Wednesday, February 25, 2009

Eat healthily

Eat healthily
Wed, Feb 25, 2009
The Star/Asia News Network

[Top: Eat an abundance of fruits and vegetables as they will give you the vitamins and fibre you need. The antioxidants that come with them will also help reduce inflammation in the body.]

By Lim Wey Wen

CARING for your heart is a full-time job: you have to eat right, exercise correctly, take life easy and treat heart disease early.

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But if you think that is too much work, think about the possibility of having a heart attack and bypass surgery at the age of 40.

The truth is, a hearts attack is almost always the end product of years of unhealthy lifestyle choices.

Long before a major cardiac event, the damage is often already done by diabetes, hypertension, the metabolic syndrome and obesity. Perhaps, we are either too distracted or too busy to care.

Once you pick up any of the above risk factors, accelerated ageing starts in your body. This is the recipe that is going to give you a heart attack, says senior lecturer in cardiology Dr Jeyarajah Sivalingam.

That is why more emphasis should be placed on the prevention of these risk factors, rather than remedial actions after heart disease sets in.

One of the easiest way is to watch what you eat. As the saying goes, you have the final say over what goes into your mouth and stomach.

The trick is to know how.

Revisiting dietary advice

Until recently, the story of atherosclerosis (the narrowing of arteries due to plaque build-up) went like this: You have high cholesterol, the cholesterol gets deposited in your arteries and they get clogged. The heart muscles are deprived of its oxygen source - blood - and you get a heart attack.

Nevertheless, as almost half of those who have had heart attacks are found to have normal cholesterol levels, doctors began to suspect there may be something more than cholesterol causing the problem.

In 1999, a review article noted that the cause of hardening of arteries is clearly attributed to inflammation of the arteries. Subsequently, studies also found increased levels of the inflammation marker, C-Reactive protein (CRP), in those who had heart attacks.

"Now, the consensus among cardiologists today is that inflammation of the lining of the arteries is more of the root cause," Dr Jeyarajah explains. Inflammation, a protective response of the body against infections and injury, may damage blood vessels if it goes out of control.

This does not mean, however, that other risk factors should be ignored. High cholesterol, high blood pressure, diabetes, smoking and a sedentary lifestyle are still the main causes of heart disease.

What it means is there are extra measures we can take to protect ourselves.

Armed with this new knowledge, dietary recommendations are starting to change. Curbing the inflammation process is the new goal.

"One of the things that contributes to inflammation is what you eat. When food is consumed, it can be inflammatory or anti-inflammatory," Dr Jeyarajah says. "Resulting metabolites that are toxic to the cells can trigger an inflammatory response."

While some factors that trigger inflammatory responses, such as polluted air, excessive noise and high emotional stress, are less controllable, food is something you can choose most of the time.

Fats, sugar and inflammation

Instead of giving the lowdown on how to avoid meat, fat and cholesterol, Dr Jeyarajah says we should be more careful about the types of fat we eat and pay attention to our sugar and carbohydrate intake as well.

The reasons: precursors of inflammation are actually trans-fatty acids (TFA), saturated fats and sugar and carbohydrates.

For the uninitiated, TFAs can be found naturally in both animal and plant fat.

But the bulk of trans-fatty acids we take in now are the by-products of partial-hydrogenation, a process which adds hydrogen molecules to unsaturated fatty acids (usually from a vegetable source) as a means to make liquid oils last longer and take a semi-solid form at room temperature.

Margarine and vegetable oil spreads. Easy to spread,
not so great for your heart.

In food, TFAs are mostly found in hydrogenated oils like margarine or vegetable oil spreads. And the use of margarine and vegetable oil in other food such as snacks, fried food, ice cream and baked goods contribute to a large amount of trans fat consumption.

"We have always been told to stay away from saturated fats, but now we know that TFAs can increase the risk of a heart attack more than saturated fats," says Dr Jeyarajah.

A review of studies on trans fats published in the New England Journal of Medicine concluded that "on a per-calorie basis, trans fats appear to increase the risk of coronary heart disease more than any macronutrient".

Another study which analysed data from 900 coronary events out of 120,000 nurses over 14 years revealed that the increase of 2% intake of calories from trans fats have been found to double the risk of chronic heart disease (CHD) - an increase that could only be achieved with more than a 15% increase in saturated fats calories intake.

