I have been living in Athens for a few months now and you cannot walk a block without meeting a neighborhood cat. They are everywhere. They sleep under cafe tables, guard the entrances to ancient ruins, and sun themselves on the hoods of parked cars.

To most people, they are just a charming part of the city. But after looking into the data, I realized they are actually a perfect example of a scientific framework called the One Health model.

One Health is the idea that you cannot separate the health of humans from the health of animals and the environment. They are all connected. When we ignore the health of the 3 million stray cats in Greece, we are ignoring a major part of our own public health safety net.

Why the Pandemic Connection Isn’t Insane

It might sound extreme to link a friendly neighborhood cat to a global pandemic, but it is actually a simple math problem. According to the CDC, nearly 75% of new or emerging infectious diseases come from animals.

Scientists view cats as a bridge species. Whether a virus escapes from a lab or spills over from a forest, it needs a middleman to reach a city. Cats hunt the rodents and birds that carry hidden germs (the “wild” leg) and then they come to sit on our scooters or in our laps at dinner (the “human” leg).

When you have millions of animals living in high density, you have a giant, city-wide petri dish. The more a virus bounces around a large population, the more chances it has to mutate. Managing the health of these cats is not about being scared of them: it is about stopping a spillover event before it starts.

What One Health means in plain language

Scientists at the WHO use this model to track diseases. Think of it as a three-legged stool:

1. Animal Health: If the cats are sick, they become a reservoir for germs.

2. Environmental Health: If the streets are dirty, parasites spread faster.

3. Human Health: If the first two legs fail, humans get sick.

The Animal Leg: Looking Healthy vs. Being Healthy

Because Athenians are so good at feeding these cats, they often look robust and clean. I’ve seen some exceptionally comfortable-looking cats. However, clinical data tells a different story.

• Parasites: A study in Thessaloniki found that over 50% of stray cats carried internal worms.

• Viruses: Roughly 9.2% of Greek strays test positive for FIV (Feline Immunodeficiency Virus), according to a prospective study of 435 cats. This is a virus that weakens a cat’s immune system. It makes them more likely to carry other diseases that could potentially reach humans.

This calico cat on a scenic railing shows the peaceful public face of Greece’s feline population, providing a “cute buffer” before we look at the serious risks below.

The Human Leg: Zoonotic Risks

When animals live this close to us, their germs can jump to humans. These are called zoonotic diseases.

• Toxoplasmosis: This is a parasite found in cat waste (Toxoplasma gondii). A countrywide study of 1,554 cats found that 21.8% of Greek cats have been exposed. This parasite can cause serious flu-like symptoms and is a major concern for pregnant women.

• Cat Scratch Fever: This is a bacterial infection spread by fleas (Bartonella). In tourism-heavy areas, 35.4% of cats were found to be carriers. In humans, it can cause fever, headaches, and painfully swollen lymph nodes.

The Environmental Leg: The “Landscape of Fear”

One reason you rarely see rats in Athens is because of the cats.

• Rodent Suppression: Scientists call this the “landscape of fear.” The mere presence and smell of cats force rodents to stay deep in the sewers. This is a natural form of pest control. It keeps us from having to use toxic chemical poisons in the city.

• The Pigeon Paradox: I have wondered why they do not eat the annoying pigeons. The answer is Caloric Economics. In a city where locals provide free, high-protein kibble, a cat will not waste energy hunting a bird that can easily fly away.

The Rules: Project Argos

Greece is trying to modernize this system with Law 4830/2021 (Project Argos). As of early 2026, the government is conducting a major review to see how well it is working.

• Mandatory Neutering: Cities must sterilize strays to keep the population from growing.

• Registration: All pets and community cats must be microchipped and put in the national database.

• Municipal Duty: It is now the legal job of each city to provide medical care for strays. However, most of the work is still done by volunteers and NGOs like Animal Action Greece.

Quick Answers to Common Claims

• “The cats are fine because they are fed.” Food keeps them alive, but it does not stop parasites or viruses.

• “I never see rats, so the cats must be killing them.” They are mostly just scaring them into hiding.

• “It is okay to have millions of strays.” From a One Health perspective, no. High density increases the chance of a disease jump to humans.

• “Is it safe to pet them?” Usually yes, but always wash your hands. Most risks come from fleas or waste rather than the fur itself.

Bottom Line

The neighborhood cats of Athens are more than just a local quirk. They are a living laboratory for the One Health model. Managing their health through TNR (Trap-Neuter-Return) and medical care is not just about being kind to animals. It is a vital part of urban biosafety. If we want to prevent the next pandemic, we have to pay attention to the interface right outside our front door.

Links if you would like to learn more:

• Zoetis: Driven to Care — Our One Health Approach

• Support Nine Lives Greece (Athens-based TNR NGO)

• Animal Action Greece: Transforming Stray Lives

• CDC Guide to One Health and Zoonotic Diseases

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I saw a video last week on Instagram that said.

“Creatine causes hair loss.”

It was getting clicks. It was also using old research to scare people.

Here is what the story left out. In 2009, a small crossover study in college rugby players reported a rise in DHT after three weeks of creatine. The trial did not measure hair loss. It was short and small. Yet it keeps getting shared as proof that creatine makes you bald.

Newer data do not back that claim. A 12‑week randomized trial published in 2025 tracked hair and hormones and found no difference between creatine and placebo in hair growth or DHT.

Creatine is also legal in sport, not on WADA’s 2025 Prohibited List.

What creatine does, in plain language

Creatine helps your cells recycle energy fast. Your muscles and brain store it as phosphocreatine. During short, hard efforts, this system helps you push a bit harder and recover faster.

