The eating cholesterol blues

For some time now, the UK has dropped the recommendation that you should limit cholesterol intake, because there is no good evidence that consuming cholesterol has an impact on our blood cholesterol levels - which is why eggs are now considered good again. But it has taken a while longer for the US to catch up on this one. Now they have.

This was indirectly drawn to my attention as a result of a blog post comment. Back in 2009 I moaned about a radio ad featuring Gloria Hunniford in which the veteran presenter said 'A while ago I used to have high cholesterol,' (or words to that effect). I pointed out that saying 'A while ago I used to have...' was just repeating yourself. It should either be 'A while ago I had high cholesterol' or 'I used to have high cholesterol', but not both.

I've had a comment from Nicole Lascurain, the Assistant Marketing Manager of a US health firm pointing out that their website listed what '100% of your daily value of cholesterol looks like.' The page has various pictures of foods like friend chicken and cheese showing their cholesterol content, telling us that 'it's no secret that eating fatty foods raises your bad cholesterol levels'. Unfortunately, they're confusing cholesterol levels in the food with fat levels, which aren't the same thing. Yes, high fat levels, particularly transfats, push up your cholesterol levels, but eating cholesterol doesn't.

They based their 300mg a day limit on a genuine but out-of-date US standard. To quote the Scientific Report of the 2015 [US] Dietary Guidelines Advisory Committee:

Previously, the Dietary Guidelines for Americans recommended that cholesterol intake be limited to no more than 300 mg/day. The 2015 DGAC will not bring forward this recommendation because available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol, consistent with the conclusions of the AHA/ACC report.

Simples!

Sugar tax

Brighton and Hove Council in the UK, teamed with Jamie Oliver, the chef and food campaigner, have announced that they are going to recommend a voluntary 10p 'health tax' on soft drinks with added sugar. 

While it's a good move, it doesn't go far enough. I suspect 10p isn't enough to make a huge difference- it probably should be something like 50p. But also it should be an all high sugar drinks - fruit smoothies for instance - not just those with added sugar. 

Are taller people more at risk of cancer?

Most of the newspapers have reported on a study from Sweden showing that taller people are more likely to get cancer. This follows an earlier study in 2011 which came up with similar results.

As a piece of news it isn't particularly helpful - if you are tall, there's not a lot you can do about it. But also it seems reasonably logical.

It's normal, in this kind of study, to factor out other potential contributory factors, such as being under/over weight, so effectively we are comparing like with like. If two people have the same body mass index and one is taller than the other, then the taller person will have more cells in their body. As cancer is, given similar environmental and genetic background, essentially a statistical disease, the more cells available, the more likely it is that there will be a cancerous cell or cells forming. So it doesn't seem entirely surprising as a result.

The figures show a relatively small difference, and like all such studies it is very difficult to be sure that everything else has been adequately controlled for. There does indeed seem to be a small increase in risk, but we are all subject to a whole host of risks that make us different to other people (diet, hereditary, environment, exercise, smoking etc.) so to worry about a small factor we have no control over seems unnecessary.

Would an obesity tax work?

In a comment piece in the i newspaper yesterday, Julia Hartley-Brewer made a plea for a tax on fatty foods and sugary drinks. She was clear about what needed to be done: 'Forget about a few pence on a litre of cola or a cheeseburger and fries, though. We need obesity taxes at 50 or 100 per cent to hike up the cost of the foods and drinks we should only be consuming as an occasional treat, not as part of our daily diet.'

Is this true? Would a tax work at all? A study of 'heath related food taxes' from Oxford University was supportive, though the results were based largely on modelling and controlled trials, as the first real health-related food tax in Denmark has not been running long enough to provide anything other than anecdotal evidence.

One specific piece of evidence comes from Ireland, where a 10% soft drinks tax, introduced in the 70s, intended to bring in revenue rather than improve health, saw an estimated 11% drop in consumption. Because of this, the report recommends a 20% tax on sweetened drinks (though interestingly not on sugary drinks like smoothies, which can contain more sugar than a cola). They also suggested putting VAT on unhealthy foods like chocolate biscuits, confectionary and soft drinks.

