Oils & Fats between Confusion & Controversy
When you go shopping do you go for the margarine because you have been told it’s healthier & avoid butter because it’s not?
When you cook & fry foods do you happily throw in the corn or vegetable oil because you have been told its healthier for you than ghee or butter?
Does fat make you fat?
There is much controversy when it comes to fats & oils, inevitably this has lead to much confusion amongst the public. Infact fat has almost become a swear word. Is this the correct understanding of fats & oils. Where & how did it all start?
The History
At the beginning of last century, we should bear in mind that people ate meat & fats, vegetable oils were practically unheard of. Gradually margarine & shortenings were introduced into the market. Heart disease began to increase. In 1956 in the US a scientist by the name of Ancel Keys published a six country study that showed a virtually perfect relationship between fat intake & heart disease. This influenced official dietary guidelines issued by organisations like the American Heart Association (AHA) & government bodies. These were based on the principles of replacing butter, lard, beef & eggs with corn oil, margarine, cold cereals & chicken. In 1957 it was pointed out that had Ancel Keys used data from all of the 22 countries in his study the perfect relationship between fat intake & heart problems did not exist.
In the meantime cardiovascular disease was on the increase & so was obesity in both the US & the UK. Studies that showed that polyunsaturated fats in the form of margarine & using vegetable oils to fry with were responsible for heart problems were given minimal attention until the 1970s.
Cholesterol
1958 saw the publication of the first scientific text on cholesterol by Russian scientist David Kritchevsky Phd of the Wistar Institute. It brought to the forefront the possible association between the lipid compound, cholesterol & heart disease risk. In the same year a study was released on the South African Bantu tribes in relation to dietary intake & plaques in the arteries. The Bantu led a virtually vegetarian lifestyle. The study compared the degree of arteriosclerotic plaques (which block the arteries)to other South African tribes that ate higher amounts of meat & fat. The degree of plaques in the arteries was found to be similar regardless of differing dietary habits. In 1961 the Diet - Heart hypothesis reached new levels of public awareness when Ancel Keys made the cover of Time magazine. Cholesterol at this point was known to be elevated in those with coronary heart disease. Dietary intake causing increased cholesterol was still an unproven theory- it was still just a hypothesis.
Dietary Guidelines
The American dietary guidelines from then on placed great emphasis on reducing saturated fat & substituting polyunsaturated fats. Nutritional guidelines in the UK were very similar to those in the US. However obesity figures were on the increase in both countries. In 1980 US obesity was at 15% & in the UK 7% by 2001 it was 31% in the US & 21.5% in the UK. Over the years many studies & reports have been released pointing out the harms of trans-fatty acids like margarine & that ¾ of the fat in artery clogs was polyunsaturated. Coronary heart disease death rates were not declining rather there was an improvement in the management of medication. In the US in 1979 there were 1.2 million heart disease medical procedures whilst in 1996 there were 5.4 million.
Dubious Evidence
In 2004 Dr Walter Willet MD a professor of Epidemiology & Nutrition at Harvard & one of the most cited nutritionists admitted on PBS television that the evidence to leave saturated fats & cholesterol in favour of polyunsaturated fats was minimal. Dietary guidelines advocating low fat diets had neither helped people reduce weight nor avoid heart disease. Rather reduced carbohydrate diets are the key to losing weight. In reference to the official US dietary guidelines Walter Willet said, “Scandalous, they say, “You really need a high level of proof to change the recommendations, which is ironic, because they never had a high level of proof to set them!”
Make A Change
So what are the practical lessons we can take in light of the dietary guidelines & 30 year of weight gain? Namely we should be more careful in the choice of oils & fats & how we prepare food with them in order to avoid heart problems.
- Avoid Trans- fatty acids like margarine & hydrogenated vegetable fats in products. Always check the ingredients. Why are these so bad for us? These polyunsaturated oils are subjected to a chemical process including high heat. This changes the structure of the molecule meaning that our bodies no longer recognise these fatty acids & they become very damaging to the structure & function of our tissues. Some experts believe that trans fatty acids are closer in structure to plastic than fat. These are the bad fats, which are increasingly associated with a variety of diseases, including Cardiovascular diseases. It is these fats which are being used increasingly & saturated fats which are being used less since the beginning of the last century.
