Reviewed by 
The next time hunger strikes, your first instinct may be to grab a snack—but that rumbling stomach might actually be sending your brain a powerful protective signal. Scientists are discovering that a hormone best known for triggering hunger, plays a surprisingly important role in brain health, memory, and even protection against neurodegenerative diseases like Parkinson’s. Here's how you can use the science to help you and your loved ones...
Key Takeaways
Ghrelin supports brain health by protecting dopamine-producing neurons linked to movement and Parkinson’s disease.
It enhances memory and learning by stimulating neural growth in the hippocampus.
Simple habits like avoiding constant snacking, exercising, and maintaining a healthy weight can help sustain ghrelin levels.
The Surprising Brain Benefits of the “Hunger Hormone”
By understanding how ghrelin works—and making a few simple lifestyle adjustments—you may be able to turn hunger into an unexpected ally for a healthier, sharper brain.
The next time you’re feeling really, really hungry, don’t be too quick to treat yourself to a snack.
It turns out that the hormone behind that famished feeling is doing good things for your brain.
By waiting a few extra minutes before you start munching, you may add to this hormone’s brain benefits. And, once you understand how it operates, you may want to make a couple of other adjustments to your daily habits and reap even more brain gain. . .
Ghrelin, the "hunger" hormone, originates in the stomach wall and signals the hypothalamus to make you feel hungry. The stomach secretes the hormone when it’s empty and stops secreting it when it’s full.
But as scientists have learned more about ghrelin, they’ve realized that the interactions of the stomach, the brain, and ghrelin are a lot more complex and important than originally thought.
How Your Stomach Talks to Your Brain—And Why It Matters
A study at the Yale School of Medicine shows that ghrelin helps neurons in the brain stay healthier and resist the type of deterioration that leads to Parkinson's disease.
The researchers say this protection occurs when ghrelin interacts with neurons in the substantia nigra, a region of the midbrain.
The neurons in this part of the brain produce the neurotransmitter dopamine.
When their manufacture of dopamine slips, it gums up brain functions in a way that leads to Parkinson’s symptoms: simple walking and moving about become difficult; muscle movements freeze; appetite disappears; the arms, legs, and head develop tremors; chewing and swallowing are hampered; and at times, you can’t move at all.
The lab tests at Yale showed that dopamine problems and Parkinson’s symptoms in the brain can get worse as ghrelin levels go down.
Ghrelin Has a Lot Going On
The complexities of this brain-stomach interaction don’t stop there. An earlier study at Yale, for instance, found that ghrelin interacts with neurons in the hippocampus (an important brain area for forming new memories) and promotes the formation of neuronal structures that lead to "enhanced spatial learning and memory."1Another important aspect of ghrelin’s protective functions is its effects on astrocytes – immune cells in the brain that play a wide range of roles. Astrocytes help neurons communicate more effectively. They also help maintain the blood-brain barrier, which prevents unwanted proteins and other potentially damaging materials from passing from the blood into the brain.
Researchers admit they don’t really understand everything that astrocytes do in the brain. But they know their functions are important for making human brains more powerful than those of other animals – our brains contain vastly more astrocytes than other animals possess.2
And some researchers think that certain communications between neurons may not even be possible without astrocytes taking part. Plus, they’re crucial for helping the brain measure the passage of time.3
How to Boost Your Ghrelin Levels
If you want to have more ghrelin circulating in your body and brain, hold off on frequent snacking and restrict most of your eating to mealtimes. And stop eating early in the evening so you have a period of about 12 hours or so between your last meal at night and your breakfast the next morning. Aerobic exercise also boosts ghrelin. Jogging is especially effective, and walking can help too.4 But perhaps one of the most important ways to keep this hormone level higher is to keep your weight down. When your waistline expands, the stomach’s production of brain-healthy ghrelin drops.Summary
Ghrelin is a hormone released by the stomach when it’s empty, signaling hunger to the brain. Beyond appetite control, research from Yale School of Medicine shows that ghrelin helps protect dopamine-producing neurons in the substantia nigra, a brain region critical for movement and affected in Parkinson’s disease. Lower ghrelin levels were associated with worsening dopamine dysfunction. Additional studies reveal ghrelin also supports memory and learning by acting on the hippocampus and enhances brain resilience through effects on astrocytes, key immune and support cells in the brain. Lifestyle habits such as limiting snacking, spacing meals, exercising aerobically, and maintaining a healthy weight may help preserve ghrelin’s brain-protective benefits.
Meet
The Expert:
The Expert:
Susan Clark is an award-winning, Emmy-nominated journalist and author who has written about nutrition, health, and wellness for 27 years. She has developed content for articles, reports, books, videos, and television news segments featuring some of today’s top alternative and integrative doctors. She earned a bachelor of science in broadcast journalism from Texas Christian University. She lives in Los Angeles with her husband, two sons, and numerous pets.