LOW CARB diets might actually WORSEN cancer progression + outcomes, contrary to popular belief, according to a recent study.

Let's unpack this one (🧵1/8)

View Tweet

While it is true that carbs (glucose) fuel cancer cell growth,

growth of tumors is not the only piece to the puzzle.

If low carb metabolism actually promotes the SPREAD of cancer, that's much worse since this is the main cause of death in cancer.

They found that out of 22 cancers analyzed, LOW glucose metabolism was correlated / possibly correlated with 15 of them.

(2/8)

Tumors that spread actually had WORSE glucose metabolism.

A hallmark of cancer is that tumors CONSUME lots of sugar,

but here it is clear that the tumors do not METABOLIZE the sugar properly.

This aligns with what we know about the Warburg effect.

(3/8)

When animals with cancer were given low carb diets, their cancer actually worsened.

While the main tumors were smaller with low carb, and bigger with high carb,

the SPREAD (metastasis) of cancer was worse with low carb.

(4/8)

When they examined the lungs (where the cancer was spreading to),

they showed that there was a HIGHER amount of macrophages (pro-inflammatory, pro-tumor),

and a LOWER amount of natural killer (NK) cells.

These NK cells are one of the primary tumor killing immune cells in the body, and their numbers and function were cut dramatically on a low carb diet.

(5/8)

The underlying mechanism is intriguing.

Essentially, the stress of a low glucose metabolism on tumor cells triggers the release of exosomes.

Exosomes are basically tiny rafts that carry things from one cell to another.

In this case, the cancer cells sent out exosomes containing a protein called TRAIL (tumor necrosis factor-related apoptosis-inducing ligand).

Once this reaches the macrophages of distant tissues, they express a receptor called PVR,

which interacts with the natural killer cells, essentially causing them to shut down and die.

(6/8)

When looking at this in humans, it lined up perfectly.

The higher the glucose metabolism, the lower the TRAIL in exosomes,

which means less NK cell exhaustion.

People with high TRAIL levels were shown to be more likely to have both spreading of cancer and recurrence.

(7/8)

So in summary:

1. Glucose (carb) METABOLISM is worse in cancer. It is not about EATING more carbs
2. Poor glucose metabolism / low carb diets might improve the main tumor, but if it worsens systemic immunity, which is needed to prevent cancer from growing / spreading, the overall condition is worse

(8/8)

Full study here: cell.com/cell/fulltext/…