Newsletter #226

Believe it or not, it is likely that most of us have cancer cells floating around inside of our bodies.

This unsettling statement comes from autopsy studies of people who died from causes unrelated to cancer. Researchers found that 30% of women in their 40s had microscopic breast tumors, and 40% of men in that age group had precancerous cells in the prostate. And nearly 100% of examined bodies had tiny traces of cancer in the thyroid gland if the investigators looked hard enough.

That's because cancer actually takes years, even decades, to develop to the point of being clinically recognizable. Precancerous cells have to accumulate a number of mutations before they are able to grow and invade surrounding tissues. That enormous lag time is pretty encouraging because during this process, these nascent cancers are extremely vulnerable, giving us a nice window in which to bolster our natural defense mechanisms. Smart nutrition plays a key role here.

Eating a diet rich in fruits and vegetables, in general, is linked to lower risk of cancer. However, when researchers zero in on specific types, they usually find that some are better than others. And the strongest associations seem to be for cruciferous vegetables.

How come? Well, one way that our bodies combat cancer is through phase 2 detoxification. Basically, enzymes tag potentially cancerous toxins with specific molecules to neutralize them and make them easier to safely excrete before they can cause trouble. Metabolites generated from cruciferous vegetables, like sulforaphane, have been shown to boost production of these powerful antioxidant enzymes. This is why having people consume broccoli sprouts has been shown to ramp up excretion of carcinogenic pollutants, which means less DNA damage and less risk of dangerous mutations.

But again, cancer takes time. That means that in order to really see how foods affect outcomes, you have to follow people for years. With that in mind, let’s take a look at some of the long-term observational evidence examining cruciferous vegetables and their impact on cancer.

Researchers at the Harvard School of Public Health followed almost 48,000 men for about ten years, during which time 252 cases of bladder cancer were diagnosed. When they analyzed dietary data, they found that total fruit and vegetable intake was not associated with cancer risk. But when they narrowed it down to cruciferous vegetable intake, they found that there was a 51% reduction in risk of developing bladder cancer during the study period.

Researchers in the Seattle area recruited 628 participants who were newly diagnosed with prostate cancer, and compared them to 602 men from the same area who were the same age but who did not have prostate cancer. When they analyzed food and nutrient data, they found that vegetable intake in general appeared to be protective - men who consumed 28 servings of vegetables weekly had 35% lower odds of prostate cancer, compared to men who ate fewer than 14 servings. But relatively modest amounts of cruciferous veggies had an even bigger impact. Men who reported eating 3 or more servings of cruciferous vegetables weekly had 41% reduced odds of prostate cancer, compared to those who consumed one serving or fewer per week.

Researchers in Buffalo recruited 183 pancreatic cancer patients, and compared them to 732 controls (patients who had visited the hospital for a cancer screening but turned out not to have it). When researchers analyzed and compared dietary data from these two groups, they found that cruciferous vegetable intake was inversely associated with pancreatic cancer, but raw cruciferous veggies had the strongest association. Subjects consuming more than 1.5 servings per week of raw cruciferous vegetables had 40% lower odds of having pancreatic cancer, compared to those consuming less than a half serving per week. This is likely because certain bioactive compounds in cruciferous vegetables are sensitive to heat. If you can’t handle them raw, steaming is probably your best bet.

Researchers in Shanghai took urine samples from women with breast cancer, and compared them to cancer-free controls of the same age. They analyzed the urine for isothiocyanates, metabolites that are found in cruciferous vegetables and are thought to be major drivers of the cancer-fighting benefits of these foods. Those with the highest concentrations of isothiocyanates in their urine were only half as likely to have breast cancer, compared to those in the lowest quartile. This is particularly persuasive because the researchers relied on objective markers of brassica vegetable intake, rather than the self-reported dietary habits of these subjects.

Thanks for reading, enjoy the weekend, and we'll see y'all next week!

https://mailchi.mp/humanos.me/newsletter-226