When it comes to preventing and fighting cancer, food is a powerful ally in our arsenal.
So-called "cruciferous” vegetables like broccoli are especially friendly forces.
The name for this family derives from their four-petal flowers, which form a head that resembles a cross or "crucifer”.
Broccoli is the best known crucifer, but the family includes Brussels sprouts, broccoli rabe, cabbage, cauliflower, daikon, bok choy, turnips, rutabaga, radish, wasabi.
Importantly, all members of the brassica family of vegetables – which includes the crucifers – are rich in the same kinds of anti-cancer compounds.
In addition to the crucifers, the brassica family encompasses leafy members such as kale, kohlrabi, collard greens, arugula, rutabaga, watercress, mustard greens, and bok choy.
Cruciferous veggies linked to reduced risks for major cancers
Epidemiological studies – which compare people's diets to their health outcomes – cannot prove that a food or nutrient prevents a disease.
However, many such studies find that people who eat crucifers three to five times a week are less likely to get cancers of the breast, prostate, colon, skin, lung, stomach, and bladder.
Cruciferous vegetables are also linked to reduced risks for cardiovascular disease, neurodegenerative diseases (e.g., Alzheimer's and Parkinson's disease), and diabetes.
Do crucifers also provide liver protection?
Broccoli and its cruciferous cousins may also help protect our livers from disease, including cancer.
Aside from alcohol abuse, the biggest threats to liver health are diets excessively high in fat and sugars – especially fructose, which the body stores as liver fat.
Fat buildup in the liver – called non-alcoholic fatty liver disease (NAFLD) – can cause a particularly lethal cancer called hepatocellular carcinoma (HCC).
So the results of the new study, which suggest that cruciferous vegetables may be liver-protective, deserves close attention.
Mouse study finds broccoli fights liver cancer
The encouraging new study comes from the University of Illinois (Chen YJ et al. 2016).
Researchers based there divided the mice into four groups:
- Control diet – regular, healthy mouse chow
- Unhealthy mouse chow high in fat (19 percent) and fructose (31 percent).
- Control diet plus freeze-dried broccoli
- Unhealthy mouse chow plus freeze-dried broccoli
All of the mice were also fed a cancer-causing chemical called diethylnitrosamine.
After six months, the researchers discovered two major benefits in the mice fed broccoli (groups 3 and 4):
- Fewer cancer nodules in the liver.
- Less fat in the liver, reducing the risk for deadly HCC-type liver cancer.
We should note that the proportion of fat in the diets of the mice on the "unhealthy" diet (19% of calories) was not that high.
Most health authorities say that about 30 percent of total daily calories should come from fat.
It's likely that the liver-fat buildup in the mice given the unhealthy diet without broccoli (group 2) resulted mostly from the enormous proportion of fructose (31% of calories) in that diet.
To put this in perspective, the USDA's 2015 diet guidelines say that no more than 10% of calories should come from added sugars.
What makes cruciferous veggies so special?
Cruciferous vegetables are rich in chemicals called glucosinolates.
People and mice alike convert glucosinolates into chemicals called indoles and isothiocyanates.
The results of many studies suggest that these beneficial "phytochemicals" help curb the risk of breast, colon and prostate cancer.
And glucosinates aren't the only anti-cancer allies in crucifer-class veggies.
Others include vitamin C, folate, selenium, fiber, carotenoids, and polyphenols ... of which red cabbage is the richest cruciferous source.
Other allies against liver disease
Broccoli and its cruciferous cousins aren't the only liver-health allies in your kitchen.
The amount in four cups of coffee or tea per day stimulates burning of liver fat enough to reduce the risk of NAFLD.
So to keep your liver healthy, avoid added sugars, don't go nuts on fatty foods (except fish), and enjoy berries, crucifers, and daily cups of tea or coffee.
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