Team McCallum

R&D for Lifetime of Life

Looking great!

Dr Ian Stephen and colleagues from the Perception Lab have found that looking tanned isn’t the best way to look great. People prefer a face that signals it is healthy, and for that you need carotenoid, a compound that comes from eating fruit and vegetables.

The Perception Lab at St Andrews studies faces and the information we get from them. This information is quite amazing, and the Perception Lab website covers some of the things we get from the faces of others, and what they get from you!

The work published by Dr Stephen investigated the link between carotenoid consumption and facial attractiveness in humans, because in birds and fishes the yellowness produced signals health, while in humans, carotenoids are linked to better immune systems and reproductive ability.

Three studies were carried out to clarify the link.

First, it was established that both a white population and a black (South African) preferred a particular yellow pigment, called CIELab b*, in faces of Caucasians, rather than pale white or tanned.

Second, they showed that those getting carotenoids from fruit and vegetables produced the CIELab b* yellow more in their face.

Third, when people were given photos of faces and the ability to alter the colour composition, they chose to increase the amount of CIELab b* rather than other alternatives.

So if you want to look your very best, don’t get tanned, eat your fruit and veg!

January 12, 2011 Posted by | Diet, Fruit, Health, Success, Vegetables | 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

Antioxidants v stroke.

The Italian segment of EPIC (European Prospective Investigation into Cancer and Nutrition) has reported on how consumption of antioxidants relates to stroke risk.

Dr Nicoletta Pellegrini of the University of Parma analysed data on roughly 42,000 men and women who were free from stroke and heart attacks at the start of the study, and who were followed for an average of 8 years.

Those with a diet high in antioxidants had a 60% lower chance of suffering an ischemic stroke (blocked blood vessel). Most of this effect may be due to high vitamin C intake.

The researchers speculated that the protective mechanism might be a combination of anti-inflammatory action, plus generation of nitric oxide to cause dilation of blood vessels and so lower blood pressure.

However, highest intake of vitamin E appeared to be linked to a large increase in risk for hemorrhagic stroke (bleeding), but due to the small number of such events, the team suggested further research would be required to investigate this.

More than half the antioxidants consumed came from coffee, red wine and fruit, with other sources including chocolate, vegetables, whole grain cereals and nuts.

While the team checked results after adjusting for a number of risk factors, one notable item they did not account for was sodium (salt) consumption.

January 3, 2011 Posted by | Alcohol, Chocolate, Coffee, Diet, Fruit, Health, High blood pressure, Stroke, Success, Vegetables, Vitamin C - ascorbic acid, Vitamin E | 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