This does not mean saturated fats are no longer a factor in the increased risk of heart disease. Epidemiological studies have long established the link between saturated fats and heart disease - a link that still stands now.

The next culprit of inflammation is a staple of the Asian diet - sugar and carbohydrates.

However, it is no longer enough to distinguish between simple and complex carbohydrates - what we used to call bad and good carbohydrates, respectively.

Now, a more important factor in choosing carbohydrates is the Glycaemic Index (GI) - an indicator of how fast carbohydrates and sugars in a certain food raise blood sugar levels.

High GI foods such as refined carbohydrates, potatoes or table sugar break down in the body rapidly and raise blood sugar levels in a short time.

The spike in blood sugar levels generated may cause inflammation as high blood sugar levels, even if transient, favour a process called glycation, which damages and distorts body structures and functions, triggering an inflammatory response.

The middle path

With mounting evidence of the link between TFAs and heart disease, Canada has now banned trans fats from its restaurants and fast food chains. Denmark and Switzerland have introduced laws which strictly regulate the sale of many foods containing trans fats.

Australian margarine has been free from trans fat since 1996 and in the United Kingdom, Sainsbury's became the first UK major retailer to ban all trans fat from all their own food brands.

Under Malaysian food regulations, it is not compulsory to display or declare the TFA content of food products. The matter is still being examined by the Health Ministry.

However, if the manufacturers wish to declare or highlight the content of any type of fatty acids in their product, they must display the content of all four types of fatty acids, namely monounsaturated fatty acids, polyunsaturated fatty acids, saturated fatty acids and TFA.

Government initiatives aside, what can we, as consumers, do to care for our hearts?

Although there is evidence of TFAs and saturated fats contributing to the increased risk of heart disease, this does not imply that you should balk at the sight of their names printed on a nutrition label.

And eliminating fats totally from your diet may deprive you from the health benefits of essential fatty acids such as omega 3 and 6.

To choose and use your fats wisely, Dr Jeyarajah offers this advice:

- Be mindful of products listing partially hydrogenated oil as an ingredient, regardless of the type of oil.

- Be careful with vegetable shortening or products made with it.

- When buying margarine, look at the contents of TFA if available.

- Avoid fried foods in restaurants.

- Buy oil in smaller quantities and protect them from exposure to air, light and heat. Use it up quickly.

- Refrigerate (cooking) oils if you can't use them quickly.

- Never heat oils to the point of smoking. Never reuse oils that have been heated to high temperatures.

To choose your carbohydrates wisely, Dr Jeyarajah says:

- Learn about GI and try to look up the values of your common foods on the Internet.

- Reduce consumption of high GI foods; replace them with low to moderate GI foods such as whole grains.

- Eat less refined, processed and fast food

- Avoid sweet beverages

- Eat sweet fruits in moderation

In essence

Most dietary recommendations are ideals we strive to achieve for better health. Then again, our choice of food is not only based on nutritional values, but also whether it is affordable, accessible and available.

Working within these limits, these are a few rules of thumb you can live by:

- Remember amounts

Whatever the quality of food, if eaten in huge quantities, it becomes pro-inflammatory. It is always wise to eat in moderation.

- Aim for variety

Aim for a balanced diet that includes a variety of food as it provides the nutrients you need for good health.

- Include as much fresh food as possible and minimise consumption of processed and fast food

Processed and fast food may be tasty, but the processes may leach nutrients or add potentially harmful substances.

- Eat an abundance of fruits and vegetables

This will give you the vitamins and fibre you need. The antioxidants that come with them will also help reduce inflammation in the body.

- Eat your meals regularly

Studies have shown that if you eat your meals and snacks regularly, you are less likely to put on weight. That will decrease your risk of heart disease just by keeping your weight in check.

References

1. The Pennsylvania State University (2006). Hydrogenated Vegetable Oils and Trans Fatty Acids. Retrieved February 2009 from http://pubs.cas.psu.edu/freepubs/pdfs/uk093.pdf

2. American Heart Association (2008). Know your Fats. Retrieved February 2009 from http://www.americanheart.org/presenter.jhtml?identifier=532

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The Star/Asia News Network

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