Tuesday, March 31, 2009

It's not the apples inside him, it's the alcohol in cider.

WARSAW - A Polish lawmaker who failed a drink-driving test said
he had eaten too many apples, the website of daily Gazeta Wyborcza said Monday.

Asked why a traffic police check Sunday showed he had 0.7 units of alcohol in his blood, Marek Latas denied having drunk alcohol that day.

"I am diabetic, I ate a few apples before driving.

"I have been involved in no accident, I underwent a routine roadside check. I was confident there was no chance I had alcohol in my blood," said Latas, a member of parliament for the conservative opposition Law and Justice Party. The prosecutor's office is investigating his case, the website said. In Poland, the legal limit for alcohol when driving is 0.2 units.

- Reuters
Cute story. Could it be true?

Assuming their alcohol limit is 0.05% (I don't understand 'units', that usually refers to drinks consumed.), the guy had a level of three and a half times that: 0.175%.

As a rule of thumb you blood alcohol level goes up by 0.01% per standard drink and down by 0.01% per hour. That blood level is equivalent to about 20 drinks over, say, three hours.

That's about 5 litres of 'liquor', requiring the juice of about three dozen apples.

Not only do you need to eat 36 apples, you need to retain them in your stomach for 3-6 days.

Not only do you need to retain them in your stomach for 3-6 days you need a yeast that will live in there. A stomach is about 100 times more acidic than the normal cider fermentation process. You need a super yeast and you need to be able to deal with a lot of released gas from the fermentation process. (burp).

And all that assumes that his liver is not metabolising the alcohol as it is produced.

Guilty as charged, I fear.


Monday, March 30, 2009

Ah, now I see!


A Sydney doctor has been studying human retinas since 1976 and says the carrot myth, that eating carrots is good for your eyes, started in World War II, is a "complete fabrication". Dr Beaumont is the director of the Macular Degeneration (MD) Foundation.

"When the English ... were flying at night they used radar but the Germans didn't know that radar existed," Dr Beaumont said from his Sydney clinic. "The English certainly didn't want them to know so they put out a myth saying they were feeding their pilots carrots to improve their night vision and that's why they could fly and see things at night.

Dr Beaumont recommends eating lutein rich foods for eye health. The lutein (found in spinach, corn and egg yolks) helps protect the eye from sight-damaging light that causes MD and blindness, Dr Beaumont explains.

On the flipside, ironically, foods rich in beta carotene - like carrots - can damage the eye's protective shield, doubling your risk of contracting the disease.

So much for old wive's tales.

Related to that, there is at least one recorded case of a person dying from drinking excessive amounts of carrot juice.

While we need Vitamin A (beta carotene is a Vitamin A precursor), it is actually quite toxic.

Thursday, March 26, 2009

Prostate Cancer and Red Wine


The Australian media was abuzz last week with a report that alcohol consumption increases the chances of prostate cancer. Two drinks a day will increase your risk by 20%. The risk increased with the number of drinks consumed in a day.

Before I pour my home brew down the drain, there are a few things I need answered.
(If you haven't read my previous post, now's a good time. I'll wait.)

Could alcohol consumption cause/increase the risk of prostate cancer? Possible.
Could prostate cancer risk cause drinking? Improbable.
Could a third factor be in play? Possible. Here are a few possible other factors:

People who drink large amounts of alcohol a day are often overweight. Is BMI a factor?
The consumption of chips, nuts and snack foods is probably proportional to drinks consumed.
Big drinkers often eat more meat.
Is consumption of other foods an issue - fibre, greens, fruit?
Do drinkers live longer, due to the heart benefits of alcohol, and get cancer due to longevity?

That will do. I'm sure we could come up with more. You can begin to see the difficulty of extracting two issues from a very complex life-matrix.

Crud Factor
Is a crud factor in play? Possibly. Sometimes a big survey like this finds statistical significance where no practical significance exists or will average out differences in reports.

Compare the following two extracts from studies into prostate cancer and alcohol consumption:

Our present study suggests that consumption of beer or liquor is not associated with prostate cancer. There may be, however, a reduced relative risk associated with increasing level of red wine consumption. Int. J. Cancer: 113, 133–140 (2005).

Wine or beer consumption was unassociated with prostate cancer; however, moderate liquor consumption was associated with a significant 61–67% increased risk of prostate cancer. International Journal of Epidemiology 2001;30:749-755

Looks as if beer is neutral, red wine gets a sort of a plus and spirits get a sort of a minus.

So does the report mean anything?

Too early to tell really but I will put a punt on the benefits of moderate alcohol consumption outweighing the possible down side.