- It has to be said that frying & deep frying are not healthy practices. Subjecting fats to high temperature through frying produces some trans fatty acids & other oxidation products which are even more toxic. Fats which are least damaged by frying are in fact saturated fats such as butter, ghee & virgin coconut oil. These can be taken up to a higher heat than polyunsaturated oils like corn oil, sunflower oil & vegetable oil. In fact these oils begin to undergo chemical changes as soon as they exposed to light, oxygen & heat let alone frying. Because we do not drop dead after eating these toxic substances hence they seem harmless but over 10, 20, 30 years our cells accumulate altered & toxic products from which our bodies cannot detoxify themselves & so they interfere with our biochemistry. Our cells degenerate & these degenerative processes manifest as degenerative diseases like heart disease & cancer.
- Monounsaturated oils such as extra virgin olive oil are acceptable for low temperature frying & cooking. It must not be taken over it’s smoke point, which is 163°C (325°F). The smoke point is the point at which the oil when heated becomes rancid, discoloured & toxic to our health. Extra virgin olive oil is perfect for salads or even adding to cooking after its done.
- Practically speaking we need to avoid deep fried foods like samosas, pakoras, chips & parathas. Alternative ways to cook these should be tried such as baking. If one is suffering from a degenerative disease, frying should definitely be abandoned.
- We need to redress the balance of EFAs (Essential Fatty Acids). Generally speaking we are deficient in Omega 3 fatty acids & consume too much Omega 6 fatty acids. Omega 3s are found in oily fish ie salmon, trout, mackerel, flax seed oil, walnuts. Omega 6s which are important are found in sunflower oils, seeds, pumpkin seeds & hemp oil. An ideal ratio of Omega 6 to Omega 3 fatty acids is 2:1 - 1:1. In a modern diet the ratio of Omega 3 to Omega 6 is 1:15-16. This ratio is shown to promote the development of CVD, cancer & autoimmune diseases. These oils should be consumed in their natural state or cold pressed definitely not used for frying & deep frying as mentioned above. Fat consumption should be not more than 15-20% of our total calories.
- Eat meat in moderation. Eating it twice a day every day is excessive. If you can source healthy, organic, grass fed animals all the better. Consuming meat from animals that are fed antibiotics, hormones & grains will inevitably affect us. However for communities like Muslims living in Western countries who are obligated to eat Halal meat then at the present time there is no other choice but to eat meat in moderation & as lean as possible. Remember toxins are stored in the fat.
- Eat more fresh vegetables as part of your meals. These provide fibre, anti oxidants, vitamins & minerals which are essential for health & the avoidance of degenerative diseases like CVD & cancer. Of these in particular is Vitamin C.
- Eat less sugar & refined foods like white rice, white pasta & white flour. Our body transforms refined carbohydrates into hard, sticky fats & cholesterol. They increase blood fat levels which block our arteries & increase the risk of CVD. It is one of the main causes of obesity which is now widespread. It is this villain which makes you overweight not fat. Sugar is actually quite a toxic substance. It inhibits our immune function & causes diabetes to name but a few effects. Unfortunately it is found in most processed foods & it is fed to our children in abundance. In the last 200 years sugar consumption has increased from 15 pounds per person annually to 135 pounds.
- Exercise. Our bodies are meant to be active. If our nutrition is optimal, being active is natural & comes easily. If we remain inactive, even good nutrition will not keep us healthy. Improve your flexibility, aerobic capability & strength, these three forms of exercise are part of all round physical fitness.
In conclusion knowing what foods to eat & what foods to avoid is essential. We are fortunate enough to have an abundance of food around us in developed countries but that means we are equally at risk of being mal nourished as people who are starving. The only difference being we choose to eat insufficient amounts of foods that are required for nourishment & instead consume foods that harm us. Rather we have to be familiar with what foods consist of & what functions they fulfil in our bodies & also be aware of the bad effects that certain foods & substances can have on us in particular in relation to obesity, Cardiovascular disease (CVD) & diabetes. Consuming the correct fats & oils is key to attaining good health. For further information do not hesitate to contact me. If you feel that you may be at risk of a fatty degenerative disease such as obesity, CVD or diabetes & are not sure how to tackle this problem, then I can design a healthy food programme & physical activity plan to get you back on track to health.
References:
Fats that Heal Fats that Kill - Udo Erasmus
Stop Trans Fats - www.stop-trans-fat.
Advanced Nutrition for Weight Management - Premier Training International