Mythbusting The Mask Debate

We asked you for your mask policy this respiratory virus season, and got the above-depicted, below-described, set of responses:

• A little under half of you said you will be masking when practical in indoor public places
• A little over a fifth of you said you will mask only if you have respiratory virus symptoms
• A little under a fifth of you said that you will not mask, because you don’t think it helps
• A much smaller minority of you (7%) said you will go with whatever people around you are doing
• An equally small minority of you said that you will not mask, because you’re not concerned about infections

So, what does the science say?

Wearing a mask reduces the transmission of respiratory viruses: True or False?

True…with limitations. The limitations include:

• The type of mask
  • A homemade polyester single-sheet is not the same as an N95 respirator, for instance
• How well it is fitted
  • It needs to be a physical barrier, so a loose-fitting “going through the motions” fit won’t help
• The condition of the mask
  • And if applicable, the replaceable filter in the mask
• What exactly it has to stop
  • What kind of virus, what kind of viral load, what kind of environment, is someone coughing/sneezing, etc

More details on these things can be found in the link at the end of today’s main feature, as it’s more than we could fit here!

Note: We’re talking about respiratory viruses in general in this main feature, but most extant up-to-date research is on COVID, so that’s going to appear quite a lot. Remember though, even COVID is not one beast, but many different variants, each with their own properties.

Nevertheless, the scientific consensus is “it does help, but is not a magical amulet”:

• 2021: Effectiveness of Face Masks in Reducing the Spread of COVID-19: A Model-Based Analysis
• 2022: Why Masks are Important during COVID‐19 Pandemic
• 2023: The mitigating effect of masks on the spread of COVID-19

Wearing a mask is actually unhygienic: True or False?

False, assuming your mask is clean when you put it on.

This (the fear of breathing more of one’s own germs in a cyclic fashion) was a point raised by some of those who expressed mask-unfavorable views in response to our poll.

There have been studies testing this, and they mostly say the same thing, “if it’s clean when you put it on, great, if not, then well yes, that can be a problem”:

❝A longer mask usage significantly increased the fungal colony numbers but not the bacterial colony numbers.

Although most identified microbes were non-pathogenic in humans; Staphylococcus epidermidis, Staphylococcus aureus, and Cladosporium, we found several pathogenic microbes; Bacillus cereus, Staphylococcus saprophyticus, Aspergillus, and Microsporum.

We also found no associations of mask-attached microbes with the transportation methods or gargling.

We propose that immunocompromised people should avoid repeated use of masks to prevent microbial infection.❞

Source: Bacterial and fungal isolation from face masks under the COVID-19 pandemic

Wearing a mask can mean we don’t get enough oxygen: True or False?

False, for any masks made-for-purpose (i.e., are by default “breathable”), under normal conditions:

• COVID‐19 pandemic: do surgical masks impact respiratory nasal functions?
• Performance Comparison of Single and Double Masks: Filtration Efficiencies, Breathing Resistance and CO2 Content

However, wearing a mask while engaging in strenuous best-effort cardiovascular exercise, will reduce VO₂max. To be clear, you will still have more than enough oxygen to function; it’s not considered a health hazard. However, it will reduce peak athletic performance:

Effects of wearing a cloth face mask on performance, physiological and perceptual responses during a graded treadmill running exercise test

…so if you are worrying about whether the mask will impede you breathing, ask yourself: am I engaging in an activity that requires my peak athletic performance?

Also: don’t let it get soaked with water, because…

Writer’s anecdote as an additional caveat: in the earliest days of the COVID pandemic, I had a simple cloth mask on, the one-piece polyester kind that we later learned quite useless. The fit wasn’t perfect either, but one day I was caught in heavy rain (I had left it on while going from one store to another while shopping), and suddenly, it fitted perfectly, as being soaked through caused it to cling beautifully to my face.

However, I was now effectively being waterboarded. I will say, it was not pleasant, but also I did not die. I did buy a new mask in the next store, though.

tl;dr = an exception to “no it won’t impede your breathing” is that a mask may indeed impede your breathing if it is made of cloth and literally soaked with water; that is how waterboarding works!

Want up-to-date information?

Most of the studies we cited today were from 2022 or 2023, but you can get up-to-date information and guidance from the World Health Organization, who really do not have any agenda besides actual world health, here:

Coronavirus disease (COVID-19): Masks | Frequently Asked Questions

At the time of writing this newsletter, the above information was last updated yesterday.

Take care!

From Apples to Bees, and High-Fructose C’s

We asked you for your (health-related) policy on sugar. The trends were as follows:

• About half of all respondents voted for “I try to limit sugar intake, but struggle because it’s in everything”
• About a quarter of all respondents voted for “Refined sugar is terrible; natural sugars (e.g. honey, agave) are fine”

• About a quarter of all respondents voted for “Sugar is sugar and sugar is bad; I avoid it entirely”
• One (1) respondent voted for “Sugar is an important source of energy, so I consume plenty”

Writer’s note: I always forget to vote in these, but I’d have voted for “I try to limit sugar intake, but struggle because it’s in everything”.