What is solid for muscle and performance

Across randomized trials and meta‑analyses, creatine plus resistance training improves strength and often lean mass compared with training alone, as summarized by Burke et al., 2023 and Wang et al., 2024.

Europe has two narrow authorized claims: daily 3 g creatine increases performance in successive short, high‑intensity efforts, and in adults over 55, daily creatine can enhance the effect of resistance training on muscle strength. That language comes from EFSA’s 2011 opinion and EU Implementing Regulation 2017/672.

Brain claims, with caveats

Hype is ahead of proof. In 2024, EFSA reviewed the file and rejected a broad cognition claim, stating that a cause‑and‑effect link is not established.

That said, there are interesting signals. Under sleep loss, a single high dose improved processing speed and brain energy markers in a small lab trial. A 2024 meta‑analysis reported small benefits for memory and attention time, with mixed results elsewhere. Vegetarians and vegans often respond more, likely due to lower baseline stores, in studies such as Benton et al., 2011 and Rae et al., 2003.

Concussion and depression: early, not settled

Small pediatric TBI pilots reported better recovery with long‑term creatine, with similar findings in a second open‑label study in 2007 (Acta Paediatr), but they need confirmation.

For depression, a double‑blind trial in women found faster and greater SSRI response with 5 g creatine per day versus placebo. A 2025 randomized add‑on study to CBT also suggests benefit, but more work is needed.

Safety: kidneys, cramps, dehydra

tion

In healthy adults using standard doses, controlled trials and reviews do not show kidney harm. Creatine can raise the lab marker creatinine without damaging the kidneys, as reported in a 2019 meta‑analysis. A 2024 Mendelian randomization study also found no association with impaired renal function.

The old claim that creatine causes cramps or dehydration has not held up in team‑sport data. In Division I football, creatine users did not have more cramping, heat illness, or dehydration. Reviews, including the ISSN position stand, reach the same conclusion.

Pregnancy and breastfeeding

Creatine is a normal component of human milk. Human supplementation data in lactation are limited, so major databases advise caution unless prescribed. A 2025 pharmacokinetic study in third‑trimester adults suggests dosing is feasible, but this is not a go‑ahead for routine use.

The form that works

Pick plain creatine monohydrate. Head‑to‑head studies have not shown buffered creatine or creatine HCl to outperform monohydrate on real outcomes, according to the ISSN position stand and an earlier overview by Cooper et al., 2012.

Powder is very stable when dry. In solution it slowly degrades to creatinine, faster in acidic drinks and with heat, based on classic stability work and a broader 2022 review.

A note on gummies

Independent tests in 2024 and 2025 found several popular creatine gummies contained little or no creatine. Heat and acidity during production likely break creatine down.

How to use creatine

Two simple dosing options used in research:

1. Loading then maintenance. Take 20 g per day split into 4 doses for 5 to 7 days. Then 3 to 5 g per day. Fast saturation, more early water weight. Guidance in the ISSN stand.

2. No loading. Take 3 to 5 g per day. You will reach similar muscle levels in a few weeks. Easier on the stomach.

Timing. Consistency matters more than the clock. If you lift, taking it near workouts is fine. A small trial hinted at a post‑workout edge, while others found similar results or mixed effects.

With food. Pairing creatine with carbohydrate, or carbohydrate plus protein, can increase retention during the first days.

Who tends to benefit most

• People who lift or do short, intense efforts.

• Older adults who lift.

• Vegetarians and vegans, who often start with lower muscle creatine and may see a bigger jump, per Chilibeck et al., 2017 and Benton et al., 2011.

Product quality and certifications

Supplements are not pre‑approved by FDA. Contamination and mislabeling happen. If you are an athlete, use products vetted by programs that test for banned substances. USADA points athletes to NSF Certified for Sport and you can also look for Informed Sport. You can search certified creatine products here: NSF listings and Informed Sport search.

Quick answers to common claims

• “Creatine causes hair loss.” Not shown in modern trials. See the 2025 RCT above.

• “Creatine hurts your kidneys.” Not in healthy adults at studied doses. See the kidney meta‑analysis above.

• “Creatine dehydrates you and causes cramps.” Team‑sport data say no. See the football study above.

• “Other forms are better than monohydrate.” No convincing head‑to‑head advantage.

• “It is banned in sports.” False. Check the WADA list.

Bottom line

Fear sells. The 2009 rugby paper is real, but it is not the whole story. In 2025, creatine monohydrate remains one of the best‑studied, most useful, and most boringly safe supplements for healthy adults when used as directed. If you use it, keep it simple. Pick monohydrate. Use 3 to 5 g daily. Lift. Choose third‑party tested products if you compete or want extra assurance.

Affiliate Links:

Nutricost Creatine Monohydrate

THORNE Creatine - Micronized Creatine Monohydrate Powder

Affiliate revenue supports The Health Signal’s independent reporting.

I was in a debate recently about why people often say they can eat bread, cheese, and desserts in Europe without gaining weight, but not in the United States.

Their take was that “there’s something in the food here making us fat.”

My response was simple. The food is not that different. What changes is how much we move. In many European cities, it is normal to walk 8,000 to 10,000 steps a day just getting to work, running errands, and using public transit. In the U.S., the same day might involve fewer than 4,000 steps and a lot of sitting.

Walking an extra 5,000 steps burns roughly 200 to 250 calories for most adults. Over a week, that is about 1,400 to 1,750 calories, close to half a pound of body fat. Over a year, the difference can be more than 20 pounds, even if the food is exactly the same.

