So I read this book “How to Kill Your Husband“…I don’t remember the author, but it was about how just like humans, plants have evolved to protect themselves from being eaten, so that they can survive and reproduce (and I certainly hoped my spouse didn’t get food poisoning just after I returned that book to the library). It said that most plants are very toxic, and the ones we are used to, that humans have “domesticated”, like cabbages and carrots…are actually the rare ones that our species has collected. We take for granted (and indeed most of us have lost) a whole body of knowledge about which plants are edible how to identify and find them and the complex art of saving seeds. All we need to know now is how to drive to the nearest supermarket’s the vege aisle, or the seed section of the garden centre. But this knowledge was gained over thousands of years by individuals risking their lives, and was critical to the survival of our own species.
So as a discordant note against the loud chorus of “veges are good for you”, the book went into detail about the multiple ways plants have developed to kill you: take parsley, which makes you more susceptible to sunburn. Apparently this was an early (and fairly ineffective) strategy to deter grazing animals (pass me more yummy tabbouleh). Traditional societies developed ways to prepare plants to reduce or neutralise plant toxins. And we bred safer and safer versions of our favourites – sweeter apples, bigger corn and huge cabbages. Ever seen one of the original woody little carrots? A bit like dandelion root is now (yes, OK, I did try to make dandelion coffee the cheap way.)
Paul Jaminet points out that grains were among the most grazed and had to develop protective toxins, or anti-nutrients, to survive constant grazing on the open grasslands by herds and herds of gazelles or gnus or whatever huge flocks of herbivores roamed the earth. Beans and seeds are the plant’s offspring hence protected.
Most fruit is benign; it uses you as a way to distribute its seed near and far, wrapped in a warm wrapping of fertiliser. Symbiosis at its tasty best. Root vegetables didn’t endure constant grazing and are storehouses rather than plant babies.
So this is one picture of the vegetable kingdom that is a bit less benign than you’ve been used to, yes? Now how about the next amazing part in the story. Why are vegetables good for you? Bet you never thought…because they’re toxic. Yes, its not the anti-oxidant content, but their toxins’ ability to shock your body into over-producing your own internal anti-oxidant factories. There is much not known about the magical mysterious properties of phytochemicals, and their actions on cell signalling. May I now refer you to another font of remarkable brilliant insights, Vince Giuliano (now with James Watson). Fair disclosure, before you enter, Vince’s Ageingsciences blog needs a graphic warning “Caution: will make your brain hurt (even if you are a certified genius” (www.anti-agingfirewalls.com – use search term ‘hormesis’). Turns out that no matter how many anti-oxidants you eat, you can’t really measure any difference in anti-oxidants at the cell wall, where they matter. Which is why PubMed shows dismal research results for anti-oxidant supplements.
Bear with me a moment while I take a wee diversion about ‘mice and men’… (or rodents and humans, to be accurate and inclusive). If you put a mouse or person on a treadmill, it creates oxidative stress – pro-oxidants if you like (also known as ‘rust’). The mice age more quickly, and die sooner. In contrast, homo sapiens has evolved a powerful internal anti-oxidant system which, get this, over-reacts to these pro-oxidants. They have long cool names: glutathione peroxidase, superoxide dismutase, catalase, CoQ10 and alpha lipoic acid. So people, you get younger and live longer if you exercise. Quite unlike wee moosies, yes? And should make you sceptical about over-applying moosie research to humans (Aubrey de Grey’s longevity Methuselah mouse awards notwithstanding: www.mfoundation.org/work#mouse-prize. Mice also have very very long telomeres, so don’t age like humans either.)
So for humans, there is a curve where a little bit of some (not all) stresses are good for you, while none, or a lot, are bad for you. Yes, there’s a Goldilocks amount of exercise, vegetables, radiation and even hot and cold. (Have a wee play on Vince’s site with the search term ‘heat shock proteins’ to inspire you about saunas and icy midwinter dips).
Now it turns out that you can’t necessarily eat glutathione, because it gets broken down during digestion, but there are things (real wasabi, for example) that can stimulate your body to produce more (you knew there was a reason wasabi can blow your head off, right?)
Another thing is that many of the really effective phytonutrients, like resveratrol, are the result of the plant’s best fight against its own predators. Resveratrol is only produced by grapes that have fought fungal infections, so is higher in red grapes with thin skins, not thick, and not present in grapes that have been bred to be fungus resistant.
So next time ‘science’ finds a ‘toxin’ in your favourite vegetable, take it with a grain of salt…or some (endogenous) antioxidants. And when faced with some new study that shows something that’s good for you is bad for you, remember to keep an open mind. Science doesn’t really understand the mechanisms of action and what is important in a vegetable. So eat a wide range of real whole things, don’t rely on supplements or nutrient calculators.
To conclude: what ‘science’ thinks it knows about micronutrients is not as much as it actually knows. As Hamlet said “There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy“. And eat whole foods that have fought the good fight.