Salt satisfaction

salt2Sodium serves a vital purpose in the human body as it helps nerves and muscles to function correctly, and it is an important compound involved in maintaining fluid balance. Most of our dietary sodium intake is provided through the consumption of sodium chloride (common or table salt). About 80 per cent of this would come from processed foods and 20 per cent from salt used at the table or in home cooking. Table salt is made up of just under 40 per cent sodium by weight, so a 6 g serving (1 teaspoon) contains about 2,400 mg of sodium (note that some of the calculations below use the more exact 39 per cent of sodium).

Apart from table salt, it has been estimated that a further ten per cent of dietary sodium intake would be provided from naturally occurring sodium or sodium-containing food additives.

So far so good, but unfortunately high intakes of sodium can increase blood pressure, and high blood pressure can increase the risk of developing heart and kidney problems. To limit the negative effects of consuming too much sodium the World Health Organization (WHO) recommends that daily sodium intake should not exceed 2,000 mg (equivalent to 5 g of salt).

Initial reassuring results for the Australian population

Estimates of salt intake is most often made using a 24 h diet recall methodology. Using this method, Food Standards Australia New Zealand (FSANZ) in 2008 estimated that daily intake of salt across all Australians was 5.5 g. This amount of salt would deliver an average of around 2,150 mg sodium per day. Taking into account non-salt sources of sodium and salt added by the consumer, FSANZ assumed a probable daily sodium intake of around 2,500 mg. Even if small reductions in sodium intake can lead to big health benefits, this was considered to be close enough to the WHO recommendations. However, because this is an average, there would be a lot of Australians who eat more than this and more than the recommended maximum intakes.

A repeat diet recall survey to update the estimate of mean daily salt intake was performed in 2011-12 through the Australian Health Survey (AHS) with slightly higher results at 6.2 g for the Australian population, equivalent to 2,404 mg of sodium. In this case the amount included sodium naturally present in foods as well as sodium added during processing, but excluded the discretionary salt added by consumers in home prepared foods or at the table. Adjusting for the latter might indicate a daily sodium intake of 2,600 mg per person, which is still only marginally higher than the WHO’s recommended maximum of 2,000 mg and therefore little cause for alarm.

But now for the bad news.

eat-less-saltNow new research shows that the dietary recall method used by the AHS and others likely substantially underestimate mean population salt consumption. The researchers suggested that Australians are consuming 50 per cent more salt than what was previously thought.

Researchers at George Institute for Global Health analysed the salt intake of 419 residents of Lithgow in NSW using two methodologies – the previous 24 h diet recall questionnaire but also 24 h urine samples. Based on the diet recall method, which was used by AHS, the average Lithgow resident consumed 6.8 g a day when including discretionary use. But based on 24 h urine collections, the researchers were able to conclude that the average was actually 9.0 g per day, equivalent to 3,545 mg of sodium. Correcting for salt lost through non-urinary excretion, the average was adjusted to 9.9 g per day or 3,900 mg of sodium.  This is almost double the WHO’s target for daily salt and sodium intake and suggests a several folds greater disease burden attributable to excess salt consumption in Australia.

The lesson

This is but one example of the challenges involved in estimating food intake. The 24 h recall method is considered superior to the food frequency questionnaire method so often used in epidemiological surveys. Still it showed a considerable bias. Again I suggest that epidemiological correlations between food intake and disease should be taken with a grain of salt (pun intended).

Rosemary benefits – believe it if you must

diet_(Christina_Roervik

Benefits of a balanced diet.

I might be a bit repetitive here, but allow me to be clear at the beginning of this blog. There are no magic individual foods.

Sure there are good and bad foods that might tilt your habitual diet towards being more beneficial or detrimental to health. But it is the overall balance that is most important for a healthy life.

With that caveat in mind, we are going to look at purported health effects of rosemary, a perennial woody herb.

The ageing population of Acciaroli

There’s a little village in Italy called Acciaroli that has been doing the rounds in the international press during 2016. The reason: an unusual number of the small southern Italian township’s population is over the age of 100. And they have the micro-circulation of significantly younger people. These are the small blood vessels that send nutrients to the brain and organs and pull out metabolic waste products, but which tend to deteriorate with age.

Could it be something about the air, the ocean, the mountains, the hills, the olive and berry trees?

Or maybe the food. Scientists found that at every meal they’re eating anchovies, and they eat them fried and greasy. Typically, that will be washed down with a glass or two of wine. Greasy anchovies and wine – maybe a little far fetched for supporting a long life.

