The Good Oil?
There are mixed messages in the media concerning good and bad fats. But this isn't some kind of marketing spin. The health benefit of replacing saturated fats with mono and polyunsaturated options is scientific fact.
From a nutrition standpoint, edible oils and fats all fall into the same category. They are a type of fat or lipid called a triglyceride. As a food source they supply the body with 9 calories per gram.
This article focuses on oils derived from both plant and animal origins and considers their health benefits.
Vegetable oils have been harvested and extracted for thousands of years. A comprehensive list of the different varieties can be found here.
What you should know
Mono and Polyunsaturated oils are better choices than saturated fats. Getting enough Omega-3 and Omega-6 fatty acids will protect against at least heart disease and potentially much more.
But the essential fatty acid requirements make up about 3% of total required calories so this is no excuse to overeat any oils, which are so calorie dense that they will contribute to weight gain if misused.
Detail:
The human body is capable of synthesising many fatty acids but not all. The ones the body must consume are referred to as essential fatty acids. Examples of these are the much publicised Omega 3 fatty acids of which fish oils are a primary and efficient source. The body can synthesise these from Omega 6 fatty acids also.
Omega 3 and Omega 6 oils have been shown to have numerous health benefits when consumed in sufficient quantaties. They have definitely been shown to reduce risks associated with heart disease but may also have positive effects ranging from reduction in cancer risk, bipolar disorder, hypertension, eye disease, asthma, cognitive decline and depression.
Choosing the right oil may assist in keeping your cholesterol level within acceptable limits. Cholesterol is an essential requirement for building and maintaining membranes and membrane fluidity. Cholesterol is separated into two types, referred to as 'LDL' and 'HDL' cholesterol.
So cholesterol isn't the bad guy it is made out to be. It is too much of it, and specifically too much of the wrong type of cholesterol that increases health risks.
Studies worldwide have drawn links between increased LDL cholesterol, decreased HDL cholesterol and cardiovascular disease. What this means is that we need to keep our total levels within a reasonable range, and importantly, keep our LDL levels down. When you get your standard check-up with your local Doctor, one thing they are likely to check is your cholesterol levels, which they do through a simple blood test.
All fats (and oils) are thought to increase HDL cholesterol levels but mono and polyunsaturated fats will not increase the more damaging LDL cholesterol levels and can in fact reduce it.
Accordingly, in a choice between a fat that will raise LDL cholesterol and one that will not, the healthier choice is to choose a mono or polyunstaurated fat, like those listed below.
The FDA recommends up to 3g of Omega-3 per day.
In addition to the Omega 3 and 6 oils (which are polyunsaturated), other oils can also be classified as follows:
| Type |
Monounsaturated |
Polyunsaturated |
Saturated |
| Properties |
This oil could contain another hydrogen atom. |
This oil could contain more than one more hydrogen atom. |
This oil cannot contain any more hydrogen atoms. |
| Examples |
Avocado, Olive, Peanuts |
Canola, Sunflower, Corn, egg yolks, Deep-sea fish, walnuts |
Coconut, palm |
| What to do |
Consume in moderate amounts |
Consume in moderate amounts |
Keep to a minimum |
Bottom Line:
For those concerned with calorie intake, moderation of oil consumption is essential and obtaining enough good oils will require careful dietary monitoring or the use of oil supplements. Focus on getting enough Omega-3 and Omega-6 and avoid saturated fats where possible.
Sources:
Essentials of Human Nutrition, Third Edition, Oxford University Press
http://www.merckmanuals.com/home/disorders_of_nutrition/overview_of_nutrition/carbohydrates_proteins_and_fats.html
http://en.wikipedia.org/wiki/Vegetable_fats_and_oils
http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/fats_and_oils
http://www.health.gov.au/internet/healthyactive/publishing.nsf/content/eating
http://www.csiro.au/Organisation-Structure/Flagships/Food-Futures-Flagship/Good-oils-now-in-health-guidelines.aspx
http://www.heartfoundation.org.au/healthy-eating/fats/Pages/omega-3.aspx?gclid=CPywwNHorrACFcVMpgodwwO0WA
http://www.umm.edu/altmed/articles/omega-3-000316.htm
http://en.wikipedia.org/wiki/Fish_oil
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