Previously, I’ve explored the beneficial effects of flaxseeds on prostate cancer (Flaxseeds vs. Prostate Cancer), as well as breast cancer prevention and survival (Flaxseeds & Breast Cancer Prevention and Breast Cancer Survival & Lignan Intake). The cancer-fighting effect of flaxseeds is thought to be because of the lignans, which are cancer-fighting plant compounds found in red wine, whole grains, greens (cruciferous vegetables), and especially sesame seeds and flaxseeds, the most concentrated source on Earth. But this is based on per unit weight. People eat a lot more grains than seeds. Of the grains people eat, the highest concentration of lignans is found in rye. So, can rye intake decrease the risk of cancer? Theoretically yes, but unlike flaxseeds, it’s never been directly put to the test… until now.

In my video Does Rye Bread Protect Against Cancer?, I discuss the evidence that does exist. If you measure the levels of lignans in the bloodstream of women living in a region where they eat lots of rye, the odds of breast cancer in women with the highest levels do seem to be just half that of women with the lowest levels. But lignans are also found in tea and berries, so we couldn’t be sure where the protection is coming from. To get around this, researchers decided to measure alkylresorcinol metabolites, a class of phytonutrients relatively unique to whole grains.

Researchers collected urine from women with breast cancer and women without, and the women with breast cancer had significantly lower levels compared to those without. This suggests that women at risk for breast cancer consume significantly lower amounts of whole grains like rye. But if we follow older women in their 50s through 60s, the intake of whole grain products was not associated with risk of breast cancer. A similar result was found in older men for prostate cancer. Is it just too late at that point?

We know from data on dairy that diet in our early life may be important in the development of prostate cancer, particularly around puberty when the prostate grows and matures. If you look at what men were drinking in adolescence, daily milk consumption appeared to triple their risk of advanced prostate cancer later in life. (Learn more about milk and prostate cancer in my video Prostate Cancer and Organic Milk vs. Almond Milk.) So, researchers looked at daily rye bread consumption during adolescence.

Those who consumed rye bread daily as kids did appear to only have half the odds of advanced prostate cancer. This is consistent with immigrant studies suggesting that the first two decades of life may be most important for setting the pattern for cancer development in later life. These findings are certainly important for how we should feed our kids, but if we’re already middle-aged, is it too late to change course? To answer this question, researchers in Sweden put it to the test.