It seems likely that there would be some impact, but one cause for suspicion about the level of benefit is that there is already, in a sense, an 'unhealthy foods' tax if you compare the price of typical single chocolate bar with, say, a banana, which addresses many of the same desires for sweetness, is equally filling and is significantly healthier. The chocolate bar has the equivalent of a 4-500% price hike on the banana... and yet we still know which many of us pick up from choice.

How something with 6.8 per cent fat can be 'fat free'

As we've previously discovered, it's possible for food to contain more than 100 per cent of its ingredients according to a misleading industry regulation. Now we discover that it is possible for a substance that is 6.8% fat to be labelled fat free. Take a look at this label from Nestlé's instant cappucino product:

Yes it's 6.8 per cent fat - yet it is also labelled 'Fat Free'. This is too big a discrepancy to be a mistake, so there has to be an industry weasel mechanism to enable this apparent contradiction - and there is. Nestlé responded to a query by saying:

Hi Brian, in order to make a fat free claim a beverage should contain no more than 0.5g fat per 100 mls

So, leaving aside the fact that 0.5g per 100 millilitres isn't actually fat-free, the get-out clause is that the drink as consumed only contains 1.2g of fat, which with the volume of powder and 200 ml of water probably takes it down to 0.5g per 100 ml.

For me, this remains a dubious concept. The fact is that the product itself is certainly not fat free, so the label in the 'Good to know' box is confusing at best.

Retin-A and Retinol

There are two types of cosmetic 'science': magic and pharmaceutical.

The magic kind is where you take a substance that has value inside the body and use it in a way that can't deliver the same benefit. A good example is hyaluronic acid. This was original discovered as part of the gunk that fills eyeballs, and later was shown to be an important part of the matrix that supports cells in the body. The way it is generally sold is that it somehow replenishes this support function, plumping up skin. But this is a bit like saying that food gives you energy, so if you plaster food on your skin you should feel energised.

The good news about hyaluronic acid is that is a genuine humectant - it grabs water, so acts as a reasonable moisturiser - but no better than much cheaper substances like vaseline.

Products with a pharmaceutical background, on the other hand, certainly have an effect, but we have to recognize that all pharma comes with side effects, some of which can be worse than the condition treated. And they need to be used with care. Often the cosmetic industry gets round this by putting so little of an active substance in a product that it doesn't risk side effects, but equally produces very little in the way of results.

So we come to our topic, Retin-A, Retinol and various other names applied to chemical variants on Vitamin A. Retin-A is a brand name for tretinoin, aka retinoic acid, the carboxylic acid derivative of Vitamin A and has been a topical treatment for acne since the 1960s. In the 1980s it was accidentally discovered that it seemed to reduce the appearance of skin wrinkling. Since the original anecdotal benefits there has been some research suggesting positive results. It has since been sold as a skin treatment in the US, though is not widely available in this form elsewhere because of its pharmaceutical nature.

Weaker and more dilute forms turn up in commercial skin creams, often based on retinol, one of the animal forms of Vitamin A. In these cases there may be a small effect, but it certainly will be limited as the dosage is restricted to avoid the side effects. In the more concentrated form (Retin-A, Renova etc.) it can have make a more noticeable change, but can result in a number of side effects, most notably skin irritation and burning, dryness and increased sensitivity to sunlight. For some users this fades over time, for others it will come back each time the cream is used - and the product is only effective while in regular use.

Overall this seems a borderline product. It does have a genuine effect, but it is a pharmaceutical product with known side-effects being applied outside its intended use. As such, the negative aspects may outweigh the positive, and I have not been able to find any research on long-term impact, which may be another concern.

Links

• Hyaluronic acid - page 386

Can drinking tequila help you lose weight?

If I had £1 for every new story where [insert your favourite alcoholic drink] is shown to have some positive effect, I could retire immediately. And, surprise, surprise - this is yet another such story that has no basis whatsoever as far as the headline goes. But it does have one interesting possibility for an alternative to sugar.

All the press coverage comes up with statements like 'You won't believe why drinking tequila might actually help you lose weight,' or 'You won't feel so guilty after that extra shot.' To be clear. Tequila will definitely not help you lose weight, and even if the implied benefit were true, which it isn't, the dangerous impact of alcohol would far outweigh the benefit. In fact the research specifically points out that the beneficial substance this report is based on, of which more in a moment, is not found in tequila.

