We’ve all heard that eating broccoli, cauliflower, Brussels sprouts, and other cruciferous vegetables is good for us, but let’s look further into how these vegetables can be beneficial. It’s a fascinating journey into the nutrigenomic potential of sulforaphane.
What are cruciferous vegetables?
Cruciferous vegetables are also known as Brassicas. Cruciferous refers to the cross-shaped flower that these plants have as they grow. We often don’t see this flower as we’ve eat the vegetable before it goes to flower.
The family of cruciferous vegetables includes the following:
Phytochemicals in cruciferous vegetables
There are several phytochemicals in cruciferous vegetables that can have potential health benefits in the body.
Cruciferous vegetables are good sources of phenolic compounds such as flavonoids, and also carotenoids. But what sets them apart from other vegetables is that they are also a source of glucosinolates. Glucosinolates are not themselves beneficial but they are converted into bioactive compounds such as isothiocyanates (ITCs).
Don’t worry – yes this is a little bit of chemistry, but not too much! And I won’t test you on it later.
Different ITCs derived from cruciferous vegetables include:
- sulforaphane (sulphoraphane)
You may have heard of sulphoraphane – the best known ITC! And the most studied.
Biological activity of ITCs
Studies have shown that ITCs/sulforaphane can have quite a range of effects. These include:
- protection against pathogens
- induction of heat shock proteins HSP (remember my sauna blog posts – HSP are beneficial)
- increase glutathione expression
- improve detoxification
- anti-cancer and cancer chemo-prevention
Nutrigenomic potential of sulforaphane
Many of these effects listed above come about through nutrigenomics i.e. the ITC affects our genes which then leads to a change in our body. Nutrigenomics is all about how certain food-derived chemicals can switch on certain genes associated with health.
The key action of sulforaphane and other ITCs is that they activate a cellular “switch” called Nrf2. This Nrf2 “switch” – think of it like an on-off switch, controls around 200 different gene effects. Sulphoraphane is considered to be the most powerful natural Nrf2 switch activator.
Nrf2 is a really powerful switch as activation impacts the cell’s natural defense system in the body. It does this via three main processes:
- detoxification systems;
- production of primary anti-oxidant enzymes like glutathione;
- and what are known as “efflux pumps” – which are mechanisms to pump toxic waste out of the cell, through the cell membrane.
These cellular defense mechanisms are key to our survival.
Eating and preparing cruciferous vegetables
What this means is that eating cruciferous vegetables can lead to cell defense genes being switched on to protect the cells in our body. With all this potential, we want to make sure we eat cruciferous vegetables regularly – preferably daily. But also we need to prepare them in a way that means we get the most beneficial activity from them. Remember, ITCs aren’t pre-formed in the vegetables themselves, they have to be created so our preparation and cooking techniques are important and impact this greatly.
Next week we’ll look at how ITCs are formed in the plant and how we can maximize that for our benefit through the way we prepare, cook and eat them.