New liquorice warnings

liquorice_candy_(US_Government)

Liquorice is a popular sweetener found in many soft drinks, food products, snacks and herbal medicines. It has a rich history as an old remedy that was used by ancient Egyptians and Assyrians made into a sweet liquid drink. There is a traditional belief that liquorice is a healthy natural substance without side effects driving its liberal consumption that can occasionally be hazardous.

If you have followed this blog for a while you might remember that we have covered the good and the bad of liquorice before. Now we also cover the ugly.

The good

Liquorice is extracted from the roots of the plant Glycyrrhiza glabra, a member of the pea family. Most liquorice roots are wild-harvested with collection occurring mainly in Central Asia (Iran, Turkmenistan, Afghanistan and China). Liquorice extract is produced by boiling liquorice root and subsequently evaporating most of the water. Large-scale extraction is limited to China and Iran. Glycyrrhizin, that is 50 times sweeter than sugar, is the main active component in liquorice extract and apart from sweetness also provides the desirable liquorice flavour. Moderate consumption of liquorice is associated with several health benefits in that it can quickly soothe sore throats and coughs among some other positive effects.

The bad

Unfortunately, it has long been known that excessive and prolonged consumption of glycyrrhizin intensifies the effects of the stress hormone cortisol by inhibiting the enzyme that inactivates cortisol and may interfere with the sodium and potassium balance. High levels may increase hypertension. Thus, it has been suggested to limit consumption of glycyrrhizin to 100 mg per day, the approximate amount found in 60–70 g of liquorice candy. However, it is not that easy to estimate intake of glycyrrhizin as various forms of candies, beverages, supplements and extracts contain very different amounts of the active components.

The ugly

Pregnant womenRecently new warnings were issued by the Finnish National Institute for Health and Welfare to women to avoid consuming large amounts of liquorice during pregnancy as it can have long-term harmful effects on the development of the foetus. A new Finnish study had shown that youths previously exposed to large amounts of liquorice in the womb performed less well than others in cognitive reasoning tests carried out by a psychologist. The difference was equivalent to approximately seven IQ points.

Those exposed to liquorice also performed less well in tasks measuring memory capacity, and according to parental estimates, they had more ADHD-type problems than others. With girls, puberty had started earlier and advanced further.

In this study a large amount was defined as daily consumption of more than 70 mg and compared to consumption of less than 35 mg glycyrrhizin.

The lesson

Although cortisol is essential to the development of a foetus, large increases initiated by excessive consumption of liquorice can be detrimental.

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Known impossibles

There are a number of known knowns say food safety types and they insist that we follow their sometimes impracticable or impossible advice. But is scientific opinion always right?

Impossible hand washing advice

handwash_(Marmotto)

The ever important hand wash (Photo: Marmotto)

They want us to wash our hands for an impossible 20 seconds. It doesn’t sound much but you stand there with cold hands since it might take more than 20 seconds for the warm water to flow through the long pipe.

Well, Health Canada is a little more sensible reducing the washing time to 15 seconds but insisting it should be warm water. However, contrary to popular belief scientific studies have shown that using warm instead of cold water has no effect on reducing the microbial load on hands. Scientific results also show that soap is more effective than water only and drying with a paper towel is preferable to using hand driers for removing the bugs on your hands.

So the practical recommendation? Above all wash your hands before preparing food with a method you feel comfortable with.

Impossible fruit and vegetable advice

They want us to eat 2 portions of fruits and 5-6 portions of vegetables per day. Translated to weight that would be 300 grams of fruit and 450 grams of vegetables or a full 750 grams in total on a daily basis. Are they mad, there will be no place for anything else.

However, to be fair a meta study showed that a diet with more than five servings of fruit and vegetables reduces a person’s risk of developing conditions such as heart disease and diabetes. But according to the Australian Bureau of Statistics, in 2014-15, while half of Australians aged 18 years and over met the guidelines for recommended daily serves of fruit (2 or more serves), only 7% met the guidelines for serves of vegetables (5-6 or more serves). A paltry one in twenty adults met both guidelines.

See what I am saying? And the situation is similar in many other countries. So the practical recommendation? Sure, try to increase your consumption of fruit and vegetables. An extra leaf of lettuce and a tomato on your lunch sandwich might help.

Impossible rule change for dropped food

chocolate_cake

A dropped slice of chocolate cake might be rescued.

And now we cannot follow the 5-second rule any longer, that is if you drop a piece of food on the floor but pick it up within 5 seconds you are safe to still eat it. What a waste of food. Just imagine you drop a nice slice of chocolate cake on the floor but pick it up immediately before the dog can take it and you still have to throw it away. No way I would say and by the way chocolate is dangerous for dogs so you have to be quick anyway.

Though scientists have backed up the new advice. They experimented with different food and contact surface types and concluded that the 5-second rule is a significant oversimplification of what actually happens when bacteria transfer from a surface to food. Bacteria can actually contaminate the food instantaneously. The scientists demonstrated that the 5-second rule was relevant in the sense that longer contact time resulted in more bacterial transfer, but factors like the nature of the food and the surface it falls on are of equal or greater importance.

