Professor Tim Spector: I was wrong about Vitamin D & sunlight! The 7 health habits he's changed his mind about

What It Covers

Professor Tim Spector reviews 7 health habits he changed in 2026, covering oral health, microplastics, omega-3 testing, B12 and folic acid supplementation, vitamin D, exercise diversity, and sleep optimization — explaining how new evidence shifted his thinking on each and how to evaluate emerging health claims.

Key Questions Answered

• •Oral Health & Dementia Risk: Optimal daily flossing or using interdental picks reduces dementia risk by 20–40%, according to recent studies. Bleeding gums signal active inflammation, which sends pro-inflammatory signals through the immune system to the brain, accelerating cognitive aging. Continue flossing until bleeding stops completely — that indicates inflammation has resolved.
• •Omega-3 Index Testing: Standard omega-3 blood tests are insufficient; the omega-3 index — measuring EPA and DHA levels inside red blood cells — is the current clinical research gold standard. Low index levels correlate with elevated heart disease risk. Eating anchovies, sardines, and salmon weekly can raise levels without supplements, as Spector confirmed through retesting.
• •Folic Acid Beyond Pregnancy: Folic acid is not exclusively relevant to pregnant women. Multiple long-term randomized trials show folic acid supplementation supports cognition in older adults. However, excess folate can trigger epigenetic gene-switching changes. Get blood levels tested before supplementing — leafy green consumption alone is sufficient for most people with normal levels.
• •Exercise Diversity Over Cardio Dominance: Cardio alone is insufficient as people age. Adding resistance training 2–3 times weekly — including Pilates for core strength — builds lean muscle mass and reduces aging-related decline. Creatine supplementation produces only a 1.7% average muscle mass increase and shows insufficient evidence for cognitive benefits currently, making it low priority.
• •Sleep Optimization Protocol: Stopping food and alcohol intake at least 2 hours before bed prevents the digestive system from disrupting deep sleep cycles. Additional measures — blackout curtains, sound-blocking earplugs, and mouth taping — can significantly improve sleep quality. Mouth taping is highly personalized: beneficial for some, potentially harmful for others, requiring individual experimentation.