Tired, anxious, gaining weight? It could be your hormones | Dr Helen O’Neill

**Jonathan** (0:00)
Welcome to ZOE Science and Nutrition, where world leading scientists explain how their research can improve your health.
Every second of your life, there's an invisible orchestra in your body whose music is coordinating every aspect of your health. That orchestra consists of over 50 hormones. Each one is an unseen but constantly changing chemical signal. Together, they make beautiful music that helps us wake up ready to go, tells us we're hungry, or psychs us up for an argument. They shape your energy, your metabolism, and over the course of a lifetime, your health itself. However, if just one instrument in the orchestra drifts out of balance, everything can feel wrong. In the modern world, many of us are living in ways that quietly but persistently disturb that music. Stress, disrupted sleep, highly processed food, everyday chemical exposures. Over time, they can all interfere with how our hormones work. And often, we don't realize this is happening. We just live with the symptoms and assume it's normal. The good news? It doesn't have to be this way. Misbehaving hormones can be identified, and lifestyle changes can have a profound impact on hormones, even returning the whole orchestra into tune. In this episode, I'm joined by Dr. Helen O'Neill, a lecturer in reproductive and molecular genetics at University College London, who has measured reproductive hormones in over 100,000 people. And I'm also joined by Dr. Federica Amati, ZOE's head nutritionist. Together, we explore the incredible power of hormones, how modern life leads them to misbehave, and what the science says about restoring balance, from fertility and PCOS, to gut hormones and testosterone injections. By the end of this episode, you'll have a clearer understanding of what may be influencing your hormones, and what matters most if something feels wrong. So you're empowered to take charge of your hormonal health. Helen, thank you for joining me today.

**Dr Helen O'Neill** (2:12)
Pleasure to be here.

**Jonathan** (2:14)
And Federica, wonderful to see you again.

**Dr Federica Amati** (2:15)
Excited to be here, Jonathan.

**Jonathan** (2:17)
So Helen, we have a tradition here at ZOE where we always start with a quick fire round of questions from our listeners. We have these very strict rules for scientists. You can only say yes or no, or one sentence if you absolutely have to. Willing to give it a go?

**Dr Helen O'Neill** (2:30)
Challenge accepted.

**Jonathan** (2:31)
All right. Are there any parts of the body that aren't influenced by hormones?

**Dr Helen O'Neill** (2:37)
No.

**Jonathan** (2:38)
Do women have testosterone?

**Dr Helen O'Neill** (2:39)
Yes.

**Jonathan** (2:40)
Do men have estrogen?

**Dr Helen O'Neill** (2:42)
Yes.

**Jonathan** (2:43)
Federica, does what you eat change your hormones?

**Dr Federica Amati** (2:47)
Yes.

**Jonathan** (2:48)
Can body fat influence a man's testosterone levels?

**Dr Federica Amati** (2:51)
Yep.

**Jonathan** (2:52)
Helen, what's your favorite fact about hormones that still blows your mind?

**Dr Helen O'Neill** (2:58)
I would say that the gut itself is like a hormone factory.

**Jonathan** (3:03)
That's amazing. I'm still coming to terms with the fact that men have estrogen which tells you how little that I understand hormones. I think we should start at the beginning because we've already established that I have no idea what our hormones are. What are they, Helen?

**Dr Helen O'Neill** (3:18)
Our hormones are essentially like chemical messengers that are responsible for pretty much every aspect of our lives. Our inflammation, our immune systems, our metabolism, our reproduction, our cognitive function. They are these fundamental and powerful messengers that are produced all over the body, whether it's individual organs or glands or the traditional endocrine organs like our ovaries or testes, but also in non-traditional places like our gut and our fat. We are constantly producing hormones to essentially travel throughout our bloodstream to do various functions, but almost every function relies on hormones or a collection of them.

**Jonathan** (4:03)
Why do we need hormones? Because we also have these nerves and my brain controls things. So why do I have hormones wandering around my blood?

**Dr Helen O'Neill** (4:11)
I guess when we think about hormones, they are there to protect us to a certain extent. So the best example I always give of a hormone to give you an impact of just how one hormone produced by a single organ can have a multi-organ and systemic effect on you. So when we talk about our adrenal glands or adrenaline junkies, that is our adrenal gland producing adrenaline.
How do we get an adrenaline shot or how do we get that kind of shock? It's if you see someone, so either a visual cue, you could see your ex, you get this jolt, you could hear something, it's a big bang, you get a jolt. And what happens when you get that production of adrenaline, your heart starts racing, your cheeks go red, your blood is literally pumping faster around your body. And that's a protective thing, it's to get you out of danger. But equally, sometimes if you get a big enough shock, you might feel like you need to defecate. Pretty much almost every aspect of your body is responding to this threat. And it may not be a threat, it may be something exciting, but regardless, what it's doing is it's telling you that actually one small hormone can go to the entirety of your body and affect your bowel, affect your heart, your breathing, your skin, all of these things are happening in that instant with the production of one hormone. So that is always the example I give you, gives you an idea of the power of one hormone and you imagine the collection of hormones constantly working. They really do keep us going in both survival and just maintenance.