Sunday 14 October 2018

Soft drink


A hard drink is one that contains alcohol. The advantages and disadvantages of drinking hard drinks are well known.
A soft drink doesn’t contain alcohol.  A soft drink is promoted as a glass of happiness. A nice, happy and joyful drink. 

They are actually nasty, evil and harmful.

In our community they cause about as much pain and suffering as tobacco. Tobacco is often considered the largest preventable cause of death and disease in our society. Some experts disagree and say obesity costs the community more than tobacco. Others still see tobacco as the main miscreant.

It is indisputable that, in our society, tobacco and obesity are the two major preventable causes of disease.  With both tobacco and obesity there are large social and economic costs to individuals and the community. The government taxes tobacco, promotes smoking cessation and regulates smoking advertising. The government sees tobacco as unmistakably nefarious and bad. 

While tobacco is often seen as the black hooded Darth Vader, sugar has snuck under our guard. It has gone along pretending happiness while spreading misery.  At least tobacco doesn’t pretend.

According to the NHMRC in 2012 around 60% of Australians were overweight or obese.  25% were obese.  These figures are increasing.

Obesity has been associated with heart disease, hypertension, high cholesterol, diabetes, stroke and many types of cancer.
Heart disease, a stroke or diabetes are not a normal part of life. They will shorten your life. You will spend time in hospital with concomitant pain and suffering. When in hospital your family will be stressed and anxious about your future.  You will add to the crowd in ED.

When obese you will look fat which means you will have less pride in yourself and more emotional problems. You will be less able to play sport or be physically active in our society.

You will have more days off sick and finish work at an earlier age. You will be less productive.

An obese community will have a less productive workforce generating less money. It will spend more on health care and less on schools, roads and police.

Soft drinks are one of the major causes of obesity. They contain empty, added sugars. There is absolutely no health benefit in consuming such sugars.

Studies have shown obese people drink more soft drink. People who sit around drinking soft drinks are more likely to be obese, do less exercise and have unhealthy lifestyle.

When working as a dentist people with rampant decay were present. Often I would ask a few questions to find out why so many holes. The answer would often be soft drinks. When I saw someone with rampant decay and a soft drink habit I had something to work with. If they then took my advice I would see dramatic and immediate improvements in their oral health.

Soft drinks cause holes in teeth. Different soft drinks contain different carbohydrates. All the carbohydrates feed oral bacteria which produce acids which dissolves the hard tissue of teeth. This is called dental caries.

Soft drinks also cause dental erosion. Many soft drinks are acidic. The acids erode away tooth substance.  This erosion is different from decay but leads to irreversible loss of hard tooth materials.

Soft drinks also decrease bone density. Many studies have shown decreased bone density in regular high drinkers of soft drinks who are also often low drinkers of milk.

Soft drinks also cause kidney stones. Regular consumption of soft drink is associated with increased risk of developing kidney stones.

The average can of soft drink, energy drink or fruit juice contains 128-160 calories; 32-40 gm of sugar; 8-10 teaspoons of sugar.

One recommended daily intake is:

For a male:

2,500 calories per day with 150 calories 37.5 gm 9 teaspoons coming from added sugar.

For a female:

2000 calories per day with 100 calories 25 gm 6 tsp coming from added sugar

Experts can argue about what is the largest preventable cause of death and diseases. What has the largest social and economic cost?  Tobacco or obesity.

Tobacco and obesity both precipitate a lot of death and disease.  Both result in a large cost to individuals and our community. The government taxes tobacco in order to discourage tobacco use and to help pay for resulting health costs. It is time for the government to also discourage the eating of sugar.

It is time for the government to ban advertising and sponsorship of soft drinks during sport events.

It is also time the government promoted healthy nutrition, physical activity and obesity prevention.

Taxing soft drinks as well as tobacco is logical; already occurs in many countries and will save our community money.

Sunday 23 September 2018

Bleaching teeth


Should you bleach your teeth?
                                                    
If I was a working dentist I would begin by assessing your expectations. If you expect bleaching a few teeth to change their life then I would be wary.  If you turn up with a picture of a famous celebrity I would be wary. If you expect lighter teeth to give you slightly more pride in your teeth then good.

I would then consider timelines. Do you have wedding photos coming up? A deadline may necessitate more rapid bleaching such as in office based light activated bleaching. Regular home based bleaching may take weeks.  
I would then consider present appearance of your teeth. If they are obviously evenly dark then the staining is probably associated with some long forgotten medication or illness. If the staining is uneven it is more likely a dental problem. Either a dead tooth or fillings or crowns.

