Emerging Research

In rheumatoid arthritis, the joint's repair cells run out of fuel and burst

What they studied

Cornelia Weyand and Jörg Goronzy at Stanford reviewed how aging changes the way immune cells make and use energy, and why rheumatoid arthritis so often begins after 50. A companion study from the same group took joint tissue from people with active RA and followed one group of cells closely: the macrophages whose job is to calm inflammation and repair tissue. They compared these cells with macrophages from age-matched healthy people, then tested what they found in mice carrying grafts of human joint tissue.

What they found

With age, immune cells get worse at sensing nutrients and switching between fuels. In RA, their mitochondria are also underpowered, leaving cells short on ATP, the cell's energy currency, and NAD⁺, a molecule mitochondria need to make it.

The repair macrophages release a protein called C1q and carry its receptor, so they signal themselves. In RA cells, that signal moved into the mitochondria and switched on an enzyme called SARM1, which broke down NAD⁺. Energy production stalled and the cells burst open, spilling their contents into the joint. Up to half the macrophages in RA joint tissue were dead or dying, and inflammation was worst where the most were dying. Healthy macrophages held up under the same signal. In the mice, adding C1q doubled inflammation, while blocking SARM1 calmed it and cut macrophage death by about half.

What it means for you

RA has long carried a puzzle: the cells meant to heal the joint are there in large numbers, yet the damage keeps going. This work suggests they are failing for lack of fuel. The inflamed joint is low in oxygen and glucose, and its macrophages lean on glutamine, much of which the body draws from muscle. That ties joint inflammation to the same metabolic and mitochondrial health we build through strength training, sleep and blood sugar care. Whether that work changes the course of RA has not been tested.

Disease-modifying medications remain the foundation of RA treatment. In the lab, nicotinamide (a form of vitamin B3) partly protected the cells by restoring NAD⁺. That is a lead for researchers and no reason to start a supplement.

How solid is it?

ACOG's new menopause guideline puts hormone therapy first and widens the toolkit

What they studied

The American College of Obstetricians and Gynecologists (ACOG) replaced its 2014 menopause guidance with Clinical Practice Guideline 13. The writing team included a reproductive endocrinologist and a Menopause Society Certified Practitioner. They reviewed randomized trials and meta-analyses published from 2013 through March 2026 on hot flashes, night sweats, sleep and mood during perimenopause and after. Every recommendation is graded by how strong it is and how good the evidence behind it is.

What they found

Hormone therapy is the most effective treatment. It earned a strong recommendation for hot flashes and for sleep broken up by them. In one analysis of 32 trials, estradiol through the skin paired with a progestogen ranked first for cutting hot flash frequency.

Timing still matters. The best balance of benefit and risk comes from starting before age 60 or within 10 years of your final period. Starting later is an individual conversation, not a closed door. Continuing past 60 is acceptable when symptoms persist.

Two newer nonhormonal medications earned strong recommendations. Fezolinetant (Veozah) and elinzanetant (Lynkuet) quiet the brain signal that sets off hot flashes, and elinzanetant also showed better sleep results. SSRI and SNRI antidepressants were strongly recommended too, for hot flashes and low mood. Gabapentin is the fallback option.

Five approaches without medication received conditional support: cognitive behavioral therapy, mindfulness, exercise, clinical hypnosis and acupuncture. In one hypnosis trial, five weekly sessions cut hot flashes by 74%, compared with 17% in the comparison group.

On mood, hormone therapy may ease depressive symptoms during perimenopause but has not been shown to help after menopause. Depression that meets diagnostic criteria is treated as depression first.

On supplements, ACOG found that the evidence does not support phytoestrogens or herbal products for hot flashes.

What it means for you

ACOG named something women have lived with for two decades: earlier hormone trials were misread, and the fear that followed kept many from treatment that would have helped. This guideline sets that record straighter.

Hot flashes start in the hypothalamus, the brain's thermostat. As estrogen falls, a cluster of neurons there turns up their signaling and narrows the comfortable temperature range. A small rise in body heat then sets off a full cooling response. Estrogen calms that signal at its source, and the newer medications block it further down the line. That is why both work, and why you have real choices if hormones are not right for you.

