Dear community,
Thank you to each of you for being here — and for co-building this community to transform our well-being.
As we wrap up our summers, I’d like to introduce a new column type, Reader QnA — a standing space where I answer the health questions you’ve had on your mind.
You can let me know your burning questions here at any time — including anonymously. No question is too inconsequential. If you’re wondering about it, chances are that others are, too.
Whether you’re new here or an original member of this tribe — as we settle into the second half of the year, I’d love to ask you for feedback on how we’re building this community so far. What topics and column types have you most valued; what do you want to see more or less of; and what other inputs do you have for building this community in a way that’s inclusive and transformative? Please let us know your thoughts here.
Finally, today, I’m launching a reader referrals program. If you enjoy being part of our community at Ask Dr Devika B, it would mean the world to me if you invited friends to join in this health and well-being journey with us. When you refer friends, you’ll receive complimentary access to Ask Dr Devika B. Here’s how:
1. Share Ask Dr Devika B. Use the referral link below or “Share” button on any post to get ‘credit’ for referring new subscribers. You can share the link in a text, email, on social media, or any other way you’d like.
2. Earn benefits. Whenever someone subscribes (free or paid) to our community using your referral link, you’ll accrue the following benefits. As a reminder: paid subscribers get access to all posts and private Zoom chats.
Get a complimentary 1-month subscription for 5 referrals
Get a complimentary 3-month subscription for 10 referrals
Get a complimentary 6-month subscription for 30 referrals
Thank you again for all your support and for being such a crucial part of this community!
Wishing you light,
Dr Devika Bhushan
1. I’ve noticed that my hair has started to go grey recently. There’s definitely been a number of new stressors in my life… am I imagining this or can stress cause us to go grey? —AK, Mexico City, Mexico
Presciently, just before the pandemic, a study came out in the high-impact journal Nature that elegantly showed us that in mice, stress indeed literally turns hair grey. The same pattern has been found in humans. So it’s not just your imagination! There’s a legend when Marie Antoinette, the infamous 18th-century queen of France, was due to be executed by guillotine, her hair turned white overnight.
Here’s the basic mechanism in mice: Stress causes activation of the sympathetic nervous system all over the body, including in the nerves that feed hair follicles. During times of stress, the mouse study found that these nerves release norepinephrine into the hair follicle, which causes the cells that make hair pigment (melanocyte stem cells, making melanin) to migrate out of the hair follicle, turning hair white with no further source of ongoing pigment production.
This is a prime example of how a specific cellular process is “directly influenced by the overall physiological state of the organism,” in the authors’ words. Our stress levels absolutely impact our biology in many ways, and can speed up or slow the processes of biological aging — including this very visible stress residue on our heads.
In humans, there’s evidence that hair greying is reversible to some degree — after a period of acute stress, when we are subsequently faced with lower levels of stress, newly grey hair can sometimes reverse course to getting its original color back — to a point. Martin Picard, PhD, who led this study, noted this example in an interview: “There was one individual who went on vacation, and five hairs on that person’s head reverted back to dark during the vacation.”
The authors posited a stress threshold model for human hair greying and reversal: “[T]here might be a threshold for temporary greying; if hairs are about to go grey anyway [because of biological age], a stressful event might trigger that change earlier. And when the stressful event ends, if a hair is just above the threshold, then it could revert back to dark.”
Picard warned that like other processes of aging, this one has to accord with certain biological norms: “[W]e don’t think that reducing stress in a 70-year-old who’s been gray for years will darken their hair or increasing stress in a 10-year-old will be enough to tip their hair over the gray threshold.”
The study also found that in humans, mitochondria — the powerhouses of the cell — play a critical role in detecting and translating stress levels to a hair greying or reversal outcome.
If you missed it, be sure to check out our Stress and health mini-series, linked below, to help you transform how stress affects health, both for yourself and for loved ones. These pieces are particularly useful at this moment — as our kids transition back to school.