Age is also important. Teeth become darker with age. The main difference with age is sensitivity. As teeth age shrinkage of the gums can make the teeth more sensitive.

As teeth age they acquire chromogens.  These are large compounds which stain teeth. Hydrogen peroxide changes these compounds lightening teeth. Hydrogen peroxide can be delivered to teeth direct or as carbamide peroxide. 
You need to place hydrogen peroxide in contact with your teeth. The laws relating to amount of peroxide vary from country to country which says nobody knows the right amount and the laws were draw up by politicians. New Zealand legalizes higher amounts than in Aus. The UK has much lower levels. 

There are many ways of placing the bleaching gel on the teeth. Some dentists do this in the chair.  Main advantage is it’s quicker.

Another common way is with a dentist made tray. An impression of your teeth is taken and a specific tray made.  The trays keep the bleaching gel in contact with the teeth longer. You normally wear the trays at night when you are asleep.
Bleaching toothpastes. If used regularly they do what they say. What they don’t say is that the teeth will become more sensitive. This may or may not be an issue for you. They will take much longer to work.  Main advantage is no change to your oral care habits.

Bleaching mouth rinse. Similar to toothpaste. Will not be in contact with the teeth for long period of time.  Therefore it will need a lot of contact times. Need a large number of applications because each application is very short.

Once bleaching has finished the teeth begin to reacquire chromogens. Bleaching teeth doesn’t stop chromogens from returning. There is a constant movement of compounds between teeth to saliva. After bleaching they resume staining.  You can’t combat this by bleaching continually. Over bleaching your teeth will damage them.

Is it safe and what can go wrong?

The most common side effect is increased sensitivity. Teeth can become more sensitive to hot, cold, food, drinks or the air.  Teeth are like chalk. They are a porous living material.  If you change the hard substance the internal nerve reacts differently.

The increased sensitivity is unpredictable. How much of an increase, how long it will last and how people will react is all unknown.

Irritation of the gums or mucous membranes is possible. If it occurs it will resolve immediately you cease bleaching.
Uneven bleaching is possible. Normally occurs initially and with further bleaching it evens up.

Another possibility is after bleaching your fillings, crowns and veneers will appear darker.  The bleach will affect these existing fillings and crowns but it will be so light it can be ignored.

No study has shown an increase in decay.

Should I see a dentist?”

Yes. Anybody can buy bleaching toothpaste or bleaching strips but if you want a lifelong healthy mouth you need a good relationship with a dentist. If you bleach by yourself at home the dentist will know and it will affect their treatment.

A smile is indicator of lots of things. Socio-economic status for one.

But, personally, for me a smile comes from within. You can’t fake it with whiter teeth.  A relaxed, confident and unique smile is more beautiful than a picket fence of perfect teeth.



Thursday 26 July 2018

Diet and a healthy heart: from the ABC



Reprinted from ABC website where it is was published on 25.7.18

Its common wisdom that a healthy diet is key to having a healthy heart, but exactly what that diet looks like still has some people scratching their heads.
A research paper out on Tuesday aims to answer the common nutrition questions people ask their heart health specialists.
The Journal of the American College of Cardiology study aims to act as a guide for cardiologists who, despite having patients look to them as a source of information on heart-healthy diets, don't get a lot of nutrition training in their formal studies, according to lead author Andrew Freeman.
"The vast majority of cardiologists, and actually lots of medical doctors surprisingly, have very little practical, day-to-day nutrition knowledge," Dr Freeman said.
"So the goal here was really to hit on the things that people ask us about a lot." 
Cardiovascular health benefits of controversial foods. 
(Journal of the American College of Cardiology: Andrew Freeman)
The authors looked at previous studies to see where the balance of evidence fell on specific foods like dairy, energy drinks and fermented foods, and nutrients such as omega-3 and vitamin B12.
The bottom line, according to Dr Freeman, was that whole, plant-based foods where nutrients are delivered in their natural form seem to be healthiest.
"A heart-healthy diet and, I would argue, a healthy diet overall really, is a predominantly plant-based, whole food, minimally-processed, no added salt, no added sugar type of a diet. And everything else is sort of the details," he said.
"For instance, people are very wary about if there's sugar or carbs in fruits and vegetables and those really don't seem to be harmful. Whereas if we extract those and have that added sugar, those do seem to be harmful.
"Same thing when we pull out caffeine to make energy drinks, versus caffeine that's naturally occurring in coffee and tea — one's harmful and one's not so harmful."
So what's the verdict on the heart-healthy credentials of each of the products the authors investigated? Let's take a look.

