Pass the salt

Posted on March 22, 2011


Today I have the hangover from hell. I took Luton boy out to celebrate his birthday yesterday and after several afternoon pints we were joined by my dear friend from Ireland, Mr D, who just happened to be in London. Why is it always the impromptu meet-ups that get you into trouble?

I used to pride myself in coping with the morning-after, but who am I kidding, it gets harder with age and the headaches are definitely more pronounced. According to researchers hangovers result when the brain is depleted of vital salts and minerals. Alcohol is a diuretic, which means you expel more water than you absorb, some say up to four times. In my case I feel like a giant prune and I’m seriously wondering how I’m going to get through my lectures this afternoon. All those visits to the loo also means you flush out salt and potassium, which is why it’s suggested that you replenish your body with energy drinks that have minerals and electrolytes. There is nada in my fridge at the moment, so tapwater will have to suffice.

How we get our daily intake of salt is something that I’ve never really spent much time thinking about. Yes we all know that too much salt is bad for you, but all mammals need sodium to function and that includes non-human primates.

The Northerner goes up the wall if he sees diners adding salt to food before they try it – in fact that’s the number one pet hate for chefs!! Unlike people, animals don’t have the privilege of sprinkling salt onto food before they devour it. Different species will get their sodium intake from different sources. Professor Vernon Reynolds, who founded the Budongo Conservation Field Station in West Uganda has been investigating where chimpanzees in this particular area get their salt from. He’s been looking into this for a few years now and has published a paper.

chimpanzee in Budongo

The Budongo Forest Reserve is an area that is close to my heart as it was my first taster of a jungle environment. The study community of chimpanzees is named the Sonso community after the River Sonso which runs through its range. Here the Sonso chimpanzees (Pan troglodytes schweinfurthii) can get sodium from meat, if they catch other mammals as prey – but this uses a lot of energy and they are likely to lose salt during a vigorous hunt. Reynolds and colleagues have found that the chimps also get their sodium intake by eating the pith of decaying palm trees (Raphia farinifera). An analysis of the pith for mineral content showed high levels of sodium.

Raphia farinifera

Professor Reynolds told me: “At various places along the river there is swamp forest which contains several Raphia farinifera palm trees. After a single flowering and fruiting, the trees lose their foliage and die. The dead bole remains standing and is 15–30 ft high. The bole rots down until it consists of a hard outer bark with a soft, moist, fibrous woody pith. Chimpanzees make a small hole in bark at the base of the dead tree with their teeth, widen it with their fingers and later their hands. Through the hole, they extract dead pith, chew it thoroughly, swallow the juice and some particles of woody matter, and finally spit out a fibrous wadge of chewed pith.

“We’ve been studying the Sonso community of chimpanzees since 1990, individuals and small parties of the animals have been seen occasionally eating the pith of dead Raphia trees, but not until now did we realise why.”

Raphia farinifera

The problem is this source of sodium is under threat because it’s also a valuable source used by tobacco farmers. The  farmers kill the palm tree during its growth period, before it has time to flower and fruit. They strip its leaves for Raphia string (‘raffia’), which is then used to tie tobacco leaves during and after the drying and curing process.  Raphia palms are now becoming scarce in Budongo Forest and this is of major concern to researchers including Professor Reynolds.

Tobacco farmers and British American Tobacco (BAT),  which buys a lot of this crop have been approached about this issue. There’s no solution at present but hopefully a compromise or an agreement can be found sooner rather later.

My brain is refusing to work at maximum capacity and I’m late for lectures! I’ll update this post this evening where I hope to have added some wonderful video footage of the Sonso chimps getting their dose of salt courtesy of researcher Cat Hobaiter……!

(7 hours later)

……so I’m back home after a particularly interactive and taxing day at uni. My pounding headache has now become more of a dull thud, but it still hasn’t disappeared and my cognitive ability is about as good as a two-year-old. I think the only way to prevent future hangovers is to (a) stop drinking – that’s never going to happen; (b) insert a saline drip intravenously overnight, not practical I know and certainly not achievable when I’m squiffy (I can barely take my contact lenses out) or (c) embrace hair of the dog. So no prizes for guessing which one I’ve opted for. I’m about to get back on the wagon and have a glass of wine – purely medicinal I assure you. Here’s the video clip I promised you. Cheers!