That balance of calories in versus calories out is the core of weight change. But the way our bodies burn calories is more complicated than a simple math equation.

What’s Driving the Debate

“CICO is not a fad, it’s physics,” said Kevin Hall, a senior investigator at the National Institute of Diabetes and Digestive and Kidney Diseases, in a January 2025 NIH interview. “But the body is not a simple math equation.”

The principle is clear. Burn more calories than you consume, and you lose weight. Consume more than you burn, and you gain.

The reality is that metabolism is always adjusting to what you eat, how you move, and how your body changes.

Metabolism in Motion

Basal metabolic rate is the energy your body uses at rest. It accounts for most daily calorie burn. That number can change.

Dieting can slow it down, a process called adaptive thermogenesis. Illness or poor sleep can do the same.

Gaining muscle can have the opposite effect. Muscle burns more calories at rest than fat tissue. The more muscle you have, the more energy your body uses even when you are not moving. Strength training can raise daily calorie needs and help maintain weight loss.

A 2024 review in Obesity found that energy expenditure can drop by 10 to 15 percent during prolonged calorie restriction, making weight loss harder over time.

A more recent study found that after very low‑calorie diets or bariatric surgery, resting energy expenditure dropped by about 322 kcal per day beyond what would be expected

The Quality Question

Not all calories are equal in how they affect hunger and energy.

A 2023 American Journal of Clinical Nutrition study found that people eating higher protein and higher fiber meals consumed fewer calories later in the day than those eating ultra-processed meals with the same calorie count.

Practical Takeaways

Experts recommend using CICO as a framework, not a strict rulebook. Tracking can be helpful, but food quality, muscle mass, sleep, and stress all affect the outcome.

“Calories matter, but they are not the whole story,” said Hall. “The foods you choose and the lifestyle you lead will determine how well the math works for you.”

Bottom Line

CICO still applies. It is also incomplete. Energy balance drives weight change, but metabolism, behavior, and body composition make the equation a moving target.

Affiliate Links:

• Garmin Forerunner 265 GPS Running Smartwatch

• Garmin Venu 3 Fitness Smartwatch

• Garmin epix Gen 2 Premium Smartwatch

Affiliate revenue supports The Health Signal’s independent reporting.

From TikTok kitchens to fast-food fryers, beef tallow is back. Once dismissed as artery-clogging animal fat, it’s now being repackaged as a stable, “ancestral” alternative to seed oils. Some brands market it as a source of fat-soluble vitamins. Others lean on flavor and tradition.

Chefs, influencers, and some nutrition advocates are embracing it. Federal guidelines are not.

What's Driving the Shift

"People are rethinking their fear of saturated fat," said Dr. Anthony Gustin, a functional medicine provider and founder of Perfect Keto. "Beef tallow is stable at high temperatures, and unlike seed oils, it doesn't oxidize easily."

Tallow is rich in saturated and monounsaturated fats. It was a staple of American cooking until the 1980s, when public health campaigns pivoted to promoting vegetable oils. That shift was largely driven by concerns over cholesterol and cardiovascular disease.

Now, with more scrutiny of industrial seed oils like soybean and canola, some consumers are turning back to animal fats.

Flavor First

Chefs are also fueling the revival.

"It just makes everything taste better," said Matt Jennings, a chef and food strategist. "Whether you're frying potatoes or searing meat, it adds this incredible mouthfeel and flavor."

Several brands are banking on that appeal. Epic Provisions and Fatworks offer jarred beef tallow for home use, sometimes infused with herbs or garlic. Primal Kitchen recently added it to a new high-heat cooking line.

Health Claims Under Fire

Beef tallow is especially popular in paleo and carnivore circles. Influencers tout it as “clean,” “anti-inflammatory,” and “nutrient-dense.” Some highlight its vitamin A, D, E, and K content.

But nutrition experts are skeptical.

"I don’t see any health benefit of using tallow," said Dr. Alice Lichtenstein, senior scientist at Tufts University’s Human Nutrition Research Center on Aging. In an April 2025 explainer from Tufts, Lichtenstein stated there is "no data" showing typical seed oil consumption causes inflammation. She emphasized diets high in unsaturated fats remain best supported by evidence.

She also warned consumers to be cautious about influencer claims not grounded in peer-reviewed science.

Beyond the Fryer: Skincare Controversy

Tallow’s resurgence isn’t limited to food. A growing number of brands now sell it as a face or body moisturizer, often labeling it “ancestral” or “biocompatible.”

Beef tallow has a comedogenic rating of 2 out of 5. That places it in the moderate range — similar to coconut oil or cocoa butter — meaning it may clog pores in some individuals, especially those with acne-prone or sensitive skin.

A 2024 scoping review, Tallow, Rendered Animal Fat, and Its Biocompatibility With Skin, found minimal clinical research backing topical claims. While tallow’s fatty acid profile does resemble human sebum, the authors concluded there is no robust evidence showing therapeutic benefit compared to other moisturizers.

Other reviews, including Vegetable Butters and Oils as Therapeutically and Cosmetically Active Ingredients for Dermal Use (International Journal of Molecular Sciences, 2020), have more thoroughly documented the properties of plant-based emollients like shea butter. A separate publication, A Review of Moisturizers (Cosmetics, 2021), outlined common ingredients such as lanolin, glycerin, and mineral oil — but did not include tallow among standard or well-studied agents.

Dr. Farah Moustafa, a dermatologist at Tufts Medical Center, said beef tallow may help retain moisture due to its fatty acid content. But she warned that it can clog pores and cause irritation, particularly when combined with essential oils. “Its vitamin A content isn’t comparable to retinol,” she told Tufts researchers.

