Friday, October 27, 2006

Nutrition - Fat that make you thin ..... K!

Since the beginning of processing and hydrogenation of oils during the 1930’s to mass produce and preserve food for longer, many of the beneficial Essential Fatty Acids (EFAs) naturally present in nuts, seeds, grains, vegetables and their oils have been lost, as they are very susceptible to damage by heat, light and oxygen.

Much of the benefits of oils are found in their natural or unrefined states and when processed they are destroyed and can lose nutrients such as sterols and fat-soluble vitamins A, D, E and K, needed for the use of fats in the body but also many functions, including the correct regulation of blood cholesterol and triglyceride fat levels.

The food industry likes foods that are cheap and have a long-shelf-life and so use processed fats in abundance. The hydrogenated and ‘trans’ fats found in processed foods are ‘deadly’ fats, damaging to health and to be avoided; they also interfere with the use of the ‘good’ natural EFAs in the body.

Fat has been blamed for its part in contributing to heart disease and weight gain to name a few and yet recent research disproves the popular perception that all fats are bad. It is the quality of fats that matters and if you have been avoiding fats it is time to rethink and perhaps increase your intake but of the right fats, the EFAs.

The EFAs cannot be made in the body and are known as essential fatty acids as they must be obtained through the diet from fresh nuts and seeds and their oils, vegetables and oily fish like mackerel, sardines, tuna and salmon. They are vital for energy, achieving ideal body weight, healthy skin, good mood and memory, brain and mental health (60% of the brain is made of fats) and protecting against infections. They also help to reduce pain and inflammation, balance hormone production, and are vital for a healthy heart, lungs and all cell membrane structures.
For all these reasons, research has shown that we are programmed to eat fat for survival. However, if our needs are not satisfied with essential fats and we consume saturated or processed fat alternatives, the need for the ‘good’ fats is never met and we will continue to crave and eat fatty foods. Eat enough EFAs and the balance between taste versus satiety should eventually be restored, as the body’s fat requirements are met.

EFAs are destroyed in foods such as margarines, frying oils, supposedly healthy ‘low fat’ spreads, and all the biscuits, baked produce, ‘ready’ meals and junk foods they are used in; even the healthy Omega 6 and 3 EFAs (polyunsaturated fats) that these products contain have been damaged by the processing and turned into hydrogenated fats, trans fats and other toxic substances which the body cannot recognise or use for vital EFA functions.

Think healthy Mediterranean diet, with olive oil and unsaturated fats like fish, nuts and seeds, whole grains and wild or free-range, organic meats and dairy produce vs. ‘supersize’ me processed foods. The significance of this is hugely important as studies have revealed the latter, with these damaged fats are known to increase the risk of degenerative diseases including various forms of cancer, adversely affect immune health and weight control, compromise infant development and raise the risk of heart disease.

The truth is that the beneficial, health-giving oils, high in EFAs, have a short shelf-life, should be used fresh and should never be used for cooking, as destroyed by heat. They should be cold-pressed oils, stored in dark glass bottles, in a refrigerator to prevent oxidation damage, and consumed in a higher ratio to other fats, as saturated fats (from meat and dairy produce) can stop them being used in the body – the exception is those found in oily fish. For cooking it is best to use other healthy oils, which are less damaged by heat, therefore cold-pressed virgin olive oil, canola oil or a little organic butter.
The EFAs can be divided into two groups, the Omega 3 and Omega 6 oils. The Omega 3 oils are found in oily, coldwater fish such as mackerel, herring, salmon, trout, sardines and anchovies. However, these can contain high levels of mercury so it is best to limit your intake to about three times a week, the smaller the fish, the less mercury it will have accumulated. Also go for wild, organic fish where possible and limit your intake of farmed fish, especially salmon, as the latter has been found to be high in industrial toxic wastes, which have been dumped in the sea. The best vegetarian sources are flax (or linseed), hemp and pumpkin seeds, walnuts and their cold-pressed oils. The Omega 6 oils are found in hemp seeds, evening primrose oil, borage oil, sunflower seeds, pumpkin seeds, sesame seeds and their cold-pressed oils. Nuts, except peanuts, are also good sources.