Of sharks and ice-creams...


Really this post is about statistics but you wouldn't have come if I had said that.

The thing is that there are reports published everyday on every possible subject, many of them food and health linked. My next post, which prompted this pre-post, is on prostate cancer and red wine. I am doing this post separately as I think I will be referring to it time and time again.

Newspapers happily publish these 'shock-horror' health reports, edited, cherry-picked, sensationalised and often unverified.

Readers, knowing no better, accept them on face value.

To help me explain, let me now call on some sharks and ice-creams.

Sharks & Ice Creams - the pursuit of causality.
There has been shown to be a strong correlation between shark attacks and ice-cream consumption in Australia.

Does that mean eating ice-creams make you more prone to being eaten by a shark?

Does it mean that, having been attacked by a shark, you start craving dairy food?

Or could it possibly be that a third thing, maybe the season, is controlling both things?

Indeed it is the case that it is in summer that both shark attacks and ice-cream consumption increase.


Causality is fundamental to interpreting any report. What caused what? Whenever you see a report in the papers linking two things, ask yourself the following three questions:

  • Is A really causing B, as claimed?
  • Could B actually be causing A?
  • Could something else, C, be causing both A and B?

The Crud Factor
The crud factor in statistics is an acknowledgement that everything is correlated.

If I was to find the data for tin production in Bolivia for the last ten years and also find the number of deaths in bicycle accidents in Belgium over the same period and plot them on an X-Y graph there would almost certainly be a correlation between the two.

A chance correlation.

It may be negative, it may be positive, it may be big or small, but it is most unlikely to be zero.

That is why all scientific research needs to be replicated; scientists test the same hypothesis (that tin production in Bolivia is impacting on bicycle fatalities in Belgium) using different data. If they can replicate the results then their confidence in the hypothesis increases.

It is not uncommon for replicate testing to fail to reproduce the original work.

Sadly, journal editors are not as keen to publish a negative result as they are to publish a positive and interesting one and such work often never gets beyond the waste bin. And, should they publish an article negating previous work, news media are far less likely to run it because it is not "news" and not shocking enough.

So, if there is a news item showcasing some horror relationship between a food and health or even some wonder cure, be ready to ask yourself if the implied causality makes sense and could it just be a chance correlation.

There you go. That didn't hurt, did it?

Wednesday, March 25, 2009

More on Yoghurt


Laveviewer asked: I have two questions: Are homemade yogurt and ice-cream better for you than the commercial varieties? I'm thinking that if you make these products and use them within a week or two, you don't need to worry about preservatives.

Neither yoghurt nor icecream have preservative generally. If they do, it is usually from the flavourings. Sauces and fruit purees often have preservatives, notably sulphites and sorbic acid. The preservative are there to keep the flavourings from going off before being used.

Once a frozen product, like ice cream, is produced it has a considerable lifetime as freezing is a natural form of preservation.

Part of the benefit of yoghurt is its bacteria content, so in this type of product preservatives can be a problem in a different way. Yoghurt usually relies on it's acidity to inhibit stray bugs.

Both can be made at home, time and enthusiasm permitting. You also have a better input into possible flavours. I made a delicious grapefruit and honey sorbet last summer. You wont find that in the shops.

But are they better for you? Hard to say. Commercial icecream had a pile of stabilizers and emulsifiers, and often a bare minimum of fat, possibly not even dairy fat if they call it iced confection. But home made icecream can be made with eggs and cream, it is really a frozen custard - infinitely superior in flavour but moderation required!

Home made yoghurt is fine as long as you use proper care and sanitation for making it.

The Silver Bullet School of Nutrition.


This is a previous post from "A Curate's Egg" but one which rightly belongs here and, in part, answers Kris loves Chocolate's question about which food are the healthiest for us.

I am not a fan of the ‘silver bullet’ school of nutrition.

By silver bullet, I mean the belief that some foods that are super foods.

Granted, some plants will kill you. That does not automatically mean that, in an effort to maintain even-handedness in the universe, there are some plants out there that are designed to save you.

But people seem to like wonder foods. Every year we hear about some berry, root or leaf from some exotic location that the native people know about and it keeps them happy, healthy and fucking like a hamsters, until they die of sexually induced exhaustion well into old age.

Oddly, these wonder foods seem to be most often sold by some multi-level marketing crowd.

Always, my first question is always the same: If this product is so good, why aren’t the pharmaceutical firms growing it, refining it, and mass producing it? Quinine was an example of where that did happen.

