For years now, eating foods which contain Omega-3 fatty acids have been strongly recommended by experts. Studies have been carried out to show just how much difference a diet rich in omega-3 can make not just to health but to behaviour. For instance, children who lack Omega-3 in their diet are more likely to suffer behavioural problems and have low IQ. Initially the message was a black and white one – Omega-3 fatty acids are good for us while Omega-6 fatty acids are bad.
But communications from nutritionists have become more subtle over time and we are given to understand that Omega-3 and Omega-6 are called essential fatty acids for good reason. The human body needs both of them for many functions, from building healthy cells to maintaining brain and nerve function. Since our bodies can’t produce them, the only source is food.
The problem is our diet. We don’t eat enough Omega-3 fatty acids and some of us consume excessive amounts of Omega-6 fatty acids. While the former protects us from illness, if we have too much of the latter, we are more vulnerable to heart disease. Some studies suggest Omega-3 fats may also protect against arthritis, Type 2 diabetes, Alzheimer’s disease, and age-related brain decline.
How does this translate into dietary advice? Well, Omega-3 is to be found in oil-rich fish like mackerel, fresh tuna, herring, sardines, and fresh or canned salmon. Two servings of oily fish a week are recommended. Nuts and flaxseed are also important sources.
Omega-6 mostly comes as linoleic acid from plant oils such as corn oil, soybean oil, and sunflower oil, as well as from nuts and seeds. The American Heart Association recommends that at least 5% to 10% of food calories come from Omega-6 fatty acids.
Proportion is critical
The reason there is a risk of over consumption of Omega-6 is that the oils are to be found in many processed foods. According to one website I looked at scientists are still debating the optimal amount of fat in a healthy diet, as well as the best proportion of Omega-6s and Omega-3s.
For now, there are several simple changes most of us could make. Replacing saturated fats with unsaturated fats is still one of the healthiest decisions. Saturated fats, which come mostly from animal sources, raise LDL, the form of cholesterol that clogs arteries. Unsaturated fats from vegetable oils, nuts, and fish can help lower cholesterol levels.
Nuts abound in Omega-3s and Omega-6s, which may explain why they have been shown to help protect against heart disease. In a 2010 analysis of four studies, researchers found that a weekly serving of nuts lowered the risk of dying of coronary heart disease by an impressive 8.3%. So another simple change is to add nuts to the weekly shopping list.
It remains a confusing area with knowledge gradually unfolding. The reason for my optimism is that a new scientific advisory council is to be set up to educate the public about the benefits of Omega-3. Hopefully this council will play a role in demystifying the science and making clear recommendations so that we all know how to eat healthily.