TODAY'S AJENDA #86

Let’s talk coffee.  ☕ Most of what you see online about caffeine isn’t exactly glowing. It could raise blood pressure, cause jitters, mess up your sleep, or [insert other downside here]. 

But here’s some (good) news out of New Orleans. A study just presented at the annual clinical meeting of the American Heart Association found that coffee drinkers with a history of atrial fibrillation (AFib) had a lower risk of AFib recurrence than those who abstained completely from drinking coffee. 

• Zoom In: Researchers at UCSD studied 200 people in several countries and followed them for 6 months. While some may have expected those who drank coffee (at least 1 cup a day) to have had a HIGHER risk of AFib recurrence, the opposite result was found: the coffee drinkers were at 39% lower risk of having AFib than the group who abstained.

Rejoice! More good data about coffee! In the spirit of evidence-based celebration, let’s review how coffee affects your health. 

Caffeine Can Benefit The Heart 

The recent study, cutely called DECAF (although it used regular coffee), isn’t the first to look at how caffeine influences heart health: 

• A 2022 meta-analysis reported that daily coffee consumption is not associated with an increased risk of atrial fibrillation; in fact, some studies suggest a LOWER risk among moderate coffee consumers.

• A 2025 analysis found that moderate coffee drinkers had a lower risk of hypertension, type 2 diabetes, heart failure, and overall mortality compared to non-drinkers. 

Caffeine Can Boost Clarity & Physical Performance 

Beyond helping us get up from bed? Caffeine can enhance our mental function and physical strength:  

• A 2020 study found that people on a low caffeine dose (about 1-2 cups of coffee) performed better on the Stroop test and showed greater prefrontal cortex activity. 

• A meta-analysis found that women who consumed 1-3 cups of coffee before exercise showed greater muscular strength and endurance, especially in upper-body exercises. 

How Long Does Caffeine Stay in Your System? 

Caffeine has upsides. But how long does it actually stick around? Well, for most healthy adults, its half-life (the time it takes for your body to clear half of it) is 2.5 to 5 hours.  

But that window can stretch or shrink depending on dose, genetics, liver health, whether you smoke, are pregnant, are taking oral contraceptives or hormone replacement therapy (HRT), and more.   

• Zoom In: Women on oral contraceptives metabolize caffeine more slowly, about 10.7 hours vs. 6.2 hours in non-OC users. HRT may have a similar effect.   

Translation: if you’re drinking coffee later in the day and have any of these factors, the “buzz” might last longer. 

How Much Caffeine is Too Much? 

Caffeine and coffee aren't risk-free. Go beyond 400 mg of caffeine per day (about 3-4 cups of brewed coffee), and you might get side effects like anxiety, heart palpitations, or restless sleep. 

For some, too much caffeine causes more than just jitters. It may raise blood pressure, increase stroke risk, or, in rare cases, trigger arrhythmias, especially if you have underlying heart conditions. 

And because caffeine is a stimulant, it’s not always friendly to the nervous system. If you live with anxiety, insomnia, or bipolar disorder, the extra dose of adrenaline and cortisol can worsen your symptoms. 

A Nutritionist’s Guide to Caffeine 

1) Drink up to 2-3 cups of caffeinated coffee per day. 

This is what appears to align with many of the cardiovascular and cognitive benefit data. 

2) Go for caffeinated coffee instead of decaf (unless you are sensitive to the effects of caffeine).

It seems that caffeinated coffee is where much of the “heart benefit” signal is found. There’s not as much reliable data about decaf or other caffeinated beverages like teas.

3) Make sure it’s right for you. 

If you have insomnia, anxiety disorders, arrhythmias, or are pregnant (pregnancy doubles caffeine half-life), you may need to cut back or drink it earlier in the day. 

4) Don’t load up late in the day. 

As you get older, your body metabolizes caffeine more slowly, so that afternoon cup can linger and keep you wired well into the night. I NEVER have coffee after 2:30 PM unless I plan to be awake all night. Protect your sleep!

Bottom Line 

Keep your coffee habit, but make it work for you. And don’t listen to the wellness ‘noise’ out there that tries to convince you that coffee is bad for you! What IS bad for you is the mountain of whipped cream, syrup, and/or sugar that often accompanies the coffee at various popular coffee chains! 

