Health "facts" that you believe to be myths and why. See if you can change my mind.

[TattyDevine]

Anyone got any? I've got a couple.

First one is this bullshit that you have to drink a certain amount of water a day that isn't dictated by your body's thirst or cues, but by some arbitrary amount.

Why the hell would your body not tell you if it needed water? How have we evolved this far not realising we needed to be drinking double or triple the amount of water we feel we need to? Thirsty, have a drink. Not thirsty, don't. Like food. Hungry, eat. Not hungry? Shouldn't eat. What terrible fate will befall us if we don't drink 2 litres of water a day? And how did we evolve for thousands and thousands of years before this bit of knowledge was bestowed upon us?

2nd one - don't eat at night because you won't burn it and it will be stored as fat, but if you eat the same amount but during the day you will burn it.

Well, surely if you have done the same level of activity in a day and had the same amount of food within that day it will even out? Over a 24 hour period, I've taken in x amount of energy and burned y amount. If I took most of it in at night it makes up for the deficit in the morning. If I take it evenly over the day there was no deficit to make up for but I've still taken in the same amount and burned up the same amount.

3rd one - coffee and tea dehydrates you because it is a mild diuretic. Okay so its a mild diuretic but you are still more hydrated drinking it because it doesn't make you piss out more than what you took in in terms of extra fluid by drinking it in the first place. So it still counts as a drink. (In fact my GP surgery has a poster saying about taking plenty of fluids if you have a cold, and that it doesn't have to be water but a cup of tea or coffee is just as good). When I read that, I was so revived by the no nonsense common sense approach I had to restrain myself from licking the poster with delight.

Yours please, and try and convince me otherwise with non bullshitty science if you think I'm wrong (which I'm happy to be with a proper science-boffiny cut-down)

Guinness IS good for you. It does not count towards your alcohol units per week.

I find the water advice helpful. I don't seem to ever get thirsty - apparently could be an Aspie thing - so knowing how much water I should drink is useful. I still don't do it though - I get distracted & forget to drink!

Studies might show that interro, on paper, different sources of protein may look the same but in practice there seems to be a difference in how our bodies utilise/require animal protein specifically. Even a trawl on MN alone will throw up plenty of anecdotal evidence of people who have been committed vegetarians or vegans, who have become ill (possibly after years of good health) and found the only dietary change that brings improvement is the reintroduction of animal protein, even when it has been much to their distress...I think with this too, evolution/epigenetics play a part, vegans who come from generations of vegans have a much better chance of being absolutely fine for a lifetime staying that way. Maybe less likely for a typical Western person coming from 'meat and two veg' background...

18 months ago I had an emergency appendectomy after a hideous day of D&V. I had a drip put in to rehydrate me.

The next morning I hobbled along to the bathroom and my first thought was, "ooh my skin looks good"

I needed to wee every hour though so not a long-term solution to skin care.

But yes, our bodies will take in any liquid that is ingested, including from fruit, gravy etc.

Yes Funnyosity - very expensive nonsense!

That stuff costs more than wine!

HOw is one supposed to measure hydration levels by checking your wee if one is peeing down the pan?

Surely you are pissing into water and diluting it and different toilets hold different amounts of water in their u-bend

That facebook and youtube are good places for accurate health advice...

The coffe thing seems to be true . During A level biology revision ( helping , not me doing ) I learned that caffeine prevents the actually water part of the coffe being absorbed through ( the loop of Henley / or some sort of part of the kidney ) so you do not actually get to absorb it. Sadly I'm still a huge coffe addict though. Eating at night may not matter as long as you don't eat all night and all day too .

I think a lot of the health myths are probably started by companies with a vested interest that just want you to buy their products.

"Wasn't 5 a day a marketing ploy cooked up by a marketing board for fruit and vegetables?? So people with a vested interest in getting us to at least buy more? It was so successful that governments have virtually adopted it as policy. It doesn't have much basis in scientific fact, as far as I know."