Stress and health mini-series:
II: Turning off the stress response in the moment: article | video
III: How to reverse the health impacts of stress: article | video
II and III+: My personal favorite ways to destress: article
IV: Supporting a loved one after a traumatic event: article | video
2. Should women pee after sex to prevent a UTI? —ST, New York City, USA
At baseline, the urinary tract is normally free of any organisms — or as we like to say in our family, ‘pee is sterile.’ And when that’s disrupted, as many of you may know first-hand, it can be exquisitely painful and costly.
Urinary tract infections (UTIs), where bacteria set up shop in the usually sterile or bacteria-free urinary tract, are very common — between 40 and 60% of women will have at least one in our lifetimes and 30 to 40% of women will get recurrent UTIs. UTIs matter because when untreated, they can cause kidney damage and high blood pressure, not to mention incurring pain and costs from missed work or school and greater health care needs.
Women and people assigned female at birth have a UTI risk that’s up to 30 times higher than men’s given our anatomy. One, there’s a shorter distance from the urethra (opening to the urinary tract, or where we urinate from) to potential sources of bacteria like the anus or vagina. And two, we have shorter urethras, meaning there’s a shorter distance for bacteria to ascend to the bladder (for a lower UTI or cystitis) and kidneys (for an upper UTI or pyelonephritis).
Any activity — like sex — that repeatedly jostles the urethra makes it more likely that bacteria from the anus or genital tract make it to the otherwise bacteria-free urethral opening and from there, up into the bladder, or higher into the kidneys — causing an infection. By one estimate, bacteria in the urethra and bladder can increase 10-fold after sex (though I couldn’t find a primary source for this claim).
Urinating is the body’s simple method of flushing out the urinary tract (in addition to dumping unneeded fluids and solutes). And by the way, increasing fluid intake to enable more frequent urination is one known way to generally decrease UTI risk — by flushing out possible bacteria more frequently.
A case-control study did not conclusively support the efficacy of urinating after sex for lowering UTI risk. However, the study relied on self-reported recall of urination patterns after sex rather than an objective measurement, which is subject to some bias for both the group of interest with UTIs in the past month (whereby asking this question may have prompted more ‘yesses’ than true due to a social desirability bias or desire to have displayed the ‘correct’ behavior and not have the UTI be one’s ‘fault’) and in the control group (where women may actually have said ‘no’ more often and under-reported this behavior because it is harder to recall routine behaviors like this definitively after the occurrence a non-event — ie after not having a UTI — since the events surrounding it are less salient in our memories).
Despite this null finding, many clinicians, some (but not all) clinical practice guidelines, and public health authorities such as the Centers for Disease Control and Prevention (CDC) and National Institutes of Health (NIH) continue to recommend the practice of urinating after sex, especially for those prone to recurrent UTIs, because it makes intuitive sense and has few downsides.
Bottom line: I would recommend you urinate within 20-30 minutes after having any kind of sex (masturbation, anal, vaginal, or oral) because it’s a good way of flushing out any bacteria that made it to the urethra or bladder before it can potentially set up an infection. Given how costly and painful UTIs can be, this trivial step is well worth taking. It definitely can’t hurt, even if it hasn’t (yet) been shown to definitively help.
PS: Check out this article from our archives for a surprising natural remedy that can help prevent recurrent UTIs.
“Although there is no proof of prevention, women should urinate after sexual intercourse because bacteria in the bladder can increase by ten-fold after intercourse.”
–Bono et al, National Library of Medicine, National Institutes of Health, StatPearls: Urinary Tract Infection
Here are some more supportive data, for those interested:
Recent sexual intercourse (eg: in the past month, odds ratio 5.8) and also higher frequency of intercourse is associated with greater recurrent UTIs in women (odds ratio 10.3 for intercourse 9 or more times relative to 0-3 times in the past month), showing the direct correlation between sexual activity and likelihood of bacterial UTI
Intercourse increases vaginal colonization with Escherichia coli, the most common bacterium causing UTIs, making it easier for it to reach the urinary tract