Team McCallum

R&D for Lifetime of Life

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

Alcobesity increases in US.

Dr Richard A  Grucza, and colleagues at the Washington University School of Medicine in St Louis, found that ‘alcobesity’ is on the rise in the US.

Before this research, it was known that where alcohol abuse runs in families, due to genes, there is also an increased risk of other behaviour that stimulates the same reward centres in the brain, so the risk of substance abuse is also higher.

Dr Grucza compared two national US studies, one in 1991-1992 and the other in 2001-2002, each of which involved just under 40,000 adults.

In the 1992 study, a link between alcohol abuse running in the family and obesity running in the family was weak, at just 6% higher risk and not reaching statistical significance.

But by 2002, this had climbed to 26% for men and was statistically significant. While in women the additional risk was a whopping 48% higher.

The team ruled out other possible explanations, such as stopping smoking in this period, leaving them trying to explain the following. If there is a cross-over genetic effect, where when alcoholism runs in families people are also more at risk of obesity, how can this be explained when genetics have not altered in so short a time?

The idea that excess alcohol consumption, which means excess calories, might be making people fat was ruled out. Alcoholics tend to be thin as they get a large percentage of their calories from alcohol rather than food. And the subjects tended to be either obese, or alcoholic, rather than both.

So genetics gives some people a higher risk of alcoholism (or of substance abuse) while for others the risk is food ‘abuse’.

The researchers speculated that the change from the 90s to the naughties is in the make-up of food, with particular emphasis on fat, sugar and salt, that now  makes food hyper-palatable.

And that those people genetically at risk of reward centres that dance to the tune of alcohol or other drugs, may find their reward centres fire up on hyper-palatable food. The particular preference leads to an addiction to either alcohol, (or drugs), or to obesity, so explaining the rise of  ‘alcobesity’ in the US.

January 2, 2011 Posted by | Alcohol, Brain, Gender, Genetics, Health, Obesity, Success, Sugar, Weight management | 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

Fat kids v teen heart risk.

A study in the UK has looked at over 5,200 children, to see whether being overweight at age 9-12 is associated with cardiovascular risk factors at age 15-16. It also investigated whether body mass index (BMI) is useful, or whether other measures are better.

Dr Debbie A Lawler and colleagues took measurements of BMI, waist circumference and fat/lean mass by dual energy x-rays at start point and end point. For 75% of the children, the start was before age 10.

At the end, at age 15-16, a wide range of risk markers associated with cardiovascular disease (CVD) were measured.

Different detailed results were found for boys and for girls. However, in general, those overweight at the start point were at higher risk  of factors linked to CVD. (The ‘overweight’ definition used was that of the International Obesity Task Force.)

The following risk factors were all predicted – high systolic blood pressure, high ‘bad’ LDL cholesterol, low ‘good’ HDL cholesterol, high triglycerides, high insulin in blood. BMI was linked to high fasting glucose levels in boys only, and risk for some of the others was worse in boys than girls.

Diastolic blood pressure at the end was not predicted by BMI at the start measurement.

Girls who went from overweight at the first point into the normal range by the end were found to have no more risk than those girls in the normal range at both times. However, boys who improved their weight status also improved their risk profile, but it remained poorer than those in the normal range at both times.

Finally, the team found that although BMI is much criticised, it was as good a predictor as the other two methods, even the very precise x-ray method. So BMI was validated as a simple and easy way to predict a child’s future health profile.

November 28, 2010 Posted by | BMI - body mass index, Child Health, Cholesterol, CVD - cardiovascular disease, Gender, Health, High blood pressure, Metabolic syndrome, Obesity, Success, Waist circumference, Weight management | Leave a comment

Alcohol v gender.

A team of researchers in the US has studied the brain response of young men and women to an alcoholic drink to find out why men are around twice as likely to become alcoholics as women.

21 young adults (college students) who were social drinkers (not dependent on alcohol) underwent a brain imaging scan on two occasions – once drinking just juice and the other time a mix of juice and alcohol.

In the men but not in the women, a particular region of the brain (called the ventral striatum) activated with dopamine release. High dopamine in this region is associated with pleasure and rewards, such as sex and drugs.

Additionally, this pleasure-related alcohol-induced dopamine release reduced with repeated heavy drinking, explaining why addiction could lead to greater consumption.

N.B. Apart from the small size of the study, a limitation is that the alcohol was drunk, and absorption varies from person to person. Other studies have overcome this problem by injecting a known quantity of alcohol into the bloodstream.

October 18, 2010 Posted by | Alcohol, Brain, Gender | Leave a comment

Diabetes – US v UK.

Dr James Banks has found that the much higher rate of diabetes in US adults, compared to the UK,  is mainly due to a larger waist circumference for any given body mass index (BMI).

The team examined results from one study of 6,900 adults in England and a second study of 4,600 US adults of European descent.

Conventional risk factors for diabetes differed little between the two groups, yet rates of diabetes are nearly twice as high in the US.

While obesity was higher in US men (32% v 27% of English males), the BMI profile was very similar in women across the 2 nationalities, so BMI alone could not account for the difference.

