Swishing With Oil for Oral Health: Not Recommended

Oil pulling—the Ayurvedic practice of swishing oil in your mouth—may not be bad for you, but there's little evidence that it cleans teeth and none that it can cure anything else.

(from The Atlantic)

The Internet’s new quasi-health obsession is actually very old. Oil pulling—swishing oil  (coconut and sesame seem popular, preferably unrefined) around in your mouth for 10 to 20 minutes—is an oral health practice that has been done in India for years and years. It’s mentioned in the Charaka Samhita, one of the key texts of the Indian traditional medicine known as Ayurveda.

It’s also mentioned by kooky celebrity darling Shailene Woodley, star of the upcoming films Divergent and The Fault in Our Stars, in an interview for beauty website Into the Gloss. In between recommending eating clay to “clean heavy metals out of your body” and extolling the virtues of getting sunlight on your nether regions, the natural medicine enthusiast says:

You can do something called ‘oil pulling’ where you swish coconut or sesame oil in your mouth when you wake up and spit it out. It’s amazing! It really makes your teeth whiter, because the plaque on your teeth is not water soluble, it’s fat-soluble. So the lipids have to dissolve in fats, which is why oil works in your mouth.

But Robert J. Collins, a clinical professor at the University of Pennsylvania School of Dental Medicine says there is no evidence that plaque is fat-soluble.

“Even if it was, it doesn’t mean that it would disrupt the plaque,” he says. “We’re learning more every year how sophisticated those colonies are.” The only things we know of that work to remove plaque are chemical (like Listerine) or mechanical (the tooth-scraping you go through at the dentist’s office).

A Google search for “oil pulling” brings up more than two million results, many from the past few weeks. This late February post on the blog Fashionlush,received around 800 comments. The main claims being bandied about are that the practice cleans and whitens your teeth, helps with bad breath, and eases jaw pain. More dubious are the assertions that it cures diabetes, hangovers, acne, and all manner of other bodily ills. (A good rule to live by, I think, is not to trust anything that claims to get rid of “toxins,” especially if it does not specify what these toxins are. “We have these magic organs called kidneys and livers and [detoxifying] is what they do,” Collins says. “We don’t necessarily need to be swishing things around in our mouth.”)

There have been a handful of studies on the practice (published in Indian journals, it’s worth noting) that found it to be equally or nearly as effective as mouthwash in reducing halitosis, plaque-induced gingivitis, and the presence of streptococcus mutans, a bacteria that contributes to tooth decay. But these studies had very small sample sizes—20 people total—which makes them, Collins says, “one step away from case studies.”

When I contacted the American Dental Association, I was told it could not comment on the practice “because additional research is needed.” The organization pointed me to its statement on “unconventional dentistry,” which reads in part:

The ADA… supports those diagnostic and treatment approaches that allow both patient and dentist to make informed choices among safe and effective options. The provision of dental care should be based on sound scientific principles and demonstrated clinical safety and effectiveness.

Oil pulling is far from a sound scientific principle. Collins says that, in his opinion, there’s no harm in it (though if you swallow it, he posits you might have some gastrointestinal issues), but neither is there any solid evidence of benefits.

“From a public health point of view, we certainly do not want to encourage people to use things that, while they may be harmless, we have no evidence that they work,” Collins says. “It’s kind of like chiropractic. If somebody feels that they can go to the chiropractor, get a back adjustment, and it makes them feel better, I’m okay with that. If people start selling chiropractic as a mechanism to cure cancer then I have a problem with that.”

Basically, if you feel that swishing oil between your teeth for 20 minutes a day is a good use of your time, it probably can’t hurt you. But don’t use it as an alternative to brushing your teeth, and certainly don’t expect it to cure any real conditions. No matter what the movie stars say.

The strange reason diet soda makes you fat   

Calorie-free sweetness may confuse the brain into craving more sugar, research suggests.

 Want one reason for your beer belly? How about 100 quintillion? That's about how many bacteria live in your gut. And scientists now believe these bacteria can have a significant impact on your weight. 

Consuming high amounts of fructose (a type of sugar), artificial sweeteners, and sugar alcohols (another type of low-calorie sweetener) cause your gut bacteria to adapt in a way that interferes with your satiety signals and metabolism, according to a new paper in Obesity Reviews. (If you've noticed you've been feeling tired all the time and gaining weight, your metabolism may be slowing.) 

"An evolution of the gut flora to this new sweetener-rich environment has a potential to negatively impact our health," says Amanda Payne, Ph.D., lead author of the review. 

How does that happen? As bacteria in the gut process food, they give off byproducts called short-chain fatty acids. These can be beneficial and serve as energy in the body. But as the sweetener-adapted bacteria thrive and become more efficient at processing large amounts of high-fructose corn syrup, artificial sweeteners, and sugar alcohols, they also produce more and more short-chain fatty acids. (Not to imply that sugar is any better than artificial sweeteners. 

In those high amounts, Payne says, short-chain fatty acids decrease satiety signals. "This signaling may cause disruptions in our feeling full and hence prevent us from stopping to eat when we should," Payne says.

As if overeating isn't enough, the short-chain fatty acids also promote inflammation in the lining of the gut. Just how? Scientists aren't yet sure. But they do know that inflammation damages gut tissue and results in leaky gut syndrome. Pleasant as it sounds, it means bacteria leak through that damaged gut tissue into the blood stream and cause further inflammation there. That's a serious problem that can lead to insulin resistance and an increased risk for coronary artery disease, stroke, and type 2 diabetes. 

 Is This Sugar Making You Fat? 

This could partly explain the link researchers have found between drinking diet soda and being overweight. In one study, people who drank two or more diet sodas a day had five times the increase in waist circumference over a 10-year period compared to people who didn't drink any diet soda. There are a few explanations for the findings. Maybe people drink more diet soda because they're trying to lose weight. Calorie-free sweetness may also confuse the brain into craving more sugar. 

As for your gut, at this point it's not clear if one diet soda a day is less damaging to the gut flora than ten. "I will say from a personal perspective that I don't drink sodas--diet or regular--and I rarely eat processed foods, especially if they have high-fructose corn syrup listed on their label," Payne says. Your best bet is to consume products containing these sweeteners in moderation, and drink mostly water. For gut flora to thrive, eat a wide variety of fruits, vegetables, and whole grains.