The Beauty and Wellness Odyssey

The Beauty and Wellness Odyssey Health/beauty

Artificial enamel is even stronger than real teeth
When enamel starts wearing off, cavities are not far behind. This new material could finally bring dentistry in the 21st century.
Enamel, the hard mineralized surface of teeth, is the hardest thing in the human body. Pound for pound, enamel is tougher and harder than steel. Its unique mix of minerals, water, and organic material makes it tough enough not to dent while at the same time making it durable enough to withstand decades of grinding and tear – but only for so long. Depending on your diet and how well you take care of your teeth, you can stave off tooth decay but you can only postpone the inevitable for so long. The problem is that once teeth lose their enamel, it never comes back, and tooth decay is right around the corner.

Despite many attempts to replicate the wondrous properties of enamel, most efforts have proven in vain. A new study, however, has reignited hopes that such a thing is actually possible after researchers at the University of Michigan have devised a way to make artificial enamel. It goes without saying that this would be a huge leap for dentistry, which still uses decades-old filling technology to repair cavities.

Mimicking enamel in the lab is incredibly challenging due to its complex structure of interwoven hydroxyapatite nanocrystals, which are one-thousandth the thickness of human hair. These crystals are arranged in wires, which become coated in magnesium by enamel-producing cells, and then are woven together into a very strong mesh, which is further organized into twists and bunches.

Researchers have struggled while attempting to reconstruct the complex and multi-layered organization of enamel. But where others failed, the authors of the new study finally succeeded. They encased wires of hydroxyapatite in a malleable metal-based coating, resulting in a structure that has a soft layer that can absorb the powerful shock of a bite but is strong enough to take a lot of pressure without denting.

In fact, the artificial enamel is stronger than the natural variation due to swapping the magnesium-rich coating with the much stronger (and non-toxic) zirconium oxide. To test the material’s strength and elasticity, the researchers cut a piece with a diamond-bladed saw then used a mechanical press to apply pressure steadily until it started to crack. The artificial enamel surpassed natural enamel in six different measures, including hardness, elasticity, and shock absorption.

Now, the artificial enamel doesn’t mimic natural enamel to the tee. It lacks the complex 3D woven patterns of natural enamel, but its parallel wire structure is the closest scientists have come to true enamel thus far.

The research could drastically improve the construction of artificial teeth, as well as significantly reduce tooth decay through new and improved fillings that last much longer. However, the best dental treatment is still prevention, which is why doctors recommend having a good dental routine and opting for teeth straightening as early as possible. Comparing options currently available on the market shows there is a good number of quality aligners and braces manufacturers to choose from.

But beyond dentistry, the hard artificial enamel could prove highly useful when incorporated into implantable electrons and biosensors, such as pacemakers and blood pressure monitors.

“This method of making artificial enamel lends itself to commercial production and it can be produced for the manufacture of artificial teeth,” Nicholas A. Kotov, of the University of Michigan, told i.

It’s still early to make any predictions when this product might reach the market, but since all the components of the material are biocompatible, researchers hope to soon begin trials on both animals and humans. The artificial enamel hasn’t been binded to natural enamel yet, a crucial step in tooth repair, so this will be one of the many tests the material needs to pass before we can finally enter a new age of dentistry.

Just one extra hour of sleep can help overweight people eat less
If you struggle with weight loss, simply getting more sleep could do wonders.
Research conducted over the years has increasingly linked poor sleep (particularly sleeping less than the minimally recommended 7 hours per night) to the risk of weight gain over time. Not sleeping enough may result in hormonal imbalances that affect appetite, leading some to eat more than they normally would on a healthy sleep regimen.

To investigate in more detail how sleep affects calorie intake, researchers from the University of Chicago and the University of Wisconsin-Madison conducted a randomized clinical trial involving 80 young, overweight adults who habitually sleep less than 6.5 hours a night.

“Over the years, we and others have shown that sleep restriction has an effect on appetite regulation that leads to increased food intake, and thus puts you at risk for weight gain over time,” said lead investigator Esra Tasali, director of the UChicago Sleep Center at the University of Chicago Medicine. “More recently, the question that everyone was asking was, ‘Well, if this is what happens with sleep loss, can we extend sleep and reverse some of these adverse outcomes?’”

The volunteers were randomly split into two groups. One received personalized sleep hygiene counseling, which involved changing one’s routine to avoid the things that hinder sleep (caffeine in the evening, heavy meals close to bedtime, excessively warm bedroom, etc.) and introduce activities that aid sleep (going to bed at the same time, using your sleep only for sleep or s*x, etc.). The other group received no intervention at all and acted as a control.