Dairy:

Dairy products are a good source of vitamins, minerals and protein — but they also can contain high levels of saturated fat and salt, which can contribute to heart disease risk.
"It was very widely split on whether [dairy carries] harm or benefit. It's very confusing and confounding," Dr Freeman said.
"But all the authors agree that dairy appears to be the number one source of saturated fat and salt in the American diet."
Achieving a healthy intake of dairy is possible if you make good choices within the Australian dietary guidelines of two and a half serves a day, according to advanced accredited practicing dietician Melanie McGrice.
"It depends on the type of dairy products you're talking about," she said.
"If you're talking about full cream milk versus low fat milk you're talking about a 1 per cent difference in fat … whereas if you're talking about the difference between, say, milk and cream, then you're talking about a 50 per cent fat difference.
"As long as people stick to lower-fat types of dairy product like milk, yoghurt and even cheese, then they're going to be fairly safe in terms of cardiovascular disease."

Added sugars:

Links between added sugars and increased risk of cardiovascular disease started to surface in the 1950s, and the weight of evidence has built steadily since, the authors wrote.
Studies they looked at showed added sugars, especially the fructose portion of table sugar or syrups used in food manufacture, contributed to fatty deposits in arteries, even if the person consuming the sugar wasn't gaining weight.
But, as Dr Freeman said, naturally occurring sugars in whole foods like fruit and vegetables don't seem to have the same detrimental effects.

Legumes:

Lentils, chickpeas, soybeans and their ilk have a range of heart-healthy benefits, the study found, including a reduced risk of death from all causes, reduced risk of coronary heart disease, and better blood glucose control. For this reason, the authors issued an enthusiastic endorsement of legumes.
But Dr Freeman admitted getting people excited about brewing up a batch of lentils was harder than selling a new breakthrough drug or procedure.
"Which is sexier? The latest statins or percutaneous and minimally invasive valves, or peas and carrots? There's not a lot of money in peas and carrots and, if given an option, there are lots of people who would rather take a pill or have a procedure than to change something drastic in their lifestyle," he said.
"But I would tell you if you go to certain parts of the world where diets are predominantly legumes, you know, beans, rice, vegetables, heart disease is extremely low."

Tea, coffee:  

Added sugar and fat notwithstanding, both coffee and tea are linked to cardiovascular health, the study found.
Coffee sometimes gets a bad rap for increasing blood pressure, but the authors noted this wasn't a problem in people who drank it regularly. In fact, it contains antioxidants that are linked to good health, and habitual coffee drinking is associated with a lower risk of death from cardiovascular disease.
Similarly, both black and green tea have a high antioxidant content and have been shown to benefit cardiovascular health.
But if you think getting caffeine in any form is going to help your heart, think again.
"Coffee and tea seem to be somewhat healthful, whereas the energy drinks, which have extracted the caffeine out of the plant and created a synthetic cocktail, seem to be somewhat harmful," Dr Freeman said.
Energy drinks were linked to cardiovascular issues, including arrhythmia, elevated blood pressure, seizures and even death.
While the previous studies the authors looked at weren't of the highest quality, they warned people to avoid energy drinks just in case.

Alcohol:

Anyone with even a casual interest in health news would be familiar with the seemingly contradictory advice around alcohol consumption. The problem is it's a complex issue with so many variables, as the authors of this review noted.
Low to moderate alcohol consumption is associated with a reduced risk of cardiovascular disease, and wines specifically contain compounds that have been shown under certain conditions to have beneficial effects.
But don't start drinking if you're currently a teetotaler just to get a health benefit, the authors cautioned, because drinking carries risks too.
"There is also some risk of falls, certain cancers, and liver disease," they wrote.
"As such, it is not recommended that individuals initiate alcohol consumption for [cardiovascular] benefit, and for those already drinking, consumption should be limited to recommended amounts, preferably consumed with meals."

