the new ussr illustrated

welcome to the Urbane Society for Skeptical Romantics, where pretentiousness is as common as muck

the low-down on antioxidants

leave a comment »

forget ORAC, just eat them coz they look so yummy

forget ORAC, just eat them coz they look so yummy

I’m going to risk alienating other colleagues here, but this post follows on from the last set in being inspired by work conversations, this time about plants and antioxidants. A plant was brought in by a staffer who apparently dabbles in naturopathy on the side, and its antioxidant properties were extolled. What do I know about antioxidants? Very little, except that some years ago red wine and various berries were being sold to us as containing life-enhancing quantities of these good molecules or whatever they are. It had something to do with binding to and neutralising ‘bad’ free radicals in our bodies. Of course I had no idea what free radicals were. Then later, via the Skeptics’ Guide to the Universe and other sources, I heard that the experts were back-tracking heavily on these life-enhancing properties.

So, what with being told in the staff room that antioxidants could cure cancer or some such thing, while elsewhere hearing that they’ve been wildly over-hyped, I’ve been considering for some time that I should do a post on these beasties, for dummies like me.

As usual, the first thing that greets me when I attempt to research this kind of thing is the pile of propadandist rubbish you have to wade through in order to find bona fide, science-based info sites. The good thing is that, over time, you get quicker at dodging bullshit.

I immediately homed in on a link saying ‘beware of antioxidant claims’, as being right up my alley. It took me to the ‘Berkeley Wellness‘ site out of the University of California. There I’m given the first definition – that an antioxidant is ‘a substance that helps mop up cell-damaging substances known as free radicals’, which leaves me hardly the wiser. I’m also told that selling products with claimed antioxidant properties is real big business in the US.

I’m also introduced to the ORAC (oxygen radical absorbance capacity) concept. My neighbour has an ORAC diet book and I’ve wondered what it meant. It seems that in the USA there’s a trend towards advertising the ‘antioxidant power’ of products based on ORAC scores – 7,300 ORAC units per 100 grams for a certain cereal, for example, or 6000 ORACs for a pack of corn chips. Are these numbers reliable, and what do they mean exactly?

Not much, apparently. The fact is that antioxidant interactions in the body are extremely complex and little understood. ORAC is only one of a number of different antioxidant tests used by different scientists in different labs, and even when they use the same test, such as ORAC, different labs come up with widely different results. Let me quote the Berkeley site directly:

Moreover, ORAC and other tests measure antioxidant capacity of substances only in test tubes. How well the antioxidants suppress oxidation and protect against free radicals in people is pretty much anyone’s guess.

A lot can happen to antioxidants once a food is digested and metabolized in the body, and little is known about their interactions. What has high antioxidant activity in a test tube may end up having little or no effect in the body. Preliminary research has found that when people eat high-ORAC foods, their blood antioxidant levels rise, but such results still don’t prove that this translates into actual health benefits.

The article ends with the usual smart advice. Choose a balanced diet, don’t eat too much, not too heavy on the meat, and with a fair quantity of whole grains, nuts and legumes, fresh fruit and veg, and you’ll get all the antioxidants and other nutrients you need. Actually, this article from I fucking love science, which gathers together expert advice on avoiding cancers, covers it all – keep your weight down, keep to the above-mentioned diet, exercise regularly in moderation, watch the sugar and salt intake and usually she’ll be right, whether it’s cancer, heart disease or whatever.

Not much more to say, really. But no doubt a lot more can be said about the science, and I’ll say just a bit about it here. Antioxidants, as the name suggests, are compounds that reduce oxidation in the body. Free radicals – unstable molecules – are produced when oxygen is metabolised. Free radicals remove electrons from other molecules, damaging DNA and other cellular material. They’re necessary for the body to function, but an overload can cause serious problems, and that’s where a common-sense diet comes in – though there are other factors which can bring about an overload, including stress, pollution, smoking (pollution by another name), sunlight and alcohol. Everything counts in large amounts.

Antioxidants come in many varieties. Nutrient antioxidants found in a variety of foods include vitamins A, C and E, as well as copper, zinc and selenium. Non-nutrient antioxidants, believed it have even greater effects (raising antioxidant levels), include phytochemical such as lycopene in tomatoes, and anthocyanins, found in blueberries and cranberries. I can’t find any clear info on the difference between non-nutrient and nutrient antioxidants, and it doesn’t appear to be important. There is, of course, a lot of ongoing research on all of this, and it would be easy to get obsessed with it all, raising your stress levels and sending those free radicals zinging through your body in legions. And if that’s what you want, why not buy this book, for a small fortune, and find out all that we currently know about how frying food affects its nutritive value, with particular attention to antioxidants. Of course, by the time you’ve finished it, it’ll likely be out of date.

There’s a ton of material out there on antioxidants, but Wikipedia is an excellent place to start, and to finish. One key piece of advice, in this as with other matters of diet, is – don’t rely on supplements when you can simply improve your diet (recent large-scale trials have shown they don’t work anyway). Get what you need from real food, as far as you can.

Advertisements

Written by stewart henderson

February 1, 2015 at 9:52 pm

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: