The Wellness Brew - Issue 28

Earlier this year, the US Dietary Guidelines quietly removed a number that had been in place since 1980. For forty-five years, federal guidance told Americans how much alcohol was acceptable. Now it doesn't. That shift didn't get much coverage, but it reflects a real change in what the research shows, and the gap between that research and what most people still believe is wide.

But first, we filtered the noise — here's what's worth knowing this week.

When BPA was banned from baby bottles across most of the developed world in 2011 and 2012, manufacturers needed a replacement fast. They mostly landed on bisphenol S and bisphenol F, and they put "BPA-free" on the label. The problem is right there in the names. These compounds sit in the same chemical family as BPA, share a nearly identical structure, and a comparative review of the research found they show estrogenic activity similar to the chemical they replaced. Toxicologists have a term for this pattern: regrettable substitution. Swap one compound for a structurally similar one, market it as the safe version, and find out years later that it behaves the same way. The exposure data tells the story. As BPA levels in the population fell, BPS and BPF levels rose, and BPS now turns up in the urine of the large majority of people tested across multiple countries. The takeaway isn't really about bottles. It's that a label advertising the absence of one chemical tells you nothing about what replaced it. Glass and stainless steel sidestep the question. — Rochester & Bolden, Environmental Health Perspectives, 2015.

Melatonin may not be as harmless as everyone assumes

Researchers pulled five years of health records for 130,828 adults with insomnia and compared those with documented melatonin use of twelve months or more against matched non-users. The long-term users had roughly 90% higher odds of developing heart failure over those five years, were about 3.5 times more likely to be hospitalized for it, and twice as likely to die from any cause. Worth keeping the absolute numbers in view: 4.6% of long-term users developed heart failure versus 2.7% of non-users. Several caveats matter here. This is preliminary research presented at a conference and hasn't been peer-reviewed. It's observational. And everyone in it had chronic insomnia, which is itself a cardiovascular risk factor, so the poor sleep may be doing some of the work the supplement is getting blamed for. Still, melatonin is a hormone, it can be safe and effective when used appropriately, but should not be taken indefinitely. — Nnadi et al., American Heart Association Scientific Sessions, 2025.

A genetic look at GLP-1 drugs and hair loss

Hair thinning has been a persistent complaint among people taking Ozempic, Wegovy, and similar drugs, and the usual explanation is rapid weight loss, which causes temporary shedding. Researchers at NYU Langone tested whether something else might also be going on. Rather than following patients, they used the same genetic approach described in this week's Deep Dive: some people naturally carry gene variants that produce more activity at the GLP-1 receptor, the target these drugs act on. Because those variants are set at conception, they let you separate the drug's biological effect from the weight loss it causes. Men with genetically higher GLP-1 receptor activity had about 7% higher odds of male-pattern baldness per standard increase. Small effect, and the study didn't follow a single person taking the medication. It also applies only to men so far. But it suggests the hair loss may not be entirely temporary for everyone, and that's worth knowing before starting rather than after. — Ramessur et al., Journal of Investigative Dermatology, 2026.

In the first week of 2026, the US Dietary Guidelines quietly dropped the number.

Since 1980, federal guidance had specified an amount: no more than two drinks a day for men, one for women. That's where the phrase "moderate drinking" came from, and for forty-five years it functioned as the benchmark most people measured themselves against. The 2026–2030 guidelines removed the figure entirely. What replaced it is a sentence saying adults who drink should "consume less alcohol for better overall health." [1]

No ceiling. No number. Just less.

People took that and interpreted it in different ways. Some see an honest admission that there's no defensible threshold to publish. Others see guidance that got vaguer instead of stricter, which is a fair criticism. 

This week, we dive into what the research actually shows, because it has changed considerably and most people haven't caught up.

For decades, the data really did seem to show that moderate drinkers lived longer than people who didn't drink at all. This wasn't fringe. It was the J-curve, it was the French paradox, it was the red wine and resveratrol story, and it appeared in enough large studies that it became conventional wisdom.

Then researchers found the problem.

The comparison group was broken. Studies were measuring moderate drinkers against "non-drinkers," and that non-drinking group quietly included a lot of people who had stopped drinking because they were already sick. Researchers call this the sick quitter effect. If your abstainer group is partly made of people who quit after a cancer diagnosis or a heart attack, the drinkers will look healthier by comparison, and it has nothing to do with the alcohol. [2]

There's a second version of the same problem. Lifelong abstainers differ from drinkers in other ways too, and some of those differences point toward worse baseline health rather than better. [3]

So researchers needed a way around the problem entirely, and they found one.

Some people carry genetic variants that change how their bodies process alcohol, which affects how much they drink. Those variants are assigned at conception, long before anyone gets sick, so they can't be contaminated by people quitting for health reasons. Comparing outcomes across those genetic groups gets you much closer to a clean answer.

Those studies consistently find no benefit at any level of drinking, and increased risk even at low doses. [4]

That's the crux of it. The studies showing a benefit had a known flaw. The studies designed to eliminate that flaw show no benefit.

The most useful recent analysis was published in June in the Journal of Studies on Alcohol and Drugs. It found no protective effect at any level of consumption. [5]

At roughly seven drinks a week, the lifetime risk of dying from an alcohol-caused death is about 1 in 100.

