Team McCallum

R&D for Lifetime of Life

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

St Andrew’s Day!

Well we are Team McCallum.

The blue shown here is because before we can turn pink-ish, first we have to turn blue.

The white is because it is frosty-freezy slippery frozen white here. No chance of turning pink, or white. Chance of turning blue – absolutely excellent!

Enjoy St Andrew’s Day.

November 30, 2010 Posted by | Uncategorized | Leave a comment

Are you too clean?

Triclosan is used in a variety of common household products, including soaps, mouthwashes, dish detergents, toothpastes, deodorants, and hand sanitisers. It is antibacterial and antifungal. Now a study led by Prof Allison E Aiello has found that triclosan is linked to higher rates of asthma and hay fever.

Triclosan has been around since the 1960s and became widespread in the 70s and 80s. However, it is now seen as an endocrine disruptor, interfering with the hormone system. Prof Aiello wanted to know whether triclosan had an impact on the immune system.

3,700 people from the 2003-2006 NHANES survey in the US were used, where data on asthma and allergies was known, and the level of triclosan in the person’s urine was established.

Triclosan was associated with a greater risk of asthma and allergies. The increase was not significant in those over 18, but was significant in people under 18.

High triclosan levels were also linked to high socioeconomic status. As asthma is usually linked to lower socioeconomic status, the impact of triclosan may be greater in reality than that found in the study.

Studies published in 2009 and 2010 found that a properly functioning immune system was a major determinant of health across the course of life, that those with childhood asthma may have a higher risk of adult lung cancer, and that immune disregulation in oldest age groups is linked to dementia.

The triclosan effect is thought to be that is removes microorganisms required by the immune system to train it to develop the right balance between two types of T-helper cells, and this imbalance may lead to immune system reactions and allergies.

So it looks like you can be too clean for your own good.

An earlier study from the University of Michigan found that triclosan in hand wash was unnecessary, with decent soap being just as effective.

November 29, 2010 Posted by | Allison E. Aiello, Asthma, Cancer, Child Health, Dementia, Health, Success | 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

Jet-lagged hamsters?

What can we learn from jet-lagged hamsters? Quite a lot, according to a study by a team from the University of California Berkeley.

Syrian hamsters are used regularly in the study of circadian rhythms because they follow these very precisely.

The team jet-lagged the hamsters twice a week for four weeks by shifting their light-dark cycle by six hours. This is about the same as flying the North Atlantic, or what you might get on rotating shift patterns.

During this period, the team was not surprised to find that the hamsters had more difficulty when set learning tasks. However, the effects were found to persist for a month after the time switching was stopped. This suggests the human equivalent would last much longer.

The researchers dug deeper to identify the mechanism for this. Using a number of procedures they were able to rule out secondary effects produced by stress from elevated cortisol.

This left only one explanation. A part of the brain called the hippocampus is essential for memory and learning, and it works by neurogenesis – creating new neurons to ‘store’ the new memories. The time shift was cutting neurogenesis, so the hippocampus was not producing enough new neurons for efficient memory formation. This same problem occurs in humans suffering from cognitive decline.

Rotating shift work has been associated with learning and memory problems, decreased reaction times, higher incidences of diabetes, heart disease, hypertension and cancer, and reduced fertility, and has been listed by the World Health Organization as a carcinogen.

November 27, 2010 Posted by | Brain, Cancer, Cognitive decline, CVD - cardiovascular disease, Health, High blood pressure, Learning, Memory, Success | Leave a 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

Keeping weight off.

Getting weight off during a diet is easier than keeping the weight off afterwards. The Diogenes (diet, obesity and genes) project investigated the best way to keep it off. High protein and low glycemic index (GI) were the keys.

77o people in 8 European countries who had lost at least 8% of their body weight (an average of 11 kg) on an 800 kcal diet were randomly assigned to one of 5 maintenance diets for 26 weeks. Each of the five was eat as much as you want and got about 30% of total energy from fat.

The control diet had middling protein and did not worry about glycemic index. Of the others, two were high protein (25% of energy intake) and two were low protein (13%), with one in each group high GI and one low GI.

The higher the GI the bigger the spike in blood sugar levels after eating. Refined grain products (white rice, white pasta) tend to be high GI, while low GI foods include non-refined grains, fruit and non-starchy vegetables.

550 people completed the maintenance phase. The drop out rate in the low protein high GI group was markedly higher than average, with the other high GI group second worst.

Being in a high protein group was associated with further weight loss, and the chance of losing a further 5% of body weight was 90% higher with high protein.

The only group where weight regain (at an average of about 1.7 kg = 3.5 lbs) was statistically significant was the low protein high GI one.

High protein cut weight by an average of 1 kg compared to low protein. Low GI cut weight by about the same, compared to high GI, and since there was no difference in fibre, the effect is purely down to GI.

