1. It’s often said that we should drink two litres of water a day? Is it really necessary?
There’s no study to suggest this is the case so it falls firmly in the “myth” category. There is no evidence that we are all permanently dehydrated. You need to monitor your urine. If it is dark then you’re not taking in enough liquids. If it is straw-coloured, all is fine. It’s the output, not the input, that you need to monitor.
2. Aspirin is said to be good at warding off heart disease and suppressing types of cancer. Is it OK to take as a drug of prevention?
A study published in The Lancet in 2012 suggested there’s a 37 per cent reduction in cancer risk, particularly colon and prostate cancer, for those who take a therapeutic low dose of aspirin – anything from a quarter of a 300mg tablet to a whole one – once a day over a period of five years.
Aspirin is also great at preventing heart attacks, especially if you’ve had one already. However, a side effect is that it may make your stomach bleed. Experts have flatly contradictory views about aspirin. Part of the problem seems to be that people self-medicate and therefore take too much. Also, no one can quantify the risks. A stomach bleed can be catastrophic so I am not going to take as aspirin as I don’t like the idea of bleeding internally. In the end, it depends what you are most afraid of.
3. Do we really need seven hours’ sleep every night?
Broadly speaking, yes. There is a huge variation in how much people need, but seven to eight hours is ideal. Some can get by on a lot less, but studies show if you increase from six hours a night to seven, it reduces your risk of heart disease. It seems that if you cut back on sleep in the long term it makes your blood sugar levels go crazy and, after a week or so, you can enter a diabetic state. The longest anyone has stayed awake is 12 days. A man from Cornwall holds that record! Sleeping more than ten hours is also bad for you, yet no one knows why.
4. Can eating too many eggs give you high cholesterol?
No. Eggs have been wholeheartedly demonised for no reasons at all. All those rumours of eggs giving us high cholesterol have now been utterly disproved. The advice from the British Heart Foundation is to eat as many as you like. Eggs are brilliant, full of nutrition and protein. I eat two a day in every form but not fried as that does raise cholesterol because of the fat in the oil.
5. Are people who eat breakfast really slimmer than those who don’t?
The problem with the studies on eating habits is that they ask people about their eating patterns and then base their results on that. For example, they talk to people who don’t eat breakfast then make them eat breakfast, and they get those who do eat breakfast to stop and take their evidence from these studies. However, the problem with making non-breakfast eaters eat breakfast is that it makes them want to eat more during the day and so they actually put on weight, so this falls into the fallacy category I think. If you don’t like eating breakfast, just don’t eat it.
6. Does St John’s wort work for depression?
Yes. There is a strong body of evidence that shows it does work for mild depression.
7. If drunk in moderation is red wine better for me than white wine?
Sadly, there’s no evidence to support this or any real benefit of drinking wine. Anything beyond a quarter of a glass is drunk for pleasure rather than medicinal purposes. The level of resveratrol in red wine – sometimes hailed as a wonder drug that can extend life and cure cancer – is so tiny that there really is no health benefit of red over white or wine in general at all.
8. Is there such a thing as a successful hangover cure?
I suffer very badly with hangovers and the only thing that works for me is two paracetamol before bed and lots of water. Beyond that, not much and by the time you wake up it’s too late anyway!
9. Is HRT OK for women to take or is it health-wise a disaster?
This totally divides the experts. The effects of HRT depend on the age of the woman taking it. There is evidence it reduces the risks of heart disease and obviously it reduces the symptoms of the menopause, but it can also raise the chances of breast cancer. It’s really for each woman to make her own informed decision about it.
10. Is there any evidence that eating sugar ages your skin?
Yes. In a recent study 600 men and women had their blood glucose levels measured and were rated for how old they looked. The older people appeared – on average it was five months older than they actually were – seemed to correlate with a high rate of blood sugar. The reason is that glucose attacks collagen and makes skin more brittle.
Trust Me I'm a Doctor, Thursday 8:00pm, BBC2