When BMI was taken out of the equation by comparing people of the same BMI in both nationalities, it was found that the major risk factor was waist circumference, so larger US waists meant more US citizens at risk at each level.

The team used 3 sizes to grade as low risk (94 cm for men, 80 cm for women) medium risk, (up to 101 cm /88 cm respectively) and high risk (above these sizes).

Abdominal fat cells produce more triglycerides and proinflammatory markers than fat cells deposited elsewhere, contributing to higher insulin resistance and diabetes.

The researchers found waist circumference explained around three quarters of the country difference in diabetes rates for women and around 40% of the difference for men.

Even at the normal weight range, 41% of US women had a waist circumference in the high risk range, compared to 9% of English women.

October 10, 2010 Posted by | Diabetes, Gender, Health, Obesity, Success, UK, United States, Weight management | 1 Comment

Gender v stress.

Prof Mara Mather has found that when stressed, the brains of men and women handle recognition of emotions from another person’s face in completely opposite ways.

To process facial emotions requires activity in the basic visual processing area of the brain (the fusiform face area) and connectivity to interpretation areas. Without stress, this is the same for both men and women.

Add stress, in the form of the cold pressor test, a standard method where your hand is dipped in iced water for a significant length of time. Then look at a photo of an angry face or a fearful face and repeat the brain activity scan.

Men were found to shut down the basic visual processing area and disconnect this from the emotional interpretation areas.

Women did the opposite. They ramped up visual processing activity and increased connectivity to the interpretation areas.

According to Prof Mather “Under stress, men tend to withdraw socially while women seek emotional support.”

September 29, 2010 Posted by | Brain, Gender, Mara Mather, Psychology, Relationships, Stress, Success | Leave a comment

Kids & Tools of the Mind

Professors Claire Valloton and Catherine Ayoub have been studying kids aged 14 months to 3 years old to see how words fit into their ability to self-regulate.  This is important as lower self-regulation is linked to poorer results at school, with an impact that may be larger than IQ or socio-economic status.

They conducted detailed assessments at age 14 months, 2 years and 3 years. (Studies above this age already exist).

14 months is when the ability to self-regulate (to express feelings and emotions rather than acting them out, and to understand and act according to societal norms) starts to develop. Kids with low self-regulation have difficulty in focussing on a task, are more disruptive and are less likely to allow others to take turns.

A key finding was that boys and girls develop quite differently, with girls going steadily up from 14 months to 3 years, while boys actually dropped from 14 months to the 2 year mid-point.

While talkativeness had a minor connection to self-regulation, the major predictor was range of vocabulary – a larger number of different words in use, thus different ways of expressing the same thing.

The professors found that current vocabulary and past vocabulary taken together were predictors of self-regulation, so an early start is better.

They were also able to show that it is specifically this richer ability to express yourself that mattered, rather than general cognitive capability.

Finally, boys with a richer vocabulary would recover to reach the same level as high scoring girls.

A theory of the psychologist Lev Vygotsky is that an extended vocabulary gives more ability to use inner speech to control thoughts and behaviour. Tools of the Mind is based on this approach and attempts to accelerate kids’ success pre-school an in the earliest school days.

September 22, 2010 Posted by | Brain, Catherine Ayoub, Claire Valloton, Gender, Learning, Lev Vygotsky, Success, Tools of the Mind | Leave a comment

Active helps heart.

Nearly 60,000 Finnish men and women followed for over 18 years showed that physical activity levels at the start predicted heart failure risk.

Dr Gang Hu analysed activity levels in 3 key areas – at work, commuting, and leisure – to find out what impact being physically active had.

Being highly active at work for men, moderately active at work for women, or moderate plus in leisure time for both sexes led to a significant cut in heart risk.

For women only, active commuting also cut the risk.

For those active in all 3, the risk was cut by about one third in total, with workplace activity contributing just over half of this.

September 20, 2010 Posted by | Activity, Gang Hu, Gender, Health, Heart failure, Success, Work | 1 Comment

Boys and 0-6 months.

In boys, better nutrition in the first 6 months of life is linked to adult features of greater height, more muscle mass, better grip strength and higher testosterone, but not disease characteristics. Girls did not show a link between height, strength and early nutrition.

Prof Christopher W Kuzawa analysed results from 770 Filipino males aged around 22 who have been followed from birth.

Those gaining weight the fastest in the first 6 months were, typically, breastfed and lived in wealthier households with better hygiene.

Prof Kuzawa considers the result is the effect of changes in links between the brain (hypothalamus), pituitary gland and gonads, as this circuit is sensitive to environmental factors during this period.

According to Kuzawa “Male infants in the first six months of life produce testosterone at approximately the same level as an adult male.”

The effect of better feeding is to launch the child on a strategy of high reproduction, as for these people the age of first sex was earlier, the men reported more sexual partners, and more had had sex in the last month.

September 15, 2010 Posted by | Brain, Breastfeeding, Christopher W Kuzawa, Gender, Success | Leave a comment