Insulin. Cortisol. GLP-1s. These appetite hormones have gotten the celebrity treatment, especially GLP-1s (the hormone in Ozempic). But there’s another hormone that regulates your appetite, and most people have no idea it exists. 

Meet: Peptide YY (PYY). This tiny hormone is your built-in “stop eating” signal. And understanding how it works could help you keep the scale from creeping up in your 50s and beyond. 

What’s PYY? 

As you eat, food moves through your stomach into your intestines. When it reaches your lower intestines (the ileum and colon), PYY is released into your bloodstream and travels to the brain's hypothalamus with a simple message: “You can stop eating now.” 

Here’s how that fullness signal unfolds: 

• 15-30 minutes: PYY starts to rise and nudges you to slow down or stop eating. 

• 1-2 hours: Levels peak, sending a strong “I’m full” signal to your brain. 

• 4-6 hours: PYY gradually tapers off as digestion winds down. Hunger returns. 

Not all foods release the same amount of PYY. Protein (Greek yogurt, eggs, fish, legumes) and fiber (vegetables, oats, beans) trigger the fastest and strongest release, keeping you full for hours. 

Fat from sources like olive oil, avocado, and nuts also releases PYY, but to a lesser extent. Meanwhile, refined carbs like white bread or sugary snacks produce the weakest response (which explains why you’re still starving after eating an entire bag of chips). 

How Menopause Impacts Peptide YY  

One of the most common things I hear from women 50 and above is: “I’m eating the same, but gaining weight. What gives?” 

PYY could explain. After menopause, estrogen drops, which has been linked to lower PYY levels and higher hunger hormones like ghrelin. (This double-whammy is one of the not-fun side effects of menopause.) 

That hormone shift makes it harder to feel full, so you may end up eating more than you realize. 

Can I Naturally Boost Peptide YY? 

The good news: Absolutely! Here are four science-backed things you can do: 

1. Eat protein first thing. 

Eating a protein-rich breakfast kick-starts your fullness hormone, helping you stay satiated and eat less as the day goes on. Aim for 30 grams of protein per meal. A few of my high-protein breakfast favorites are salmon, eggs, and Greek yogurt.  

2. Add fiber to every plate. 

Fiber slows digestion and boosts PYY. Load up on vegetables, beans, chia seeds, and oats. 

3. Avoid constant snacking. 

It’s best to space meals 3-4 hours apart. When meals are predictable and spaced out, your body releases more PYY and is more responsive to its fullness signal. 

4. Build muscle. 

Exercise (especially resistance training) improves insulin and satiety hormone responsiveness. 

• Zoom In: More muscle means better metabolic health. And better metabolic health means your body picks up on fullness signals better.

Will PYY Medications Be A Thing in the Future? 

Most likely. A 2003 study found that PYY infusions helped both obese and lean people cut their caloric intake by 30%. Newer trials combining PYY, GLP-1, and oxyntomodulin also found significant weight loss. 

But don’t expect to see it at a CVS anytime soon. Scientists are still working on how to deliver PYY without the nausea and cramping side effects. 

Even if it never becomes a drug, PYY remains one of your body’s most elegant tools for appetite control. And for women over 50, supporting PYY naturally is a powerful weight management strategy.

You’ve probably never looked at your pasta and thought, “That could help my hair.” But that’s exactly what the latest trend suggests (and no, we’re not talking about the rigatoni-as-curlers thing on TikTok). 

The idea: Rinsing your hair with leftover pasta water boosts softness and shine, courtesy of starches (the carbohydrates released when your penne boils). 🍝

• Zoom In: Starches coat the hair with a film that helps strands slide past each other more easily. It’s the same mechanics many hair conditioners use. 

That said, dumping your leftover spaghetti water on your head feels odd. Where’d this even come from? 

Well, before pasta water, there was rice water. Japanese court ladies in the Heian Period (794-1185 AD) reportedly used rice rinse water (Yu-Su-Ru) to grow floor-length hair and prevent graying. 

