diet, Frank B Hu, Glycemic index, Health, HFCS - high-fructose corn syrup, Metabolic syndrome, Obesity, Soft drinks, Success, Sugar, UK, United States, Waist circumference, Weight management | Leave a comment

Truth v belief v propaganda.

Two professors at the Ohio State University have carried out a study regarding the proposed mosque at the 9/11 Ground Zero site in New York that illustrates the relative merits of truth and propaganda when it comes to changing beliefs.

750 adults participated in a survey conducted between 14 Sep and 19 Sep 2010.

The core concept was a prevailing belief that Feisal Abdul Rauf, the Imam behind the proposed mosque, is a terrorist sympathiser who has refused to condemn extremist Islamic attacks on civilians.

Professors R Kelly Garrett and Erik Nisbet checked this using two services specialising in checking the truth (FactCheck and PolitiFact) and found this rumour to be false.

Then they took this information and presented it in different ways to those surveyed. Some got a bald rebuttal while others saw this accompanied by additional contextual information.

No matter what they did, only about one third of people surveyed who believed the rumour to be true actually modified their view, and only just over a quarter actually agreed the rumour was false.

Adding a photograph of the Imam with others when all were dressed in typical Arab clothes weakened the positive response.

Adding information that is true but might be objectionable to some US citizens, (that the Imam has said that the US bears some responsibility for the harm caused by its policies towards the Middle East though terrorism was never justified), meant the rebuttal had no impact. This point is of interest as balanced media sources would try to provide a report that was wider than a simple rebuttal.

The ‘propaganda’ effect also worked the other way. Adding a photo of the Imam and those around him in typical Western clothes meant the rebuttal was more likely to be effective.

So it seems that when it comes to belief, propaganda may outweigh the truth.

October 27, 2010 Posted by | Psychology, Success, United States | Leave a comment