Whether eating processed foods affects breast density seems to depend on what part of the menstrual cycle a girl is in - it only shows an effect during the first half of the cycle, not the second half.

Scientific Claim

The relationship between ultra-processed food consumption and breast density appears to be influenced by menstrual cycle phase, with effects only observed during the follicular phase and not during the luteal phase.

Original Statement

“A stratified analysis was performed according to the stage of the menstrual cycle at the time of BD measurement [...] In the adjusted model, girls in Q2 of UPF consumption (as a percentage of grams) had 12% increase in %FGV [Q2 vs. Q1: ß: 0.12; 95% CI 0.01, 0.22] and a 25% increase of AFGV [Q2 vs. Q1: ß: 0.25; 95% CI 0.07, 0.43] than those in Q1 during the follicular phase [...] No significant associations were observed for participants in the luteal phase.”

From study:Consumption of ultraprocessed foods and breast density in adolescence

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

The claim correctly states 'appears to be influenced by' which appropriately reflects the observational nature of the study and the specific subgroup finding. It avoids causal language and accurately describes the observed pattern.

Evidence from Studies

Supporting (1)

Consumption of ultraprocessed foods and breast density in adolescence

Cohort Study

Human

2025 Nov 10

Contradicting (0)

No contradicting evidence found

Source Study

Consumption of ultraprocessed foods and breast density in adolescence

Score: 58

DOI: 10.1038/s41598-025-23030-x

Similar Assertions

The effect of processed foods on breast density during the first half of the menstrual cycle only happened at medium levels of consumption, not at the highest levels.

86%

When looking at how much of the total calories came from processed foods (instead of how many grams), there was no consistent link to breast density at any point in the menstrual cycle.

86%

When looking at how much of the total calories came from processed foods (instead of how many grams), there was no consistent link to breast density at any point in the menstrual cycle.

83%

When teenage girls eat more processed foods, their breast tissue might look denser on scans only during the first half of their menstrual cycle, but this doesn't happen all the time or during other parts of the cycle.

83%

When looking at all teenage girls together without considering where they were in their menstrual cycle, eating more processed foods didn't consistently change how dense their breast tissue looked on scans.

82%