What about rosemary? Well, research recently released showed the almost daily consumption of rosemary by the Acciaroli population – infused in the local olive oil, cooked in pasta dishes and chewed raw. And this habit has been linked to improved micro-circulation and a concomitant effect on longevity.

The benefits of rosemary

rosemary

Potential health impact of rosemary consumption.

The first benefit – rosemary tastes great. Italian cooking uses rosemary in abundance. It’s an easy and reliable herb to grow. A light prune once a year will keep the rosemary bush in shape. One plant will provide more than enough for regular use. It works in both savoury and sweet meals. Rosemary, along with roughly chopped garlic, onion, carrots and celery sautéed in olive oil and cooked, forms ‘soffrito’ – the basis for many different stocks, soups, sauces and other dishes.  It can also be used in desserts, like a panna cotta, with some grappa.

The second benefit – rosemary contains a number of phytochemicals, including rosmarinic acid, camphor, caffeic acid, ursolic acid, betulinic acid, and the antioxidants carnosic acid and carnosol. A lot to take in, but let’s focus on rosmarinic acid. Research has shown that it has a number of interesting biological activities, e.g. antiviral, antibacterial, antiinflammatory and antioxidant. The presence of rosmarinic acid in medicinal plants, herbs and spices has beneficial and health promoting effects. In plants, rosmarinic acid is supposed to act as a preformed constitutively accumulated defence compound. If you don’t like rosemary, rosmarinic acid can also be found in many other culinary herbs such as basil, lemon balm, marjoram, sage, thyme and peppermint.

The third benefit – it is also a good source of iron, calcium, and vitamin B6. Although as a herb it is consumed in such small amounts that this might not be important enough to influence health.

No harm done

Convinced yet? Maybe not and the researchers also kept an open mind. Further studies are underway to further explore the findings. But in the meantime there’s certainly no harm in increasing your consumption and use of rosemary or related herbs.

A bathtub of sugary soft drinks

bathtub

Consumption of sugar sweetened beverages equal a bathtub worth per year.

Can you believe it, when analysing data collected through the UK National Diet and Nutrition Survey, Cancer Research UK found that teenagers aged between 11 and 18 drink almost a bathtub full of sugary drinks on average in a year. To be more precise the average soft drink consumption for this group equalled 77L per year. That is actually a very small bathtub as they normally vary in size from 77L to say 170L. However, when taking a bath the water volume is most often just half that so drinking a bathtub of soft drinks per year is a fairly accurate estimate.

The figures shed light on the extreme sugar consumption of UK teenagers in that they eat and drink three times the recommended limit, with sugary drinks being their main source of added sugar. This contributes to the development of overweight and obesity and obese children are around five times more likely to grow into obese adults. The situation is similar in many other countries. Sales of sugar sweetened beverages in Australia equates to 75L per year for every adult and child, while overall consumption of sugar sweetened beverages per person in the USA has been estimated at 115L per year.

And on it goes. So what can be done?

Taxing sugar in soft drinks

In an effort to reduce the detrimental effects of consuming excessive volumes of sugary drinks, a tax has been suggested similar to the tax on tobacco. Several countries have already imposed a tax while others are in the process to do so.

Norway has had a generalised sugar tax on refined sugar products, including soft drinks, in more than 35 years. Hungary’s tax introduced in 2011 has seen 22% of people reduce energy drink consumption and 19% of people reduce their intake of sugary-sweetened soft drinks. France introduced a targeted tax on sugary drinks at a national level in 2012 and found that sales of soft drinks declined in the year following the introduction of the tax, following several years of annual growth. Annual sales of soft drinks in Mexico declined 6% in 2014 after the introduction of a tax in 2013.

South Africa, Ireland and the United Kingdom have all decided to introduce soft drink taxes in 2017-2018. The United States does not have a nation-wide soft drink tax, but a number of cities have or will soon introduce their own taxes. There has been a growing debate around taxing soft drinks in various cities, states and even in congress in recent years. This debate alone has raised awareness of the problem and soft drink consumption is on the way down.

Other countries are still debating the benefits of a sugar tax. In Australia there is an expert group proposal to introduce a tax of 40 cents per 100 grams of sugar, which would lift the price of a two-litre bottle of soft drink by about 80 cents.

What about diet beverages?

dietsodadrinker

Diet beverages might not be the solution to reduce the incidence of obesity.

The reduction in the consumption of sugar sweetened beverages is all good if it is replaced by water. But what about diet beverages? Sugar substitutes like aspartame are supposed to promote weight loss, but a number of clinical and epidemiologic studies have suggested that these products don’t work very well and may actually make things worse. This is quite confusing as energy intake is reduced. However, there has been some evidence that artificial sweeteners actually can make you more hungry and thus may be associated with increased energy consumption.

