The Morning Drill: August 15, 2011

A collection of dentistry and health related links/comments for your day.

Preparing Triathletes for the Chaos of Open Water

The deaths of two athletes stricken by cardiac arrest in the Hudson River during the New York City Triathlon on Aug. 7 have focused attention on the dangers of the open-water portion of such events.

Officials at USA Triathlon, the sport’s governing body in the United States, said Friday that heightened safety measures were continuing “to be discussed and evaluated,” but that no changes were imminent.

Nevertheless, the dangers, mostly related to the stresses of breathing in open water amid a mass of swimmers, have long been known to triathlon coaches. And their training of triathletes incorporates ways to cope with an environment not found in the neat confines of a pool.

“What do you do if you hyperventilate?” said Neil Cook, the head multisport coach with Asphalt Green Triathlon Club at the Asphalt Green amateur sports center on Manhattan’s Upper East Side. “What do you do if your goggles come off? If you bump into a boat? If someone swims over you? If any of these things happen in the open water and you’re not prepared for it, you can panic and can get into real trouble.”

A 2010 study published in The Journal of the American Medical Association showed that 13 of the 14 deaths in triathlons from 2006 to 2008 took place during the swim legs. Autopsies on nine of the victims found that seven had heart abnormalities, which researchers think were exacerbated by the stress of swimming in open water.

The risk of sudden death in a triathlon is 1.5 deaths per 100,000 participants compared with 0.8 deaths per 100,000 participants in a marathon.

Saturated fatty acids linked to periodontal disease

Could filling up on saturated fatty acids (SFA) be bad not only for your body but your teeth as well? The authors of a study in the Journal of Dental Research (July 2011, Vol. 90:7, pp. 861-867) suggest it could be.

"Saturated fatty acids produce an inflammatory response," the authors wrote. "Hyperinflammation is now recognized as one of the key underlying etiologic factors in periodontal disease."

A high intake of SFA -- typically found in meat fats, milk fat, butter, lard, and certain oils -- is associated with nearly double the rate of periodontal disease compared with a lower SFA intake, particularly in nonsmokers, they noted. However, smokers seemed to be immune to the deleterious effects of saturated fatty acids on their dentition.

Tanning Beds, UV Rays Change Brain Activity, Cause Addiction

It's fairly common knowledge that UV rays from tanning can cause skin cancer. A new study now also shows that exposure to UV light from tanning beds changes brain activity. Like alcohol, tanning can become addictive. Physicians released their findings in the Addiction Biology Journal.

Subjects were tested using regular tanning beds and sham beds with UV ray filters. Subject brain activity was measured in response to UV- filtered and non-filtered tanning beds, with researchers randomly switching filters. Subject brain activity demonstrated reward effects, similar to those of mood-altering drugs and alcohol, in response to the UV lights. Without knowing which was which, subjects also expressed fewer positive feelings and less desire to tan in the non-UV lit beds.

Living on Lake Michigan, tanning addiction comes as no surprise to me. Sun worshipers coat our beaches all summer long. Some spend hours every day, laying in the sun. They frequent tanning salons in winter. There are some who use tanning beds even in summer.

Salons tout tanning beds over direct sunlight, advertising that this method of tanning is safer than exposure to the sun. Mayo Clinic says that tanning beds are no safer than sun tanning. UV rays are UV rays, no matter what the source. In fact, tanning beds actually increase risk of skin cancer because they use UVA rays. UVA rays are directly linked to melanoma, the most deadly form of skin cancer.

I have friends that are tanning addicts. One woman has not actually tanned so much as developed a body-covering of freckles. Freckles have long been associated with skin cancer. Tanning makes them prematurely old, with shriveled, dry skin and masks of wrinkles. Time spent in the sun has added 15-20 years to their faces. Even young women and teens look older when they tan. Tanning addicts, barely out of their teens already show facial wrinkles. UV ray addiction explains why they continue to tan, despite the evidence in the mirror that it detracts from their looks.

Autism risks for siblings are higher than thought

A new study suggests nearly one in five children with an autistic older sibling will develop the disorder too — a rate much higher than previously thought.

Researchers followed 664 infants who had at least one older brother or sister with autism. Overall, 132 infants or about 19 percent ended up with an autism diagnosis, too, by their third birthdays. Previous smaller or less diverse studies reported a prevalence of between 3 percent and 14 percent.

"We were all a bit surprised and taken aback about how high it is," said lead author Sally Ozonoff, a psychiatry and behavioral sciences professor with the Mind Institute at the University of California at Davis.

The highest rates were in infants who had at least two older siblings with autism — 32 percent of them also developed autism. Also, among boys with autistic siblings — 26 percent developed autism versus 9 percent of girls. Autism is already known to be more common in boys.

The study involved 12 U.S. and Canadian sites and was published online Monday in Pediatrics. Earlier studies were more local or involved fewer sites.

Enjoy your day!