Anecdotal reports are more favorable. “I wash my face with water, use a standard quality lotion, and layer tallow on top before bed,” said Gavin Wilson, founder of The Health Signal. “Since starting that, I’ve had zero facial acne and deeply moisturized skin.”

Still, no clinical trials to date have directly tested beef tallow against synthetic or botanical moisturizers for acne, hydration, or skin barrier repair.

The Health Signal Has Contacted:

• Epic Provisions, Fatworks, and Primal Kitchen: sourcing, product demand, and health messaging

• Fuddruckers and chef-led restaurants: customer reactions and culinary rationale

• Tufts researchers and independent dietitians: saturated fat risks and seed oil comparisons

We will update this story if responses arrive.

Bottom Line

Beef tallow’s return is more than a flavor trend. It reflects growing distrust of industrial fats and a shift toward whole-animal cooking. Whether science catches up to the hype is still an open question.

Affiliate Links: Our Picks for Everyday Use
These are tallow balms we recommend:

• Grass Finished & Grass Fed Beef Tallow and Honey Balm Body & Face Moisturizer

• Santa Cruz Paleo Grass Fed Beef Tallow & Beeswax Lip Balm

• Organic Grass-Fed Beef Tallow Balm with Raw Honey

Affiliate revenue supports The Health Signal’s independent reporting.

Colorectal cancer is climbing fast among young adults. At the same time, Americans are eating half the recommended amount of fiber. The link between these trends is more than nutritional trivia — it may be a major public health blind spot.

The latest national data show colorectal cancer (CRC) remains one of the deadliest cancers in the U.S. But a closer look reveals something new: rates are declining among older adults while rising sharply in people under 50. In fact, CRC cases in people aged 15 to 19 have grown more than 300% since 1999.

This generational shift has already prompted earlier screening recommendations, now starting at age 45. But some doctors warn even that may be too late.

“We’re seeing patients in their 30s and even 20s,” said Dr. Kimmie Ng, director of the Young-Onset Colorectal Cancer Center at Dana-Farber Cancer Institute. “And in many cases, diet is playing a big role.”

Fiber: The Anti-Cancer Nutrient Most Americans Lack

Fiber's most well-known benefit is promoting regular bowel movements. It is also crucial to colon health. By adding bulk to stool and speeding up transit time, fiber helps flush out potential carcinogens more quickly, reducing the time harmful substances remain in contact with the intestinal lining.

The USDA recommends 25–34 grams of dietary fiber per day at a minimum, depending on age and sex. Yet the average American gets only 15 to 16 grams; barely half.

This isn't just a matter of digestion. Research links fiber to a reduced risk of colorectal cancer through multiple mechanisms:

• Feeding beneficial gut bacteria that produce short-chain fatty acids like butyrate, which can inhibit tumor growth

• Reducing inflammation and improving immune response in the gut

• Binding and eliminating carcinogens, including harmful bile acids

• Accelerating transit time, limiting the colon’s exposure to potential toxins

“Fiber helps reduce the risk of colorectal cancer — and several other cancers — through multiple mechanisms,” said Christina Fasulo, a registered dietitian with UCLA Health’s GI Nutrition Program. “When gut bacteria ferment fiber, they produce short-chain fatty acids like butyrate, which have anti-cancer properties, including inhibiting cell growth and promoting apoptosis in cancerous cells.”

A study led by Stanford geneticist Michael Snyder found that microbial fermentation of fiber modulates gene expression, activating tumor suppressors and suppressing genes linked to cancer growth. “We found a direct link between eating fiber and modulation of gene function that has anti-cancer effects,” Snyder said.

These benefits come mostly from whole plant foods: legumes, fruits, oats, vegetables, and whole grains. Added or "functional" fibers in processed foods don’t offer the same protection, despite marketing claims.

Who Gets Fiber — And Who Doesn’t

Fiber intake, like CRC risk, is uneven across demographics. Hispanic Americans average the highest fiber consumption (9.2g/1,000 calories), while Black Americans consume the least (7g/1,000 calories).

This tracks with CRC disparities: Black Americans are more likely to develop CRC at younger ages and have worse survival rates, even when diagnosed at the same stage.

And among low-income groups, older adults, and those without private insurance, fiber intake remains significantly below average.

The Fiber Supplement Trap

What about fiber powders, gummies, and bars? Some, like psyllium or inulin, can help with digestive regularity. But experts caution they shouldn’t replace real food.

Supplements lack the "matrix effect," which is the synergistic mix of vitamins, minerals, and antioxidants found in whole plants. And in high doses, some can cause bloating or cramping.

More troubling are ultra-processed snacks labeled as "fiber-enriched." These often contain isolated fiber additives but remain high in sugar, fat, and sodium. Studies show they may create a "health halo" that misleads consumers while still raising chronic disease risk.

Colon Health Is Microbiome Health

When fiber is fermented in the colon, it fuels good bacteria that produce short-chain fatty acids. Butyrate, in particular, helps regulate inflammation and can stop tumor cells from multiplying.

“One important type of fiber is resistant starch… Fiber… acts as a prebiotic, feeding beneficial gut bacteria and producing short-chain fatty acids, like butyrate, that play a key role in reducing inflammation, protecting the gut lining and promoting healthy cell growth,” said Johannah Katz, a registered dietitian at EatingWell.

Diets low in fiber starve these microbes, weakening the gut barrier and increasing susceptibility to disease. Some research even shows low-fiber diets may shift gut bacteria to consume the gut’s protective mucus layer.

“It’s not just about what we eat. It’s about what our microbes eat. And fiber is their food,” Fasulo said.