The problem with some of these wonder foods is that they are not supposed to cure a specific (and hence measurable) illness, such as malaria, but are generalists. They will stop cancer, aging, heart disease or some other intangible thing. Yes, death rates are measurable but you must keep an eye on causality. What’s that? The Hellarwi tribe never got heart disease AND the ate the wacko berry every day. Great! Perhaps the fact that they spent the day running around on foot and didn’t have an ounce of fat on them played a part too.

And the small matter of crocodile induced mortality.

Mind you, the crocodiles who eat the Hellarwi live to a ripe old age.

If you drink $40 worth of exotic berry juice a day and never get cancer, how do you prove it was the berry’s doing?

Perhaps you just weren’t going to get cancer anyway.

Beef Jerky



Don said "I did a post about making jerky - dried meat. Someone asked if adding something sweet, like honey, might make the jerky less tough. The reasoning was because the sugar content makes a cake "softer". I don't know about the cake but do you think the sweetener would make the jerky less tough? (Not that I care, we don't like sweet jerky and go through this stuff as fast as I make it.)"

In theory honey or corn syrup would keep the jerky more supple but I would find the sweetness off-putting. Glycerine (Glycerol) may also work and is not so sweet.

Probably the best solution is to not dry it as much.

I occasionally make my own jerky. I use a variant of a recipe I found on line called Cliff's Fantastic Jerky. I vary it by using crushed garlic and chopped onion rather than the powders.

Far too nice to make too often.

Wine & Champagne


Kris loves Chocolate wrote "When I drink (one glass, I am not talking getting tipsy here) wine, I get a horrible migraine. Once in awhile I can sip on white wine and be ok, but never red wine. I can drink Champagne though. Someone said I am allergic to the sulphates? No sulphates in Champagne?"

Most alcoholic drinks contain sulphites; it is added to stop fermentation, to kill off unwanted yeasts and generally as a sterilizer in the brewing process.

If the sulphites were the source of your migraines you would get it from wines other than red ones. And foods other than wine. Sulphites are probably the most ubiquitous preservative in our foods, often in levels far higher than found in wine. It is found in anything from dried fruit to manufactured meat. Some people do respond badly to sulphites but it is rare.

Possibly your response is to the histamines in red wine. These are absent (or low) in white wines. Taking an antihistamine tablet before consuming some red wine would tell you whether you are responding to histamines or not. Again, it is possible but rare.

Tannins are another possibility as red wine has more of them than white wine. The colour of red wine is extracted from the grape skins and tannin is also extracted in the process. If this was the case you would expect eating dark grapes would produce a headache. Even drinking tea may give a headache, though obviously different tannins are present in tea.

The short answer is that no one knows why some people get a headache from red wine.




Indi wanted me to "write about yoghurt". This is a broad sort of request! I will deal with it with a heap of observations and if there is anything people want to expand on we can deal with that later.

Yoghurt is a fermented milk product where the bacteria convert the lactose in the milk to lactic acid. The lactic acid gives the yoghurt the sour taste and ‘sets’ the milk by coagulating the proteins. The acidity also helps prevent other, possibly harmful, bacteria growing.

As the lactose in the milk is largely converted to lactic acid, yoghurt is usually well tolerated by people who are lactose intolerant and is easy to digest generally.

I am not a big fan of the fruit yoghurts, usually too sweet for me, but there is nothing wrong with them.

I like Jalna yoghurts but, for the one pictured above, take philosophical exception to the idea that (1) the product is fat free, it isn’t, (2) that fat free milk is in anyway natural, it isn’t. Not from the cows I know, anyway. Sadly, I don’t think they make full fat plain set yoghurt any more but their Swiss Custard Yoghurt is far too nice.

That hard white stuff you find on the top of ‘health’ bars might be called yoghurt but it isn’t. It is yoghurt flavoured fat, mostly saturated fat.

Probiotic yoghurt drinks probably do no harm (though they are twice as sweet as Coca Cola) but it is a open question as to whether they do any good. While the bacteria used will pass through the stomach into the intestines, they are not self sustaining and disappear from the system in a few days if not constantly replenished. I do not see their value and take the view that the flora that has thrived in the intestines over the eons are probably the best ones to have there.

Greek yoghurt has a higher fat level (10% cf normal yoghurt of 3%) and hence is more creamy.

Thursday, March 19, 2009

Lady Fi's Onions and a bit on gold, for good measure.


Lady Fi asks: Have you read my post about onions?
Why not tell us more about the tearful reactions they can trigger in lots of us?

Also - what's the deal about alchemy turning stuff into gold? How did it start? Why did people try? And is it really impossible?

