Could eating curry be an effective therapy for Parkinson’s?
There is, unfortunately, more to it than that (the answer to my question is “no”), but some recent research indicates that curcumin, a compound found in the spice turmeric (used in many Indian dishes), may reduce the formation of Lewy bodies in the brain. Lewy bodies are clumps of a protein called alpha-synuclein, and their formation is strongly associated with the symptoms of Parkinson’s. There’s a bit of background information on alpha-synuclein and Lewy bodies here.
The study that prompted my optimistic suggestion on diet claims, in its “capsule results”:
Curcumin binds to monomeric α-synuclein, prevents aggregation, and increases the reconfiguration rate, particularly at high temperatures.
I’m not sure about that “high temperatures” bit. I don’t think brains like being very hot*. But then, these guys seem to be physicists* (they hail from the Department of Physics and Astronomy at Michigan State University; I suppose that they could be astronomers…). Which, I have to say – as someone who once studied Chemical Physics – seems a bit odd. This sort of thing is generally considered to be at the opposite end of chemistry. Biochemistry. Or even biology. But enough disciplinary quibbles; they don’t affect the validity of the results. Which say that curcumin stops that pesky misfolding of alpha-synuclein. Go, curcumin!
Except that there is one big problem. How do you get it into the brain?
Like many things, curcumin isn’t very good at crossing the blood-brain barrier. Professor Lisa Lapidus is quoted as saying that “Curcumin’s usefulness … may be pretty limited since it doesn’t go into the brain easily where this misfolding is taking place.”
I imagine that this means that eating tumeric-laden dishes isn’t going to do the trick.
However, even if curcumin itself isn’t useful, the researchers were able to identify a potential mechanism for the prevention of alpha-synuclein from folding into Lewy bodies – and to theorise why alpha-synuclein is prone to this “aggregation” in the first place. It is, of course, always useful to have an insight into the hows and why of these processes; and this knowledge may be useful in identifying another substance that may be able to cross that blood-brain barrier.
The abstract states that curcumin binds strongly to alpha-synuclein and that it “complete[ly] inhibit[s]” the formation “of oligomers or fibrils”. (This means that it stops alpha-synuclein from folding into clumps; it does this by speeding up the protein’s natural folding.)
We conclude that α-synuclein is prone to aggregation because its reconfiguration rate is slow enough to expose hydrophobic residues on the same time scale that bimolecular association occurs. Curcumin rescues the protein from aggregation by increasing the reconfiguration rate […]
The “Capsule Significance” part of the abstract emphasises the potential for future research:
The search for aggregation inhibitors should account for changes in chain dynamics by the small molecule.
So maybe eating spicy food won’t stop those alpha-synuclein molecules from folding into Lewy bodies, and maybe the spice extract itself won’t be the answer; but we do see to be a step closer to a potential answer to this fundamental problem. And if the physicists and astronomers want to help find the answer, then more power to them!