Title: The ‘healthy fats dinner’.
Key words: CHD, coronary heart disease, cholesterol, saturated fats, saturated, PUFA, polyunsaturated fatty acids, arachidonic acid, saturates, red meat, dairy, n-6, n-3 PUFA, immune system, Eskimos, fish oil, rheumatoid arthritis, RA, green vegetables, tuna, salmon, fruit, oats, walnuts, safflower, anchovies, flaxseed, rapeseed oil, olives, olive oil, monounsaturated fatty acids, monounsaturated, antioxidants, Benecol, stanol, eggs, brown bread, potatoes, satiety, yoghurt, carbohydrate, protein
Date: Oct 2006
Author: Morgan, G
The ‘healthy fats dinner’.
Interest in the role of fats in the aetiology of coronary heart disease (CHD) goes back many years. In an important early study, Keys (Keys 1970) showed a close correlation between blood cholesterol, saturated fats intake and the incidence of CHD. Even earlier in 1956 Sinclair had pointed out that saturated fat excess was but an indicator of polyunsaturated fatty acid (PUFA) deficiency and that this was the true modulator of atherogenesis. This would appear to be born out by the low levels of arachidonic acid found in the cell membranes of CHD cases (Riemersma 1992). Further studies have confirmed that the presence of the atherogenic lipid profile characteristic of CHD is associated with a low polyunsaturated to saturated fatty acid ratio. Concern over the high rate of CHD in the developed world in the 1970’s focused initially on the levels of dietary saturated fats. Government and medical agencies and the food industry addressed the problem by promoting the reduction in consumption of saturates and increase in consumption of n-6 PUFAs.
This led to recommendations to decrease the consumption of red meat and dairy produce and to increase the consumption of fruit, vegetables, vegetable oils and margarine spreads derived from n-6 PUFAs. Reduction in the rate of CHD in the USA and other countries followed these dietary interventions but at the same time a rise in the incidence of asthma and atopic eczema was also noted (Calder 2000). Interest in an imbalance between n-6 and n-3 PUFA consumption leading to dysregulation of the immune system was further stimulated by the observations on Eskimos (Bang 1980). This population had a very high intake of long chain n-3 PUFA’s and a very low incidence of CHD with evidence of far less pro-inflammatory immune system. Subsequent trials such as the GISSI trial (1999) have confirmed the effectiveness of fish oil supplements in significantly lowering the incidence of CHD. Other workers have shown have confirmed the ability of n-3 PUFAs to modulate immune or autoimmune inflammatory disorders such as rheumatoid arthritis (Mayer 1998 for review). It is also clear that daily consumption of n-3 PUFAs in the UK falls well short of recent government recommendations (DOH 1994, Gregory 1990).
The Healthy Fat Diet
In the light of the above observations the recent ‘Healthy Fats Dinner’ at Surrey University serves to illustrate how dietary changes can bring about a more healthy lipid profile. The meal featured the following:
The above meal thus contained something close to the ideal balance between the n-3 and n-6 PUFAs whilst retaining a healthy balance of other essential nutrients. It fulfilled all the recommendations laid down by the government for a healthy diet and achieved this target in a way which was both practical and delicious.
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