The research appears in the New England Journal of Medicine.

In summary, to keep the weight off, eat as much as you want on a mix of protein (25% of energy), fat (30%), carbs for the rest and choose low GI (non-refined, non-starchy).

November 25, 2010 Posted by | Diet, Fruit, Glycemic index, Success, Vegetables, Weight management, Whole grain | Leave a comment

Alpha-carotene v death etc.

The new anti-oxidant on the block is alpha-carotene, which has been found in a study to cut the risk of all causes of death, of death from cardiovascular disease (CVD), and death from cancer.

Alpha-carotene, like beta-carotene, is a precursor to vitamin A in the human body, and is found in many types of fruit and vegetables.  However, it is likely that it impact here is as an anti-oxidant, where it is thought to be much more potent than beta-carotene.

The researchers followed up on over 15,000 US adults who had taken part in the Third National Health and Nutrition Examination Survey (NHANES) for an average of 14 years. They compared death risks against the level of alpha-carotene in the blood at the start of the study.

They compared the risks to those with a level 0 to 1 micrograms of alpha-carotene per litre of blood. Those on 2-3 micrograms cut their risk of death from all causes by 23%. At 4-5 micrograms, the cut was 27%. At 6-8 micrograms, the cut was 34%. Those on the highest level of 9 or more micrograms were 39% less likely to die from all causes.

The researchers did not tie up the amount of alpha-carotene in the blood with levels of fruit and vegetable consumption required to produce this.

Alpha-carotene is found most in carrots, sweet potatoes, squash, broccoli, kale, cantaloupe, brussels sprouts, kiwi fruit, spinach, mangos and spinach. Alpha-carotene is fat soluble, so dietary fat is required for proper uptake. Cooking may break down plant cell walls and improve absorption. 

Supplements containing alpha-carotene are dunaliella and palm oil/fruit. These also contain beta-carotene. Beta-carotene in supplement form is thought to be associated with an increased risk of lung cancer in those at risk (smokers, ex-smokers and those exposed to asbestos).

In the Archives of Internal Medicine the researchers concluded “Serum alpha-carotene concentrations were inversely associated with risk of death from all causes, CVD, cancer, and all other causes. These findings support increasing fruit and vegetable consumption as a means of preventing premature death.

November 24, 2010 Posted by | Alpha-carotene, Cancer, CVD - cardiovascular disease, Diet, Fruit, Health, Success, Vegetables | Leave a comment

Daily drug prevents HIV.

Dr Robert Grant of the University of California San Francisco has published the result of a trial of a drug called Truvada. This is already used to manage HIV in those who have acquired it, but Dr Grant looked at whether Truvada could be used to prevent infection in those free from HIV.

The study was worldwide and involved a high-risk group – men and transgender women who have sex with men. 2,500 people took part and the basic finding was that Truvada cut the risk of infection by 44% compared to a placebo.

However, the actual impact is likely to be much higher than this. The main side-effect of Truvada was nausea, particularly when first using it. In the Truvada group, there was a higher rate of people catching HIV in this period than when they were taking it daily.

Those taking it 90% of the time cut their risk of getting HIV by 73%. Blood tests performed by the researchers suggest the protective effect when taken daily may be even higher.

The researchers noted that other measures of safe sex should continue, including the use of condoms. Trials of Truvada in other high-risk groups are underway.

The research appears in the New England Journal of Medicine, while details on current use of Truvada are at www.truvada.com.

November 23, 2010 Posted by | HIV/AIDS, Success, Truvada | 1 Comment

Pomegranate for kidneys.

The American Society of Nephrology (the study of kidneys) is meeting in Denver. Dr Batya Krystal of Western Galilee Hospital has reported on significant benefits of pomegranate juice for kidney dialysis patients, but the findings appear to have a more general benefit.

The team was interested in pomegranate juice because of its high anti-oxidative action, since kidney disease involves a lot of oxidative stress and inflammation.

Just over 100 patients on dialysis drank either a litre of pomegranate juice 3 times a week, or a placebo drink, while they were having their dialysis sessions.

A string of inflammation markers were measured and those on pomegranate juice showed significant improvements in all of these.  The rate of those needing hospital treatment for infection was cut by 40%. The rate of those needing a second such treatment in hospital was cut by 80%. Hospital visits for cardiovascular problems were also cut by 40%

The improvement due to pomegranate juice was cumulative over the year of the study.

Dr Kristal noted that pomegranate juice contains high levels of potassium and recommended that people with kidney problems who drank a lot of pomegranate juice should be monitored by a physician for potential potassium overload.

November 22, 2010 Posted by | CVD - cardiovascular disease, Pomegranate, Success | Leave a comment