Proper Sunscreen Use

Julia Belluz does a great job of reviewing some of the frequently asked questions about sunscreens.

Do chemicals in sunscreens hurt me?

• So far, there is no evidence of organ injuries or cancers being caused by chemicals in sunscreens.  Certainly, there is a known risk of skin damage and skin cancer in not using them.

Do sunscreens cause Vitamin D deficiencies?

• No.

Do sunscreens expire quickly or get damaged by heat?

• Consumer Reports found that sunscreens last for years after purchase, but
• they can be rendered ineffective by being over-heated at the beach or in your car.

 Is higher SPF better?

• SPF 30-40 is fine.  Many sunscreens overstate SPF, so if you want a general purpose SPF 15, get SPF 30 just to be sure.  On the other hand, there is very minimal additional benefit at SPF 45 or higher.

How much do I need to use?

• Quite a bit, actually.  It takes about a fluid ounce (1 shot) to cover your whole body, on average.
• Plus, it needs to be replenished every two hours as the chemicals have absorbed harmful UV radiation.  

The back and forth pendulum swing of narcotic pain-killer use.

The story of Prince being found to have died due to an overdose of fentanyl is reflective of narcotic pain killer use in our country.

I say our country because the U.S. represents less than 5% of the world's population but uses over 95% of its narcotic pain-killers.  I think it's unlikely that we have 95% of the world's physical pain.

Not long ago, pain-killers such as morphine, Demerol, Dilaudid, Percocet or Vicodin were pretty much only used right after a surgery or in people dying of cancer.  Prescribing these medications for long periods of time was very much frowned upon and could result in doctors coming under investigation or prosecution for over-prescribing them if complaints arose from families, pharmacies or other doctors.

Some time in the late 1990's, the pendulum swung fully in the opposite direction.  The above link does a pretty decent job of describing it.  In California, doctors were required to take a course covering this change: pain was "the fifth vital sign", pain-killer addiction was rare, tolerance to them uncommon, and patients reporting more pain were to be assumed to be suffering a worsening in their condition (as opposed to narcotic pain-killer tolerance or addiction).  Along with this, there were a number of laws, regulations or legal precedents requiring doctors to prescribe the perfectly right amount of narcotics or risk sanctions and lawsuits.  Doctors got found against for over-use and also for under-use, or for not referring patients to doctors who would prescribe pain-killers.  A surgeon on a widely read medical website shares his recollections of these times, too.

At this point, it is fair to say that this didn't work out as intended.  And mind you, intentions were good.  Chronic pain not related to cancer exists, and no one liked to see people suffering with it.

It was certainly a tipping point when Purdue Pharma developed and heavily marketed OxyContin.  I remember  a pharmacist from a big hospital center in Seattle giving a presentation on it to doctors at Marshall right after the FDA approved it.  It was touted as being a slowly released, long acting, abuse-proof non-addictive 12-hour narcotic pain killer.  It was sold as being insoluble with water so could not be injected, and providing good pain relief with only two doses a day.  Turns out, none of these statements are true.  It didn't take long for people to realize that injecting it for a fast high was impossible, but smashing it and snorting it worked just fine.  Worse yet, the pills in no way lasted 12 hours; more like 8 hours.  Worst of all, Purdue Pharma knew this, but lied.  They knew that doctors would be a lot less likely to prescribe a medication that had to be taken every 8 hours to work.  Only now are they admitting to this fraud.

Certainly, narcotic pain medications have a role in the treatment of acute and chronic pain.  It is simply time for the pendulum to swing back to a reasonable point somewhere in the middle.

Do acid reducing medicines cause dementia?

Recent press coverage suggested that proton-pump inhibitors can cause dementia.  Unfortunately, press coverage seems to have overstated this a bit.

Proton-pump inhibitors (PPI's) are a specific type of acid reducing medication used to treat a variety of conditions such as acid reflux, esophagitis and ulcers.  They include a number of prescription and over-the-counter medications such as Prilosec, Prevacid, Protonix, Nexium and Dexilant.

Basically, an article printed in April in the Journal of the Amercan Medical Association (JAMA) described a German study showing a correlation between PPI use and dementia.

Thing is, correlation is not causation.  This study did not define particular types of dementia, such as Alzheimer's, Parkinson's, Lewy body, vascular or senile dementias.  Also, it did not take into account risks such smoking or drinking.  Both of these would cause stomach problems and are common causes of being on PPI's, and both are by themselves associated with Alzheimer's disease risk.

In other words, a limited study with a number of significant weaknesses reports that many patients with various forms of dementia have taken PPI's.  It in no way establishes that PPI use causes dementia. 

Other acid reducers, called the H2 blockers include Tagamet, Zantac and Pepcid.  These, so far, have not had any  harm from long-term use associated with them.

Generally, it makes sense to use PPI's for very specific conditions such as treatment of Barrett's esophagitis or ulcer prevention with anti-inflammatory pain (NSAID) medication use and to otherwise use H2 blockers or non-medication related supportive care (such as not smoking, and modest alcohol consumption).

Staring at screens all days can hurt your eyes; cell phone use still not linked to brain cancer. Just saying.

The recent media coverage suggesting a link between cell phone use and brain cancer is so far a bit histrionic and less than nuanced.

So far, numerous studies have (happily) failed to demonstrate a link between cell phone use and brain cancer.  The recent media coverage involves an unpublished interval report on a long and unfinished study on such risk. 

Long story short, to suggest that this report proves that cell phone use can cause people to get brain cancer would assume:

• risk of brain cancer due to cell phone exposure in rats equates to risk in humans (the study is using mice as test animals)
• female brains are protected from cell phone exposure (no cancers occurred in the female rats)
• controls are cured of cancer (the control population had lower rates of cancer than the experimentals)

This does not invalidate this ongoing study; it simply points out that the study is unfinished, the interim report unpublished and it contains a number of findings raising reasonable concerns of its scientific validity to date.  Vox and NYT did a good job of critiquing this study and its media coverage.

On the other hand, it does seem likely that staring at screens all day can make your eyes feel itchy, dry and uncomfortable. (Which makes it harder to read the screen...)  Jane Brody covers some studies on this well, and also offers some useful solutions.