The Truth About Seed Oils, Sweeteners and Your Health w/ Nick Barringer PhD

Barringer ranks monk fruit and stevia as clearly better options than sucralose or aspartame. His household has made the switch. He acknowledges that monk fruit/stevia can have an aftertaste if not formulated well, but the trend toward better formulations is making them more palatable. Xylitol (common in gum) is an additional option with dental benefits.

Barringer does not call seed oils 'poisonous' and explicitly pushes back on that framing. The oxidation concern is real; the blanket condemnation is not supported by evidence. His practical household stack: avocado oil for heat, olive oil for salads and cold use, butter as a complement. Coconut oil's unusual lipid behavior — elevated intake doesn't affect LDL the way other saturated fats do — makes it a reasonable option.

Barringer and Lyon use a plate-visualization approach for compliance: half the plate is non-starchy vegetables, one quarter is complex carbohydrates (potato, rice), one quarter is lean protein. Snacks should always include protein and fat to blunt insulin response and sustain satiety. Both explicitly reject the idea that patients lack information — implementation and habit formation are the real bottleneck.

Barringer came out of Dr. Richard Crider's lab — arguably the world's leading creatine research group. He self-dosed 30 g (~0.3 g/kg) four hours before recording this episode specifically to protect cognitive performance after a night of interrupted sleep with a toddler. His broader recommendation: creatine monohydrate is the supplement he would put in anyone's stack before any other.

Barringer's research showed the depression-deficiency correlation strengthened at higher latitudes (Alaska vs. Texas), tracking with sun availability. His dissertation work at Fort Cavazos documented the 40% insufficiency in a sunny region. He supplements daily and achieves an optimal level. Food sources of D3: fatty fish, cod liver oil, chicken liver. Avoid D2 sources like mushrooms if D3 is the target form.

Barringer frames the risk pragmatically: if you're switching from sugar-sweetened beverages to diet sodas specifically to lose weight, that's still a net positive at this point. The concern is for chronic, habitual consumers who aren't using it as a transitional tool. He would not say it's 'poisonous' but the 2023 data gives him genuine pause. The genotoxicity was detected at microgram-level doses — doses that would be exceeded by most people consuming a Celsius or Coke Zero. He also notes the leaky-gut concern from the same paper cluster.

Barringer's household uses avocado oil for high-heat cooking, olive oil for salads, and butter. He notes that even elevated coconut oil intake does not affect LDL the way other saturated fats do, per some papers. His practical guidance: there are better options than seed oils, and any way to reduce omega-6 and increase omega-3 moves health in the right direction — but the hype is overblown.

Lyon frames this as 'carbicide' for sedentary people: their muscle cannot absorb glucose fast enough at guideline-recommended intake levels. The fix is not necessarily low-carb — it's carb intake calibrated to training volume. Her rule of thumb: non-training days get 100–150 g/day ceiling; training blocks open the window proportional to activity. Post-workout carbohydrate timing matters especially for back-to-back training days — a missed window within ~4 hours visibly degrades performance the next day, per one paper Barringer cited.

Barringer's target optimal level is 60–80 ng/mL. He recommends D3 (not D2, which is less bioavailable and is inexplicably still stocked in many DoD formularies). Daily supplementation at 2,000–5,000 IU is his risk-to-reward-positive recommendation for most people, particularly those not reliably exposed to midday sun. Food sources of D3 include fatty fish and cod liver oil; mushrooms provide primarily D2.

The standard maintenance protocol of 3–5 g/day reaches tissue saturation in about 30 days. Loading (20 g/day split across doses for 5–7 days) is warranted only when a high-demand event is imminent and time is short. The GI sensitivity issue with large single doses can be managed by splitting into smaller doses throughout the day. Individual response to creatine varies partly by dietary baseline — heavy meat eaters already have higher baseline tissue creatine levels and see a smaller response increment.

AMPK activation (berberine's proposed mechanism) is the fasted-state metabolic regulator — opposite of mTOR which drives fed-state muscle protein synthesis. Lyon notes that individual genetic variation in enzymes probably explains why some people are strong responders and others non-responders. The source quality of berberine supplements matters enormously given that dye adulteration of plant-based supplements has been documented in the field.

The adulteration risk is bidirectional: heavy metals (from soil) on the ingredient side, and nitrogen-spiking (adding cheap nitrogen compounds to inflate protein numbers on labels) on the manufacturing side. Lyon prefers animal-based protein powders for patients who cannot tolerate whey — egg white protein, beef isolate — over plant-based blends. Collagen is flagged as not a complete protein.