String Theory

Published March 1, 2025

Morning Report — Not Your Typical Medical Newsletter

We get it, you see a lot of medical newsletters, so hear us out. Once a month, we’ll highlight important medical news sprinkled with witty commentary, fun facts, giveaways, and more… because learning should be fun! Subscribe to receive the Morning Report directly.

New Study Pours Support for Milk in CRC Prevention

CANCER CONCLUSIONS

Big Dairy has insisted for generations that milk does a body good, but scholarly sentiment keeps ping-ponging—and may shift again before you finish this newsletter. As of now, a 2025 study throws its weight behind the wholesome beverage, this time highlighting its potential benefit in reducing colorectal cancer (CRC) risk.

Got evidence?

In this prospective study—the largest of its kind—researchers explored the link between intake of 97 dietary products and CRC risk in >500,000 postmenopausal UK women. Over an average of 16 years, >12,000 participants developed CRC. Dairy products—especially milk—emerged as the most protective against the disease. Why? Likely, the calcium. Just 300 mg of calcium per day (a tall glass of milk) cut risk by a relative 17%. First author, Dr. Keren Papier, explains, “It’s suggested that calcium might protect against bowel cancer by binding to bile acids and free fatty acids to form a type of a harmless ‘soap,’ which stops them from damaging the lining of our gut.” The study also reinforced ties between CRC risk and intake of alcohol and red/processed meat. 

Limitations curdle the results  

This study carries the usual pitfalls of observational dietary research—self-reported data and confounding factors. Plus, a narrowed focus on a single country and one gender limits generalizability. 

Key takeaways 

Incidence of CRC could skyrocket to 3.2 million by 2040, but the milk glass is still half full—diet and lifestyle could prevent more than half. This study shows that calcium from milk, yogurt, and, to a lesser extent, leafy greens and other calcium-rich foods may help curb CRC risk. Whether calcium supplements and fortified foods offer the same benefit remains unclear. For now, the authors suggest sticking with a tall glass of milk. Will these findings finally put the milk debate out to pasture? Nah—this clash will keep churning for years.

For more education on colorectal cancer, check out this CME podcast episode: Don’t Miss the Red Flags for Early-Onset Colorectal Cancer  

This Simple Habit May Get Between Patients and CVD

CARDIO CORNER

Americans fall far short of the 167 meters of floss the American Dental Association (ADA) urges us to use annually. The reality is closer to 16 meters of dental rope—adequate for Tom Cruise suspended over a CIA vault, but insufficient for oral hygiene. And the difference matters. A new study strings together compelling evidence linking more frequent flossing with lower cardiovascular (CV) risk.

Exploring the string theory

The American Stroke Association’s International Stroke Conference 2025 highlighted a preliminary study in which researchers assessed the oral hygiene habits and CV events of >6,000 participants for 25 years. Flossers, making up 65% of the cohort, showed a 22% lower risk of ischemic stroke and a striking 44% lower risk of cardioembolic stroke than non-flossers. And the greater the frequency of flossing, the greater the reduction of stroke risk. Further, the flossers had a 12% lower likelihood of developing atrial fibrillation (AF).

Strings attached

The study doesn’t untangle potential confounders, like do flossers have a superior diet, perhaps with ample kale? Do kale eaters floss more because they have to? Also, the study relied on self-reported flossing habits and didn’t track long-term changes in oral care.

Key Takeaways

The evidence linking oral hygiene with CV health keeps stacking up, but this study singles out flossing as a key component—regardless of brushing and dental visits. Lead author Dr. Souvik Sen suggests why: “Flossing may reduce stroke risk by lowering oral infections and inflammation and encouraging other healthy habits.” So, what do you tell patients? Floss at least weekly—ideally daily—for CV protection. And stick to standard dental floss (~18 inches). That may seem obvious, but another study exposed the alternative implements Americans use: fingernails (61%), folded paper (40%), cutlery (21%), safety pins (14%), and hair strands (7%)—as Sally from When Harry Met Sally already warned us.

For more education on CVD prevention, check out this CME podcast episode: The PREVENT Risk Calculator: A New Equation for Predicting Heart Health

Harnessing Skin Bacteria for a Novel Vaccine Modality

EMERGING TRENDS

"It’s incredibly dry, way too salty for most single-celled creatures and there’s not much to eat. I can’t imagine anything would want to live there,” says Dr. Michael Fischbach, painting a bleak picture of life on the human skin. But Staphylococcus epidermidis thrives in this harsh landscape. And this innocuous skin-colonizing microbe may be the linchpin for revolutionizing vaccine delivery. 

Dropping the needle?

S epidermidis—once as overlooked as a childhood goldfish—is now turning heads among immunologists, who have uncovered its surprising ability to provoke a robust immune response. When Stanford researchers identified the protein Aap, an immune trigger within S epidermidis, lightbulbs flashed. What if they genetically modified Aap to display fragments of disease-causing toxins, eg, those from tetanus or diphtheria? Could S epidermidis become a “living vaccine"?

In a mouse trial with more twists, turns, evolving theories, and surprises than every season of The White Lotus, researchers demonstrated that bioengineered S epidermidis effectively primes the immune system against lethal toxins. Mice rubbed with the modified strain developed strong antibody responses against tetanus and diphtheria. The team then shifted to chemically stapling a tetanus-toxin fragment to S epidermidis, expecting the immune response to weaken as the bacteria divided. Nope. Immunity only strengthened, leaving excited researchers to quote Mean Girls—“The limit does not exist!” These findings suggest that human skin could serve as fertile ground for a topical vaccine—one that is cheaper, more accessible, side-effect free, and kid approved. 

Key takeaways 

This study establishes proof of concept for a novel vaccine modality leveraging bugs that, as Fischbach puts it, “reside on every hair follicle of virtually every person on the planet.” Next up: trials in monkeys, then humans (projected within three years). The researchers anticipate this prototype to work against “viruses, bacteria, fungi, and one-celled parasites,” and without triggering the inflammatory response typical of traditional vaccines. And with patients of all ages likely to favor a needle-less option, this innovation could achieve an approval rating worthy of Dolly Parton. 

For more education on immunization updates, check out this CME activity: Adult Immunization Updates: More Tools, More Opportunities for Better Health