And the practical recommendation? Obviously it doesn’t help to be quick, the bugs will still beat you. But you might wash off a hard surface and scrape off a little bit of the chocolate cake before eating the rest. If the food is still to be heated there is no problem. But a buttered sandwich surface down might be best to put in the garbage bin.

Impossible fiddling with temperature probes

They also say that when you prepare your hamburgers you cannot rely on your visual senses anymore. That is colour, firmness and smell are not considered sufficient. You have to use a digital thermometer and make sure that the centre of the hamburger reaches 71ºC. You have to fiddle with the thermometer tip sticking it into the side of the burger to reach all the way to the middle while at the same time avoiding getting your fingers burnt. And you have to do it for each burger separately.

Scientists explain that heat-induced denaturation of myoglobin, responsible for the characteristic dull-brown colour of cooked meats, is influenced by a multitude of factors. The interactions between these factors critically influence the internal cooked colour and can confuse the consumers who often wrongly perceive cooked colour to be a reliable indicator for doneness and safety. But there are some hope. Another scientific study agreed that colour alone was a misleading guide for the core temperature of a hamburger. However, when including texture of the meat and clarity of the meat juice in the judgement the situation improved.

And the practical recommendation? It might pay off to invest in a meat thermometer but once familiar with the cooking time needed to reach the recommended core temperature a bit more flexibility might be possible. As long as you promise to not eat rare or medium-rare hamburgers.

Impossible cross-contamination prevention

cutting-board

Use different cutting boards to avoid cross-contamination. 

And there’s more. You are not allowed to keep the same cutting board and utensils you just used to cut your raw chicken for subsequently preparing your vegetables to eat without further heating. Come on, the food will be cold before you have done all the washing up.

Well, I am sorry to say that scientists are unequivocal on this point. You just have to use different utensils for raw and cooked meat and utensils that have been in contact with raw meat can never be used for produce that will be consumed without further heating.

Known unknowns and unknown unknowns

For all the food safety rules for known knowns, there is little said for the known unknowns that we might worry more about.

What about the bisphenol A in our food packaging material and cash register receipts? There have been several reports of damaging endocrine effects on unborn babies, but this science is still controversial so you’re on your own on this one.

And of course nothing can be said about unknown unknowns.

Acrylamide, a carcinogen, has been present in some heated foods since time memorial following the invention of fire. But it was not until the late 20th century that it was detected by a coincidence. Since then there have been many attempts to reduce its presence in food.

What else is lurking around? That is impossible to say so better relax. Overall, a balanced diet is the best protection for a healthy life. Stay sufficiently safe to stay healthy might be the best motto!

Ordinary salt a killer, or not!

Excess sodium can cause heart disease (Photo: Wolf Soul)

Excess sodium can cause cardiovascular disease (Photo: Wolf Soul)

Some simple facts:

  • Cardiovascular disease is the number one cause of death in the world
  • Excess sodium intake raises blood pressure
  • High blood pressure is one of the major contributors to the development of cardiovascular disease

Research just published modelling populations across 187 countries attributed more than 1.6 million cardiovascular-related deaths per year to sodium consumption above the World Health Organization’s recommendation of a maximum of 2.0 g per day.

The details of the study

The researchers collected and analysed existing data from 205 surveys of sodium intake in countries representing nearly three-quarters of the world’s adult population, in combination with other global nutrition data, to calculate sodium intakes worldwide by country, age, and sex.

The researchers found the average level of global sodium consumption in 2010 to be 3.95 g per day, nearly double the 2.0 g recommended by the World Health Organization. All regions of the world were above recommended levels, with regional averages ranging from 2.2 g per day in sub-Saharan Africa to 5.5 g per day in Central Asia.

The proportion of deaths from heart attacks and strokes attributable to sodium ranged quite a bit. In Canada, the United States, Australia and New Zealand, about 10% of cardiovascular deaths were linked to high salt intake. But in a wide band stretching from Eastern Europe all the way across into Central Asia and East Asia, the percentage of cardiovascular deaths attributed to sodium consumption jumped up to 20 to 25%. This happens to be the Old Silk Road, where people traveled vast distances on trade missions and needed salt to preserve their food. This tradition of eating salt-preserved foods has survived to our days.

The researchers found that reduced sodium intake lowered blood pressure in all adults, with the largest effects identified among older individuals, blacks, and those with pre-existing high blood pressure. They stated that because the study focused on cardiovascular deaths, the findings may not reflect the full health impact of sodium intake, which is also linked to higher risk of nonfatal cardiovascular diseases, kidney disease and stomach cancer, the second most-deadly cancer worldwide.

So that’s settled then, is it? Doom and gloom, since limiting salt consumption is difficult given that 80% of a person’s daily salt intake comes from the foods they eat, rather than the salt shaker.