Onions make you cry because, when you cut them, you release Propanethial S-oxide, a volaile compound that reacts with the moist surface of your eye to form sulphuric acid. Your eyes then water in response to this irritation.

Interestingly, onions do not contain propanethial S-oxide and it is thought that onions produce this tear inducing compound to protect the plant from herbivores. It is the product of a series of chemical reactions that occur once the onion has been damaged. Cells are broken open as the onion is cut and this releases the enzyme alliinase and water, which react with S-1-propenyl-L-cysteine sulfoxide forming a mixture of products including propanethial S-oxide.

Various suggestions are about to stop this process - cutting onions under water, chilling onions to reduce the volatility of the compound, heating the onion to kill the enzymes that create the compound, or what I sometimes do if the stove is free, cutting the onions under the exhaust fan on the stove.

And gold?

The alchemists have dreamed of turning lead into gold but, alas, had to fall back on other retirement schemes. Modern day nuclear physics has successfully transmuted lead into gold, but the expense far exceeds any gain. Ironically, it transpired that, under true nuclear transmutation, it is far easier to turn gold into lead than the reverse reaction, which was the one the alchemists had ardently pursued.


Tuesday, March 17, 2009

The most dangerous food in the world!

This is a repost from A Curate's Egg, but it is topical (re The Fat Duck post) and really belongs here .

In my previous incarnation as a food chemist I was often asked ''What food shouldn't we eat?"
I'm not sure what people expected me to say.

Butter, maybe.

In the incarnation prior to that one, I worked at the Coroner's Court doing post-mortem drug analyses. No one ever asked me what drugs they shouldn't take.

However, there I am, Food Chemist, at a dinner party or a BBQ and after the obligatory "What do you do for a living?" question I get the "Oh, really? What food shouldn't we eat?" question. Always tricky if you don't know what is on the menu. But few people are ready for my reply.

Alfalfa sprouts.

Yes, those clean, green, biodynamically pumped shoots are one of the most treacherous foods on the menu.

"Surely not! You're joking, right?"


Think about it. Seeds of any sort are open to the environment. They will have bacteria on them. So what do you do with them? You soak them in water and leave them somewhere warm for three days. Water, warmth, and the seed, a good souce of protein. Bacteria heaven.

"But sprouts have been eaten for centuries." they protest.

"Cooked" I respond. Eating sprouts raw is a recent 'healthy' practice.

Cooking sprouts will kill any bacteria.

That doesn't mean that raw sprouts are bad, just that they are high risk. There is no safety net.
You can reduce the risks by using boiled or chlorinated water and changing the water frequently.

"Now, would you like my thoughts on curry powder? Or margarine?"

"Ah ... that's very kind of you but I can see an actuary over there that I have been dying to talk to ... "

Monday, March 16, 2009

The Fat Duck & Quantum Chemistry


Chairman Bill asked: "Would you care to comment on The Fat Duck interpretation of quantum chemistry."

He expanded later, with: The Fat Duck is a 3 star Michelin restaurant in the UK run by Heston Blumenthal, who is renowned for using the principles of chemistry in his menu design. Unfortunately he had to close down for a couple of weeks due to an outbreak of vomiting and diarrhoea, although the health inspectors gave his place the all clear.

I have met up with a Spanish equivalent, el Bulli. My son, Richard, gave me a megabook on a day in the life of el Bulli for Christmas.

I find it a cute idea but I can't afford to go to the restaurant and I can't afford the equipment needed to do a lot of it at home. They do things like use liquid nitrogen to freeze things. Fascinating but out of the reach of the home cook. There must be a few things I can do so that I can impress Richard; I have a dehydrator for example. (Watch this space.)

What really caught my attention was the comment by Chairman Bill that the UK restaurant had been closed due to food poisoning. It may well have been coincidental and nothing to do with the restaurant (that is often the case) but it does play to one of my food safety themes: be very wary of food prepared in non-traditional ways.

I will write more another day on the subject but most food is safe because we prepare it the way countless previous generations have prepared it. And survived. The problem is most people don't understand why this is the case and, in ignorance, try shortcuts.

With quite dire results, sometimes.

Grey Water

Anonymous said:

Not sure if this is up your alley, Lee, but I've heard you shouldn't put grey water (say water from the shower that might have a bit of soap and dead skin in it) onto plants that you intend to harvest for food later, like herbs or pumpkins. If this is your sort of area, what's the deal?

The issue is that the water has more than soap and skin. It will have faecal matter, no matter how well you have wiped your bum. Blunt but true. The same applies to laundry water that has been used to was undies etc.