Policy and Labeling: Still Behind the Science

The FDA recognizes fiber as a "nutrient of public health concern," but regulation hasn’t kept pace with marketing.

Many processed foods include added fiber to boost label appeal, yet offer little nutritional value overall. And while school meals, WIC, and SNAP programs aim to improve fiber access, disparities persist.

Meanwhile, critics warn of conflicts of interest in dietary guideline committees, particularly from USDA-affiliated agricultural promotion programs. Some scientists say this undermines efforts to prioritize fiber-rich plant foods over meat and dairy-heavy diets.

Everyday Shifts That Make a Difference

You don’t need to go vegan or count grams to improve your fiber intake. Here are some real-world strategies:

• Mix it up: Add lentils or quinoa to white rice to double the fiber content.

• Upgrade breakfast: Choose foods with 5g+ of fiber per serving. Add fruit and seeds to yogurt or oatmeal.

• Use frozen and canned smartly: Beans, peas, berries, and artichokes retain fiber and nutrients.

• Snack better: Swap chips for nuts, veggies, or unsweetened dried fruits.

• Beware health halos: Don’t rely on processed bars or powders as your main source.

Final Take

The fiber gap isn’t just a diet issue. It’s a cancer risk multiplier, especially for younger generations and underserved communities.

Closing that gap could help reverse the rise in early-onset colorectal cancer. But it will take more than individual effort. It requires better policy, labeling reform, equitable access to real food, and public health messaging that matches the science.

Affiliate Links: Our Picks for Everyday Fiber Fixes
These are whole food staples we recommend (and personally use) to support better colon health:

• Sprouted Rolled Oats

• Banza Chickpea Pasta

• Mission Low Carb Flour Tortilla

Affiliate revenue supports The Health Signal’s independent reporting.

In 2025, the sunscreen aisle is looking different. New state-level bans, fresh lab tests, and growing scrutiny over chemical ingredients are reshaping what consumers can buy, and what they should trust. At the same time, public health officials still emphasize sunscreen as a critical tool in preventing skin cancer.

But many Americans don’t know: Do you apply it correctly? Do your kids? And is your SPF harming more than it helps?

Understanding Sunscreen: Absorbers vs. Reflectors

Chemical sunscreens work by absorbing UV rays and converting them to heat. Common ingredients include avobenzone, oxybenzone, and octinoxate. These filters offer clear, lightweight coverage but are absorbed into the skin, and in some cases, the bloodstream.

Mineral sunscreens use zinc oxide or titanium dioxide. They sit on top of the skin, reflecting and scattering UV rays. Zinc oxide in particular blocks both UVA and UVB rays effectively, making it ideal for sensitive skin. But these formulas often leave a white cast and can feel heavier.

Notably, zinc oxide also absorbs some UV radiation, blurring the old dichotomy between "chemical" and "physical" sunscreens.

Safety and Environmental Concerns

Chemical sunscreens have come under fire for several reasons:

• Systemic absorption: Studies have found ingredients like oxybenzone in blood and breast milk.

• Endocrine disruption: Some filters mimic hormones and may interfere with thyroid and reproductive systems.

• Photostability: Ingredients like avobenzone degrade in sunlight unless stabilized.

• Environmental damage: Oxybenzone and octinoxate are linked to coral bleaching, even at low concentrations.

That’s why regions like Hawaii, Palau, and parts of Mexico have banned certain chemical sunscreens.

Mineral sunscreens, particularly those labeled non-nano, are generally considered reef-safe and are recommended for children and pregnant women.

Sunscreen Meets Chlorine: An Overlooked Reaction

The risks of chemical sunscreens don’t stop at the shoreline. Even your swimming pool might be reacting with your sunscreen.

Newer studies suggest that chemical sunscreens can break down in chlorinated water, such as pools, creating potentially harmful byproducts. For instance, avobenzone may degrade into compounds with unknown long-term health impacts. Consumers swimming in chlorinated pools should take note.

The EWG Sunscreen Guide: Trusted but Contested

The Environmental Working Group (EWG) reviewed more than 2,200 SPF products in 2025. Only 23% met their safety and efficacy criteria. EWG favors mineral sunscreens and flags products with oxybenzone, octocrylene, and undisclosed fragrances.

EWG also warns about misleading SPF claims boosted by chemical enhancers, and strongly advises against sprays due to inhalation risks.

Critics argue EWG's methods can be overly conservative, but dermatologists agree on key points: choose broad-spectrum SPF 30+, reapply every 2 hours, and avoid known irritants if you have sensitive skin.

Global Regulation: Who Says What's Safe?

The FDA currently lists only zinc oxide and titanium dioxide as Generally Recognized as Safe and Effective (GRASE). All other filters await more safety data.

The EU, by contrast, permits over two dozen UV filters, thanks to its more proactive and precautionary approach. Advanced filters like Bemotrizinol offer superior protection but remain unavailable in the U.S.

Australia's TGA, known for its rigorous Therapeutic Goods (Sunscreen) Determination standards, recommends restrictions on oxybenzone and homosalate due to potential endocrine effects but hasn’t issued outright bans on all chemical sunscreens, focusing instead on strict concentration limits and continuous review. The U.S. market remains caught between slow FDA reviews and growing consumer pressure.

Application Matters More Than You Think

Most people apply only 25-50% of the amount needed for full protection. Dermatologists recommend:

• One ounce (a shot glass) for full-body coverage

• Reapplication every 2 hours, or after swimming/sweating

• Starting 15 minutes before sun exposure (for chemical sunscreens)

And the stakes are real. Research shows that five or more blistering sunburns between ages 15 and 20 can increase the risk of melanoma by 80% and non-melanoma skin cancers by 68% later in life.