Yeah I heard this somewhere as well; I think it was an American marketing ploy originally. Their agricultural industry used the 5-a-day slogan to basicially encourage more people to buy fruit and vegetables and it was nothing to do with health apparently. I thought most of our nutrients come from animal products like dairy and meat rather than fruit and veg anyway.

My dentist once told me not to eat too much fruit or fruit juices because they are really really bad for teeth. I drink some juice daily for the vitamin C, but that's it really.

Yeah, all that fruit and veg being good for you nonsense, stick to the meat and dairy, that'll be great for you

"(See also: if I needed to wear factor 50 all the time on my face in the UK my ancestors wouldn't have bothered evolving this skin colour)."

I forgot about the sunscreen stuff; I guess they'll be trotting out the skin cancer scaremongering articles soon, now that we're getting towards March. In my opinion sunlight is good for you as long as you don't get drunk and fall asleep shirtless in it all afternoon to get burnt. I read an article once about a woman who developed rickets due to always wearing high sunscreen and covering herself up all the year round. A tan is your skin naturally protecting itself as far as I'm concerned.

The latest fad of cooking a cake with maple syrup and calling it "sugar free"- surely this is nonsense?

Yes. I once came across a 'no added sugar' brownie recipie which included a whole jar of raspberry jam.

The '5 a day' seems to be a number plucked out of the air, but there is plenty of epidemiological data which associates high fruit and veg intake (especially the latter) to better health.

"Absorbing" water from coffee. What does "absorb" mean? We don't absorb water, we assimilate it and eliminate it. If you can't absorb the water from coffee, or process it, or assimilate it, does it just stay in your body forever? It has to be assimilated and eliminated like all other water we injest, otherwise every single cup of coffee we ever drink will be sloshing around in our bodies for eternity.

Can anyone clarify?

Eating 5 different fruits and/or vegetables a day is going to be "better for you" than not, unless you are allergic. I don't think anyone is going to argue against that really, regardless of the origins of the campaign. Fibre, antioxidants, vitamins and minerals.

Nobody will instantly drop dead if they don't meet their 5 a day obviously. That said a diet pretty much devoid of any kind of fruit or veg can't be that healthy - forget the vitamins (easy enough to get them from other foods and/or supplementation) but the fibre element, particularly the non-starch polysachrides that are present in them are pretty useful for gut health and bowel stuff.

Sunscreen - in this country, I think it is a bit overused and there is a bit more emphasis on it than there needs to be for HEALTH. If you are talking about anti-ageing, that's a different thing. But actual health, or sun as a health hazard, I totally agree.

Sun protection is a different issue in countries with a hotter climate but people who weren't designed for that climate (so White Australians for instance) and countries with a hole in the ozone layer above (Australians again)

Can you tell I'm Australian

The last big report showed the most good (unsurprisingly) comes from going from 0 to 2 portions of fruit & veg, but the more the merrier!

Green leafy veg always seems to be A GOOD THING, in any study too. So I do believe that and force it onto my poor kids.

I think the caffeine in the tea and coffee take some water to metabolise but far less than that contained in the drink. So overall tea and coffee are hydrating.

If tea was dehydrating all my older family members would have been desiccated.

When I was on maternity leave and watching utter crap daytime TV, on of the presenters bemoaned the fact that modern food had all these additives and preservatives. Her example? Look, these pickled onions contain acetic acid - they'd never have contained that in the olden days
Because presumably vinegar never used to be used to make pickled onions

A quick google scholar search on the caffeine hydration thing:
this indicates it's a myth.

Oh, found a good review on the '8x8 water' myth here

all you people disagreeing about the need for sunblock obviously do not have red-haired children like me.

If you burn in 10 minutes in the sun of course you should use it. We should vacate Northern Scotland and let all the type 1 skin people have first dibs on it really.

Kissangel what we need is to hook ourselves up to a drip AND a catheter overnight, wake up with bouncy skin, do nothing during the day. Job done!

Your cells can't tell which water molecules came from coffee and which came from plain water. So they get absorbed through the lining of the gut just the same. The loop of Henle is in the kidney, so the water molecules which get to that point have already been absorbed by your body and some are on their way out.