New study below [1].
I tried to ignore this, but the story is everywhere. It will undoubtedly drive some men to low-fat diets.
Here is the ever-unreliable Daily Mail [2]:
"Fatty acids fuel prostate cancer: study"
"Men who eat more saturated fats are at greater increased risk of aggressive prostate cancer than those with a healthier diet, Melbourne scientists have found.
"The study released on Thursday, initiated by scientists at two Melbourne universities, found fatty acids are taken up into prostate cancer cells, increasing tumour growth. Researchers then blocked the key fatty acid transporter and showed they could slow the cancer's development.
"There is a strong link between obesity, diet and poor outcomes in men who develop prostate cancer. In particular, those men who consume more saturated fatty acids seem to have more aggressive cancer," Associate Professor Taylor said in a statement."
***
The new study looked at fuel preference in normal & cancerous prostatic cells.
"... we showed that fatty acids were taken up into prostate cancer cells and increased tumour growth ..." "In contrast, we saw that normal tissue had a preference for using the sugar glucose as fuel for growth."
The first thing to point out is that proliferating cells have a higher energy requirement and they typically have no problem finding fuel. Fuel itself does not drive the proliferation rate. The proliferation rate determines the amount of fuel that is taken up.
There was an old cell study that sought to determine the preferred PCa fuel. Cells preferred fatty acids over glucose, and palmitic acid / palmitate over other fatty acids.
Palmitic acid is a saturated fat of 16 hydrogenated carbons. The name is due to the high levels in palm oil.
(The demonized saturated fat is the 18-carbon chain stearic acid (of candle wax fame). It isn't implicated in PCa.)
100g (3.5 oz) porterhouse steak has 1.65g of palmitic acid. A pork chop has 1.83g. Incidentally, the chop also has 3.33g of "healthy" oleic acid - as found in olive oil.
The human body contains a significant amount of palmitic acid, and this is true for vegetarians too. "In humans, one analysis found it to make up 21–30% (molar) of human depot fat ..." [3]
It might seem tempting to cut out all fats that have a palmitic component, but here's what happens with a low-fat (high-carb) diet:
"Excess carbohydrates in the body are converted to palmitic acid." [3]
We can't escape it. And there is a good reason for that. The body manufacture an essential range of fatty acids:
"Palmitic acid is the first fatty acid produced during fatty acid synthesis and is the precursor to longer fatty acids." [3] i.e. larger carbon chains.
In addition to the above, we also have the creation of fatty acids within PCa cells:
"Fatty acids synthesis in tumor tissues also occurs at very high rates, as first demonstrated more than half a century ago [Medes et al., 1953]. Importantly, (14)C glucose studies have shown that in tumor cells almost all fatty acids derive from de novo synthesis despite adequate nutritional supply [Sabine and Abraham, 1967; Ookhtens et al., 1984; Weiss et al., 1986]. In addition, tumors overexpressing fatty acid synthase (FAS), the enzyme responsible for de novo synthesis of fatty acids, display aggressive biologic behavior compared to those tumors with normal FAS levels, suggesting that FAS overexpression confers a selective growth advantage." [4]
The new study was not concerned with de novo fatty acid, but with the CD36 transporter:
""We designed antibodies that specifically targeted the CD36 transporter. By binding to the transporter, the antibodies effectively create a roadblock for fatty acids trying to enter the cell," says Professor Watt."
"The ultimate goal is combining the fatty acid therapy and existing treatments like chemotherapy and radiotherapy at lower doses to kill the cancer and reduce any side effects."
But I fear that the media message is to stay away from fat.
How will tumors respond to CD36 inhibition? Probably with an upregulation of fatty acid synthase (FAS). The critters are very resourceful.
-Patrick
[1] medicalxpress.com/news/2019...
[2] dailymail.co.uk/wires/aap/a...