Not All Sun Is Bad

Moderate, non-burning sun exposure can have clear health benefits. Just 10 to 20 minutes of unprotected sunlight on the arms and legs helps the body produce Vitamin D, supports sleep-wake cycles, and may even boost mood. The key is avoiding overexposure — especially during peak UV hours.

“Reef-Safe” Isn’t a Buzzword; It’s a Biocide Warning

Tourism-heavy beaches like Hanauma Bay in Hawaii test sunscreen chemicals at levels that exceed toxic thresholds for coral by 12-fold. Ingredients like oxybenzone have been shown to damage coral DNA, disrupt fish reproduction, and bioaccumulate in marine mammals. And it’s not just oceans — freshwater runoff and wastewater can carry these chemicals far inland.

Switching to non-nano zinc oxide sunscreens — many of which are top-rated by the EWG — protects both you and aquatic ecosystems.

Smart Sun Safety

Choosing the right sunscreen isn’t just about SPF. It’s about what your skin absorbs, how your sunscreen behaves in water, and what ends up in your bloodstream or the sea. Mineral sunscreens are rising for good reason. But correct use still trumps perfect ingredients.

Where to Buy (Affiliate Links) Top EWG Certified Sunscreens

• Thinksport Mineral Sunscreen, SPF 50

• Well People Bio Tint SPF 30 Tinted Moisturizer

• STREAM 2 SEA SPF 30

• Mustela Baby Mineral Sunscreen Stick SPF 50 Broad Spectrum

  These links help support The Health Signal’s independent reporting. I use Thinksport Mineral Sunscreen, SPF 50, when I have a lot of UV exposure.

Summary: Despite growing fears online, linoleic acid — the main omega-6 in seed oils — is essential, not dangerous. Here’s what modern science says about its effects on inflammation, heart health, and longevity.

Social media has turned linoleic acid (LA), an essential omega-6 fatty acid abundant in seed oils, into the dietary villain of the decade. Influencers warn it triggers inflammation, fuels chronic disease, and poses severe health risks. Yet, mainstream nutrition science tells a very different story: linoleic acid is not only essential but beneficial. So, what's the truth?

Let's clear away the confusion and dive into what the science truly says about how LA affects your health.

What Exactly Is Linoleic Acid?

Linoleic acid is a polyunsaturated fatty acid (PUFA) that's crucial for human health, primarily because your body can't produce it—you must obtain it from your diet. Historically, LA was first isolated from flaxseed oil in 1844, and today it's a major component of many widely used cooking oils.

Top dietary sources of LA include safflower oil (72–78%), grapeseed oil (~70%), corn oil (~52%), soybean oil (~51%), walnuts (50–72%), and chicken fat (18–23%), according to "Omega-3 and Omega-6 Fatty Acids: Dietary Intakes and Health Implications" published in MDPI and EUFIC's overview on omega-6 fatty acids.

Why Your Body Needs Linoleic Acid

LA helps form ceramides in your skin’s outer layer, improving hydration, healing, and barrier strength. Research has shown this can benefit conditions like eczema and psoriasis, as noted in the 2020 review "Linoleic acid and skin barrier function".

It also converts into arachidonic acid, a building block for eicosanoids—key signaling molecules that control immune responses. These are both pro- and anti-inflammatory, as explained by Creative Proteomics and detailed in the NIH's Arachidonic Acid Metabolism chapter. According to the MDPI review, this process is tightly regulated in the body.

Large cohort studies consistently show that replacing saturated fats with LA improves cholesterol ratios and lowers risks of cardiovascular disease and type 2 diabetes. Johns Hopkins Medicine, ScienceDaily, and Technology Networks all report that fears around seed oils are often overstated.

Unrefined LA-rich oils also contain antioxidants like vitamin E, phytosterols, and polyphenols that protect against oxidative damage. These findings are supported by a study on rapeseed oil’s oxidative stability, the NIH Vitamin E fact sheet, and a 2018 study on linoleic acid and inflammation.

That said, some refined oils—such as highly refined olive or avocado oil—remain stable and safe for cooking and can still be healthy choices even if they lack some of the natural antioxidants found in unrefined options. The key is to evaluate oils within the context of an overall balanced diet.

Debunking LA Myths: Oxidation, Inflammation, and Ratios

Although linoleic acid is theoretically prone to oxidation, this risk is often exaggerated. A 2019 paper on oil oxidation explained that natural antioxidants in unrefined oils offer significant protection. The body also has robust systems to prevent oxidative stress, as described in studies of oxidized linoleic acid metabolites (OXLAMs) and lipid peroxidation mechanisms.

While LA can produce inflammatory molecules, it also generates anti-inflammatory and pro-resolving mediators. This dual role is well documented in the MDPI review, and clinical research shows that moderate intake of LA does not increase inflammation in healthy people, according to Johns Hopkins and ScienceDaily. An exception may exist in conditions like cystic fibrosis, as indicated by this clinical study.

The often-cited omega-6 to omega-3 dietary ratio has little scientific backing. Agencies like the WHO and EFSA emphasize total intake of both rather than a fixed ratio, as discussed by Golden Valley Flax.

So why do these myths persist? Nutritional science is complex, and social media often favors simplified explanations or “elimination diet” trends that promise fast results. Misinterpretation of early or outlier studies can quickly become mainstream belief—especially when amplified by influencers or brands seeking attention.

