We have explored the topic of vegetable oils previously in Odyssey Mail, but growing evidence that our Omega 3: Omega 6 (n-3:n-6) ratio is crucial to our cardiovascular health has brought us to highlight this again.
The graph below demonstrates the relationship between vegetable oil consumption (high in Omega 6), saturated fat and heart disease deaths. As you can see, there is no relationship between saturated fat and heart disease, but a strong relationship with vegetable oil consumption. You will note the graphs diverge after the year 2000 due to improved health care saving more lives – not preventing the disease.
So what’s going on here? We are told that we need Omega 6 in our diets because our bodies can’t create it, but it appears to be killing us?
If we go back in time, our ancestors ate a diet based on an Omega 3: Omega 6 ratio of 1:11 Very little of their diet came from seed sources (vegetable oils aren’t from vegetables at all, but mostly seeds).
With the growth of food industrialisation, consumption of n-6 fats increased at the expense of n-3 fats. This change was due to both the advent of the modern vegetable oil industry and the increased use of cereal grains as feed for domestic livestock (which in turn altered the fatty acid profile of meat that humans consumed).
Vegetable oil consumption rose dramatically from the beginning and end of the 20th century, and this had an entirely predictable effect on the ratio of omega-6 to omega-3 fats.
Between 1935 and 1939, the ratio of n-6 to n-3 fatty acids was reported to be 8.4:1.
From 1935 to 1985, this ratio increased to 10.3:1 (a 23% increase). Other calculations put the ratio as high as 12.4:1 in 1985.
Today, estimates of the ratio range from an average of 10:1 to 20:1, with a ratio as high as 25:1 in some individuals.
Omega 6 oils are necessary in the diet but have an inflammatory effect on the cardiovascular system.
Since it is now known that inflammation is involved in nearly all major diseases1, including obesity and metabolic syndrome, it’s hard to overstate the negative effects of too much omega-6 fat.
Sources of Omega 32
The following are good sources of EPA and DHA. You can choose from fresh, canned or frozen fish.
Salmon (line caught if possible)
What if I don’t like fish?
Plant based sources of omega 3 (AHA)
Oils especially flax, walnuts, krill and algal oils
Nuts especially walnut, pecan, hazelnut
Seeds especially pumpkin, chia, hemp
It is always best to get your omega 3’s from foods, however, if you choose to top up on EPA and DHA from supplements you need to follow a few golden rules:
Opt for a fish oil or an omega 3 supplement not a fish liver oil (Phil Richards fish oils are excellent)
If pregnant or breastfeeding avoid supplements that contain vitamin A (as retinol) altogether
Aim for an intake of EPA & DHA of 500mg each day, or as advised by your practitioner or doctor.