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Mannitol and Iron for Parkinson's Disease

Hope you enjoyed the first weekend of summer! Well, for my last post, I kept things short so you could start your weekend. For this post--since the weekend is over--I'm going to keep you here until the end time! :)

Here are two new studies for the prevention of Parkinson's disease. First, a study on mannitol, a sugar alcohol that is the steroisomer of sorbitol. Alpha-synuclein is a protein that leads to the development of Parkinson's. Due to this, researchers decided to first identify the structural characteristics that lead to the development of clumps of alpha-synuclein. Once they had this information, they searched for a compound that could inhibit the proteins' ability to bind together, which led them to mannitol.

To test mannitol against alpha-synuclein, they used fruit flies genetically-engineered to carry the human gene for alpha-synuclein.

They then measured the ability of flies to climb the walls of a test tube, which indicated their locomotive capability. For the normal flies (control group), 72% of them were able to climb up the test tube. For the GE flies, only 38% could climb. Then the researchers added mannitol to the food of the GE flies, and after 27 days, 70% of the flies could complete the test.

Further, the team saw a 70% reduction in aggregates of alpha-synuclein in mutated flies that had been fed mannitol, compared to those that had not.

Apparently, these findings were then confirmed in a second study on mice, where after four months, the researchers found that mannitol-fed mice also showed a dramatic reduction of alpha-synuclein in their brains.

That's very exciting for a natural sweetener that's already approved for various medical uses.

Next was a meta-analysis that showed increasing iron levels could lower the risk of Parkinson's. This was surprising to me because I would think that if iron was even related to Parkinson's disease risk, it would have been the opposite. However, in this study, the researchers found that every 10 mcg/dL increase in iron levels resulted in a 3% lower risk of the disease.

However, the mechanism of action uncertain. The researchers speculated that, Low peripheral iron levels may reduce the functioning of neuronal enzymes or receptors, since iron is a crucial cofactor of tyrosine hydroxylase, which plays a role in the synthesis of monoamine neurotransmitters, and is involved in dopaminergic neurodevelopment.”

Tyrosine hydroxylase is the rate-limiting enzyme in the synthesis of dopamine.

“Furthermore, low iron levels may decrease neuronal iron storage in the form of ferritin…A reduction in ferritin could decrease neuronal iron utilization by decreasing the pool of iron available for neuronal enzymes…”

Another point I could add is that some cases of Parkinson's seems to involve dysfunctional mitochondria (the organelles responsible for the cells' energy production), and iron is important in not only delivering oxygen to the nervous system cells (by making up hemoglobin in the red blood cells), but also the iron-sulfur complexes that are critical in the Complexes that make up the electron transport chain in the inner membrane of the mitochondria.

So if you're still reading, STOP! Get out and enjoy the summer before it's winter again.

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  1. Interesting article on mannitol as it relates to Parkinson's. Surely, people will wonder if they can ingest mannitol on their own in an effort to affect their PD symptoms. Is mannitol available as an OTC supplement? Do you know of a safe dosage limit?

    1. Great question, Mark. Most sugar alcohols have an osmotic effect in the digestive system, so any significant quantity of mannitol is likely to cause diarrhea. So it's likely ideal to start small and increase the amount very slowly as your body adjusts.

      The glycemic index is also lower for sugar alcohols (compared to sucrose), so likely safer for diabetics, but keep in mind it's still a sugar.

      Many people probably already ingest some mannitol in varying amounts, either through food, or as an additive in nutritional supplements, prescription medications. I'm not sure if it's available OTC or as a supplement, but it is widely available as an ingredient on the supply side of the industry.

      Also, many may have heard me say before, "it's the dose that makes the poison." So while a certain amount may be beneficial for different reasons (like Parkinson's), too much is likely going to do some harm. So until more research is done, I wouldn't be self-prescribing any more than what is typically already consumed by many in the course of a day.



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