Now a research team has found a possible mechanism explaining why use of the sugar substitute aspartame might not promote weight loss. Their report show how the aspartame breakdown product phenylalanine blocks a gut enzyme called intestinal alkaline phosphatase (IAP). And IAP is normally protective in that it has been shown to prevent obesity, diabetes and metabolic syndrome.

The researchers also showed that mice receiving aspartame in their drinking water gained more weight, had higher blood sugar levels, which indicates glucose intolerance, and higher levels of the inflammatory protein TNF-alpha in their blood, which suggests the kind of systemic inflammation associated with metabolic syndrome.

So what to do?

It is quite clear that just a debate around the detrimental effects of excessive consumption of sugar sweetened beverages can have an effect. Add to that an increase in the price and the benefits are obvious as shown already in several countries.

But it is equally important that the new choice of beverage doesn’t add to the problem. The use of artificial sweeteners might not be as innocent as could be expected.

A teaspoon of horseradish

Horseradish

Horseradish another superfood if you believe there are such foods.

Here we go again, another superfood. This time with cancer fighting properties. And the scientists say that a teaspoon is enough to achieve the beneficial effects. So what’s not to like?

Well, the pungent aroma and the bitter taste of the food in the first place. We are talking about glucosinolates found in a range of cruciferous vegetables, but in horseradish in particular.

And when the glucosinolates are activated some of the resulting compounds have proven to be protective against cancer. And that we like.

A bit of background

Glucosinolates are natural components of many pungent plants such as mustard, broccoli, cabbage, and yes horseradish. About 132 different glucosinolates are known to occur naturally in plants. As is common, these natural chemicals contribute to a plant’s defence against pests and diseases.

The pungent taste of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damaged. The plants contain the enzyme myrosinase that is released during chewing and transforms the glucosinolate into mainly isothiocyanate (mustard oil), the active form. The myrosinase and glucosinolates are stored in separate compartments of the plant cells so not to damage the plant itself until chewed.

Glucosinolate type and quantity vary depending on the plant variety, although closely related taxonomic groups typically contain only a small number of the different compounds. Many reviews have addressed the occurrence of some glucosinolates in vegetables with a major focus on negative aspects, like antinutritional or goitrogenic effects. However, there is a positive side now getting increased attention represented by beneficial health properties of some other glucosinolates.

So what are the health benefits?

The metabolic activation of glucosinolates results in the formation of isothiocyanates that in turn have been found to inhibit the development of cancer in several organs in rats and mice, including the bladder, breast, colon, liver, lung, and stomach. Also human epidemiological studies suggest that isothiocyanates are protective against cancers of the lungs and alimentary tract. Studies in animals and experiments with cells grown in the laboratory have identified several potential ways in which these compounds may help prevent cancer by:

  • protecting cells from DNA damage
  • inactivating carcinogens
  • having antiviral and antibacterial effects
  • having anti-inflammatory effects
  • inducing cell death (apoptosis)
  • inhibiting tumor blood vessel formation and tumor metastases.

And now a research team has studied the effects of the glucosinolates present in horseradish. The researchers found different concentrations of allyl isothiocyanate (AITC) and  1-cyano 2,3-epithiopropane (CETP) depending on the horseradish variety. And AITC is the one you want. The team suggests that AITC is a good dietary anti-carcinogen, not only because it activates the enzyme responsible for detoxifying cancer-causing molecules, but also because a large proportion of it, 90%, is absorbed when ingested.

Getting sufficient protection

horseradish-prepared

A teaspoon of horseradish is beneficial to health.

Eating 3–4 portions of broccoli per week has previously been shown to provide a protective effects against certain cancers.

And now the researchers showed that horseradish contains approximately 10 times more glucosinolates than its superfood cousin, broccoli.

So your choice. You can eat 3-4 teaspoons of horseradish a week if you can stomach it, or you can replace each teaspoon by a portion of broccoli if that is more appetising. Or a range of other cruciferous vegetables.

2015 in review

The WordPress.com stats helper monkeys prepared a 2015 annual report for this blog.

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 13,000 times in 2015. If it were a concert at Sydney Opera House, it would take about 5 sold-out performances for that many people to see it.

Click here to see the complete report.

2014 in review

The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog.

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 12,000 times in 2014. If it were a concert at Sydney Opera House, it would take about 4 sold-out performances for that many people to see it.

Click here to see the complete report.

