It's no coincidence that more than 300 research studies on broccoli have converged in one unique area of health science—the development of cancer—and its relationship to three metabolic problems in the body. Those three problems are (1) chronic inflammation (2) oxidative stress, and (3) inadequate detoxification. While these types of problems have yet to become part of the public health spotlight, they are essential to understanding broccoli's unique health benefits. Over the past 10 years, research has made it clear that our risk of cancer in several different organ systems is related to the combination of these three problems.
The Cancer/Inflammation/Oxidative Stress/Detox Connection
In health science research, there is a growing body of evidence relating cancer risk to a series of environmental, dietary, and body system factors. Understanding this set of factors can be very helpful in making sense of broccoli and its health benefits.
Anti-Inflammatory Benefits of Broccoli
When threatened with dangerous levels of potential toxins, or dangerous numbers of overly-reactive, oxygen-containing molecules, signals are sent within our body to our inflammatory system, directing it to "kick in" and help protect our body from potential damage. One key signaling device is a molecule called Nf-kappaB. When faced with the type of dangers described above, the NF-kappaB signaling system is used to "rev up" our inflammatory response and increase production of inflammatory components (for example, IL-6, IL-1beta, TNF-alpha, iNOS and COX-2). This process works beautifully in temporary, short-term circumstances when healing from injury is required. When it continues indefinitely at a constant pace, however, it can put us at risk for serious health problems, including the development of cancer.
Isothiocyanates (ITCs) in Broccoli
Research studies have made it clear that the NF-kappaB signaling system that is used to "rev up" our inflammatory response can be significantly suppressed by isothiocyanates (ITCs). ITCs—the compounds made from glucosinolates found in broccoli and other cruciferous vegetables—actually help to shut down the genetic machinery used to produce NF-kappaB and other components of the inflammatory system. These anti-inflammatory benefits of ITCs have been clearly demonstrated in lab and animal studies. However, it can sometimes be tricky to translate the results of these lab and animal studies in practical take-away recommendations for everyday eating.
The primary anti-inflammatory ITC provided by broccoli is sulforaphane. This ITC can be directly produced from broccoli's glucoraphanin content. Numerous anti-inflammatory mechanisms for sulforaphane are well known, including inactivation of the NF-kappa B pathway. In this context, it is interesting to note that the predominance of sulforaphane in broccoli is limited to the heading version of this vegetable. Also widely enjoyed worldwide is "non-heading" broccoli, often called sprouting broccoli, broccoli raab, broccoli rabe, or rapini. In these non-heading varieties of broccoli, iberin is the most common ITC, and it is derived from glucoiberin, which is one of the more common glucosinolates in non-heading broccoli). Yet another anti-inflammatory compound present in both heading and non-heading varieties of broccoli is glucobrassicin. (And in this case the corresponding ITC derived from glucobrassicin is indole-3-carbinol.)
Omega-3s in Broccoli
Lack of omega-3 fat is dietary problem that can cause over-activation of the inflammatory system. The reason is simple: many key anti-inflammatory messaging molecules (like PGH3, TXA3, PGI3, and LTE5) are made from omega-3 fats. While we are not accustomed to thinking about non-fatty vegetables as sources of omega-3 fats, it would probably be a good idea for us to change our thinking in this area. While there are limited amounts of omega-3s in low-fat vegetables like broccoli, it is equally true that their levels of omega-3s can still play an important role in balancing our inflammatory system activity. In 100 calories' worth of broccoli (about 2 cups) there are approximately 400 milligrams of omega-3s (in the form of alpha-linolenic acid, or ALA). That amount of ALA falls into the same general ballpark as the amount provided by one soft gel capsule of flax oil. While we would not want to depend on broccoli as our sole source of dietary omega-3s, we still get important anti-inflammatory benefits from the omega-3s it provides.
Other Anti-Inflammatory Benefits of Broccoli
Broccoli is a rich source of one particular phytonutrient (a flavonol) called kaempferol. Especially inside of our digestive tract, kaempferol has the ability to lessen the impact of allergy-related substances (by lowering the immune system's production of IgE-antibodies). By lessening the impact of allergy-related substances, the kaempferol in broccoli can help lower our risk of chronic inflammation.
Broccoli's Antioxidant Benefits
Vitamins, minerals, and phytonutrients all contribute to the antioxidant benefits provided by our food. Broccoli is a premiere example of a vegetable providing all three types of antioxidants. In the vitamin category, among all 100 of our WHFoods, broccoli represents our 3rd best source of vitamin C,10th best source of vitamin E, and 16th best source of vitamin A (in the form of carotenoids). It also serves as our top source of chromium, a very good source of manganese, and a good source of selenium and zinc. But it is the phytonutrient category in which broccoli's antioxidant benefits stand out. Concentrated in broccoli are flavonoids like kaempferol and quercetin. Also concentrated are the carotenoids lutein, zeaxanthin, and beta-carotene. All three of these carotenoids function as key antioxidants. In the case of lutein and beta-carotene, broccoli has been shown not only to provide significant amounts of these antioxidants but to significantly increase their blood levels when consumed in the amount of 2-3 cups per day.
No comments:
Post a Comment