Hidden beneath the 'drink your way to weight loss' stories is a much more interesting possibility. The actual research, reported at an American Chemical Society meeting, showed that the agave plant, which happens to be the plant tequila is produced from, contains some very interesting sugars called agavins. Instead of the usual fruit sugar fructose, these sugars are fructans, which are effectively fructose polymers. The result of this different structure is that the sugars can't be used by the body and so don't have the negative impact of sugar. They even appear to somewhat reduce blood sugar levels - and they still give a sweet taste. Admittedly not as sweet as a conventional sugar, but still offering the hope of a sweetener that has few potential side effects (some people are intolerant to agavins) and no negative impact on blood sugar levels.

It should be noted that this was a trial on mice, and was funded by a food company and a company making agave products - but that doesn't necessarily mean that the research is dubious.

A really interesting story - but almost entirely hidden by the baloney about tequila being 'good for you.'

Links

• Artificial sweetners - page 9
• High fructose corn syrup
• Sugar - page 102

Balancing hormones

Thanks to reader Yuka for pointing out the wide range of products that are advertised to 'balance the hormones', particularly targeted at women consumers.

There are some parallels here with attempts to 'boost the immune system' (see page 301 in the book). We aren't talking about a simple system or individual entity that can somehow be put back in balance by taking a supplement.

Hormones comprise a vast range of signalling chemicals produced by various glands in the body to control different functions from digestion to sleep and the reproductive system. Various illnesses result in unusual hormone levels, and require proper medical treatment. But the idea that you can 'balance your hormones' by eating something seems more oriented to the ancient and baseless idea of your body having four humours that need to be kept in balance. There is no good scientific evidence for taking supplements to balance your hormones, nor any clear mechanism by which many recommended supplements could even have an influence on hormone levels.

There are many hormones and many products said to 'balance' them, but this article gives an example of some specific products claiming to be 'bioidentical hormones', recommended by their vendors as alternatives to hormone replacement therapy, and also said to improve quality of life. As the article makes clear (with proper testing to back it up) these products have serious potential problems.

Overall, then, if you suspect you have a hormonal problem, the last thing you want to do is self medicate. See your GP.

Vitamin B17, aka laetrile or amygdalin

Flipping through Facebook today I saw someone had shared a post titled 'Vitamin B17: the greatest cover-up in the history of cancer.' There's certainly a cover-up here, but not in the way that was intended by the author. Substances labelled 'Vitamin B17', 'laetrile' or 'amygdalin' (technically a slightly different compound) are sold as cancer cures that the pharmacological industry doesn't want you to know about. But they aren't anything of the sort.

Amygdalin is found in apricot pits, while laetrile is a synthetic compound which is similar in structure. Despite the 'vitamin B17' label it is frequently given, this is not a vitamin in any way, shape or form. Amygdalin, which enzymes can break down to give off the deadly hydrogen cyanide, was tested as a cancer treatment over 100 years ago and found both not to work and to be extremely toxic. Neither of these problems seem to have got in the way of those promoting it as a cure.

One of the reasons that laetrile continues to be rediscovered as a supposed cure is that it was heavily marketed by a self-styled doctor, Ernst Krebs who claimed that cancer was caused by a deficiency of 'vitamin B17.' For decades there have been attempts to make money from those suffering from cancer by promoting this unsubstantiated substance as a cure.

A thorough review of studies of the use of laetrile in the treatment of cancer made in 2011 concluded: The claims that laetrile or amygdalin have beneficial effects for cancer patients are not currently supported by sound clinical data. There is a considerable risk of serious adverse effects from cyanide poisoning after laetrile or amygdalin, especially after oral ingestion. The risk-benefit balance of laetrile or amygdalin as a treatment for cancer is therefore unambiguously negative.

Pepsi and aspartame

It's in the news that Pepsi in the US is removing aspartame from their diet cola. Those who are concerned about the dangers of artificial sweeteners may think that this is a clear sign that there is something wrong with aspartame. It isn't. A Pepsi representative has said:

While decades of studies show aspartame is safe, we recognize that consumer demand is evolving.

They are not changing because there is anything wrong with aspartame, but because the name has become tainted by the constant unscientific suggestion.