Energy burning brown fat

The painful way of forming brown fat (Photo: Pavel Trebukov)

The painful way of forming brown fat (Photo: Pavel Trebukov)

You’re out there freezing (assuming you live in the Northern Hemisphere, here in Australia it’s summer). You’re shivering and actually feel some warmth. It is your muscles burning off energy to warm you up a little bit. But what you don’t know is that at the same time the muscles release irisin. The irisin goes straight to your white fat cells and some are gradually transformed into brown fat cells and activated. And the brown fat cells burn energy rather than storing it relieving the muscles from some shivering activity. Clever don’t you think?

Some puzzling findings

But let’s take a step back. Babies are actually born with a supply of brown fat in the neck region. This is nature’s way of helping infants to keep warm by burning energy when needed. When growing up the brown fat disappears. Or so it was thought. But brown fat has been rediscovered in adulthood in the same neck region. Now a new study suggests that shivering and moderate exercise are equally capable of stimulating the conversion of energy-storing white fat into energy-burning brown fat. Around 50 g of white fat stores more than 300 kilocalories of energy. The same amount of brown fat could burn up to 300 kilocalories a day. Quite a difference. There are a few puzzling findings here. It makes sense for shivering to produce and activate brown fat to help in the process of keeping warm. But the communication between muscle and fat through the irisin hormone to achieve this is quite astonishing. Even more surprising is the fact that exercise can achieve the same result. It is not intuitive since exercise produces heat. It is speculated that muscle contractions during exercising mimic shivering and thus achieve a similar effect. The scientists found that around 10-15 minutes of shivering resulted in equivalent rises in irisin as an hour of moderate exercise. Just be aware that it might take up to a week for the brown fat to be fully developed.

The facts about brown fat

The less painful way of forming brown fat (Photo: Steve Garner)

The less painful way of forming brown fat (Photo: Steve Garner)

We now know that brown fat is present in most, if not all, adults. Adults with more brown fat are slimmer than those without. When we are cold, we first activate our brown fat because it burns energy and releases heat to protect us. When that energy is insufficient, muscle contracts to produce shivering, thereby generating further heat. The brown fat can provide around 20% of the heat needed, representing a proportion of total energy expenditure sufficient to impact the body’s long-term energy balance. There is excitement in the brown fat field because its energy-burning capacity makes it a potential target to combat obesity. Glucose levels are also lower in humans with more brown fat, potentially providing protection against diabetes.

Your daily treat

So there you have the food connection. As long as you regularly exercise for about an hour or, if you prefer, spend 10-15 minutes in a cold room at 12-14˚C you can have your daily ice cream without putting on weight. I know what I prefer to do.

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Taking stock of a year of blog posts

We have now been blogging for more than a year and published 70 blogs on a range of food safety topics. I have started to lose track of all the blogs and thought it was about time for both you and me to list them all to jog our memories. Thus you can now find a list of blogs in the top most menu.

Blogging efforts (Illustration: Francesco Pozzi)

Blogging efforts (Illustration: Francesco Pozzi)

So far we have been sparse with coverage of bad bugs with only 4 published blogs. This is of course an important food safety topic but covered extensively by many others.

Bad bugs not extensively covered (Photo: Wikimedia)

Bad bugs not extensively covered (Photo: Wikimedia)

Dangerous foods and not so dangerous foods have been more fun to write about. This has resulted in 21 blogs published so far and this seems to be the most popular topic on this website. Rucola and coffee-leaf tea have been the most visited topics. Kale received the most comments both on the blog and in private emails.

Rucola received a lot of interest

Rucola received a lot of interest

Debated additives have also received limited coverage with only 5 published blogs. Additives are often high up on the public risk list but are in most cases strictly regulated. Aspartame has been covered in several blogs but has now received a conclusive opinion by EFSA. If that will prove sufficient is still to be seen.

Aspartame and additive debated a lot

Aspartame and additive debated a lot

Nasty chemicals is an area close to my heart and this has resulted in 24 blogs published so far. Sometimes these blogs can cover quite complex issues difficult to digest. Most official opinions are difficult to read so I have attempted to simplify the issues without compromising on the science. Not an easy task but you be the judge if I have been successful.

Infant development

Juvenile brain development can be hampered by lead contamination

There has been a lot of activity in relation to health claims assessment in Europe with new legislation enforced. Here we have covered what we have called spurious health claims in 16 blogs. Some have been valid claims, some still not proven, but many just old tradition.

Healthy kale (Photo: Mike)

Healthy kale (Photo: Mike)

I would be happy to take requests for new blog topics, just add a comment in the bottom of this blog.

With this summary it is time to celebrate the festive season and take a break from blogging. We will come back in the new year with renewed vigour.

Many thanks for your interest and please come back many times.