Not so fast!

On the contrary, another recent study suggests that many dietary guidelines for sodium intake are unrealistic, and that the low recommended level of sodium could be associated with a higher risk of cardiac disease and mortality.

Although it has long been the view that eating too much salt will raise your blood pressure, a comprehensive global study now says that too little salt in your diet also can harm your heart health. There appears to be a “sweet spot” for daily sodium intake between 3 and 6 g (equal to 7.5 to 15 g of salt) associated with a lower risk of death and heart disease than either more or less.

The study included more than 100,000 adults from the general populations of 17 countries, providing a broad sample of people that varied greatly in socioeconomic, geographic and demographic makeup. The study found that those who consumed more than 6 g of sodium daily had higher blood pressures than those who consumed less sodium. Within this group, blood pressure increased with higher sodium intakes. The effect of dietary sodium intake on blood pressure was less dramatic for those in the medium (3 to 6 g) range of sodium intake and none for those in the low range of sodium intake (less than 3 g). However, sodium intake of less than 3 g per day was tied to a 27 percent increased risk of death and heart disease, according to their findings.

The study thus provided evidence that both high and low levels of sodium intake may be associated with an increased risk of death and cardiovascular disease and that healthy people probably can eat about twice the amount of salt compared to what is currently recommended — or about as much as most people consume anyway. Since only one in 20 people in the world currently eat what is recommended, it’s not a very practical recommendation.

The good news

Potassium in bananas can counter effects of sodium (Photo: Branko Collin)

Potassium in bananas can counter effects of sodium (Photo: Branko Collin)

But there is more. Before you start to worry too much about a futile effort of counting your exact intake of sodium think potassium. The study provided new evidence about the association of sodium and potassium intake with blood pressure, death and major cardiovascular events. It showed that consuming larger amounts of potassium counterbalanced the adverse effect of high sodium excretion on blood pressure. Potassium is a nutrient found in fruits, vegetables and beans. Rather than focusing on sodium, maybe it is better to focus on eating an overall healthy diet and pursuing healthy lifestyle changes.

It is probably safe to say that if you don’t already have high blood pressure and you’re not over 60 or eating way too much salt, salt won’t have much impact on your blood pressure.

But this is controversial news that could potentially undercut current public health messages about salt. It will take some further time before scientists can agree on the way forward.

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Italy at it again – identifying your taste profile

Your genes might ask for Russian caviar (Photo: Kai Hendry)

Your genes might ask for Russian caviar (Photo: Kai Hendry)

It’s all in the genes, even your food preferences. And you thought that your food choices were due to your degree of sophistication or financial situation. No, you can only hope that your genetic setup doesn’t require that you survive on Australian rock lobsters, Russian caviar and French champagne. Better your cravings demand Swedish meatballs, German bratwurst and Czech beer to lighten your financial burden.

In the future you will be able to blame your Mum and Dad for your food bias and not the school lunch program insisting that you eat up the fish balls in white sauce that were so disgusting that you had to swallow them whole. You just didn’t have the fish ball gene that seems to be so common among our Norwegian friends. Sorry for digressing here, but did you know that in Norway they even have a fish-based dessert? Yes, probably genes again.

And this new information is based on the findings of Italian scientists from the University of Trieste and the IRCCS Burlo Garofolo Institute for Maternal and Child Health. They have been busy identifying  genes and pathways involved in taste perception and food choice and to check their impact on diet-related disorders such as overweight, obesity, and diabetes. Most previous studies have focused on specific taste receptors, especially bitter ones, in an attempt to understand the genetics behind the perception of specific compounds such as caffeine and quinine. The new study covered the whole genome, with the aim of identifying specific genes that drive individual differences in taste perception and food preferences.

The scientists undertook genome wide association studies to try to unravel the genetic basis for certain food preferences. Over two thousand Italian subjects participated in the discovery step, and another couple of thousand from other European countries and from Central Asia were used in order to further verify the findings.

The dark chocolate gene found

Amazingly, the scientists uncovered 17 independent genes related to liking for certain foods, including artichokes, bacon, coffee, chicory, dark chocolate, blue cheese, ice cream, liver, oil or butter on bread, orange juice, plain yoghurt, white wine and mushrooms. Surprisingly, none of the genes identified so far belonged to the category of taste or smell receptors.

There is still much to be done at the detailed level. Although they identified the gene for white wine liking, they still have no idea which of the characteristics of white wine that the gene sought out. It might have been the oaky flavour of a Barossa Valley Chardonnay, or the tropical fruit aroma of a New Zealand Sauvignon Blanc. Who knows?

Salt replacements might be identified by gene testing (Photo: Travis Forsyth)

Salt replacements might be identified by gene testing (Photo: Travis Forsyth)

They also identified the gene sequence responsible for preferring salty foods. Salt perception and the related genetic variation in taste receptors are important determinants of individual differences in salt intake, which in turn represents an important risk factor for the development of hypertension and cardiovascular diseases. Such information could play an important role in the development of salt substitutes, in which there is a growing commercial interest.

