I receive lots of letters from readers asking for a 'second opinion' on minor issues after they've been given advice or instructions by their GP or Practice Nurse. Here I've picked out a baker's dozen of the most frequently recurring topics. The letters I receive generally run along these lines.
Q. Dear Medical Detective, can you please clarify something for me? I've been told by my GP/Practice Nurse that . . .
1 ... with the wear and tear on your knee, arthroscopic surgery-where a tiny camera (arthroscope) is inserted into the knee joint through a tiny slit to examine or treat the problem-will help you.
A Arthroscopy has been shown to make absolutely no difference in cases of knee and joint pain in general, and can even sometimes make the pain worse after the operation. During a 12-month observation period of 351 patients with either a torn meniscus (the shock-absorbing cartilaginous pad between the knee bones) or moderate osteoarthritis of the knee on imaging, no differences were found in their outcomes with arthroscopic surgery compared with the usual physical therapy.1
2 ... absolutely no sugar is permitted in the diet of children suffering from attention-deficit/hyperactivity disorder (ADHD).
A Refined sugar isn't good for anyone, including children, but there is no evidence that sugar consumption will inevitably either trigger or make ADHD worse. This has been well known for half a century. At the time, the president of The American Association of Immunologists, Prof Arthur F. Coca, spelt it out in his book The Pulse Test (1956; available online), as did Dr Richard Mackarness in Not All in the Mind (Macmillan, 1976).
More recently, between November 2008 and September 2009, 100 children with ADHD underwent a rigorous randomized placebo-controlled trial to monitor the effects of a restricted elimination diet on their behaviour. This again established that ADHD can be brought about by virtually any dietary component, not just sugar, if there's an intolerance.2
3 ... your habit of crossing your legs is causing your varicose veins.
A No, there is absolutely no cause-and-effect relationship between leg-crossing and lower-limb varicosities.3
4 ... you should drink at least eight full glasses (around 2 L in total) of water each day.
A This is definitely an old 'urban myth'.4 A good guide to your body's finely tuned fluid balance is the colour of your urine: if it's very dark, you're on the dry side and need to drink more water; if it's light or translucent, then you should be drinking a bit less.
5 ... you should avoid eating carbohydrates in the evenings-that way you'll lose weight quicker.
A In a three-week controlled study carried out by researchers at Tufts University in Boston, Massachusetts, no significant differences were found in weight loss whether carbohydrates were consumed in the evening or at any other time of day.5
6 ...you should eat no more than two eggs per week-otherwise your cholesterol will shoot up.
A According to the European Food Information Council (EUFIC) in Brussels, eggs have little impact on blood cholesterol. Instead, they make a valuable contribution to a healthy, balanced diet by providing high-quality protein and a number of vitamins and minerals. In general, the negligible safety risk posed by eggs is far outweighed by their contribution to a healthy diet for all age groups.6
7 ... you shouldn't drink coffee because it increases the lack of fluid, making your diabetes worse.
A On the contrary, moderate coffee consumption can reduce the incidence of type 2 diabetes by around 25 per cent.7
What's more, a pooled analytical review of 59 separate studies by gastroenterologists at Huadong Hospital in Shanghai concluded that drinking just one additional cup of coffee a day could lower the risk of a wide range of cancers by 3 per cent.
8 ... you should take vitamin C supplements to prevent the common cold.
A Harri Hemil"a, at the University of Helsinki in Finland, and Robert Douglas, at the Australian National University in Canberra, reviewed 55 studies going back over 65 years to determine the disease-preventing effects of vitamin C. Many of the studies in their review asked whether vitamin C can reduce the incidence of the common cold, and their pooled data could find no significant protective effect in the general population. But they did find that marathon runners, skiers and soldiers-in other words, those exposed to extreme physical and environmental stresses-had a significant 50 per cent reduction in colds thanks to vitamin C supplementation. They also found that taking this vitamin on a regular basis reduced the duration of cold symptoms by 8 per cent in adults and 14 per cent in children.8
9 ... a glass of red wine as a night cap each evening will make you sleep better.
A Although one solitary daily glass of red wine won't harm your health, a review of studies by researchers at the London Sleep Centre showed that, all things considered, alcohol is not a good way to get a good night's sleep; in fact, it only promotes snoring and breathing problems.9
10 ... after your heart attack , absolutely no sex allowed!
A There is an accepted consensus by both EU and US cardiologists that moderately performed intercourse is not stressful to the heart and, in fact, preferable to the 'heartache' that accompanies complete abstention.10
11 ... with your elevated blood pressure, you must avoid salt.
A This is poor advice. The highly respected Cochrane Collaboration did a pooled analysis of 167 studies (ranging from 1950 to 2011) on the specific effects of the consumption of table salt. The results showed that low-salt diets reduced blood pressure by a mere 1 per cent in Caucasians with normal blood pressure and by only 3.5 per cent in those with high blood pressure; the numbers were only slightly better among blacks and Asians.11
12 ... sports will reduce the muscle aches that an excessive workout in the gym has caused.
A Wrong! The cause of those aching muscles are small tears in the muscle fibres, which need time to heal. What does help with painful calves or arms is getting more magnesium via either supplements or topically applied magnesium oil,12 and cooling the affected parts with ice wrapped in a towel.
13 ... when I told my GP that inhaling lavender essential oil relieved my severe migraine attacks, he dismissed it as probably no more than a placebo effect.
A In a rigorous placebo-controlled clinical trial, inhalation of lavender essential oil was found to be a significantly effective and safe treatment for migraine headaches.13
Harald Gaier, one of the UK's leading experts on alternative medicine and a registered naturopath, osteopath, acupuncturist, homeopath and herbalist, practises at The Allergy and Nutrition Clinic, 22 Harley Street, London.
Visit his website at www.drgaier.com.
If you have a question for our Medical Detective, write to us at the usual address or email: firstname.lastname@example.org
N Engl J Med, 2013; 368: 1675-84
Lancet, 2011; 377: 494-503
Phlebolymphology, 2006; 13: 188-94
Appetite, 2009; 52: 96-103
Arch Intern Med, 2009; 169: 2053-63; Nutr Metab Cardiovasc Dis, 2011; 21: 418-23
PLoS Med, 2005; 2: e168
Alcohol Clin Exp Res, 2013; 37: 539-49
Am J Cardiol, 2000; 86: 51F-6F; Circulation, 2012; 125: 1058-72
Cochrane Database Syst Rev, 2011; 11: CD004022
Magnes Res, 2006; 19: 180-9
Eur Neurol, 2012; 67: 288-91