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HEALTHY-NUTRITION NATURAL SPORT

Prostate cancer in transgender women

close-up photo of a vial of blood marked PSA test alongside a pen; both are resting on a document showing the PSA test results

The transgender population is steadily increasing. Last year, investigators reported that 1.3% of people between the ages of 18 and 24 in the United States identify as transgender, compared to 0.55% of the country’s older adults. This trend has implications for public health, and one issue in particular concerns the risk of prostate cancer in transgender women.

Because removing the prostate can lead to urinary incontinence and other complications, doctors leave the gland in place when initiating hormonal treatments to induce female sex characteristics in transitioning people. This process, which is called feminizing or gender-affirming hormonal therapy (GAHT), relies on medications and surgery to block testosterone, a male sex hormone. Prostate cancer is fueled by testosterone, and therefore GAHT lowers overall risks for the disease. But transgender women can still develop prostate cancer in ways that remain poorly understood, according to the authors of a new paper.

“More individuals are openly identifying as transgender, particularly as advances are made in reducing the discrimination and marginalization that this group has faced,” says Dr. Farnoosh Nik-Ahd, a urologist at the University of California, San Francisco, and the paper’s first author. “Thus, it’s important to understand their health outcomes and how best to care for this population.”

Dr. Nik-Ahd and her colleagues wanted better insights into prostate cancer incidence and screening rates among transgender women, so they performed a comprehensive review of the literature that generated some notable findings. One is that that the prevalence of GAHT in the transgender population is still unknown. Some studies put the figure at roughly one in every 12,000 to 13,000 people who identify as transgender. But this is likely an underestimate, the authors claim, and it’s not broken out by sex.

Questions over GAHT

Similarly, little is known about the impact of GAHT on the likelihood of developing prostate cancer, the team reported. Prostate cancer rates do appear to be lower among transgender women than they are among cisgender men (men whose gender identify matches their sex at birth). For instance, one study found just a single case of prostate cancer among 2,306 transgender women receiving routine health care at a clinic in Amsterdam, Holland, between 1975 and 2006. Another study, also from Holland, detected six cases of prostate cancer among 2,281 transgender women over 17 years, which again is less than the comparable rate among cisgender men.

But the interpretation of these rates is limited by the fact that transgender women often experience barriers to care. Nearly a third of them live in poverty, and many avoid the health system for fear of mistreatment. Some scientists suspect that estrogen given during GAHT may somehow contribute to prostate cancer development when given over long durations. However, more confirmatory evidence is needed. Worryingly, one study found that survival among transgender women with prostate cancer is worse than it is in cisgender men with the disease, yet that research lacked data on GAHT use.

Interpreting PSA values for specific populations

Dr. Nik-Ahd’s team was especially concerned about the lack of guideline recommendations for prostate-specific antigen (PSA) screening in the transgender population. None of the available guidelines worldwide mention transgender women, and the PSA cutoff of 4 nanograms per milliliter (ng/mL) of blood — which raises suspicions for prostate cancer — is specific to cisgender men. PSA levels ordinarily plummet in people taking GAHT, so the limit for what’s considered normal in transgender women should be capped at 1.0 ng/mL, the researchers propose. In the absence of more specific guidance, they also recommend that people meeting age criteria for PSA screening get tested before starting on GAHT, in order to obtain a baseline value.

Many doctors are already familiar with other common drugs that alter PSA values — in this case with screening implications for cisgender men, points out Dr. Heidi Rayala, a urologist affiliated with Beth Israel Deaconess Medical Center in Boston, and a member of the Harvard Medical School Annual Report on Prostate Diseases editorial board. For instance, PSA values drop by half in men taking finasteride or dutasteride for hair loss (or to shrink an enlarged prostate). “Doctors take extra care when interpreting PSA in cisgender men who take these drugs,” she says. “The same care needs to be taken in interpreting PSA values in transgender women. And there needs to be broader education on this topic for both primary care doctors as well as the transgender community.

Dr. Nik-Ahd agrees. “Future research should aim to understand baseline PSA values for those on gender-affirming hormones, and to understand how to navigate some of the psychosocial barriers around PSA screening so as to not stigmatize transgender patients,” she says.

About the Author

photo of Charlie Schmidt

Charlie Schmidt, Editor, Harvard Medical School Annual Report on Prostate Diseases

Charlie Schmidt is an award-winning freelance science writer based in Portland, Maine. In addition to writing for Harvard Health Publishing, Charlie has written for Science magazine, the Journal of the National Cancer Institute, Environmental Health Perspectives, … See Full Bio View all posts by Charlie Schmidt

About the Reviewer

photo of Marc B. Garnick, MD

Marc B. Garnick, MD, Editor in Chief, Harvard Medical School Annual Report on Prostate Diseases; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Marc B. Garnick is an internationally renowned expert in medical oncology and urologic cancer. A clinical professor of medicine at Harvard Medical School, he also maintains an active clinical practice at Beth Israel Deaconess Medical … See Full Bio View all posts by Marc B. Garnick, MD

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HEALTHY-NUTRITION NATURAL SPORT

Considering collagen drinks and supplements?