Nutritional intervention could be greatly improved by tailoring it to the food preferences of each person. In a related study the gene knowledge was used to personalise diets for some of 191 obese individuals that were trying to lose weight. Half of the group was put on a standard weight-loss diet subtracting 600 calories from individual nutritional needs. The diet of the other half was modified according to the individual genetic profiles. Although there were no significant differences in age, sex and BMI between the two groups at the beginning of the trial, participants in the group with the gene-based diet lost 33% more weight than the other group over two years, and the percentage of lean body mass also increased more.

Diets based on individual genetic profiles

The ability to devise diets based on individual genetic profiles could lead to significantly better personalised nutrition plans effective not just for weight loss but also in avoiding diseases such as cancer, depression, and hypertension. Knowing why individuals prefer certain food tastes and being able to personalise health interventions based on them will help people age in a healthier way and greatly improve their quality of life, as well as engender considerable savings for health systems.

Of course the gene finding is just one part of the complexity of dietary patterns. Just the other day advice on how to get children to increase their vegetable consumption was published. By gradually increasing variety it was possible to train young children to like vegetables, but possibly not Brussels sprouts. Even the Italian scientists pointed out that further studies will be important for understanding the interaction between the environment, lifestyles, and the genome in determining health outcomes.

So Swedish meatballs with French champagne might not be your preferred combination even if your genes insist. Unless you’re born in Sweden.

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Think zinc

Numerous children die of zinc deficiency (Photo: Nina Matthews)

Numerous children die of zinc deficiency (Photo: Nina Matthews)

When you think zinc I want you to think of zinc deficiency that has been estimated to cause more than 450,000 deaths in children under the age of five annually. Of course this is a bit of a rubbery figure estimated based on zinc availability in the diet and childhood stunting rates in Latin America, Africa and Asia where zinc deficiency is widespread. But even half of that should be serious enough to raise your concerns.

It is actually currently recognised that milder zinc deficiency contributes to a number of health problems, especially common in children who live in developing countries. An estimated two billion people worldwide are affected by dietary zinc deficiency. Controlled trials of moderate zinc supplementation have demonstrated that marginal zinc deficiency contributes to impaired physical and mental development and increased susceptibility to life-threatening infections in young children.

So what is so important with zinc?

As it happens, zinc is required for the catalytic activity of almost 100 enzymes, not bad even for an essential mineral. This way zinc is involved in numerous aspects of cell metabolism.  It plays a role in immune function, protein synthesis, wound healing, DNA synthesis, and cell division. Zinc also supports normal growth and development during pregnancy, childhood, and adolescence and is required for proper sense of taste and smell.

Consequently, human zinc deficiency symptoms include retarded growth, depressed immune function, skin lesions, skeletal abnormalities, impaired reproductive ability and behavioural abnormalities such as changes in mood, loss of affect and emotional lability, anorexia, dysfunction of smell and taste, irritability and depression.

Sounds quite serious, but do you need to worry?

Zinc (green here) is an essential part of many enzymes (Illustration: Wikimedia)

Zinc (green here) is an essential part of many enzymes (Illustration: Wikimedia)

Probably not for the general population the European Food Safety Authority said, but be aware that a daily intake of zinc is required to maintain a steady state because the body has no specialised zinc storage system. And American experts claim that about 40% of elderly Americans have diets that are deficient in this important, but often underappreciated micronutrient. Makes you wonder what the difference is between Americans and Europeans, they can’t both be right.

The good thing is that zinc is naturally present in a variety of foods and added to others. Although oysters contain more zinc per serving than any other food, red meat and poultry provide the majority of zinc in the Western diet. Other good food sources include beans, nuts, certain types of seafood (such as crab and lobster), whole grains, fortified breakfast cereals, and dairy products.

But there is a catch. Phytates, which are present in whole-grain breads, cereals, legumes, and other foods that are all supposed to be healthy, bind zinc and inhibit its absorption. Thus, the bioavailability of zinc from grains and plant foods is lower than that from animal foods, although many grain- and plant-based foods are still good sources of zinc.

That is in the developed world

The situation is completely different in the developing world as we indicated above. Zinc deficiency is common in Southeast Asia, sub-Saharan Africa, and parts of Latin America. It affects more than 1 in 6 people worldwide and contributes to an estimated 1 in 58 deaths in children younger than 5 years. And it is all because of the crops that constitute the major part of the diet in the developing world.

Almost half of the world’s cereal crops are deficient in zinc. Many agricultural countries around the world are affected by zinc deficiencies. In China, around half of the agricultural soils are zinc deficient, affecting mainly rice and maize. Similarly in India and Turkey, zinc-deficient soils occupy almost 50% of the agricultural area and impact wheat yield.

