Myth: Flaxseed oil is just as good as fish oil
Fact: A client once told me she poured flaxseed oil over her breakfast cereal. My initial (private) thought was ‘yuck, that can’t taste good’, but I was also intrigued. A web-search on flaxseed oil advertisements yielded claims bordering on the miraculous. I felt relieved she wasn’t swigging it straight from the bottle! There’s a lot to the omega-3 story, but here’s a taste.
There are two types of omega-3 fatty acids: the long chain marine types (EPA, DHA, DPA), and the short chain plant type (ALA). Both the plant and marine type of omega-3 fatty acids are necessary for good health, and especially important for a healthy heart. It is recommended we consume around 2 g of short chain ALA (Alpha-Linolenic Acid) daily to reduce heart disease risk. Flaxseed oil (also called linseed oil) is one of the richest sources of ALA. One gram of flaxseed oil yields around 0.6 g of ALA. Some quick maths shows 3-4 g of flaxseed oil (less than a teaspoon) will give an optimal amount of ALA. Pouring it over cereal is a bit over the top.
If you prefer ALA in a tastier form, try a small handful of walnuts (30 g), it provides 3 g ALA – your entire day’s optimal amount, plus some change. Canola oil, mustard-seed oil, soybean oil, breads and cereals containing linseeds, and high-omega eggs also contain good amounts of ALA, while small amounts are present in a range of other foods such as soy beans, green leafy vegetables, oats and wheatgerm. The practical advantage of canola and soybean oils is you don’t need to keep them in the fridge. Flaxseed oil is very unstable and will go rancid (oxidise) quickly just left in the cupboard. For the same reason, don’t even think of cooking with flaxseed oil.
Both short chain and long chain omega-3 are needed, but when it comes to protection against dying from cardiovascular disease, it is the long chain omega-3s that have shown the most convincing benefit because of their potent anti-inflammatory and anti-arrhythmic effects (among others). Both the American Heart Association and the Heart Foundation (Australia) recommend people who have already had a heart attack, or currently have angina, need 1000 mg (1 g) of long chain omega-3s a day from food and/or supplements for further prevention. The rest of us should consume on average 500 mg (1/2 a gram) daily. You can get this from 2–3 small serves of oily fish per week, such as swordfish, salmon, sardines, herring and tuna (check your local recommendations on fish and mercury content). These long chain omega-3s are not found in flaxseed oil.
In the past it was believed the body could convert short chain ALA to the long chain forms, and the more ALA you consumed the more EPA and DHA your body would make (thus the flaxseed on the breakfast cereal I guess). Studies have since shown this elongation process is limited, inadequate, and varies widely between individuals. Conversion estimates vary from 0.1%–10%, and one third of the population are unable to convert any at all. We need to get the pre-formed long chain omega-3s as well as the short chain ALA. So, the long and the short of it is, I’m off to shallow fry some Atlantic salmon in canola oil, and I’ll be pouring low fat milk on my cereal tomorrow for breakfast. Bon appetit!
For more information about omega-3s, food sources, and high omega-3 recipes, grab a copy of Eat to Beat Cholesterol by Nicole Senior and Veronica Cuskelly from Great Ideas in Nutrition and check out www.eattobeatcholesterol.com.au