In the first two weeks, the researchers just gathered baseline information about sleep and calorie intake. Sleep patterns were measured using wearable devices while calorie intake was quantified using the “doubly labeled water” method. The doubly labeled water method is a trialed and tested urine-based test for objectively tracking calorie intake, which involves a participant drinking water in which some hydrogen and oxygen atoms have been replaced with stable isotopes that are easy to trace. With this technique, it is possible to measure every calorie a person burned over a one to two week interval, without having to hawkishly record everything a person puts into their mouths.

“This is considered the gold standard for objectively measuring daily energy expenditure in a non-laboratory, real-world setting and it has changed the way human obesity is studied,” said the study’s senior author Dale Schoeller, professor emeritus of nutritional sciences at UW–Madison.

A month after the study started, the researchers found that participants in the sleep intervention group managed to extend their sleep duration by an average of 1.2 hours. Compared to the control group, the sleep intervention reduced the participants’ daily calorie intake by 270 calories, the equivalent of a small meal.

Of important note is that this examination was performed in a real-world setting. Each volunteer slept in their own beds, ate what they wished, wasn’t prompted to exercise, and generally went about their day as they pleased and normally would. That’s in stark contrast to most weight loss studies that are generally short-lived and diligently measure calorie intake by making sure participants only consume a particular offered diet.

The only factor that was manipulated in the study was sleep duration, and this single aspect proved to have a significant impact on the participants’ calorie intake. If the average reduction in calorie intake of 270 calories per day is maintained over the long term, this would translate to roughly 12 kg (26 pounds) of weight loss over a three-year period. That’s on average; some participants consumed as many as 500 fewer calories per day.

“This was not a weight-loss study,” said Tasali. “But even within just two weeks, we have quantified evidence showing a decrease in caloric intake and a negative energy balance — caloric intake is less than calories burned. If healthy sleep habits are maintained over a longer duration, this would lead to clinically important weight loss over time. Many people are working hard to find ways to decrease their caloric intake to lose weight — well, just by sleeping more, you may be able to reduce it substantially.”

In the future, the researchers plan on studying the underlying mechanisms that may explain why more sleep can lead to weight loss. Previous research by Tasali and colleagues suggest that sleep is important for appetite regulation. Limited sleep may drive changes in appetite-regulating hormones and reward centers in the brain that could lead to overeating.

Shifting to a healthier diet can increase your lifespan by up to a decade
Many of these changes are also eco-friendly and save on cash.
New research is showcasing how a more healthy, balanced diet — including more legumes, whole grains, and nuts, while cutting down on red and processed meat — can lead to longer lives.
“You are what you eat” is an age-old saying, but a new study from the University of Bergen says that we also live as long as what we eat. The healthier and more diverse our diets, the healthier and longer our life expectancy (LE) becomes, it reports.

The paper estimates the effect of such changes in the typical Western diets for the two s*xes at various ages; the earlier these guidelines are incorporated into our eating habits, the larger the improvements in LE, but older people stand to benefit from significant (if smaller) gains as well.

Change your meals, enjoy more meals
“Our modeling methodology used data from [the] most comprehensive meta-analyses, data from the Global Burden of Disease study, life-table methodology, and added analyses on [the] delay of effects and combination of effects including potential effect overlap”, says Lars Fadnes, a Professor at the Department of Global Public Health at the University of Bergen who led the research, in an email for ZME Science.

“The methodology provides population estimates under given assumptions and is not meant as individualized forecasting, with uncertainty that includes time to achieve full effects, the effect of eggs, white meat, and oils, individual variation in protective and risk factors, uncertainties for future development of medical treatments; and
changes in lifestyle.”

Dietary habits are estimated to contribute to 11 million deaths annually worldwide, and to 255 million disability-adjusted life-years (DALYs). One DALY, according to the World Health Organization “represents the loss of the equivalent of one year of full health”. In other words, there’s a lot of room for good in changing what we eat.

The team drew on existing databases to develop a computerized model to estimate how a range of dietary changes would impact life expectancy. The model is publicly available as the online Food4HealthyLife calculator, which you can use to get a better idea of how changing what you eat can benefit your lifespan. The team envisions that their calculator would also help physicians and policy-makers to understand the impact of dietary choices on their patients and the public.

For your typical young adult (20 years old) in the United States, the team reports that changing from the typical diet to an optimal one (as described by their model) could provide an increase in LE of roughly 10.7 years for women and 13 years for men. There is quite some uncertainty in these results — meaning that increases for women range between 5.9 years and 14.1, and for men between 6.9 and 17.3 — due to the effect of factors that the model doesn’t factor in, such as preexisting health conditions, socioeconomic class, and so on. Changing diets at age 60 would still yield an increase in LE of 8 years for women and 8.8 years for men.