The irony is that Pepsi will replace aspartame with two other artificial sweeteners which will almost certainly have had less stringent testing that aspartame has.

LINKS

• Artificial sweeteners - page 9

Are microwave ovens dangerous?

At any one time there are a number of posts circulating on social media, or by chain emails, suggesting that microwave ovens present a danger to health. But is it true?

Generally speaking, the assaults on microwaves either suggest that the damage and de-nutrify food, or that the microwaves themselves are zapping us as we stand around the kitchen.

Let's take the food part first. It is certainly true that microwaving reduces nutritional value - but so does all cooking. On the whole, cooking in a microwave is more likely to retrain nutrients than using conventional means of cooking. Some of this is probably due to the reduced cooking time. Of course it's perfectly possible to cook vegetables for longer than usual in a microwave in a container with lots of water - and just like boiling vegetables excessively in conventional cooking, this is a great way to remove nutritional value. Like any other means of cooking, it's possible to microwave badly.

Another food claim is that microwaving produces carcinogens - again, this is a typical outcome of cooking, though unless you char your food, the amount of carcinogens produced is likely to be lower than the levels of natural carcinogens that are in food anyway. It is sensibly recommended that some plastics aren't used in microwaves, but this is because they melt, not because they give off nasty toxins.

How about the stray microwaves? Studies of undamaged microwaves have shown practically no leakage - well below safe levels. It is important to replace a microwave if door hinges etc. get damaged, but if your microwave is in good condition, the amount of microwaves that can leak from it is tiny and harmless. Those who don't like microwaves will always refer to them as 'radiation' because this sounds scary. They are indeed radiation, but only in the same sense that light, for instance, is radiation. We are not talking about nuclear radiation, but electromagnetic radiation - things like radio waves and light. 

Nothing that makes things hot is totally harmless. You can get burned from hot food in microwaves. Microwaves are susceptible to uneven cooking - so it's important that you make sure the turntable is working properly and that you stir food as required. And it is possible for some liquid microwaved foods and drinks to spurt when, say, a spoon is put in them - so care is important. You shouldn't leave a microwave in the charge of a five-year-old, any more than you should a conventional oven. But all the negative comments about microwaves beyond this simple safety requirement seem to come from a very small number of sources, some of which have a vested interest in selling 'radiation meters' etc., while those regarding microwaves as safe are proper scientists, engaging in well-reviewed scientific trials. 

LINKS

• Burned food - page 15

Can chocolate be good for you?

A new chocolate bar claims to 'help keep you happy and healthy every day' - can chocolate really be as good for you as this product claims?

Although we've a separate entry on chocolate, this claim seemed so dramatic that it was worth its own entry. The product in question is ohso and it's even packed in handy sets of seven, so you can eat it every day.

The chocolate's website, excruciatingly titled 'ohsolovesyourtummy.com', is a little short on facts. There is no nutritional information in the 'Nutritional Guide', for instance - I finally found them tucked away under a secondary heading, but what it didn't say was whether the list was for the 'added sugar' or 'no added sugar' variety. So far, the company has failed to respond to a request for more information. (And the site could do with a proof read, as it includes "Ingredient's" and "refferred to".)

So what are ohso's health claims?

• It's free from gluten and nuts and has 'no added dairy'. That's good if these cause you problems, though not difficult to find these days. For the vast majority of us, no health benefit.
• Has 63 kcal in the 'no added sugar' bar and 72 kcal in the others. Certainly not a scary amount of calories. So is this really low calorie chocolate? In fact it actually says 'We add no dairy, so each bar of ohso is 72 calories.' But it's not particularly the dairy that piles on the calories in chocolate. This is a small, 13.5g bar. The same amount of Cadbury's Dairy Milk, which I think it's fair to say no one, not even Cadbury, would consider healthy (and certainly does contain dairy) has, wait for it, 72 kcal in 13.5g. Exactly the same amount.
• It contains 'friendly bacteria', which survive passage through the gut 'three times better' than in a yoghurt drink. Sounds good. But just because bacteria survive the passage through the gut doesn't mean they stick around and do anything. And as the Probiotics section of Science for Life shows (see page 80), there are no proven benefits from consuming 'friendly bacteria' other than in some very specific medical conditions. 
• It's cholesterol free. So what? As you'll see in the Cholesterol section of the book (see page 28), it has been known for some time that eating cholesterol has no significant impact on our cholesterol levels.