At fourteen drinks a week, which was the old federal limit for men, that risk is 1 in 25.

The researchers also found that the pattern matters, not just the total. Above one drink per occasion, the risks of breast cancer, cardiovascular disease, and injury all climbed progressively. Seven drinks spread across a week is not the same exposure as seven drinks on a Saturday.

Other countries have already moved. Canada revised its national guidance in 2023 and now defines low-risk drinking as no more than two standard drinks per week, with three to six per week classified as moderate risk. Those thresholds are anchored to specific lifetime mortality risks: about 1 in 1,000 at the low-risk level, and 1 in 100 at moderate. [6]

Two drinks a week. That's the number a national health authority landed on after reviewing the same evidence.

The cancer link is the part most people haven't absorbed, and it's not new or contested. The International Agency for Research on Cancer classified alcoholic beverages as a Group 1 carcinogen in 1988. That's the same category as tobacco and asbestos. [7]

A Group 1 designation describes how confident researchers are that something causes cancer, not how much risk it carries. Alcohol and cigarettes are both Group 1, but cigarettes are far more dangerous.

Alcohol is an established cause of cancer at seven sites: mouth, throat, voice box, esophagus, liver, colon and rectum, and female breast. [7]

There are five primary causes:.

Acetaldehyde. Your body converts alcohol into acetaldehyde before breaking it down further. Acetaldehyde binds directly to DNA and damages it, and damaged DNA is how cancer starts. Acetaldehyde is itself classified as a Group 1 carcinogen. This is the main one. [8]

Oxidative stress. Metabolizing alcohol generates reactive molecules that damage DNA, proteins, and fats throughout the body. That damage drives inflammation, and inflammation drives more oxidative damage, which is a loop rather than a one-time event. [8]

Estrogen. Alcohol raises circulating estrogen, which is the leading explanation for the breast cancer connection specifically. [9]

Gut disruption. Alcohol changes the composition of the gut microbiome and makes the intestinal barrier more permeable. That allows bacterial products to cross into the bloodstream, which triggers inflammation body-wide. It's also part of the colorectal cancer picture. [8]

Then there's the one you notice the next morning, or think you don't.

Sleep. Alcohol is widely used as a sleep aid and it does help people fall asleep faster. What it does after that is the problem. A 2025 systematic review of 27 controlled studies found that even low doses, around two standard drinks, suppress REM sleep in a dose-dependent way, delaying its onset and reducing total REM across the night. [10] REM is where memory consolidation and emotional processing happen. Most people can't feel the difference, which is exactly why it goes unnoticed.

One more statistic that reframes all of this. Less than half the population of Europe knows that alcohol causes cancer. [7] This isn't disputed science sitting at the edge of the literature. It's established science that most people have simply never been told.

And in the WHO European Region, half of all alcohol-attributable cancers come from light and moderate drinking rather than heavy drinking. [11] The burden isn't concentrated in the people you'd expect.

It would be dishonest to present this as fully settled, because it isn't.

In 2025, the National Academies of Sciences reviewed much of the same evidence and concluded that recommendations should be tailored to individual risk rather than applied universally. Critics of that report argued it underweighted the cancer evidence and left out the genetic studies. [12]

When people stop or cut back, the damage reverses.

IARC identified three specific ways this happens. Acetaldehyde clears from the upper digestive tract and colon relatively quickly. Alcohol-related damage to the intestines and the gut microbiome reverses. And DNA damage and DNA alterations decrease over time. [7]

That's not a small footnote. Much of the damage from alcohol is not permanent.

So here's where this leaves us. There's no level of drinking the current evidence identifies as risk-free. The risks are small at low intake and they climb steadily. The old reason for drinking, that a glass of wine was doing something good for your heart, is presumed wrong.

Plenty of things people choose to do carry risk in this range, and most of us accept some of it in exchange for enjoying our lives. That's a legitimate trade and we all need to decide if enjoying a drink or two is worth it to us.

But it should be a trade you're making with the actual numbers in front of you, rather than one you inherited from a story about red wine that turned out to be wrong.

If you're going to drink, here's what the research says actually matters. 

1. Pattern matters as much as volume.
This is the most underappreciated finding in the issue. Above one drink per occasion, risk climbs progressively — so seven drinks spread across a week is a different exposure than seven on a Saturday. Limit how often you drink more than 1-2 drinks in a single setting.

2. Know where you actually land.
Most people underestimate their own intake, partly because a generous pour at home isn't one standard drink. Count honestly for a couple of weeks. Seven a week puts you near 1 in 100 lifetime risk. Fourteen puts you at 1 in 25. You can't weigh a trade you haven't measured.

3. Stop three hours before bed.
Alcohol close to sleep is what wrecks REM, and moving your last drink earlier reduces that impact.

4. Decide if it’s worth it.
Make an educated decision on if drinking is worth the additional lifetime risk to you or not. Consider limiting alcohol to special occasions or scenarios you’re not willing to give up. 

If you found this useful, please forward it to your friends and family. If you had this forwarded to you — sign up here.

Wellness, filtered.

The Wellness Brew

Sources:

Disclaimer: The Wellness Brew is for informational purposes only and does not constitute medical advice. The content published here is not intended to diagnose, treat, cure, or prevent any disease or health condition. Always consult a qualified healthcare professional before making any changes to your diet, supplement routine, or lifestyle.