Fermented foods:

In terms of food fads of the moment, fermentation would have to be among some of the most popular. But do fermented foods help your heart?
The evidence isn't strong enough to routinely recommend them, the authors said, but some studies suggest benefits for risk factors for cardiovascular disease such as high blood pressure and cholesterol.
Ms McGrice suspected the recent surge in popularity of fermented foods meant the research simply hadn't caught up yet.
And while there may not be clear evidence linking fermented foods and heart health, there was evidence for other health benefits.
"It's gut health. What we're seeing now is with benefits in our gut microbiome that that's having an influence on inflammation all around the body," Ms McGrice said.
"There's certainly a link between fermented foods and improving the gut microbiome. What we're finding is that improvement in the gut microbiome has far-ranging benefits, but its really hard to isolate exactly what those are.
"And there may be benefits for cardiovascular disease, but they haven't been detailed yet."

Omega-3s and vitamin B12:

Fish is a good source of omega -3 fatty acids, but not the only source.
Alongside food groups, the study also looked at omega-3s and vitamin B12, which have both been shown to have heart health benefits. What was the best way to get these nutrients, the authors wondered?
For omega-3s, which can be found in both fish and plants, the evidence was unclear.
"It appears omega-3s are essential to the diet; the question is … which is a better source?" Dr Freeman said.
"And the jury's still out on that but when you look at fish, even in the best places, they seem to be contaminated more and more."
The authors concluded either source was probably beneficial, especially if it came from a whole food rather than a supplement.
As for B12, the authors recommended supplementing for people who were deficient in the vitamin. But they said there wasn't much evidence to support using supplements as a preventative measure for cardiovascular disease.
"When you look all the data in sum, a particularly plant-based diet with minimal processing is really where the health is," Dr Freeman said.
"And it's probably not how most people want to eat all their meals, but it's actually very doable and very tasty.
"It's just a matter of having the clinicians, the doctors, and their associated professionals understanding how to get patients motivated to do this sort of thing."

  

Monday 23 July 2018

fruit juice


Why don’t my grandkids drink fruit juice?  It can be fresh, organic, natural, biodynamic or it can detoxify. It has to be healthy.  I feel guilty because my fridge is not full of fruit juice to give to grandkids.

I am currently helping two of my grandkids play tennis. In tennis we use the word juice. A quick look tells me juice in tennis has nothing to do with health and drinks. It comes from the French words deux du jeu which means two points away from winning the game.  Nothing to do with fruit juice. Not positive or negative.

But after a hit of tennis should I give them a drink of fruit juice.

These are the positives of fruit juice. It tastes good; is convenient; is cheap and readily accessible; is culturally acceptable; is free of bacteria and toxins.   

It is healthier than soft drink. It comes from fruit and fruit is unambiguously good.
Contains plant micro-nutrients, anti-oxidants and fibre.

The sucrose in soft drinks is worse.  Sucrose is much more cariogenic (causes caries) than the fructose in fruit juice. Strep mutans which is a major cause of dental decay only eats sucrose. 
No epidemiological evidence fruit juice causes decay. Recent studies from the USA show that children who drink fruit juice do not suffer more decay.  I worked more than 30 years as a dentist. I saw a direct relationship between soft drink or lollies and decay.  People who started or stopped imbibing lollies or soft drinks and decay came or went. I never saw the same relationship between fruit juice and decay.   

Fruit juice is not perfect. There are negatives.

High in carbohydrates.  The carbohydrates in fruit juice can cause dental decay. Bought fruit juice or fruit syrup or elixir may contain added sugar which will cause dental decay.

Fruit juice in a bottle given to a child to aid sleep results in bottle caries.

Fruit juice is acidic. Liquid acid leads to the outer enamel of a tooth being eroded away. This loss of enamel is permanent and leads to tooth sensitivity.  I have seen this problem more commonly in adults. I have seen adults who have purchased a juicer followed by dental erosion and tooth sensitivity.

Fruit juice is low in fibre compared to fruit. Fibre will make you feel full for longer and is very good for gut health.

Calories. Every soft drink and every fruit juice varies but on average they contain about the same number of calories.  At present obesity, has overtaken smoking, as the biggest preventable health problem in Australia.

Which way shall I go?

If I want my grandkids to have the nutrients and fibre and juice of an orange I will give them an orange to eat. To get an orange and separate it into juice and pulp and then throw away the pulp and drink the juice doesn’t make sense.  I will encourage my grandkids to eat fruit. I want them to develop the habit of eating fresh fruit. To learn how to feel hungry; see a fruit bowl; peel or cut a piece of fruit; enjoy eating fruit and then dispose of the peel or core into a recycling bin.

If I ever see them drinking fruit juice I will try and get them to use a straw.  I will give them a reusable metallic straw. I will also give them fruit juice with food.

