Low-fat diet and breast cancer?

Today I want to tell you about a study that linked a high-fat diet with a lower chance of survival in women after menopause . I want to talk about it on Dcomedieta for two reasons, overcoming my reluctance to talk to you about studies that link nutrition to cancer.

The first reason is that the study, conducted on two fairly important samples of the female population (just under fifty thousand women aged 50 to 79), was conducted for about eight years in a row. Furthermore, because the data collected did not come out of a questionnaire, but by dividing the group of women into two samples and providing them with two different dietary strategies : a low-fat, higher-carbohydrate diet by means of a greater consumption of fruits, vegetables and grains (fats kept at 20% of the total daily caloric requirement) versus a normal diet.
The sample at the start was made up of healthy women who did regular prevention by means of ultrasound or mammograms.

What does the study say? That women who ate a lower-fat diet survived breast cancer better than those who ate more or less normal fat.

Peccato che l’associazione tra alimentazione e tumori anche in questo caso sia totalmente inconcludente.
Come nella maggior parte degli studi che riguardano dieta e cancro. Studi che offrono dati di mera osservazione, e che non riescono mai a stabilire un nesso di causa. Infatti, nonostante i due punti a favore (grande campione e studio a lungo termine) i risultati non possono essere letti come a favore di una dieta a basso contenuto di grassi. I motivi:
– i sottogruppi non sono omogenei: il campione di donne che ha seguito la dieta low fat era di 19 mila soggetti sani; di cui alcuni di essi hanno avuto negli anni dello studio un tumore alla mammella; il campione che non ha seguito la dieta low-fat era molto superiore, circa 30 mila soggetti.
– the statistical difference in tumor survival is 4 percentage points: 82 percent survival rate in the first group versus 78 percent survival rate in the second group. A variation that for these numbers seems to be the result of chance in its fluctuations; if we then consider that the second group is much larger than the first (I am not saying double but almost), the difference in survival becomes even less significant.
What I ask myself is: what is the point of such a study?