Not a lot of health value there, then. I couldn't see it on the website, but many of the reviews of the product also contain that old chestnut that dark chocolate is 'packed with antioxidants'. How many times do we have to say this? We don't need to consume extra antioxidants - it doesn't add to our natural antioxidant level and with some supplements it has been shown to increase the risk of death.

What's particularly worrying is the way that the chocolate is packaged in 7s and is labelled as containing 'your optimal daily amount of "friendly bacteria"'. This seems to be encouraging people to eat chocolate every day and that can't be a good thing. The other thing to bear in mind is that you will paying £3.99 for under 100g of chocolate. As a comparison I took a look at a quality brand of chocolate (Green & Black's) at Waitrose, so you couldn't accuse me of skimping on price - £2.19 for 100g of their Maya Gold, around half as much.

As we say in our chocolate section, consumed in moderation chocolate is fine - and no one can doubt that it tastes good. But to suggest that chocolate can help keep you healthy stretches a point to breaking.

Brewer's yeast

Some health stores recommend brewer's yeast as a natural way of reducing cholesterol - but does it work, and is it safe?

Brewer's yeast, which is essentially a powdered fungus used in beer production, is one of the many wonder products you can find in a health food store. It is sold both as a way of getting B vitamins and chromium, and is sometimes claimed to reduce cholesterol. This claim is based on a number of studies - but the evidence is weak, with some studies showing no effect at all, and several centres of expertise suggest there is no basis for the claim.

What is certainly true is that where it has been suggested that brewer's yeast has a cholesterol reducing benefit, the product is being taken in doses of around 500mg a day (1-2 tablespoons in powdered form). One concern this raises is that this would result in receiving around 1,000% of the RNI of niacin ((the amount that is enough, or more than enough for 97% of the population), and there is good evidence that high doses of niacin can have negative effects. There are simpler ways to reduce cholesterol.

The other claimed benefits of brewer's yeast tend to be from the trace mineral chromium (for which there are various claims with mixed evidence) and a source of B vitamins, but as we make clear in the Vitamins and minerals section (page 111) a normal adult on a balanced diet should not need supplementation. By all means enjoy the brewer's yeast containing spreads like marmite or vegemite if you are in the 'love' camp - but it seems unlikely that it will provide much benefit as a supplement.

Niacin

Niacin, or vitamin B3 is added to white bread and cereals, and present in high doses in some supplements. But do we need this fortification?

As mentioned in the Vitamins and minerals section (page 111), vitamin B3, or niacin, is an essential micronutrient that supports the nervous system and is required for good skin. Deficiencies can result in weakness, loss of appetite, dermatitis, diarrhoea and, at the extreme, dementia. It is found in wholegrain products, peanuts, sesame seeds, fish and most meat.

You may have noticed that it is added to many breakfast cereals, and it is also added by law to white flour (and hence white bread) in the UK, as in the 1950s the government reacted to the new enthusiasm for white bread, which lacks some of the nutrients of the wholegrain equivalent. To be honest, the level in flour and bread isn't enough to make a huge difference - and these days few of us in developed countries lack niacin.

However, there is a concern about over-consumption of niacin in supplements. A young child, for instance, being given a multivitamin on top of a normal diet can end up with around 600% of their RNI (the amount that is enough, or more than enough for 97% of the population). And an adult taking a high dose of, say, brewer's yeast, could be on 1,000% of their RNI from that alone.

The reason this is a worry is that B3 is one of the vitamins that can cause problems in excess. At high levels it can cause skin flushes, rashes and at the extreme stomach bleeds and an increased risk of diabetes. Serious problems over and above the flushes are only likely to be caused by consumption well over 1,000% of RNI, but even so, this is a good example where unnecessary supplements can actually have a negative effect. And we particularly need to be careful with young children.

Vitamins aren't sweets and care needs to be taken with dosing, bearing in mind that most of us get a lot of vitamins already in our diet.

High fructose corn syrup

High fructose corn syrup is used as an alternative to sugar to sweeten some drinks, particularly in the US. It possesses no greater health risk than any other sugar - but do cut down on sugar!