Some roles EFAs play in the body:
• Vital energy source: providing more than twice as much energy than one gram of carbohydrate or protein, the energy produced is stable and sustained unlike energy from sugar or other stimulants.
• Increase metabolic rate: good for weight loss because it means more calories are burnt.
• Decrease cravings: obtaining the right nutrients stops us from craving ‘wrong’ foods.
• Brain health: 60% of the brain’s weight is made up of EFAs, primarily in the form of the Omega 3 DHA and EPA fatty acids found primarily in oily fish. They have been shown to elevate mood, mental ability and memory. They are crucial during pregnancy and breastfeeding for healthy development of the child and during infancy for growth.
• Heart health: help lower blood triglycerides, cholesterol and blood pressure. They may also make blood platelets less sticky rendering them less likely to form clots – this therefore protects us from heart attacks and strokes.
• Immune health: EFAs protect us from free radical damage caused by pollution, oxidation and natural respiration (increased during exercise), which can lead to diseases such as cancer. They also reduce pain and inflammation and promote healing.
• Skin health: keep skin, hair and nails healthy and flexible by providing a waterproof sheath. EFAs can also provide relief from eczema, psoriasis and other skin complaints.
• Detoxification: some toxins require EFAs to be detoxified by the liver and removed from the body.
• Digestion: can help prevent leaky gut and food allergies. May help to reduce cravings and addictions.

Embarking on a low-fat diet not only reduces the amount of harmful saturated fats (although we need some for energy and building cell membranes), but also the essential fatty acid intake which can have disastrous consequences. If you have avoided fat because of previous dieting advice or popular opinion, this may be the time to rethink. If you wish to reach your ideal weight, improve energy, reduce aches and pains, inflammatory conditions such as arthritis, skin complaints like eczema or dry skin, food allergies, recurrent infections, poor mood, memory and concentration, cravings for junk foods, or just protect against degenerative disease –start eating daily servings of EFAs.

This does not mean loading up on margarine, supermarket frying oils and lard, but looking at foods like a handful of fresh nuts and seeds a day (add to fruit smoothies, salads or warm, but not hot, soups), avocadoes, olive oil and oily fish (ideally at least 3 portions a week), which may have previously had the “high in fat” tag forced upon them. These foods which many people avoid are superfoods; they contain an incredible array of nutrients as well as extremely beneficial fats, minerals and the vitamins, A, D, E and K which can only be absorbed and transported in the body by fats, hence risk being deficient in low-fat diets.

The recommendation for normal circumstances remains to get no more than 30% of your calories from fat (so for a 2000 calorie a day diet, that is 600 calories from fat, or 67 grams worth) however follow these tips:
• Make sure your EFA, polyunsaturated fat, intake is adequate, perhaps 60% of total fat
• Reduce saturated fat to no more than a 1/3 of you total fat intake (fat from meat, milk, cheese and butter. Opt for lean, organic cuts of meat and natural sources such as free-range eggs or dairy, as these contain less antibiotics and hormones, those harm the body, and more of a good fat called CLA, conjugated linoleic acid)
• Make sure your diet is rich in nutrients that help the use of fatty acids: magnesium, zinc, vitamins
C, B3 and B6 (found in whole grains, fruits, green leafy vegetables, pulses, seafood, nuts and seeds)
• Never use omega 3 fatty acids for cooking* (try instead a little butter, olive oil or canola oil)
• Avoid hydrogenated and trans- fats (reduce processed and per-packaged foods; check food labels)
• Avoid margarine and ‘low fat’ spreads (use omega 3 spreads or olive oil spreads instead)
• Avoid fried foods where possible as these contain damaged fats (‘steam fry’ instead by adding a little water to olive oil to lower the frying temperature and cause less damage to the fat)
• Ensure that the diet contains antioxidant-rich foods that help the body to use fats and may help to protect brain membranes (including vitamins A, C, E and the minerals zinc and selenium; we will look at these in the future).

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