Here is how I put this guideline to work. I favor estradiol through the skin. When sleep is poor without hot flashes, I look for other causes; sleep apnea climbs at midlife, and my Sleep Screener is a good place to start. I still use a few botanicals that are low risk and have a plausible mechanism, and I will tell you plainly where ACOG stands on them. Bleeding that continues past six months on standard hormone therapy gets evaluated. If you are on a rhythmic regimen with me, a monthly bleed is expected, and we track it by its own set of rules.

How solid is it?

Menopause arrives as a step across the whole body, and the run-up starts a decade early

What they studied

Most health databases record a woman's age but not when her periods stopped. Because women reach their final period anywhere from their early 40s to late 50s, averaging by age blurs any sharp change into a gentle slope. Researchers borrowed an image-sharpening method from astronomy to line up more than 300 million lab results from over a million women in the United States and Israel by each woman's estimated final period. They looked at 90 routine lab tests and 31 health outcomes, with men as a comparison group.

What they found

Fifty-two of the 90 tests shifted abruptly at the final period, across hormones, bone, liver, kidney, cholesterol and blood chemistry. Men showed no such step at the same ages. Spine bone density dropped roughly 8 to 9% and LDL cholesterol rose about 10%. Ferritin, the body's iron store, rose about 80% once monthly bleeding ended. Moderate to severe depression reached 19.5% in the year after the final period, compared with 10.7% in later years. The hormone shifts started early: AMH began falling faster about 15 years before the final period, FSH began rising about 14 years before and estradiol began falling about 12 years before. Women on hormone therapy had smaller shifts, especially in bone, liver and kidney markers.

What it means for you

The biggest shifts landed in the tissues most tuned to estrogen, which tells us the whole body recalibrates together when estrogen falls. That makes the year or two around your final period the time I look most closely: lipids with ApoB, liver and kidney markers, blood pressure, bone health and mood. I check ferritin before anyone adds iron. Because the changes begin years ahead, the hormone therapy conversation belongs early, while there is still time to make an informed choice. The word "cliff" describes how fast the lab values move. It says nothing about who you become on the other side.

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Insulin resistance before conception shapes fertility treatment and pregnancy outcomes in PMOS

What they studied

Researchers went back to a large multicenter trial of 746 women with PMOS, ages 18 to 40, who were using letrozole or clomiphene to ovulate for up to five cycles. Before treatment and again at the end, each woman's insulin resistance was measured with HOMA-IR, a calculation from fasting glucose and fasting insulin. The women were split into four equal groups by their starting HOMA-IR and followed through ovulation, pregnancy and birth.

What they found

The group with the lowest insulin resistance (HOMA-IR under about 1.2) ovulated 93.5% of the time and had a 35.5% live birth rate. In the highest group (above about 5.3), ovulation fell to 73.8% and live births to 18.2%. The steepest drop came early: women in the second group, with HOMA-IR between 1.2 and 3.1, had a live birth rate of 19.7%, nearly as low as the highest group.

Among women who conceived, gestational diabetes climbed from 13.8% in the lowest group to 45.7% in the highest, and preterm delivery from 7.6% to 29.4%. Women whose HOMA-IR came down during treatment had nearly twice the odds of a clinical pregnancy and about one fifth the odds of preeclampsia. A fasting glucose of 110 mg/dL or higher before pregnancy was strongly tied to gestational diabetes. Miscarriage rates were similar across all four groups.

What it means for you

High insulin pushes the ovaries to make more androgens and disrupts how follicles mature, which is why ovulation suffers. It also strains the lining of blood vessels, the same tissue involved in preeclampsia. The second-group finding is the one I want women to see. A HOMA-IR of 2 usually passes as normal on a lab report, yet here it came with a live birth rate close to that of the most insulin-resistant women.

