This is the first guest blog post from food security expert Professor Ioannis Zabetakis of the University of Athens who will contribute occasionally on issues regarding food health and safety, environmental problems, pollution, and food security from the perspective of poverty, supply and demand and other angles.
Today, the world population is seven billion and this number is forecasted to reach nine billion by 2050 while food demand is projected to double by 2050. Also, one billion people are chronically undernourished and one billion are overweight. This is a complex challenge for all of us involved in the food arena.
From the nutritionist, agriculturist and aquaculturist points of view, our aim should be to sustainably produce food with high sensory and cardioprotective properties. The reason is simple: cardiovascular diseases (CVDs) remain the top global causes of death and stroke. According to the British Heart Foundation in the UK, in 2008, over 191,000 people died from heart and circulatory disease in the UK alone.
The prevention of atherosclerosis is, thus, one of the top priorities in academia and industry. Since the study of seven countries, a key question still remains unanswered: why cohorts in Greece and Italy had Coronary Heart Disease (CHD) at low frequencies but high levels of serum cholesterol? Is it something in the diet that prevents heart problems? And if so, then which food is the “secret weapon” against CVDs?
There is compelling literature on the beneficial role of omega-3 polyunsaturated fatty acids (omega-3 PUFAs) and there is a core belief that fish is good for our heart because of them. Mechanistically though, it is not clear how omega-3 PUFAs work. Their postulated mechanism in preventing atherosclerosis could be through lowering the levels of triacylglycerol, preventing arrhythmia, decreasing platelet aggregation or lowering blood pressure.
On the other hand, the association of omega-3 PUFAs and CVD has been revised recently by evaluating all randomized trials on the supplementation of omega-3 PUFAs to adults : the results of 20 studies on 68,680 patients were evaluated and omega-3 PUFAs were not found to be associated in a statistically significant way with CVDs in various patient populations. In the light of this study, we may need to re-focus our research quests towards feed and food components with proved cardioprotective activities.
Polar lipids of food
Lipid microconstituents of specific food that constitute important ingredients of the Mediterranean diet have been found that they have in vitro (in the test tube) important cardioprotective properties (by inhibiting the actions of Platelet Activating Factor, PAF). PAF is the most potent inflammatory lipid mediator, a well-recognized agonist of platelet aggregation that plays a crucial role in atherosclerosis. These lipid microconstituents can inhibit the onset of atherosclerosis and the development of CVDs. Such lipids have been found in a wide range of food such as red and white wine, yogurt, fish, olive oil and olive pomace. Further, in vivo tests using rabbits on olive oil, olive pomace and aquacultured fish have re-confirmed that it is the polar lipid fraction of these food sources that can reduce the thickness of atherosclerotic lesions in hypercholesterolaemic rabbits.
Food for thought
In today’s rapidly changing world, we need to face conflicting problems and issues: overproduction and waste of food, obesity, CVDs and diabetes in the developed world, famine and malnutrition in the developing countries, climate change, scarcity of water, rational use of cultivated land and sustainable use of resources and energy. In this complex and swiftly changing environment, the issue of food security and on how we can secure nutrition for the entire human population becomes a top priority for all of us in the feed and food arena.
For securing enough safe and nutritious food for all, we need to face some problems. One of them is this “paradox” for producing fish, high amounts of fish oil are required to produce fish feed and thus aquacultured fish. Fish oil is also used in the production of omega-3 based drugs and supplements without clear benefits against CVDs. The diminishing levels of available wild fish worldwide combined to the fact that polar lipids of fish have clear cardioprotective benefits should provoke a re-evaluation of today’s practices. Fish could be used in a more holistic way with higher and clearer benefits for all.
- Nasopoulou C, Karantonis HC, Perrea DN, Theocharis SE, Iliopoulos DG, Demopoulos CA, Zabetakis I. 2010. In vivo anti-atherogenic properties of cultured gilthead sea bream (Sparus aurata) polar lipid extracts in hypercholesterolaemic rabbits. Food Chem 120:831-6.
- Nasopoulou C, Stamatakis G, Demopoulos CA, Zabetakis I. 2011. Effects of olive pomace and olive pomace oil on growth performance, fatty acid composition and cardio protective properties of gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). Food Chem 129:1108-13.
- Zabetakis I, Antonopoulou S, Demopoulos CA. 2013. The Prevention of Atherosclerosis by Food Components: Polar Lipids versus Omega-3 PUFAs. Commentary on www.athero.org published on 22.1.2013 (http://www.athero.org/commentaries/comm1119.asp).