Zinc containing fertilisers the solution

Where zinc deficiency is a limiting factor, zinc supplements can increase crop yields. Balanced crop nutrition supplying all essential nutrients, including zinc, is a cost effective management strategy. Even with zinc-efficient varieties, zinc fertilisers are needed when the available zinc in the topsoil becomes depleted. Zinc sulphate is easily added to agricultural soil and taken up by most crops, which benefit from the zinc.

Adding zinc to fertilisers provide a double whammy. Cadmium and zinc are similar in their function in the human body. Cadmium may actually displace zinc in some of its important enzymatic and organ functions interfering with these functions or preventing them from being completed. The zinc:cadmium ratio is very important, as cadmium toxicity and storage are greatly increased with zinc deficiency, and good levels of zinc protect against tissue damage by cadmium. The refinement of grains reduces the zinc:cadmium ratio, so zinc deficiency and cadmium toxicity are more likely when the diet is high in refined grains and flours.

So, what should you do?

Food rich in zinc (Photo: Wikimedia)

Food rich in zinc (Photo: Wikimedia)

The best way to get zinc is through food. Red meat, like beef and lamb, and seafood are good sources of zinc. However, since such sources are not affordable in many parts of the world, the global solution is to start to incorporate zinc in fertilisers used for growing crops in zinc deficient soils. But the question is how to get farmers to pay for this. It might pay off to also make sure that the diet contains enough selenium. It’s responsible for regulating the delivery of zinc to zinc enzymes throughout the body for proper zinc metabolism. Seafood, eggs and Brazil nuts are particularly good sources of selenium.

If you’re into vigorous exercise you should be aware that excessive sweating depletes zinc. You may need to account for sweating by eating more zinc.

I am not normally a proponent of food supplements. However, in countries where zinc deficiency is common, supplements may help to reduce child deaths and related diseases in the short-term. And maybe for certain age groups also in other countries. But remember that supplements are not a substitute for a well-balanced diet and the more the better doesn’t apply. Zinc toxicity can occur in both acute and chronic forms if consuming too much of a zinc supplement. Acute adverse effects of high zinc intake include nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, and headaches. So caution is recommended.

The issue might become worse in the future

And just to sharpen your mind, be aware that rising carbon dioxide emissions are set to make the world’s staple food crops less nutritious, according to new scientific research, worsening the serious ill health already suffered by billions of malnourished people. Field trials of wheat, rice, maize and soybeans show that higher carbon dioxide levels significantly reduce the levels of the essential nutrients iron and zinc, as well as cutting protein levels.

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The Mediterranean diet unfolded

Mediterranean diet with plenty of vegetables (Photo: Maria Pontiki)

Mediterranean diet with plenty of vegetables (Photo: Maria Pontiki)

Time to put some nuts in your salad or why not a dollop of olive oil. This is now supposed to be the secret combination explaining the beneficial effects of the Mediterranean diet. This diet, recognised as an “Intangible Cultural Heritage” by UNESCO in December 2013, was originally inspired by the traditional dietary patterns of Spain, Morocco, Italy, Greece, Portugal, Cyprus and Croatia. Well, Portugal might be a bit of a stretch and most of Morocco, but the rest of the countries are situated around the Mediterranean Sea, thus the name.

The Mediterranean diet is based on the paradox that, although the people living in Mediterranean countries tend to consume relatively high amounts of fat, they have far lower rates of cardiovascular disease than in countries like the United States with similar levels of fat consumption. The important components of this diet include proportionally high consumption of olive oil, legumes, unrefined cereals, fruits, and vegetables, moderate to high consumption of fish, moderate consumption of cheese and yoghurt, moderate wine consumption, and low consumption of meat and meat products.

What about olive oil and red wine?

The Mediterranean diet has often been cited as beneficial for being low in saturated fat and high in monounsaturated fat and dietary fibre. One of the main explanations is thought to be the health effects of olive oil included in the Mediterranean diet. It contains a very high level of monounsaturated fats, most notably oleic acid, which epidemiological studies suggest may be linked to a reduction in coronary heart disease risk. The inclusion of red wine has also been considered a factor contributing to health as it contains flavonoids with powerful antioxidant properties.

Studies have shown that a Mediterranean diet appears to be more effective than a low-fat diet in lowering cardiovascular risk factors, such as cholesterol and blood pressure, thereby lowering the rate of early deaths by more than 50 per cent.  One study reported that the Mediterranean diet reduced the risk of heart disease in people at high risk by about 30 per cent when compared with individuals on just a low fat diet. Sounds marvellous, doesn’t it?

Now before we go overboard here, let’s make it clear that not all people around the Mediterranean adhere to this diet. In Northern Italy, lard and butter are commonly used in cooking, and olive oil is reserved for dressing salads and cooked vegetables. In both North Africa and the Middle East, sheep’s tail fat and rendered butter are the traditional staple fats. In Egypt, Malta, and Israel, olive oil consumption is negligible. And on top of that, the most popular dietary candidate, olive oil, has been undermined by findings that diets enriched in monounsaturated fats such as olive oil are not atheroprotective when compared to diets enriched in either polyunsaturated or even saturated fats. So what’s going on here?