 I will try and get them to drink water or plain (dairy or non-dairy) milk.  Or dilute the milk with water. Or if feeling magnanimous I will add some flavour but never sugar.  Never honey.  Nutmeg, cinnamon, vanilla, cardamom, ginger, chocolate or pureed fruit.

If their parents decide a juicer is a healthy option I will recommend eating a spoonful of fresh plain yoghurt after drinking freshly made juice. The yoghurt will help prevent sensitivity and dental erosion.

I know they will notice the color. Gertrude loves anything pink. Bruce only notices who is getting the most.

Fruit juice is not good enough to be a good, heathy food. It’s not bad enough to be an anticipated birthday treat.










Thursday 19 April 2018

Dietary guidelines : fats (which ones are the best to eat)


The ratio of omega-6 to omega-3.

Historically humans had a diet with a ratio of 1:1.  Historically the diet was rich in game, animals, seafood and plants.Today the western diet has a ratio of between 20:1 and 30:1.    Today the diet contains a lot more omega-6 than omega-3.

Both omega-6 and omega-3 fatty acids react with the same enzymes. Omega-6 leads to inflammatory agents being produced. The amount and ratio of omega-6 and omega-3 influences what hormones are produced.

Research has found a correlation between a diet high in omega-6 and disease.
Many nuts, grains and whole foods are high in omega-6 but have other health benefits and should be eaten.
Most plants contain a type of Omega-3 called ALA. Humans are inefficient converters of ALA into the active forms, EPA and DHA.  For this reason, animal sources of Omega-3 from fish and grass-fed animals are also needed.

Sources of omega-3

Flaxseed, Hempseed, Chia seeds, Fish, Mussels, Oysters
Meat. Mutton, game and grass fed cattle more omega-3 than cattle from fed lots.
Eggs. Hens fed on greens and insects produce more omega-3 than hens fed on grains, cereals and corn.
Strawberry, Kiwifruit, Broccoli, Butternuts, Walnuts, Pecans, Hazel nuts, Dairy products.

Sources of omega-6

Poultry, eggs, nuts, grains, pumpkin seeds and vegetable or plant based oils.

What fat and oil should I eat?

High in omega-6 sunflower oil, corn oil, soybean oil, cotton seed oil.
Low in omega-6 butter, coconut oil, lard, palm oil, olive oil.

Saturated fat is low in canola oil, safflower oil, sunflower oil, corn oil, olive oil, soybean oil.
Saturated fat is high in coconut oil, butter, palm oil, lard, cottonseed oil.

Omega-3 fats are good. Omega-6 fats are bad. Omaega-6 fats are probably worse for you than saturated fats. There is much stronger evidence linking refined carbohydrates to heart disease and diabetes than saturated fats and cholesterol.

I want a diet high in vegetables, fruits, whole grains, legumes, nuts, moderate amount of fish and low in processed fast foods.
I want to avoid oils high in omega-6.  Sunflower oil, corn oil, soybean oil, cotton seed oil.  When you buy fried food you do not know what oil it was cooked in. The solution is to avoid bought, fried, processed food where possible.



The oils I want to eat are:

Extra virgin olive oil.
Ghee.
Avocado oil
Macadamia oil
Coconut oil


Dietary guidelines : fats (omega-3 and omega-6)


Omega-3 fatty acids

Omega-3 fatty acids are polyunsaturated fatty acids (PUFA’s).  They have long chains of 18-22 carbon atoms with the first of double bonds beginning at the third carbon atom (counting from the methyl end). This means they are missing more than one hydrogen, and have more than one carbon double bond instead. Omega-3 means that one of the double bonds in the fat chain is at carbon number 3 in the backbone.

Omega-3 is present in the oils of seeds, grains, nuts, legumes and green vegetables. (Flax seed oil, walnuts, canola oil and chia seeds).
Also present in grasses and algaes which humans don’t eat.
Omega-3 is found in grass-fed animals, oily algae eating fish, free range poultry and oysters.
In the animals and fish it is more common in the brains, livers or eggs. 

Humans cannot synthetize fatty acids. In humans three types of omega-3 fatty acids are needed.  ALA, DHA and EPA. They are essential.  Which means they must be ingested. You can ingest the shorter chain ALA fatty acids and then make EPA and DHA acids from it.  Efficiency is about 5%. This conversion pathway competes with Omega-6 pathway. 

ALA has 18 carbon atoms and 3 double bonds.
DHA has a chain of 22 carbon atoms with 6 double bonds.
EPA has a chain of 22 carbon atoms with 5 double bonds.