What Modern Science Really Says

Meta-analyses and cohort studies show higher LA intake is associated with lower cardiovascular disease risk, fewer coronary events, and reduced mortality, according to Johns Hopkins, ScienceDaily, and Technology Networks.

These studies also show that people with higher blood levels of LA have about a 35% lower risk of developing type 2 diabetes. Dietary intake is also linked to modestly lower all-cause mortality.

Skeptic Studies Revisited

The 1960s Sydney Diet Heart Study is often cited by critics. But a BMJ reanalysis revealed design flaws, including reduced omega-3 intake and excessive safflower oil use, which limit its relevance today.

Animal studies showing LA harm often use extreme doses or specific models that don’t reflect human nutrition. This is discussed in research on high-fat diet-induced obesity and in a 2018 review of omega-6 controversies.

Many early nutrition studies lacked modern tools to measure dietary intake or isolate specific fats. “Correlation” often stood in for causation. On social media, these outdated or narrowly designed studies are often cited without context, ignoring major design flaws or population differences.

The Sydney Diet Heart Study, for example, replaced saturated fat with high amounts of safflower oil but also reduced omega-3s—an imbalance not typical of real-world diets.

Quality & Processing Matter

Refining oils strips them of antioxidants. Choosing cold-pressed or unrefined oils helps retain linoleic acid’s natural benefits. A 2021 review of edible oil production recommends minimal processing for this reason.

When cooking:

• Use avocado oil or other stable oils for high heat, based on a 2019 oxidation study and research on aldehyde formation during frying.

• For moderate heat and dressings, extra virgin olive oil or cold-pressed sunflower oil are excellent choices, as listed in this Kendall Reagan Nutrition Center guide.

  

What Health Authorities Say

The World Health Organization and FAO recommend LA make up 2.5–9% of total daily calories. The European Food Safety Authority sets adequate intake at 4% of total energy and finds no upper limit, per a 2009 EFSA report.

The American Heart Association advises getting 5–10% of energy from omega-6 fats, including LA, to lower heart disease risk, according to its 2019 guidance. The U.S. Dietary Guidelines suggest 17g/day for men and 12g/day for women, outlined in the official guidelines.

Smart Ways to Include Linoleic Acid

Use minimally processed seed oils in moderation. Balance them with omega-3-rich foods like fatty fish, flaxseed, chia, and walnuts. Prioritize whole foods—nuts, seeds, grains, and lean meats—for a complete nutrient profile.

Conclusion: Don’t Fear Fat, Understand It

Linoleic acid isn’t a villain. It’s a well-researched essential nutrient with clear health benefits when consumed in context. Skip the fear, stick with evidence, and choose balance over hype.

Looking Ahead

While current science strongly supports the benefits of linoleic acid, nutrition is an evolving field. Future research may explore how LA interacts with other dietary compounds, individual genetics, or chronic conditions in more detail. Understanding these nuances can help tailor dietary advice for diverse populations.

Salt is under fire. But the case against it rests on shaky ground.

Despite decades of public health messaging, scientific consensus around sodium and blood pressure is far from settled. New evidence, re-analyses of old studies, and a deeper understanding of human physiology are all pushing the debate in a new direction: one that favors individualized nutrition over one-size-fits-all sodium limits.

Salt has long been central to human survival. The word "salary" stems from salarium, a Roman soldier’s salt allowance—an early sign of salt's value. Historical consumption was high: pre-industrial diets, particularly in Europe, often included 40–50 grams of salt per day, largely due to preserved fish and meats. Today, Westerners average roughly half that, yet are warned that it’s too much.

Why the disconnect?

Much of modern salt policy originates with the 1988 INTERSALT Study. This large epidemiological project tracked sodium intake and blood pressure across 52 populations. The study’s conclusions—that higher sodium correlated with increased age-related blood pressure—became the foundation for global sodium limits, now typically set at or below 2,300 mg/day.

But the study had major flaws. It included only four ultra-low-sodium groups, like the Yanomami tribe, whose data heavily skewed results. Sodium intake was measured using single-day 24-hour urine collections—now widely considered unreliable. Confounders were inconsistently adjusted for, and the handling of outliers was later criticized. When reanalyzed with these issues corrected, the correlation between sodium and blood pressure weakened significantly. Still, policy had already been set.

Meanwhile, biology tells a different story. The kidneys can excrete up to 900 grams of sodium daily—far beyond typical dietary levels. When sodium is restricted, the body compensates by activating the renin-angiotensin-aldosterone system (RAAS), signaling salt cravings and conserving sodium. If intake falls too low, hyponatremia can result—leading to fatigue, nausea, confusion, and even seizures. These effects are well-documented in endurance athletes and those on overly restrictive diets.

A 2010 study of Philadelphia Eagles players found sodium losses through sweat ranging from 2.3 to 30 grams per day. Most athletes failed to replace these losses through food alone. This variability highlights that sodium needs depend heavily on lifestyle and environment.

Epidemiological evidence now suggests the relationship between sodium and heart health is U-shaped or J-shaped: both very high and very low sodium intakes are associated with greater cardiovascular risk. The optimal intake range appears to fall between 2,600 and 5,000 mg/day—significantly higher than current guidelines. Additional evidence here.

Public health policies often attribute high sodium intake to processed foods. But salt is rarely the root cause of health issues. Processed foods also contain added sugars, industrial seed oils, and preservatives—ingredients with clearer ties to chronic disease. Blaming salt oversimplifies the problem and may mislead consumers.

Sodium is a vital nutrient, tightly regulated by the body. The fear surrounding it stems more from flawed studies and outdated assumptions than from consistent scientific evidence. As research evolves, a shift toward personalized, context-aware nutrition is not only justified—it’s overdue.

