New study supports the potential for PDE5 inhibition to increase the number of children fathered by male patients, but finds no evidence of such an effect in female patients Benji Woolf #ChristmasBMJ bmj.com/content/383/bm…

Do biological mechanisms leading to penis stiffening make men happy? Do they make them more fertile? Find out in our new drug target Mendelian randomization article, led by Benji Woolf and now out at The BMJ: bmj.com/content/383/bm…

Thanks to Benji (Benji Woolf) and Dipender (Dipender Gill) for leading this work, and for Skanda, Toinét (Héléne (Toinét) Cronjé), James (James Yarmolinsky), and the BMJ editors for their willingness to engage with both the science and the humour of the article. /END

Really nice review by Héléne (Toinét) Cronjé and Stephen Burgess on the importance of sensible variant selection in MR

New paper: "A frequentist test of proportional colocalization after selecting relevant genetic variants": arxiv.org/abs/2402.12171 led by Ash Patel. We introduce a new test for colocalization in a frequentist paradigm. Thread follows!

**Flash Talks Event** Benjamin Woolf Benji Woolf shares his research "Comparison of caffeine consumption behavior with plasma caffeine levels as exposure measures in drug-target Mendelian randomization studies" Vote for your favourite talk: meg-uk.org/flash-talks-20…

New Mendelian Randomization from Loukas Zagkos Héléne (Toinét) Cronjé Benji Woolf Stephen Burgess Shuai Yuan 袁帅 Susanna Larsson Joanna Tzoulaki Dipender Gill et al.: Long-term increases in circulating #caffeine may reduce bodyweight and the risk of osteoarthrosis and osteoarthritis. shorturl.at/blySV

Our new study erj.ersjournals.com/content/early/… with James Perry, Charles Hong Mark Toshner, Stephen Burgess, Dipender Gill, Martin Wilkins, and Chris Rhodes failed to find evidence supporting the use of IL6R inhibitors on pulmonary arterial hypertension.

youtube.com/watch?v=-8Gy0s… really enjoyed watching this seminar by Harvard Epidemiology on measurement error. Lots of food for thought.

Had a lot of fun presenting our work (accepted this week at the AJE) on exposure miss-identification in MR, and how it results in directionally incorrect conclusions for studies of caffeine consumption at #mrconf24.

And the accepted m/s is now out in the AJE! academic.oup.com/aje/advance-ar… Thank you to Héléne (Toinét) Cronjé Dipender Gill Stephen Burgess Loukas Zagkos Susanna Larsson Summary can be found x.com/BarWoolf/statu…

🚨 New preprint awaiting feedback! 🚨 led by the lovely and talented Marta looking at the relationship between PDE5 inhibition and Alzheimer's disease using #mendelianrandomization (spolier: we found nada) medrxiv.org/content/10.110…

Posting a tad late, but James Yarmolinsky and Dipender Gill and I have a new research letter in @intjepidemiol where we use negative controls to illustrate why drug use phenotypes should not be used as exposures in MR studies academic.oup.com/ije/article/54…

New paper published at AJE Advances: "The role of estimation in Mendelian randomization: should Mendelian randomization investigations provide estimates?" led by Benji Woolf and myself. Brief thread:

Benji Woolf Forgot to add the link to the manuscript: academic.oup.com/ajeadvances/ad….

New pre-print online: "Context-stratified Mendelian randomization: exploiting regional exposure variation to explore causal effect heterogeneity and non-linearity", arxiv.org/abs/2507.11088. We propose an alternative approach to assess non-linearity in Mendelian randomization.

One of my students St Edmund's College, Cambridge has a really remarkable story of overcoming adversity to study Cambridge University. Sadly his scholarship can't fund the rest of his degree so he is trying crowdfunding. Any help would be really appreciated, thank you very much! gofundme.com/f/from-poverty…

New manuscript led by Benji Woolf "A cautionary note on the naive use of general-population biobanks to study pulmonary arterial hypertension" is now published at Euro Respiratory Journal ERS publications: pubmed.ncbi.nlm.nih.gov/40967765/. Summary follows:

Stephen Burgess Benji Woolf ERS publications Really important work (and delighted to help) using pulmonary hypertension as a disease exemplar. Applicable across all rare disease I expect.

New pre-print "Mendelian randomization in a multi-ancestry world: reflections and practical advice" led by Amy Mason - arxiv.org/abs/2510.17554