Omega-6 fatty acids

Omega-6 fatty acids are liquid polyunsaturated fatty acids (PUFA’s). They have their first double bond at carbon number 6 instead of carbon number 3. Whereas there are 3 important omega-3 fatty acids for human health, there is only one essential omega-6 fatty acid: Linoleic Acid (LA).
There are a number of different omega-6 fatty acids. They have a chain of 18,20,22,24 carbon atoms. They have 3, 4, 5 or 6 double bonds.
Nutritionally omega-6 comes from animal fat (10/20% omega-6) and seed oils (50-80% omega-6).

Omega-3 and omega-6 fatty acids

Omega-3 fatty acids are largely anti-inflammatory (heal yourself). They are important in preventing chronic inflammation.
They are also part of stabilizing cardiac cell membranes and in the cell membranes of the brain and the retina.
Omega-6 fatty acids are essential for inflammation (defend oneself).
If you knock yourself omega-6 will help formation of bruise.  Omega-3 will help you get rid of the bruise. Your body needs to be able to do both.  The body needs to defend itself from attack by mounting an inflammatory response and then eliminate the inflammation.  

The ratio of omega-3 to omega-6

There is evidence that our distant ancestors ate diets with a ratio of roughly 1:1.
Our more recent ancestors may have had a diet of with a ratio of from 2:1 to 4:1.
Today the average western man has a diet with a ratio of from 20:1 to 30:1.





Dietary guidelines : fats (saturated and unsaturated)


Our body stores energy as glycogen (short term storage) and fat (long term storage). Fat is an efficient, lightweight, flexible, and portable source of energy. 

A saturated fatty acid contains single bonds between the carbon atoms.  A “saturated” fatty acid has the most hydrogen atoms it can possibly carry—it is therefore “saturated” with hydrogen. Every carbon atom is attached to as many hydrogen atoms as it can hold. Each carbon-hydrogen bond carries energy, so the more hydrogen atoms that are bound to a fat, the more energy you can get out of that fat when you burn it. Saturated fat has more energy, and therefore more calories, per pound.

Saturated fats, with their full load of energy-packed hydrogen bonds, are straight molecules that pack together efficiently, and are therefore solid at room temperature. Unsaturated fats, with their weaker double bonds, are crooked, because double bonds create kinks in the backbone. When molecules have room to move around easily, they are more likely to form liquids than solids.

Most fats occurring in nature contain mixtures of saturated, monounsaturated, and polyunsaturated fatty acids. Olive oil contains approximately 17% saturated fatty acids, 71% MUFA (oleic acid), and 11% PUFA’s. Coconut oil contains more than 90% saturated fat. Beef fat contains nearly equal parts saturated fat and monounsaturated fat (most of which is oleic acid, the primary fatty acid in olive oil) and approximately 5% polyunsaturated fat, depending on what the animal is fed.

Saturated fats are very stable, whereas unsaturated fats (oils) are fragile. The carbon double bonds in unsaturated fats are weak and vulnerable to chemical attack compared to the strong carbon-hydrogen bonds in saturated fats. This is why unsaturated fats (oils) go rancid (become “oxidized”) when exposed to air, whereas you can leave lard or butter on the countertop for a long time without worrying about it. Ghee, which is butter with all of its proteins removed (pure butterfat), can be stored at room temperature indefinitely.

Saturated fat is the preferred fuel of the heart, which is why the heart has some saturated fat wrapped around it.

Saturated fats are good for things like insulation (myelin), cushioning (abdominal fat around our organs), and storage (body fat under the skin) purposes.

An unsaturated fatty acid contains double bonds between the carbon atoms and have less hydrogen.   Monounsaturated means it contains one double bond.   Polyunsaturated means it contains more than one double bond.
If a carbon atom does not have a hydrogen to bond to it forms a double bond with a carbon atom.  If a fat atom has one double bond, it is called “monounsaturated” (missing one hydrogen).
A monounsaturated fatty acid (MUFA) is oleic acid found in olive oil.
A polyunsaturated” fatty acid has more than one double bond. It is missing more than one hydrogen.

Unsaturated fats are good for flexibility and fluidity purposes, such as in membranes and body fluids.

Tuesday 17 April 2018

Vitamins and health


Presented on triple J on 30 May 2018.


In the Journal of American College of Cardiology this week, an analysis of 179 randomised-controlled studies (the highest standard of medical research) found popular supplements like Vitamin C and calcium are mostly useless, unless you have a specific deficiency of that vitamin.