Coming next in Part Two: Salt Sensitivity and Metabolic Health—Who Really Needs Less Sodium?

The internet is ablaze with claims that seed oils are toxic, inflammatory, and a root cause of modern disease. Social media feeds are flooded with dire warnings against the "hateful eight" — canola, corn, cottonseed, grapeseed, rice bran, safflower, soybean, and sunflower oils. But are these alarm bells justified, or is it just another wellness myth gone viral? Let's sift through the hype and see what the science, and global health authorities, truly have to say.

Setting the Stage: The Seed Oil Sensation

The fear surrounding seed oils has reached a fever pitch. Advocates of "ancestral" diets or "clean eating" often demonize these common cooking oils, suggesting they are a primary driver of chronic inflammation, heart disease, and other health woes. This narrative often hinges on concerns about their polyunsaturated fatty acid (PUFA) content, particularly omega-6 linoleic acid, and the industrial processing methods used to extract them.

Research Review: PUFA, Oxidation, and Inflammation — What's Legit?

PUFAs are Essential: Omega-6 fatty acids like linoleic acid are essential nutrients. Our bodies cannot produce them. They support cell membranes, hormone production, and immune response.

Oxidation Concerns: PUFAs are more reactive to oxygen due to their double bonds. But commercial seed oils contain natural antioxidants (e.g., vitamin E), and multiple RCTs show no significant rise in oxidative stress markers from consuming these oils.

Inflammation Debate: Despite claims that linoleic acid promotes inflammation via conversion to arachidonic acid, human studies consistently show no increase in inflammatory markers. Some suggest linoleic acid may actually reduce inflammation. Swapping saturated fats with PUFAs lowers cholesterol and CVD risk.

Processing and Hexane: Hexane is used in oil extraction, but trace amounts in final products are well below safety thresholds. Refining processes also remove contaminants and off-flavors.

Global Regulation: Who Restricts It, and Why (or Why Not)?

If seed oils were dangerous, we would expect global restrictions. That hasn’t happened.

Trans Fat, Not PUFAs: Most countries regulate trans fats due to clear cardiovascular harm. PUFAs remain broadly recommended.

Erucic Acid in Canola: Older rapeseed oil had high erucic acid. Modern canola is safe and widely accepted by health agencies.

Guidelines Endorse Seed Oils: The WHO, EFSA, and U.S. dietary guidelines support replacing saturated fats with unsaturated ones, including from seed oils.

What the Skeptics Say: Alternative Concerns and Critiques

Omega-6/3 Imbalance: Critics argue modern diets skew heavily toward omega-6s, potentially promoting inflammation. They cite evolutionary diets and omega-6 conversion to pro-inflammatory eicosanoids. However, the body regulates this conversion, and the impact on health markers is negligible in trials.

Oxidation from Cooking: Skeptics raise concerns about oxidation during high-heat cooking. Oxidized byproducts from repeatedly heated oils can be harmful. While valid in deep frying contexts, typical home use poses minimal risk.

Traditional Fats Displacement: Some argue that the shift from animal fats to seed oils has removed nutrient-dense foods from the diet. While animal fats do contain fat-soluble vitamins, replacing saturated fats with PUFAs has consistently shown health benefits in trials.

Industry Influence and Science Skepticism: Some critiques focus on funding bias and historical missteps in nutrition science. Notable skeptics like Nina Teicholz argue that key studies were misinterpreted or selectively published.

Key Evidence: Studies, Consensus, and Funding Sources

Meta-Analyses: Broad reviews find PUFAs reduce LDL and CVD risk. These are often funded by NIH, EU grants, or academic bodies. Example: Petersen et al. (2024), AJCN, funded by university grants.

RCTs: Studies like the Oslo Diet-Heart Study and DART trial show cardiovascular benefits from PUFA substitution. Some, like the Minnesota Coronary Experiment, found lower cholesterol but no mortality change—a favorite of skeptics, but seen as inconclusive due to design flaws. These included a lack of dietary compliance, poor data reporting, and high dropout rates that limit interpretation.

Cohort Studies: Long-term research (e.g., Nurses' Health Study) shows lower heart disease risk with higher PUFA intake. Primarily funded by NIH.

Skeptic-Used Evidence: Sydney Diet Heart Study and animal trials on oxidized oils. Critics highlight these to question the safety of linoleic acid, but the broader body of evidence finds no consistent harm.

Despite these dissenting studies and alternative hypotheses, the totality of high-quality evidence across decades, geographies, and funding sources continues to support the safety and benefits of PUFAs — particularly when they replace saturated fats in the diet.

The Bottom Line: What You Should Focus On Instead

The scientific consensus is clear: Seed oils are not killing you.

What's Hype: Claims that seed oils inherently cause inflammation or toxicity are not backed by strong human data.

What's Real: Seed oils provide essential fats and vitamin E, and can reduce cardiovascular risk when replacing saturated fats.

What to Do:

• Prioritize whole, minimally processed foods.

• Avoid ultra-processed products, many of which contain seed oils.

• Use stable fats like EVOO for dressing or animal fats for high-heat cooking.

• Don’t fear seed oils — but don’t seek them out either.

A Personal Note: Personally, I choose not to buy seed oils. In my kitchen, I use extra virgin olive oil for dressings and toppings, avocado oil and butter for low-heat cooking, and ghee or beef tallow for high-heat applications. You can use seed oils — it's a preference. If you do, try to choose oils packaged in glass or metal instead of plastic to avoid microplastics, and opt for higher-quality brands when possible.

In other words; balance, not fear, should guide your fat choices.