Nitro fatty acids lower blood pressure (Photo: Illuminati Owl)

Nitro fatty acids lower blood pressure (Photo: Illuminati Owl)

Nitro fatty acids explains the benefits

The answer now seems to be the formation of nitro fatty acids. A diet that combines unsaturated fats found in olive oil, nuts and avocados, along with vegetables like lettuce, spinach, celery and carrots that are rich in nitrates and indirectly nitrites can reduce blood pressure, suggests a new study led by King’s College London. When these two food groups are combined, the reaction of unsaturated fatty acids with nitrogen compounds in the vegetables results in the formation of nitro fatty acids. Studies in two types of mice showed that nitro fatty acids lower blood pressure by inhibiting an enzyme known as soluble Epoxide Hydrolase which regulates blood pressure.

So now you know why a diet supplemented with extra-virgin olive oil or nuts can reduce the incidence of cardiovascular problems like stroke, heart failure and heart attacks.

Time to indulge!

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Survival of the fishiest

Daily cod liver oil of the past (Credit:

Daily cod liver oil of the past (Credit: Caroline)

I was brought up on a spoonful of cod liver oil a day, not sure if that did any good at the time though. I remember I didn’t like it, not that I had much of a say. I have since resisted all overtures to take a daily omega-3 fish oil capsule, although I have praised them in previous blog posts. The science seemed to be clear, omega-3 fatty acid supplements looked to be one of the few supplements with a real health benefit. Now I take all this back.

I know, nutritional science is confusing and nutritionists seem to change their recommendations regularly. One day a green capsule a day of some obscure substance is a must and a red tablet should be avoided. The next day it is the opposite. What is an ordinary person to do? Well, at least it creates more work for nutritionists (and EFSA’s Panel on Dietetic Products, Nutrition and Allergies) and some fodder for sensationalising newspaper articles.

Eskimo diet hypothesis proven wrong

As it happens, the current recommendation to eat more oily fish as part of a heart healthy diet has mainly been based on a landmark study from the 1970s by two Danish investigators, Bang and Dyerberg. They had been told that the Greenland Eskimos had a low prevalence of coronary artery disease and set out to study their diet. They described the Eskimo diet as consisting of large amounts of seal and whale blubber (i.e. fats of marine animal origin) and suggested that this diet was a key factor in the alleged low incidence of coronary heart disease. This started an avalanche of studies that focused on the cardioprotective effects of the Eskimo diet and created an industry around fish oil supplements containing omega-3 fatty acids.

Building on 40 years of new research since the Danish findings, a team of scientists recently conducted a review of the resulting literature to examine whether mortality and morbidity due to coronary artery disease are indeed lower in the Eskimo population compared to their Caucasian counterparts. Most studies reported that the Greenland Eskimos as well as the Canadian and Alaskan Inuit had coronary artery disease as often as the non-Eskimo/Inuit populations.

Unfortunately, Bang and Dyerberg’s studies from the 1970s failed to actually investigate the cardiovascular health of the the Eskimo population, and as a result the cardioprotective effects of their dietary findings were unsubstantiated. They rather relied on annual reports produced by the Chief Medical Officer of Greenland covering cardiovascular deaths in the region. Because of the rural and inaccessible nature of Greenland, it was difficult to keep accurate records of cardiovascular disease affecting the population and the validity of Greenland’s death certificates have been questioned. Actually, 20% of the death certificates were  even completed without a doctor examining the body.

Use of omega-3 fatty acids ambiguous

Enjoy the real thing (Photo: Renée Suen)

Enjoy the real thing (Photo: Renée Suen)

The new review did not only show that the Eskimos and Inuits have a similar prevalence of coronary artery disease to the rest of the population, but in fact have very high rates of mortality due to stroke. Overall, their life expectancy is approximately 10 years less than the typical Danish population.  It is thus remarkable that instead of labelling their diet as dangerous to health, it was proposed that dietary intake of marine fats prevents coronary arterial disease and reduces atherosclerotic burden.

It is clear that many recent large and well-designed studies have shown ambiguous or negative results regarding the cardioprotective properties of omega-3 fatty acids and fish oil supplements, and yet they are still widely recommended as part of a heart healthy diet plan, supporting a billion dollar industry selling fish oil capsules based on a hypothesis that was questionable from the beginning.

I know what I will do. I will continue to stay away from fish oil capsules, but keep eating my weekly salmon or herring meals because I enjoy them.

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Stress and fast food a bad combination

Stress and fast food a dangerous combination (Photo: colros)

Stress and fast food a dangerous combination (Photo: colros)

If you are chronically stressed you should avoid fast food. Maybe easier said than done since fast food might be the only meal you have time for. What a conundrum. But new research has found that you have to choose between the two if you want to keep your current waistline (or of course refrain from fast food anyway). So either calm down and relax or make time for the healthy food.