• Zoom In: Rice grains are 80-90% starch and loaded with amino acids, vitamins, minerals, and antioxidants. 

But there’s not a lot of scientific evidence on rice water. While a 2022 review did find that rice bran products may promote hair growth, it focused on rice bran—not rice water. 

At least rice can point to some research. Pasta can’t. 

Unfortunately, there isn’t a single scientific study that has tested pasta water as a hair treatment. And pasta water comes with two potential problems that could damage your hair: salt and heat. 

1. Salt 

Most pasta water is salted. Salt pulls moisture from strands and roughens cuticles, especially if your hair is color-treated or fragile. 

2. Heat  

Heat lifts the hair cuticle. Once lifted, the cuticle can’t lock in moisture, and hair becomes rougher, duller, and more prone to tangles. 

Can I Still Try This At Home? 

Definitely! I’m all for running your own experiment. Lots of people love using pasta water (myself included) for velvety smooth strands. Here’s my “do no harm” protocol:

1. Use unsalted water only.  

2. Strain and cool. Aim for room temperature.

3. Dilute. Mix 1:1 with plain water. More starch isn’t always better. Some dermatologists warn that heavy starches may actually damage hair. 

4. Use as a post-shampoo, pre-conditioner rinse. Massage through lengths for 30–60 seconds, then rinse and follow with your usual conditioner.

5. Track your results. Limit use to once weekly and judge by how easily your hair detangles and how much breakage you see in your brush, not just how your hair “feels.” 

Pasta water isn’t for everyone. Skip it if you have a history of scalp eczema or folliculitis, very fine hair that gets weighed down easily, fresh color, or sensitivity to food proteins (gluten isn’t absorbed through hair, but residue can irritate). 

And if your main concern is thinning? Stick with evidence-based options (e.g., minoxidil and adequate protein/iron).  

As many of you know, I started a new hair experiment 3 months ago, when I learned about Wellbel* and their shampoo/conditioner and supplement.  

At this time, my hair was dull, fine, and really not in a good place. Quite literally, after the first shower use of the shampoo and conditioner, I felt and saw a difference: more moisture, more body, more shine! 

I was determined to be consistent and compliant with the 3-capsule-per-day oral supplement, and within a month, I saw a big difference in growth (which surprised me since it normally takes 3 months to see a difference in hair growth due to the life cycle of the hair follicle).   

After meeting the Wellbel founders (one of whom is a Harvard-trained doctor), I was a believer in their scientific formulations: using safe, impactful ingredients, many of which are not in other hair growth supplements.   

After just a month of using the Wellbel Women’s + supplements and shampoo/conditioner, my 26-year-old daughter, Chloe, started to notice the improvement, and she subsequently started using Wellbel.  

To date, both her hairstylist and my hairstylist have independently remarked on how much new growth we have and how shiny and healthy our hair looks. My experiment will continue, but so far, I’ve experienced great results!

Wellbel has been kind enough to extend a 15% discount to all Ajenda readers. Use the code Ajenda15 for 15% off any Wellbel order with free shipping. And if you decide to do a quarterly subscription, you’ll get another 20% off.

Did you enjoy Today’s Ajenda? It would mean the world if you left us a testimonial!

ABOUT DR. JEN

In her former roles as chief medical correspondent for ABC News and on-air cohost of “GMA3: What You Need to Know,” Dr. Jennifer Ashton—”Dr. Jen”—has shared the latest health news and information with millions of viewers nationwide. As an OB-GYN, nutritionist, and board-certified obesity medicine specialist, she is passionate about promoting optimal health for “the whole woman.” She has authored several books, including the national best-seller, The Self-Care Solution: A Year of Becoming Happier, Healthier & Fitter—One Month at a Time. And she has gone through menopause…

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^{This material is provided solely for informational purposes and is not providing or undertaking to provide any medical, nutritional, behavioral or other advice or recommendation in or by virtue of this material.  This newsletter is for general informational purposes only and does not constitute the practice of medicine, nursing or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this newsletter or materials linked from this newsletter is at the user’s own risk. The content of this newsletter is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard, or delay in obtaining, medical advice for any medical condition they may have, and should seek the assistance of their health care professionals for any such conditions.}