Cynthia Thurlow: On Women’s Health, Intermittent Fasting, Protein Intake & Hormone Therapy |TUH #207

Thurlow now leads with a risk‑stratified approach. She stresses that many women adopted fasting because they equated ‘a little is good, more is better,’ and ended up on one meal a day, consuming only 600–700 calories and losing muscle. She points to the Biggest Loser effect: the body slows metabolism to survive on less. She often anger people by telling them they are undereating and adds 100 calories of protein daily while monitoring body composition. The overarching message: if you can't sleep through the night, fix that first; fasting will only make things worse for many women.

Thurlow recalls how Dr. Gabrielle Lyon first challenged her on her own protein intake in 2020, leading to a complete shift in her practice. She now sees that most women who think they eat enough actually get about 50 g total. She works with them to add small increments (e.g., 4 oz to 5 oz of animal protein) and sometimes uses a reverse diet approach — adding 100 calories of protein daily and monitoring body comp. She emphasizes that even her athletic teenage sons can stimulate muscle protein synthesis easily, but aging women need more protein, not less. The goal is to preserve metabolic currency and avoid the catabolic state she experienced after her hospitalization.

Thurlow calls creatine a ‘foundational supplement’ for men and women. She noted that even on non-lifting days, the neurocognitive and sleep benefits justify daily use. She personalizes the dose for travel: she currently uses 20 g/day while in London to offset jet lag, and finds it improves sleep even after a bad night. She also mentions emerging science showing that during the menstrual cycle, there are times when women can benefit from more creatine — another reason to take it daily. She encourages mixing it into smoothies or plain water, and insists that good quality creatine dissolves easily.

Thurlow links constipation directly to the gut's ability to process and excrete excess estrogen via the estrobolome. She explains that many women are ‘non-public poopers’ who withhold, leading to chronic issues. She often starts with lifestyle (hydration, squatty potty, abdominal massage) before testing or supplements. When needed, the flax-chia combo is her top ‘brilliant’ tool, and she says women travel with pre-mixed portions because it's life-changing. She also notes that the loss of estrogen and progesterone in perimenopause/menopause slows motility, so these interventions become even more critical.

Thurlow is ‘very pro HRT’ when it's the right choice, but insists on shared decision-making. She describes how she often starts with progesterone because many women are still scared of estrogen. She debunks the WHI study point by point: it used progestins, not progesterone, and conjugated equine estrogens, not estradiol, in an older, high-risk population. She highlights the book Estrogen Matters by Dr. Avrum Bluming as essential reading. She also stresses that testosterone is often needed and that thyroid and DHEA levels should be checked as part of the picture. She personally avoids pellets because of the dosing roller coaster; she prefers sublinguals and patches that can be adjusted quickly.

Thurlow draws on her cardiology background to make the case that the drop in estrogen during menopause removes a critical protective mechanism — nitric oxide production falls, vessels stiffen, and inflammation rises. She connects high LP(a) directly to her recommendation for HRT, saying estrogen ‘acts like a PCSK9 inhibitor,’ the same mechanism as the expensive drug Repatha. She urges providers to move beyond the outdated total cholesterol/LDL/HDL/triglyceride quartet and routinely measure apoB and LP(a). She also points out that women are often prescribed statins based on LDL alone, missing the bigger picture.

Thurlow describes seeing ‘some of the worst endocrine disasters’ in menstruating women who compressed feeding windows to 4–6 hours, often following their CrossFit husbands. Their cortisol spiked, cycles became a disaster, and they paradoxically gained weight. She now insists that a woman's menstrual cycle is a vital sign — losing it signals the body is under too much stress. She has moved from promoting fasting as a primary tool to calling it ‘one of many strategies’ and urges women to first fix sleep, manage stress, and ensure they aren't already under-eating before even considering time-restricted eating. The shift reflects both clinical experience and a broader cultural pushback against the ‘thin at all costs’ mindset that she believes has damaged women's metabolic health.

Thurlow describes how she was ‘incredibly catabolic’ after a ruptured appendix and 13-day hospitalization, losing 15 pounds of muscle. That experience, combined with Lyon's advice, made her realize that protein is not just for gym rats — it builds antibodies, connective tissue, and neurotransmitters. She now sees women who eat one meal a day and boast of being a size X or Y but have a body composition of predominantly fat; she often tells them they are not eating enough food. She pushes for at least 100 g of protein daily and regular body composition scans, because ‘you don't know’ without data. This shift directly challenges the pro-fast, anti-calorie orthodoxy she helped popularize.

Thurlow unpacks how estrogen decline during menopause reduces nitric oxide production, impairing vascular dilation and setting off inflammatory cascades. She notes that estrogen ‘acts like a PCSK9 inhibitor,’ the same mechanism as the ultra-expensive Repatha, which lowers LP(a). Because 20% of the population (50% of African Americans) have high LP(a), she argues that estrogen replacement is not a luxury but a critical intervention for heart disease — the number one killer of women. She urges all women to check LP(a), apoB, and triglycerides, and to understand that HDL/LDL panels alone are insufficient.