This is the conclusion of a study by scientists at the University of California San Francisco. They were the first to demonstrate that highly stressed people who eat a lot of high-fat, high-sugar food are more prone to health risks than low-stress people who eat the same amount of unhealthy food. “A calorie is a calorie” seems to be the wrong assumption as they showed that two women who eat the same thing could have different metabolic responses based on their level of stress. They suggest that there could be a stress response that works through diet that could be similar to what we see in animals, where fat cells grow faster in response to junk food when the body is chronically stressed. The stress-junk food pathway has been well mapped out with rodents and primates, and this study is the first to suggest the same pathways may be at work in chronically stressed humans.

The study looked at a group of 61 disease-free women; 33 were chronically stressed women caring for a spouse or parent with dementia, and 28 were women with low stress. Over the course of a year, the women reported their consumption of high sugar, high fat foods. The chronically stressed women didn’t report eating more high sugar, high fat foods than the low stressed women. However, they did have higher levels of stress-related biomarkers.

The participants’ waistlines, fat distribution, using ultrasound scans to assess deep abdominal fat deposits, and insulin resistance, one of the core drivers of obesity and diabetes, were followed. And you guessed it: more frequent high-fat, high-sugar consumption significantly predicted a larger waistline, more truncal fat, and more insulin resistance, but only among the group of women exposed to chronic stress.

So diet appears to be a critical variable that can either amplify or protect against the metabolic effects of stress, but the exact details of how much it takes is still to be figured out.

Note that males might not come off scot-free just because the study involved only females. And stress is not the short-term adrenalin rush you get when you are trying to get to the airport in time or give a presentation in front of a large audience. It is living under sustained chronic stress.

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Even more vegetables

fruitandveg

We should eat more fruit and vegetables

The World Health Organisation advised in 1990 that the minimum daily intake of fruit and vegetables should be 400 g a day, but note that this excludes consumption of potatoes and other starchy tubers. The aim was to prevent chronic diseases such as heart disease, cancer, diabetes and obesity, and to reduce several micronutrient deficiencies, especially in less developed countries.  To promote the recommendations, WHO and FAO started a joint worldwide initiative in 2003.

But what exactly we should eat is not so easy. The definition of the word vegetable is somewhat arbitrary and subjective. All parts of herbaceous plants eaten as food by humans are normally considered vegetables. Mushrooms, actually belonging to the biological kingdom fungi, are also commonly considered vegetables. Potatoes and other starchy tubers are included in the definition of vegetables in some countries but not in others, which is not that helpful. Nuts, grains, herbs, spices and culinary fruits are normally not considered as vegetables. Botanically, fruits are reproductive organs, while vegetables are vegetative organs which sustain the plant. Nevertheless, several fruits, e.g. cucumbers and tomatoes, are also included in the term vegetables.

Confused?

A formal definition of fruits and vegetables by the World Health Organisation might help:

Fruit and vegetables are edible plant foods excluding cereal grains, nuts, seeds, tea leaves, coffee beans, cocoa beans, herbs and spices.

Fruits are edible parts of plants that contain the seeds and pulpy surrounding tissue; have a sweet or tart taste; generally consumed as breakfast beverages, breakfast and lunch side-dishes, snacks or desserts.

Vegetables are edible plant parts including stems and stalks, roots, tubers, bulbs, leaves, flowers, and fruits; usually include seaweed and sweet corn; may or may not include pulses or mushrooms; generally consumed raw or cooked with a main dish, in a mixed dish, as an appetiser, or in a salad.

Are you with me so far?

Now some countries have attempted to translate this into portions to help your calculations.

In the United Kingdom the recommendation is to eat five fruit and vegetable portions a day with each portion equivalent to 80 g. However, only about 30% of the population manage to consume the recommended amount.

Australia went one step further and recommends two fruit and five to six vegetable portions a day with the fruit portion at 150 g and vegetable portion at 75 g. This equates to an enormous total of 675 to 750 g. Quite an ambitious target. Close to 50% of Australians reported that they usually ate two or more serves of fruit per day, while 8% usually ate five or more serves of vegetables per day. Taking both guidelines into account, only 5.5% of Australian adults had an adequate usual daily intake of fruit and vegetables.

Canada previously recommended five to ten portions for all, but changed this in 2007 to specific recommendations for each age and sex group. They now recommend a minimum of four portions for young children up to a minimum of eight portions for adult males. Only 26% of the population aged 2 years and older consumed the minimum number of daily servings recommended for their respective age–sex group.

France and Germany also recommend five portions a day while portion numbers vary in other European countries. The United States abandoned the numbers in favour of a generic fruit and vegetable campaign in 2007 indicating that the more you eat the better it is. In Europe, the average consumption of fruit and vegetables is only 220 g per person per day and just 27% of European mothers consume over 400 g. The French did not reach the recommended amounts consuming fruit only 1.3 times per day and vegetables 2.3 times per day despite all the talk about the beneficial Mediterranean diet. Still this was better than the Americans. Adults in the United States consume fruit about 1.1 times per day and vegetables about 1.6 times per day. That is definitely on the low side but not breaking any non-existent recommendations.