Related to that is the issue that this bacteria will multiply if people store the water for any length of time. The resultant soup is smelly, slimey and a hazard to children.

The counter story, and there is always a counter story, is that the plants in the vegetable garden are routinely exposed to salmonella, ecoli and other such nasties from the wind, birds and insects. If normal hygienic practices are followed, there shouldn't be a problem.

Interspersed with all this bacterial culture is the litigious culture that abounds at present; no politician is going to say 'use your grey water on your vegetables' and then face the consequences of a potential food poisoning. Far safer, politically, to say don't use it.

Me? I used grey water on my raspberries; they are not in fruit until October so no problem and they survived the summer better than they ever have. A bit sunburnt but you can't help that with watering. I also used it on some rhubarb, knowing it would be comprehensively cooked and never eaten raw. I used grey water extensively around the main garden and on all the fruit trees.

Ideally, if you need to use grey water on vegetables, you should contour your garden beds so that you can water them by running the water down a ditch between rows so that it gets directly into the soil without touching the vegetables themselves.

Sunday, March 15, 2009

Chemists and Food


Chairman Bill asks: "My partner is a biochemist and maintains that if you're a half decent chemist, then you understand food and should be a natural cook (she is the best cook I've ever come across)." and "If chemistry was a compulsory subject at school, would people be more likely to tackle cooking?"

Well, my interests include chemistry and art. I take the view that cooking is where the two overlap. To my mind, art is the more important of the two - everything hinges on presentation.

To that end I only use white plates.

Food Additives


Courtney asked for my “thoughts on food additives in our diet. Specifically, what is your scientific and always logical take on artificial colors/dyes and preservatives in the food and their impact on behavior?”

The answer varies with the additive unfortunately.

Additives fall into a variety of categories but the first major split is into colours and others. Courtney specifically refers to colours, antioxidants and artificial sweeteners.

Colours are really for cosmetic purposes only and serve no useful purpose to the consumer. They can make pallid and insipid looking foods look more attractive (eg: adding yellow to pasta, cakes or ice-cream makes them look a richer colour, as if they have eggs in them.).

There is no doubt that colours are not necessary. They are an aesthetic additive.

Antioxidants (BHA, BHT, TBHQ)
These additives are generally added to oils and oil containing products to delay the onset of rancidity and extend shelf life; to this end they serve a useful purpose. As well as flavour deterioration, the by-products of rancidity, peroxides and acids, are considered to be harmful. This is where antioxidants have a problem: they are an additive but, unlike colours, they do serve a functional purpose. And this is where the regulators need to walk a fine line: the health risks of the additive vs the health risks of not using the additive.

Artificial Sweeteners
These are more insidious additives, in my mind. There is no denying that obesity is a growing problem (!) but is replacing sugar with something sweet but without calories the answer? It is not training people to enjoy unsweetened food but rather maintaining a need for a certain level of sweetness. Also people do false bargains with the devil when they say “I had a diet cola so I can have a chocolate bar”.

This is a fairly broad group of additives. Sulphur Dioxide is used very widely for different reasons. With the likes of sausages, they will not last a day raw without preservative (because you are seeding the minced raw meat with bacteria filled other components – flours, spices etc.). Dried fruit, such as apricots, go dark brown without preservative but will survive quite well without it IF they are properly dried. If they are kept still moist, (could they be being sold by weight?) yeasts can grow in them. Many soft drinks contain the preservative Benzoic Acid to prevent the growth of bacteria during storage. Again there is the issue of the health risks of using the additive vs the health risks of not using the additive.

At one level, it seems logical that manufacturers will not use additives unless they feel that they are needed in their food. Why incur an unnecessary cost? But reality is that the cost of the additive is not great and the ability of the manufacturers to control the amounts added is variable. Ultimately, as an insurance, they often use too muych rather than too little.

That was the easy bit.

“Are these additives harmful?” is a harder question. At some point everything is harmful. One grain of sand will bounce off you shoulder, a truck full dumped on you will smother you. Do additives impact on children’s behaviour? Quite possibly. There is the issue of causality though. This is something that I will probably come back to time and time again in this blog. Do colours make your child hyperactive? Or is it the sugars that are often present with the colours? Or something else altogether?

Ultimately it is something that must be decided on a case by case basis. If they affect your child, all the assurances of the ‘experts’ amount to nothing; they affect your child.

Post a Question

If you have some topic you would like me to post on, post it as a comment to this post and I will see what I can do.

Once I have posted on the topic, I will remove the comment so the comments will represent a 'to do' list for this blog.