The encouraging part is that this marker moves. Women whose insulin resistance improved did better, before and during pregnancy. That is why I measure fasting insulin and glucose before a fertility cycle and treat insulin sensitivity as part of preparing to conceive. Movement, strength training, food and medication like metformin all have a place in that work, chosen for the woman in front of me.

How solid is it?

GLP-1 medications change the menstrual cycle, and the change runs in both directions

What they studied

Two studies published a week apart came at the same question from opposite sides. The first searched the FDA's adverse event reporting system, through March 2026, for menstrual complaints in women aged 12 to 55 taking semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro, Zepbound) or liraglutide, and compared them against every other drug in the database. The second followed 96 women with PMOS and a BMI above 25 through six months of semaglutide, confirming ovulation with progesterone levels in the second half of the cycle.

What they found

Semaglutide was reported disproportionately often with heavy bleeding, bleeding between periods, clots, infrequent periods and cycles without ovulation. Tirzepatide showed signals for bleeding between periods and clots. Liraglutide showed none. In the PMOS cohort, women lost an average of 11% of their body weight and about half of those who had not been ovulating began to. Women in the overweight range did best, with nearly 95% reaching regular ovulatory cycles. A quarter of women with moderate or severe obesity did.

What it means for you

These medications act on far more than appetite. GLP-1 receptors sit in the lining of the uterus, and an early lab study this year, not yet peer reviewed, found semaglutide changed how that lining prepares for an embryo. Rapid fat loss shifts estrogen, since fat tissue both makes and stores it. Better insulin signaling can restart ovulation that has been stalled for years. A new bleeding pattern on one of these drugs deserves an evaluation, and so does a cycle that suddenly returns.

If you are taking a GLP-1 and pregnancy is not the plan, contraception matters more than you might expect. Ovulation can come back before your periods look regular. Tirzepatide also lowers how much of an oral contraceptive pill your body absorbs, so a backup method is advised for four weeks after starting and after each dose increase. If pregnancy is the plan, these medications are stopped ahead of trying to conceive, and we time that together.

How solid is it?

Astaxanthin before IVF improved egg and embryo numbers in women with PMOS

What they studied

Fifty women with PMOS-related anovulatory infertility took 12 mg of astaxanthin daily or a placebo for six weeks before egg retrieval. Astaxanthin is the red-orange carotenoid in wild salmon and algae, and one of the most potent antioxidants studied in human tissue. The team also measured autophagy, the cell's own cleanup system, inside the granulosa cells that surround and nourish each egg.

What they found

After adjusting for age, BMI and AMH, the astaxanthin group produced more total eggs and more mature eggs, more top-grade embryos and more embryos suitable for freezing. Autophagy markers rose and cell death markers fell in the granulosa cells. Pregnancy rates were higher on paper but did not reach significance.

What it means for you

Oxidative stress in the follicle is one of the reasons egg quality suffers in PMOS, and this trial shows it can be targeted. An egg spends roughly three months maturing before ovulation, which is why I start antioxidant and metabolic work well ahead of a fertility cycle.

How solid is it?

Exercise on its own lowers testosterone and insulin resistance in PMOS

What they studied

Researchers pooled 22 randomized trials covering 1,044 women with PMOS where exercise was the only intervention. No diet change, no medication added.

What they found

Exercise lowered total and free testosterone, fasting insulin and insulin resistance, and raised HDL cholesterol. Moderate and lower-intensity exercise raised SHBG, the protein that binds testosterone and keeps it inactive. Women exercising 150 minutes or more per week saw larger testosterone drops. Women without obesity saw a bigger testosterone reduction than women with obesity.

What it means for you

That last finding matters for lean PMOS, where weight loss is off the table as a lever. Muscle is the largest glucose sink in the body, and training it changes insulin signaling and androgen production directly. The SHBG result argues for steady, sustainable movement over punishing intensity.

How solid is it?

A multistrain probiotic did not improve blood sugar or cholesterol in PMOS

What they studied

Fifty women with PMOS took a nine-strain probiotic or a placebo for 12 weeks. Researchers measured fasting and two-hour glucose and insulin, insulin resistance and a full lipid panel.