This is one that is more of concern in the US than the UK, where it is unusual for high fructose corn syrup (or HFCS) to be used. The reason it tends to be used in the US is that it is cheaper than conventional sugar, apart from anything else because fructose, one of the two sugars in HFCS (the other is glucose), is sweeter than sucrose (the fructose/glucose combo in conventional sugar). This means that technically it is slightly healthier than sucrose, as you can use less HFCS than cane or beet sugar to get the same sweetness.

There is nothing magic about any of these sugars, and HFCS has less fructose concentration than, say, an apple or pear. And, to be absolutely certain, there has been plenty of good research done on HFCS which shows that there are no negative effects whatsoever, apart from the usual problems of sugar.

So that's it. It's yet another scare because HCFS sounds less 'natural' than cane or beet sugar. In the end it's the same stuff, but because fructose is sweeter than sucrose, you need less of it to get the same level of sweetness, so if you have a choice, you should go for the HCFS. Like all sugars, it's something we should consume in moderation. Like all sugars, almost all of us should consume less. But the dire warnings doing the rounds on social media making it a dietary bogeyman have no basis whatsoever.

LINKS

• Sugar - page 102

Copper bracelets for health

It's easy to find shops selling copper bracelets and other copper-based things to wear that it is claimed will help reduce chronic pain and swelling, reduce the impact of arthritis and more. But does it work?

Copper is a relatively common element that we need to consume in trace quantities for a number of functions of the body, but we get plenty of copper in our diet and an excess can result in liver damage and brain deterioration, so it's not something to take as a supplement without medical advice. But how about wearing it?

The immediate scientific response is to wonder how wearing a copper bracelet, say, could have any impact on pains in other parts of the body. One claim, for instance, is that the body can draw metal out of the bracelet to help with cartilage replacement. There is no mechanism by which this could happen - and even if copper was absorbed, it would do more harm than good. This seems little more than an appeal to magic.

A study was carried out in the UK in 2013 which reported that wearing copper bracelets had no impact on these problems, and that any perceived benefit from wearing copper was simply a placebo effect.

On a separate claim, it is just possible that copper compounds, appropriately applied, could have some antibacterial benefits - but it isn't enough to wear a piece of metallic copper, and there is no evidence as yet of a wearable product containing copper or copper compounds have such a benefit.

So by all means wear a copper bracelet if you think it looks nice - but don't expect it to make you healthier.

Herbal medicine

Herbs have been used in all cultures as medicines and some have real medical benefits. but care has to be taken with herbal cures as they are poorly regulated.

In historical times, herbs played a major part in our medical treatment, though as early as the 17th century, when herbalist Nicholas Culpeper published his Complete Herbal, there was a debate between the proponents of herbal and chemical medicine. With a modern understanding of the active ingredients in herbs we can see that the distinction is artificial. Herbs are an effective source of chemicals that have an active effect on the human body, though often this effect is improved if the chemical agent is refined and modified.

So, for instance, willow bark, containing a chemical called salicylic acid, has been used to help reduce pains and fevers for at least 4,000 years. Unfortunately salicylic acid causes sharp stomach pains and can cause internal bleeding – so that relief came with a price. At the end of the 19th century, the German pharmaceutical company Bayer produced a painkiller called aspirin, which modified the active ingredient to the much less aggressive acetylsalicylic acid. The active ingredient of medical herbs has been repeatedly isolated and improved. Quinine for malaria, atropine and digitalis for the heart, for instance, all originated with herbal cures, but are much better and safer in their pure chemical form.

Herbal medicine has a strong presence in China, and there are herbal medicine stores on many of our high streets. Unfortunately, current herbal medicine still uses theories with no basis (such as employing a herb with the same shape as an organ of the body to treat that organ) and has rarely advanced. There are also well-documented dangers in taking herbal medicines at the same time as other medications. It is always worth checking with your doctor first.

The popular herbal treatment St John’s Wort, for instance, which has proved effective in helping with mild depression, has as many possible side effects as any prescription drug, from gastrointestinal pain to dizziness. It can cause serious problems with anti-HIV, anti-cancer drugs and contraceptive pills; plus it generally reduces the effectiveness of the transport mechanism carrying drugs into the bloodstream. Because of this it has been banned in France. You can’t assume that because a treatment is herbal it is safe in all circumstances.

