"No Safe Level" Is A Red Flag For Junk Science

According to a wise man named Paracelsus (essentially the Western world's first toxicologist) long ago, it is the dose that makes the poison.  Anything (even water) can be poisonous in a high enough quantity, and conversely there is, practically speaking, a safe level for everything.  It is all a matter of degree.  So why, when it comes to things like alcohol, do the "experts" seem to lose all common sense?

Take the latest study of alcohol and the brain at Oxford, for example.  This one claims that there is no safe level of alcohol for the brain, that is, any amount will cause damage.  The observational study, which notably has not even been peer-reviewed yet, finds a negative linear correlation between alcohol drinking volume and the volume of gray matter (as well as white matter) in brain scans, even after controlling for every confounder they could think of.  While it is known that excessive drinking can damage the brain, the shocker here seems to have more to do with much lower levels of drinking previously thought to be safe.

I bet the reader can quickly spot the problem here.  If not, here it goes.  A closer look at the data shows that, given how small the overall effect size is, with alcohol explaining only 0.8% of the variance in gray matter, combined with the tendency of people (especially heavier drinkers) to undercount their drinks, the apparent harmful effects of light to moderate drinking may very well be spurious at the lower end of the curve even if likely genuine towards the higher end.  That, and the lack of peer review of course.

They also found an additive effect of "binge" drinking over and above the effect of drinking volume alone, particularly for daily "binging", which was fairly strong and consistently statistically significant.  But given the rather wide confidence intervals, for less than daily "binge" drinking, it was not always statistically significant.  Given the typically fairly low definitions used for "binge" drinking, it would not be surprising that the confidence intervals are so wide.

It also appears from this study that people with hypertension (high blood pressure) and/or a high BMI are significantly more sensitive to the apparent adverse effects of alcohol than the average person for whatever reasons as well.  The interaction was not just additive, but multiplicative.  That will certainly require further study going forward. 

We are not in any way encouraging anyone to drink alcoholic beverages. But specious inferences should not cloud the issue either.

There is a safe level everything, even arsenic apparently.  So why would that not be true for alcohol?  Especially since our own bodies can actually produce a bit of it as a byproduct, believe it or not?

On the bright side, at least the study looked largely at older adults (age 40+) and did not indulge in the usual youth drinking panic routines.  Even if the observed effects are 100% true, that would of course mean that young people are not uniquely vulnerable to the adverse effects of alcohol on the brain.

25, You Say? Let's Nip That In The Bud

A handful of psychiatrists in Minnestota, where cannabis has not yet been legalized for recreational use (but is currently being considered), is calling for the age limit to be 25 when it is legalized.  They cite anecdotal evidence of young patients with psychosis that they claim is caused by today's high-potency weed.  And here is why they are, in a word, wrong:

1. First of all, these psychoses that they cite are occurring despite recreational cannabis remaining illegal in Minnesota for all ages.  Legalizing it with an utterly unrealistic age limit of 25 will only preserve and entrench the current black market while worsening criminal justice inequities, both age and racial disparities.
2. The brain continues developing well into the 30s and 40s, and the risk period for schizophrenia continues until about 30, so 25 is arbitrary.
3. While excessive cannabis use can be harmful at any age, and starting use before age 18 and especially before 15 is likely more harmful than starting at 18 or older, there is really no clear and convincing evidence that using it at 18-20 is any worse than using at 21-24 or 25+, especially for light or moderate use.  To claim otherwise is unscientific, disingenuous, and really pushes the limits of the precautionary principle.
4. As we have noted many times before, the relationship between cannabis and psychosis is quite complex, and far more nuanced than Reefer Madness.  Though there is likely a tiny, exquisitely vulnerable sliver of the population that should really avoid weed like the plague at any age, that is no reason for blanket bans or restrictions (by age or otherwise) for legal adults.  That would be unscientific and unjust.
5. And finally, if today's high-potency weed is in fact the culprit in an alleged (and far from certain) recent increase in psychosis among young people, the solution is NOT to raise the age limit and force it deeper underground, but to put a cap (say, 10% or 15%) on the potency of THC on legal weed (and perhaps also setting a minimum level of CBD, which counteracts many of the adverse effects of too much THC), and/or taxing it based on THC/CBD levels.  And also warn people who are at increased risk of psychosis as well via honest public education messaging without sensational fearmongering.

There it is.  Problem solved.  No good reason to set the age limit any higher than 18, let alone 25.  Let's nip this ageist idea in the bud, pun intended of course.

UPDATE:  Twenty-One Debunked believes that proper labeling and tax incentives alone will likely be enough to encourage lower THC and higher CBD levels even in the absence of hard THC/CBD limits.  Taxing cannabis at a higher rate base on THC levels (whether proportionally, or perhaps disproportionally when exceeding a specific threshold or for specific product categories) and applying an offsetting tax discount based on CBD levels would do the trick, as the market would adjust accordingly.

Also, getting back to the subject of psychosis in young people, don't forget to take your fish oil.  Yes, you read that right.  Apparently a new study found that there is an inverse correlation between omega-3 fatty acid levels during adolescence and psychosis in young adulthood.  This dovetails nicely with a study from 2010 that found that just 12 weeks of giving fish oil supplements to teens at ultra-high risk of psychosis greatly reduced their risk of developing psychosis a year later compared with those given placebo.