What they found

No meaningful difference between groups on any metabolic marker, and the result held when every randomized participant was included.

What it means for you

I include studies that come up empty because they are just as useful. The gut has a real role in PMOS physiology, through inflammation, estrogen recycling and insulin signaling. A generic capsule is a blunt tool for that work. Fiber diversity, fermented foods and treating what testing actually shows remain the better starting points.

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Hormone therapy and the aging brain: two autopsy studies point the same direction

What they studied

The first study drew on two large US research databases and compared women 50 and older who had used estrogen therapy with women who had not, looking at brain tissue after death along with blood and spinal fluid markers. The second followed 1,416 women from two long-running aging studies and examined LATE, a form of dementia that mimics Alzheimer's but is driven by a different protein, TDP-43.

What they found

Estrogen users had 35% lower odds of more advanced Alzheimer's changes at autopsy and lower odds of a dementia diagnosis during life. In the second study, women who started hormone therapy within five years of menopause had 30% lower odds of LATE, and women who used it for 8 to 16 years had 56% lower odds.

What it means for you

Estrogen is a working signal in the brain, involved in glucose use, blood flow and how neurons clear damaged proteins. These findings fit the timing pattern seen across the hormone therapy literature: the window around the transition is when the brain is most responsive. Brain health belongs in the conversation about whether and when to start, even though dementia prevention alone is not a reason to begin.

How solid is it?

Starting hormone therapy near menopause tracked with lower diabetes and heart disease over a decade

What they studied

Using electronic health records from a global research network, investigators matched women who started hormone therapy within a year of their menopause diagnosis to similar women who did not, then followed both groups for at least ten years. They split results by age at menopause: before 40, 40 to 45, 46 to 60 and after 60.

What they found

For women diagnosed at 60 or younger, hormone therapy was linked to about 40% lower risk of type 2 diabetes, 30% lower risk of cardiovascular disease and 22% fewer spinal compression fractures. In women diagnosed after 60, breast cancer risk ran about 15% higher among users.

What it means for you

Estrogen shapes how muscle and liver handle glucose and how blood vessels relax, so these associations make physiological sense. The age split is the real lesson: the same therapy carries a different balance of benefit and risk depending on when the body enters it. On breast cancer and blood clots, randomized trials remain the better guide.

How solid is it?

Everyday chemical exposures may hit harder during perimenopause

What they studied

Researchers gathered every study from four major US cohorts of midlife women that measured chemical exposures alongside metabolic health: weight and body composition, blood sugar, cholesterol and blood pressure.

What they found

Phthalates (found in plastics and fragrance), PFAS (nonstick and stain-resistant coatings), persistent pollutants, heavy metals and air pollution were each linked to more body fat, worse cholesterol patterns and higher risk of diabetes and high blood pressure. Several studies suggested perimenopause is a window of heightened sensitivity.

What it means for you

Why does midlife weight shift even when nothing about eating has changed? Estrogen decline is part of it. These chemicals interfere with the same hormone and fat-storage signaling, which may explain why exposure counts more during the transition. The practical steps carry no downside: stop heating food in plastic, choose fragrance-free products, filter drinking water and retire scratched nonstick pans.

How solid is it?

A history of migraine raises ischemic stroke risk after menopause

What they studied

Researchers followed more than 130,000 postmenopausal women for a median of nearly 20 years, comparing stroke rates in women with and without a physician-diagnosed history of migraine.

What they found

Women with a migraine history had a 12% higher risk of ischemic stroke, the type caused by a blocked vessel. There was no link to bleeding strokes. The risk held steady across age groups and after accounting for standard heart risk factors and female-specific factors like age at menopause and hormone therapy use.

What it means for you

Migraine reflects how the blood vessels and the lining of those vessels behave, and that does not stop mattering after periods end. Your migraine history belongs in your cardiovascular risk picture at midlife, alongside blood pressure, lipids and blood sugar. It also shapes hormone therapy choices: estrogen through the skin avoids the clotting effects of oral estrogen and is the route I favor for women with migraine.

How solid is it?