Another significant problem with herbal treatments is that a herb rarely contains only one active ingredient – and it is almost impossible to give a well-controlled dose, as the amount of the chemical in a herb will vary from plant to plant. Where a prescription medicine will have isolated the useful chemical, in a herb you could be exposing yourself to a whole range of potentially unpleasant substances to get the beneficial one. But more worrying still is the reality that there is very little regulation of the quality of herbal medicines.

A major US study in 2013 analysed 44 processed herbal prod- ucts and 50 medicinal herbs from a range of suppliers. The results were shocking. Less than half of the products actually contained the labelled main ingredient. Nearly 60 per cent contained herbal species that weren’t listed on the ingredients. A third also contained fillers and contaminants that weren’t on the label. In three of the companies tested, none of the products contained what they said they did. In other studies, herbal medicines have been found to be contaminated with dangerous heavy metals and other extremely poisonous substances.

*UPDATE* In February 2015 the New York State attorney general's office accused four major US retailers of selling herbal supplements that were fraudulent and in some cases were contaminated with unlisted ingredients. These weren't backstreet herbalists, but Walmart, Walgreens, Target an GNC. Approximately four out of five products didn't contain any of the herbs on their labels. Many contained little more than rice and houseplants.

The products with non of the herb in included Gingko Biloba, St. John's Wort, Ginseng, Echinacea and Valerian Root. Typical fillers were rice, asparagus, wheat or grass and garlic, though oddly many of the samples actually claiming to be garlic had none in. This really emphasises how much you are at risk of getting anything but what you expect when buying herbal remedies.

So, while there are certainly benefits to some herbal remedies, the lack of a proper regulation and of a testing regime paralleling that used on conventional medication means that there will always be significant risks attached.

E-cigarettes

Electronic cigarettes, or e-cigarettes have become commonplace as a safer substitute for the real thing. But are they safe to use?

One important consideration is that at the moment e-cigarettes are not regulated in many countries, including the UK. This means, like all unregulated products that have a potential health risk, you don't know that what you are using contains only what is supposed to contain. There is no magic wand for this, apart from buying from legitimate brands, ideally through a known major retailer, who will hopefully have done some checks for you.

The liquid you put in an e-cigarette (assuming it's a legitimate one) has nicotine, extracted from tobacco, flavourings and suspension fluids that work well with the vaporising process, typically propylene glycol and glycerol which in themselves are both pretty much harmless.

When you inhale this stuff, either actively or as a passive recipient of someone else's vapour, you are taking an aerosol - fine droplets of liquid - into your lungs. This can happen perfectly naturally, for instance with some strong-smelling natural substances. But having unwanted material in the lungs always has the potential for risk, specifically for causing cancer.

The biggest concern here is not the original chemical constituents, but rather than the heating process that sends the vapour out can break down some of the suspension fluid into formaldehyde. In small quantities this isn't a problem - our bodies deal with formaldehyde all the time - but in larger quantities formaldehyde is a carcinogen, particularly around the respiratory system.

At this stage there hasn't been enough research to confirm the early findings, but if the data available so far is correct, heavy users of e-cigarettes could have a significant cancer risk - possibly as high a risk as from smoking in the first place. In the balance, cigarettes have a whole range of negative impacts, not just lung cancer, so this isn't an argument for going back to smoking cigarettes. And if an e-cigarette is used as a vehicle to fairly quickly stop smoking altogether, on balance it may be worth using (though patches, gum and other sources of nicotine don't carry this potential risk).

However, what this does suggest is that no one should use e-cigarettes just for the sake of it, and should only consider using them in a tapering off programme to quit smoking if options like patches and gum aren't working. And it also means we ought to see e-cigarettes banned from all the locations we ban conventional cigarettes - as the risk from passive inhalation is certainly present.

For the future there are a number of steps that should be taken. E-cigarettes should be regulated and licensed as vehicles for drug dispensing. There needs to be significantly more research into the production of formaldehyde and any other potentially dangerous substances. And there should be research into safer suspension fluids.