Sometimes I would like to make my own [whatever] to not have the sugar, but it takes so much more time, and often money too.

So while I make most things from scratch (and typically spend about an hour cooking each day), sometimes store-bought is the regretfully practical timesaver/moneysaver (especially when it comes to condiments).

So, where does the science stand?

There has, of course, been a lot of research into the health impact of sugar.

Unfortunately, a lot of it has been funded by sugar companies, which has not helped. Conversely, there are also studies funded by other institutions with other agendas to push, and some of them will seek to make sugar out to be worse than it is.

So for today’s mythbusting overview, we’ve done our best to quality-control studies for not having financial conflicts of interest. And of course, the usual considerations of favoring high quality studies where possible Large sample sizes, good method, human subjects, that sort of thing.

Sugar is sugar and sugar is bad: True or False?

False and True, respectively.

• Sucrose is sucrose, and is generally bad.
• Fructose is fructose, and is worse.

Both ultimately get converted into glycogen (if not used immediately for energy), but for fructose, this happens mostly* in the liver, which a) taxes it b) goes very unregulated by the pancreas, causing potentially dangerous blood sugar spikes.

This has several interesting effects:

• Because fructose doesn’t directly affect insulin levels, it doesn’t cause insulin insensitivity (yay)
• Because fructose doesn’t directly affect insulin levels, this leaves hyperglycemia untreated (oh dear)
• Because fructose is metabolized by the liver and converted to glycogen which is stored there, it’s one of the main contributors to non-alcoholic fatty liver disease (at this point, we’re retracting our “yay”)

Read more: Fructose and sugar: a major mediator of non-alcoholic fatty liver disease

*”Mostly” in the liver being about 80% in the liver. The remaining 20%ish is processed by the kidneys, where it contributes to kidney stones instead. So, still not fabulous.

Fructose is very bad, so we shouldn’t eat too much fruit: True or False?

False! Fruit is really not the bad guy here. Fruit is good for you!

Fruit does contain fructose yes, but not actually that much in the grand scheme of things, and moreover, fruit contains (unless you have done something unnatural to it) plenty of fiber, which mitigates the impact of the fructose.

• A medium-sized apple (one of the most sugary fruits there is) might contain around 11g of fructose
• A tablespoon of high-fructose corn syrup can have about 27g of fructose (plus about 3g glucose)

Read more about it: Effects of high-fructose (90%) corn syrup on plasma glucose, insulin, and C-peptide in non-insulin-dependent diabetes mellitus and normal subjects

However! The fiber content (in fruit) mitigates the impact of the fructose almost entirely anyway.

And if you take fruits that are high in sugar and/but high in polyphenols, like berries, they now have a considerable net positive impact on glycemic health:

• Polyphenols and Glycemic Control
• Polyphenols and their effects on diabetes management: A review
• Dietary polyphenols as antidiabetic agents: Advances and opportunities

You may be wondering: what was that about “unless you have done something unnatural to it”?

That’s mostly about juicing. Juicing removes much (or all) of the fiber, and if you do that, you’re basically back to shooting fructose into your veins:

• Effect of Fruit Juice on Glucose Control and Insulin Sensitivity in Adults: A Meta-Analysis of 12 Randomized Controlled Trials
• Intake of Fruit, Vegetables, and Fruit Juices and Risk of Diabetes in Women

Natural sugars like honey, agave, and maple syrup, are healthier than refined sugars: True or False?

True… Sometimes, and sometimes marginally.

This is partly because of the glycemic index and glycemic load. The glycemic index scores tail off thus:

• table sugar = 65
• maple syrup = 54
• honey = 46
• agave syrup = 15

So, that’s a big difference there between agave syrup and maple syrup, for example… But it might not matter if you’re using a very small amount, which means it may have a high glycemic index but a low glycemic load.

Note, incidentally, that table sugar, sucrose, is a disaccharide, and is 50% glucose and 50% fructose.

The other more marginal health benefits come from that fact that natural sugars are usually found in foods high in other nutrients. Maple syrup is very high in manganese, for example, and also a fair source of other minerals.

But… Because of its GI, you really don’t want to be relying on it for your nutrients.

Wait, why is sugar bad again?

We’ve been covering mostly the more “mythbusting” aspects of different forms of sugar, rather than the less controversial harms it does, but let’s give at least a cursory nod to the health risks of sugar overall:

• Obesity and associated metabolic risk
• Main contributor to non-alcoholic fatty liver disease
• Increased risk of heart disease
• Insulin resistance and diabetes risk
• Cellular aging (shortened telomeres)
• 95% increased cancer risk

That last one, by the way, was a huge systematic review of 37 large longitudinal cohort studies. Results varied depending on what, specifically, was being examined (e.g. total sugar, fructose content, sugary beverages, etc), and gave up to 200% increased cancer risk in some studies on sugary beverages, but 95% increased risk is a respectable example figure to cite here, pertaining to added sugars in foods.

And finally…

The 56 Most Common Names for Sugar (Some Are Tricky)

How many did you know?