The Genesis Protocol · Fasting

Fasting and Parkinson's: switching on the body's clean-up crew

Humans evolved eating and then not eating. Modern life removed the “not eating” part — and with it one of the body's most powerful repair signals. Fasting puts it back. It is the engine of the Genesis Protocol and our main tool for unwinding decades of metabolic damage.

What happens when you fast

After several hours without food, insulin falls, the liver's glycogen stores run down and the body begins switching to fat and ketones for fuel. Neuroscientist Mark Mattson calls this metabolic switching. His review in Nature Reviews Neuroscience (Mattson et al., 2018) describes how repeated switching between fed and fasted states triggers adaptive responses in the brain — stress resistance, better mitochondrial function, neuroplasticity and cellular clean-up. A later review in the New England Journal of Medicine (de Cabo & Mattson, 2019) summarises the same biology across health, ageing and disease.

Autophagy: the clean-up fasting switches on

Autophagy is how cells break down and recycle damaged proteins and worn-out parts. Nutrient signals keep it dialled down; when food stops coming in, it ramps up. In mice, short-term food restriction produced a striking increase in autophagy inside brain neurons (Alirezaei et al., 2010) — direct evidence that fasting reaches the cells that matter most in Parkinson's.

Every fasting window adds to what we call your cumulative autophagy time: decades of debris were built up a day at a time, and we work them back the same way.

Mitophagy: replacing tired mitochondria

Dopamine-producing neurons are energy-hungry and depend on healthy mitochondria. Mitophagy is the specialised form of autophagy that removes damaged mitochondria. Two genes linked to inherited Parkinson's, PINK1 and parkin, are core parts of this machinery: PINK1 flags a failing mitochondrion and parkin marks it for removal (Narendra et al., 2008; Pickrell & Youle, 2015). When this quality control falters, damaged mitochondria accumulate — which is why we treat mitochondrial clean-up as a central goal of fasting.

Alpha-synuclein clearance

Clumps of a protein called alpha-synuclein are a hallmark of Parkinson's. Laboratory studies show cells clear alpha-synuclein through autophagy as well as the proteasome (Webb et al., 2003), and that Parkinson's-linked mutant forms of the protein jam a selective autophagy pathway called chaperone-mediated autophagy (Cuervo et al., 2004). Supporting the cell's own clearance systems is a rational, biology-first strategy — and fasting is one of the most powerful natural signals for those systems.

Ketones: fuel and signal

As fasting continues, the liver turns fat into ketones, mainly beta-hydroxybutyrate (BHB). Ketones are an efficient alternative fuel for the brain, and they also act as signalling molecules. Researchers have reviewed how BHB may address several cellular problems seen in Parkinson's, including mitochondrial dysfunction, oxidative stress and inflammation (Norwitz et al., 2019).

BHB also boosts BDNF (brain-derived neurotrophic factor), a growth factor that supports neuron survival and plasticity. In mice, BHB produced during exercise switched on the BDNF gene in the brain (Sleiman et al., 2016). Fasting, ketosis and movement all push in the same direction — which is why we combine them with a ketogenic diet and live movement classes.

What the evidence does and does not say

We are confident in this biology, and we are precise about it. The mechanisms above come from cell, animal and genetic research; human trials of fasting specifically in Parkinson's are still limited, and no study has shown that fasting cures Parkinson's. The human diet trials we do have — such as the 2018 randomized ketogenic diet pilot — are small but encouraging. See the full key studies list.

Types of fasting we coach

• Overnight fast (12 hours): the starting point for almost everyone — finish dinner early, no snacks until breakfast.
• Time-restricted eating (14–16 hours): eating within an 8–10 hour window. Pairs naturally with a ketogenic diet, which keeps ketones up between meals.
• Longer fasts: 24 hours or more, only for selected people, with medical clearance and close coach support.

Fasting around Parkinson's medication

This is the part that matters most. Many Parkinson's medications are taken several times a day, sometimes with food to reduce nausea, and protein can affect levodopa absorption. Fasting has to be designed around your medication — not the other way round.

Your coach will help you map your dose times, symptoms and eating window, and bring that plan to your neurologist. We never advise skipping, delaying or changing medication to extend a fast. Dizziness on standing (orthostatic hypotension) is common in Parkinson's and can worsen with fasting and dehydration, so hydration and electrolytes are built in from day one.

How to start this week

• Pick a consistent dinner cut-off time and hold it for seven days.
• Drink water, and ask your doctor whether electrolytes are appropriate for you.
• Log your windows in GenesisAi so the hours start adding up.
• Join a live movement class — gentle movement during a fasting window feels better than most people expect.
• Review the week with your coach and adjust.

Why we believe in it

Genesis began with one person's search for options beyond medication alone: Dr. Sylvain Marino, diagnosed in October 2023, who went on to help build the protocol with founder Lars Konge. Fasting has been central to that work from the start.