If you're an 18th century sailor, you may need Vitamin C to ward off scurvy, but most people living today get enough vitamins from their diet.

The study examined the benefits of vitamin and mineral supplements for prevention of heart disease, stroke and premature death.

Dr David Jenkins, the lead author of the study, said he was surprised to find so few positive effects of the most common supplements people consume.

Our review found that if you want to use multivitamins, vitamin D, calcium or vitamin C, it does no harm - but there is no apparent advantage either.

 Some less common supplements did have an effect, however. Folic acid seems to lower the risk of heart disease (a good thing), although the evidence is pretty slim, and too much folic acid may also increase the risk of cancer.

Antioxidants and niacin were found to slightly increase the risk of death (a bad thing).
Meanwhile, vitamin sales are booming. The ABS's recent survey found 29 per cent of people reported having taken at least one dietary supplement.

Market research estimates Australians spend about $1.85 billion on vitamins and dietary supplements every year.

Some may be taking the vitamins on the advice of their doctor, but many will be simply popping the pills in the belief it will make them healthier.

Contrary to popular belief, Vitamin C probably won't help you get over your cold. A 2013 review of 29 trials found it had no effect on the duration or severity of colds. In very large doses, it can increase the risk of painful kidney stones.

What this means is we may be wasting a lot of money on 'magic pills'.

Without going through the science on every individual vitamin and mineral, the best advice is to just ask your doctor if you have a deficiency.

And if you have a cold, try zinc. Studies show it helps recovery


Monday 16 April 2018

Our obsession with fats and carbs means...


Article copied from ABC website

Our obsession with fats and carbs means we're looking at nutrition all wrong.
"Eating pasta helps you lose weight." "Eating more animal protein increases risk of death." "The foods helping you shred stomach fat." "How to eat carbs without gaining weight."
These are all real headlines, published in separate media articles recently.
Is it any wonder that people are confused about what they should and shouldn't eat?
Daily we hear of another nutritional dietary "breakthrough". But as a cursory look at Australia's obesity statistics attests (two in three Australians are obese or overweight), our health and wellbeing are reaping no benefit.
What's worse, fats or carbs?
So what's gone wrong? Why are clear, useful and effective messages about nutrition so difficult to find?
The answer is that we have taken a wrong turn in the way that we think about nutrition. We are too obsessed with identifying an individual culprit — a specific nutrient that causes a particular health problem.
Take for example the argument whether fats or carbs causes obesity. It began over half a century ago, and yet the debate remains unresolved.
Some experts argue that fats are to blame, others that carbs (especially sugar) are almost solely to blame, and to further complicate things, yet others suggest too much protein or too little fibre as the cause.
None of these viewpoints is entirely incorrect, but in reality, obesity is not caused by a single nutrient.
Rather, like a high-functioning sports team, particular nutrients interact in networks of other nutrients to influence energy intake and fat storage.
To solve the problem we need to reconsider the question we ask. Rather than "which nutrient causes obesity?” we should ask "which combinations of nutrients are associated with obesity?"
Nutrition is about mixtures, not single nutrients, and their actions can be indirect and unexpected.
We had bad dietary advice in the '70s
Not only has the single-nutrient approach failed to manage the obesity crisis, it might actually have contributed to it. In the 1960s and 1970s, when obesity first emerged as a serious health problem, dietary fat took too much of the rap.
Official advice was, quite logically, to reduce the amounts of fat in the diet. And we did — the public health messages worked, but it had no effect. By the 1980s it was clear there was no sign of the obesity epidemic slowing, let alone reversing.
People followed the dietary advice, but it was bad advice. It failed not because fats aren't associated with obesity — they probably are — but because the focus on a single nutrient had unintended consequences.
Rather than reduce the total amount of energy eaten, which very likely would reduce obesity, people simply replaced fat in their diet with carbs.
This was also helped, in no small measure, by the processed foods industries. Sensing an opportunity, they quickly offered foods conspicuously labelled "low-fat". What the labels didn't say is that these foods were also "high-carb".
So if fat isn't responsible, and obesity has continued to rise with increased carb intake, then surely carbs must be to blame.