The principle of e-cigarettes is good, but there is evidence that this still very young product needs significantly more work to ensure that it is a safe substitute for tobacco.

Screens and eyes

For as long as we’ve had televisions they have been accused of damaging our eyes – but now, with screens everywhere, what’s the true picture?

When I was young, older people were always telling us not to sit too close to the TV or to spend too much time watching it. Yet back then, we only had a fraction of the screen time that most of us experience today. You may well spend all day at work looking at a computer screen, then come home to spend the evening in front of the TV. And what were you doing in between these times? Looking at your phone or tablet.

In 2014 there was a scare story that overusing smartphones may damage the eyes. The concern was that the light from LED screens contains more blue/violet light than the natural light that best suits our eyes, and the higher energy blue/violet light can overload the sensors on the retina, increasing the risk of macular degeneration, a common cause of blindness.

The story particularly highlighted the risks from smartphone use, where the screen is held considerably closer to the eyes than a computer or TV screen and is often used in lower lighting condi- tions, where the dilated irises of our eyes allow more light in.

We have to approach this story with a little caution. There is no study showing that exposure to screens, even smartphones, causes eye problems – this is extrapolating from laboratory-based evidence that light in this region can cause damage to the type of cells used in the retina. So at the very most, this is a precautionary warning as yet.

What is certainly true is that our eyes don’t respond well to being focused as closely as a smartphone requires (TVs are usually positioned at a better distance) for long periods of time, and this can cause eye strain. Taking a break from screens for at least five minutes in each hour, and a few longer breaks during the day is highly recommended. Furthermore, regular screen users – which is pretty well all of us – should have regular check-ups with an optician.

UPDATE: In December 2014 a different study showed that people who read backlit screens in before going to sleep produced less of the hormone melatonin. This can make it harder to get to sleep, and in the long term, sleep deficiency can produce significant health problems. As yet the evidence is relatively limited - this was a very small study with just six people on each kind of book. However if you do have trouble getting to sleep, and you read from a screen for your bedtime reading it is worth switching to a paper book (or an e-ink reader like a basic Kindle that doesn't have a backlight) to see if it helps make sleep more easy. Ideally avoid close backlit screens (including phones and computers as well as tablets and backlit e-readers) for a couple of hours before trying to sleep. TVs don't seem to be a problem as we don't sit anywhere near as close, so the blue backlight is a relatively small part of our incoming light - and the generally darker coloured picture of video is better than the stark white of a page to read. If you have to use a backlit e-reader, try turning down the brightness.

The numbers game

The media, politicians and interest groups love to throw numbers at us to support their cause - and they can be very useful - but we always ought to ask: 'Where did those numbers come from?' and 'What does that actually mean?'

Here's a good example. In 2015, a website attacked the UK Labour Party's policy on arts funding pointing out 'Just so you know, arts funding brings in £4 for every £1 spent.' It's quite likely this statistic will get a life of its own and be used many times in the future. But what does this actually mean, and where did the numbers come from?

As far as a source, the figure seems to be genuine. After following a chain of different people using it, it originated in a 2013 report by Arts Development UK. So I was, with a little work, able to check where it came from. Yet the chances are, when a figure like this is used, it will often not be possible to easily find out its exact source.

And what does it actually mean? I asked quite a few people who all, like me, assumed that the claim 'arts funding brings in £4 for every £1 spent' meant that if you fund the arts, for each £1 you spend, £4 will come in either directly (through entrance fees, brochures etc.) or indirectly (for instance by more tourists coming and spending money in your town or city). But look at that original report and you'll find something entirely different was intended.

The report says 'For every £1 spent by local authorities on arts service, leverage from grant aid and partnership working brings in £4.04 of additional funding.' So, when a local authority spends £1 it gets that additional money from grant aid and partnership - which is largely with other authorities and with bodies like Arts Council England. In other words, £1 of local government spend brings the local authority another £4 of public money. Excellent for the local authority, but hardly supporting the argument in which it was used. Whether intentional or (probably as here) accidental, this is a kind of deception.

We usually don't have the time to trace back a statistic to its source like this - but don't be taken in by numbers picked out of the air. Anyone who uses numbers like this should expect to have them challenged - and needs to be able to show exactly what they mean and where they come from.