Given our notorious dishonesty when confronted by pollsters with questions that touch on our self-regard, there might even be a lot less five-a-day eaters than indicated above.

But if you are struggling with reaching the current recommendations just wait for it.

A new study, carried out by researchers at University College London, analysed information from more than 65,000 adults aged 35 years or older, who responded to the Health Survey for England. Researchers then followed up participants for an average of 7.7 years after their initial participation. The study found that people who ate seven or more portions of fruit or vegetables a day had a 33% reduced risk of death from any cause, a 25% reduced risk of death from cancer and a 31% reduced risk of death from cardiovascular disease, compared with people who ate less than one portion per day.

Not even 400 g is enough

Not even 400 g is enough (Chris Walton)

So not even five portions of fruit and vegetables a day may, after all, be enough. There was a surprise finding – eating canned or frozen fruit actually may not be helpful at all. This is a little confusing but it could be that people eating canned fruit may not live in areas where there is fresh fruit in the shops, which could indicate a poorer diet. And merging canned and frozen fruit might not be fair to the frozen produce.

The clear finding was that eating more fresh fruit and vegetables, including salads, was linked to living a longer life generally and in particular, to a lower chance of death from heart disease, stroke and cancer. Vegetables seemed to be significantly more protection against disease than eating fruit.

The researchers commended the Australian example as the one to follow where the balance is two fruit and five vegetables. That is if the reduced risk of disease is entirely attributable to fruit and vegetable consumption, or they are acting as a marker of a broader dietary pattern associated with improved health.

Your call, but to up your fruit and vegetable consumption to close to 800 g a day might not be easy.

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Anyone for porridge?

Beneficial compounds found in oats (Photo: Cheryl Colan)

Beneficial compounds found in oats (Photo: Cheryl Colan)

I didn’t think so, porridge might not be your favourite food. It is a bit messy to prepare and it is difficult to clean the pots afterwards. But there are other ways to increase the consumption of oats. Think breakfast cereals and why not bread or biscuits, but about all else think carefully of trying to raise your oat intake. Horse trainers already know the benefits of oats. Why should horses be the only beneficiaries?

Seriously though, there is now a new reason to eat oats for heart health and a range of other diseases. It is already known that the soluble fibre in oats helps lower total and low-density lipoprotein (LDL) cholesterol, but scientists now say that the cardiovascular health benefits of oats goes beyond fibre.

The beneficial compounds in oats identified

Eating whole grains has been consistently linked to a reduced risk of several chronic diseases, including cardiovascular disease. Most of the benefits have been attributed to the relatively high fibre, vitamin, mineral and phytochemical content of whole grains. And in particular, the soluble beta-glucan fibre found in oats has been recognised for its ability to lower both total and LDL cholesterol.

Now, scientists have emphasised growing evidence that phenolic compounds called avenanthramides might be behind most of the benefits seen.  There are about 40 or so different avenanthramides found only in oats and three of them in particular seem to act as potent antioxidants, anti-inflammatory, anti-itch and anti-cancer agents, which may provide additional protection against coronary heart disease, colon cancer, and skin irritation.

Avenanthramides are a type of oat phytoalexins that are found in the whole grain with the fibre-rich bran portion of the grain intact. Phytoalexins are substances produced in plants that act as toxins attacking organisms like fungi. They may puncture the cell wall of the fungus, delay maturation, disrupt metabolism or prevent reproduction. Accordingly, researchers have found that oat cultivars with the strongest resistance to crown rust, a fungus that affects oat grains, had the highest concentration of avenanthramides. It is thus possible for  farmers to select highly resistant oat cultivars to increase the production of avenanthramides in the grain.

So many good things linked to oats

Delicious oat bread is even good for you (Photo: Theresa Carle-Sanders)

Delicious oat bread is even good for you (Photo: Theresa Carle-Sanders)

Health-conscious consumers have long chosen foods that include oats because of prominent and snappy “heart healthy” claims made by oats producers. And right they were. Compared to vitamin E, which is a strong well known antioxidant, the antioxidant effect of the avenanthramides is initially weaker but instead the effect is prolonged. But there is more.

Scientific studies have shown that avenanthramides also hinder the ability of blood cells to stick to artery walls, and arrests smooth muscle cell proliferation. Both events known to cause arterial lesions contributing to the development of atherosclerosis, which can eventually lead to heart attack. Earlier human clinical studies have also shown that consumption of oats reduces blood pressure.

But there is even more and I don’t want to sound as a salesman. However, you need to know that colloidal oatmeal can be used for the symptomatic relief of dry skin and itching. Human skin tests have shown that avenanthramides inhibits the release of  histamine that play a major role in itch sensation and reddening of skin. Avenanthramides have already been used as an ingredient in shampoos and topical sprays for the relief of adverse skin conditions, including atopic dermatitis.

So next time you hear that oat is good for you, you better believe it.

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