Excessive carb intake almost certainly has played a role in the obesity epidemic (probably together with fat), but there are again suggestions that singling them out as "the cause" is leading to problems.
It is causing many to turn to a low-carb diet — for example the paleo, Atkins and Banting diets. But recalling the fat-carb debacle, if carbs are reduced then it is likely that something else will replace them. That something turns out to be protein.
Although low-carb/high-protein diets likely do lead to reduced energy intake, the evidence is growing that they also have nasty side-effects. They alter the balance of microbes in the gut, accelerate the onset of age-related diseases such as cancers, and shorten lifespan.
Demonising fats, carbs, salt, or zangamide (we just made that up), and implying that reducing their intake alone will solve the problem of obesity, is simply wrong. That's because attempting to solve health problems nutrient-by-nutrient is like herding cats. As soon as one nutrient is under control, another slips out of line.
Enter nutritional geometry
A method is needed to understand nutrition for what it is — the association between our biology and "teams" of nutrients that interact to influence our health.
We propose a new approach to nutrition, called nutritional geometry, which does just this.
Nutritional geometry offers a new tool to model diets as mixtures of nutrients, foods, meals and menus, and in this way helps researchers and health professionals to understand how the dietary balance influences health. It can also help individuals to manage their diet, by changing the goal from eating diets "high in this nutrient" or "low in that", to eating a diet that is balanced in nutrients.
We can now look forward to clearer messages around the relationships between nutrients, foods, diet and health.
In the meantime, one message is clear. Rather than focus on which nutrient to leave out of the diet, we need to reduce our consumption of high energy, nutrient-poor snack and junk foods and beverages. By any definition, these spell trouble for healthy eating.


This article was co-authored by the University of Sydney's Leonard P Ullmann Chair in Nutritional Ecology David Raubenheimer and Charles Perkins Centre academic director Stephen Simpson.



Tuesday 27 February 2018

Dietary guidelines : Protein


Protein is a basic building block of humans. Amino acids are the basic building block of protein.
Protein can also serve as a fuel source.
Protein is second to water as most common element of human body.

Proteins are molecules consisting of one or more long chains of amino acid called polypepetides. Proteins differ from one another in their sequence of amino acids.

Proteins are important in the structure (building and maintaining) and the functioning of all cells.
Protein is a major component of all cells especially muscle, hair and skin.
Protein is needed for all biochemical reactions in the human body.

Once formed, proteins only exist for a certain period of time and are then degraded and recycled by the cell's machinery through the process of protein turnover. A protein's lifespan is measured in terms of its half-life and covers a wide range. They can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells.

There are 20 amino acids in the human body.

Nine are essential amino acids (They cannot be synthesized by the body). phenylalanine, valine, threonine, trytophan, methionine, leucine, isoleucine, lysine and histidine.                                                                                                        

There are five amino acids which humans are able to synthesize in the body. alanine, aspartate, asparagine, glutamine and serine

There are six conditionally essential amino acids which the body is able to synthesis under certain conditions.
arginine, cysteine, glycine, glutamine, proline and tyrosine.

Sources of protein.

Meat, dairy products, eggs, fish, legumes (peas, beans and lentils) are sources of complete protein.

Whole grains and cereals.  Have limited of lysine or threonine. Whole grains and cereals with a concentration greater than 7.0% of amino acids, are buckwheat, oats, rye, millet, maize, rice, wheat, sorghum, amaranth, and quinoa.

Foods with protein concentrations greater than 7.0% percent are nuts, pumpkin seeds, hemp seeds, sesame seeds, and sunflower seeds.

Vegetables are poor sources of protein. The protein content of yams,  cassava and sweet potato is between 0 and 2 percent.
Fruits are a poor source of amino acids.

Legumes, cereals, nuts and seeds, and animal protein contain different proportions of all amino acids especially lysine, threonine and tryptophane.
No food is complete protein. Most foods containing protein also contain carbohydrates, oil, fibre, vitamins and minerals.
No food is the complete protein. The best source of protein is often a combination of various foods, because different foods are rich in different amino acids.

Digestion

Digestion involves breaking down peptides containing multiple amino acids into peptides containing 1, 2, 3 or 4 amino acids.  Digestion involves hydrochloric acid and enzymes present in the gastro-intestinal tract.
Absorption rates depend on type of protein.

Dietary requirement of protein depends on:

Body weight
Rate of growth and development (during childhood increased need of protein)
Physical activity
Carbohydrate intake
Pregnancy or breastfeeding
Presence of illness or injury
Recovering from malnutrition, trauma or an operation

Adult women need 46gm/day
Adult men need 56gm/day

Based on weight of 57 kg female and 70 kg male and 0.8 gm/kg and a sedentary lifestyle.
Active people need 1.6gm/kg-1.8gm/kg