A red-colored drink being poured from a bottle into a glass with ice; concept is collagen drinks

A tremendous buzz surrounds collagen drinks and supplements, as celebrities and influencers tout miraculous benefits for skin, hair, and nails. Since the collagen in our bodies provides crucial support for these tissues, it seems plausible that consuming collagen might lead to lush locks and a youthful glow. But what does the science say?

What is collagen?

Collagen is a major structural protein in our tissues. It’s found in skin, hair, nails, tendons, cartilage, and bones. Collagen works with other substances, such as hyaluronic acid and elastin, to maintain skin elasticity, volume, and moisture. It also helps make up proteins such as keratin that form skin, hair, and nails.

Our bodies naturally produce collagen using the amino acids from protein-rich or collagen-rich foods like bone broth, meat, and fish. But aging, sun damage, smoking, and alcohol consumption all decrease collagen production.

Collagen drinks and supplements often contain collagen from many different sources, such as fish, cattle, pigs, or chicken. Typically, they contain peptides, short chains of amino acids that help make up essential proteins in the body, including collagen itself and keratin.

What does the science say about collagen drinks and supplements?

Research on skin includes:

  • A review and analysis of 19 studies, published in the International Journal of Dermatology, that had a total of 1,125 participants. Those who used collagen supplements saw an improvement in the firmness, suppleness, and moisture content of the skin, with wrinkles appearing less noticeable. That sounds promising, but it’s unclear if these skin improvements were actually due to collagen. Most of the trials used commercially available supplements that contained more than collagen: vitamins, minerals, antioxidants, coenzyme Q10, hyaluronic acid, and chondroitin sulfate were among the additional ingredients.
  • A few randomized, controlled trials (see here and here) show that drinking collagen supplements with high amounts of the peptides prolylhydroxyproline and hydroxyprolylglycine can improve skin moisture, elasticity, wrinkles, and roughness. But large, high-quality studies are needed to learn whether commercially available products are helpful and safe to use long-term.

Hardly any evidence supports the use of collagen to enhance hair and nails. One small 2017 study of 25 people with brittle nails found that taking 2.5 grams of collagen daily for 24 weeks improved brittleness and nail growth. However, this small study had no control group taking a placebo to compare with the group receiving collagen supplements.

There haven’t been any studies in humans examining the benefits of collagen supplementation for hair. Currently, no medical evidence supports marketing claims that collagen supplements or drinks can improve hair growth, shine, volume, and thickness.

Should you try collagen supplements or drinks?

At this time, there isn’t enough proof that taking collagen pills or consuming collagen drinks will make a difference in skin, hair, or nails. Our bodies cannot absorb collagen in its whole form. To enter the bloodstream, it must be broken down into peptides so it can be absorbed through the gut.

These peptides may be broken down further into the building blocks that make proteins like keratin that help form skin, hair, and nails. Or the peptides may form collagen that gets deposited in other parts of the body, such as cartilage, bone, muscles, or tendons. Thus far, no human studies have clearly proven that collagen you take orally will end up in your skin, hair, or nails.

If your goal is to improve skin texture and elasticity and minimize wrinkles, you’re better off focusing on sun protection and using topical retinoids. Extensive research has already demonstrated that these measures are effective.

If you choose to try collagen supplements or drinks, review the list of ingredients and the protein profile. Avoid supplements with too many additives or fillers. Products containing high quantities of prolylhydroxyproline and hydroxyprolylglycine are better at reducing wrinkles and improving the moisture content of skin.

Consult your doctor before starting any new supplements. People who are prone to gout or have other medical conditions that require them to limit protein should not use collagen supplements or drinks.

The bottom line

Large-scale trials evaluating the benefits of oral collagen supplements for skin and hair health are not available. If you’re concerned about thinning or lackluster hair, brittle nails, or keeping skin smooth and healthy, talk to your doctor or a dermatologist for advice on the range of options.

It will also help to:

  • Follow a healthy lifestyle and eat a balanced diet that includes protein-rich foods.
  • If you smoke, quit.
  • Limit alcohol to two drinks or less in a day for men or one drink or less in a day for women.
  • Apply sunscreen daily and remember to reapply every two hours.
  • Wear wide-brimmed or UV-protective hats and clothing when you’re spending a lot of time in the sun.

Follow Payal Patel on Twitter @PayalPatelMD

Follow Maryanne Makredes Senna on Twitter @HairWithDrMare

About the Authors

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Payal Patel, MD, Contributor

Dr. Payal Patel is a dermatology research fellow at Massachusetts General Hospital. Her clinical and research interests include autoimmune disease and procedural dermatology. She is part of the Cutaneous Biology Research Center, where she investigates medical … See Full Bio View all posts by Payal Patel, MD photo of Maryanne Makredes Senna, MD

Maryanne Makredes Senna, MD, Contributor

Dr. Maryanne Makredes Senna is a board-certified dermatologist at at Beth Israel Lahey Health, and assistant professor of dermatology at Harvard Medical School. Dr. Senna founded and directs the Lahey Hair Loss Center of Excellence and … See Full Bio View all posts by Maryanne Makredes Senna, MD