Today’s typical Western diet is well known for its imbalance between the intake of omega-6 to omega-3 oils. Not surprisingly, there is increasing interest in what this actually means for our bodies and our long-term health, writes Complementary Medicines Australia's Miho Kikuchi.
While advances in medical science have brought wide-ranging positive health benefits, Australia is faced with ever-increasing rates of chronic disease, ranging from cancer, cardiovascular disease and cognitive decline, to arthritis, osteoporosis, obesity, and diabetes. The list goes on. What is more, one half of the Australian population suffers from at least one chronic disease. The mounting epidemic of chronic disease, and the associated healthcare costs, is rapidly getting out of control.
At the same time, interestingly, we are less likely to drink and smoke at risky levels compared to in the past. In fact, the volume of alcohol consumption is at the lowest level since 1962-63. Moreover, the number of Australian smokers has decreased by nearly half compared to 25 years ago, thanks to the national anti-tobacco campaign.
Over the last 10,000 years, there has been very little genetic change in our species. Our diet, however, has changed substantially. The rapid dietary changes over the last 100 years especially are recognised as the most potent promoters of chronic disease. We are, after all, what we eat. We consume more saturated fat, omega-6, trans-fat, and junk foods high in sugar and salt, and consume less omega-3, vegetables and fruit. We also consume more calories but have decreased our energy expenditure.
Among the various factors that either contribute to or mitigate the epidemic of chronic disease, omega-3 has arguably received the most attention in recent years. In Australia, omega-3 supplements are the second most popular form of supplementation after multivitamins, and there is extensive evidence from clinical trials supporting their beneficial use. Omega-3 supplements have been widely used for various conditions, such as joint health, eye health, prevention of cognitive decline, and also skin conditions including psoriasis.
There are also studies demonstrating the beneficial use of omega-3 supplements during pregnancy. Benefits include reducing the risk of children developing persistent asthma or wheezing and infections of the lower respiratory tract, and also for preventing perinatal depression. Due to its multiple effectiveness, omega-3 is often referred to as “good oil”.
However, it’s not enough simply to increase your intake of omega-3. While we should ensure that we consume a good amount of omega-3, we also need to pay attention to the amount of omega-6 we consume. Although omega-6 is often referred to as “bad oil” as opposed to omega-3, omega-6 plays an important role in brain function, and normal growth and development, in moderate amounts. As our body is unable to make omega-6, we need to consume it in our diet.
The important point to keep in mind here is the intake ratio of omega-6/omega-3. The typical Western diet tends to over-supply omega-6. While human beings have evolved eating omega-6 and omega-3 at a ratio of about 1:1, the current typical Western diet is extremely deficient in omega-3 and has an excess amount of omega-6.
The average omega-6/omega-3 intake ratio is calculated to be 15/1 to 17/1. Indeed, only 20% of Australians obtain an optimal omega-3 intake and only 10 per cent of women of childbearing age meet the recommended intake of DHA. Further, modern agribusiness has greatly increased the production of omega-6-rich vegetable oil and grain feeds for domestic livestock, resulting in increased human consumption of omega-6 and decreased omega-3.
This very high omega-6/omega-3 ratio leads to a pro-inflammatory state in the body and promotes the pathogenesis of many diseases including cancer, cardiovascular disease, and inflammatory and autoimmune diseases. A number of studies have demonstrated that a lower ratio of omega-6/omega-3 is able to reduce the risk of many chorionic diseases, such as cardiovascular disease, colorectal cancer, breast cancer, rheumatoid arthritis and asthma.
Considering that inflammation is seen as a foundational factor of many chronic diseases, the anti-inflammatory effect of omega-3s plays an important role for the prevention or management of these. Since many chronic diseases are considered to begin in utero or early in infancy, maintaining the balanced ratio of omega-6/omega-3 is extremely important from the earliest stages of development, or even prior to pregnancy.
In the end, it’s all about balance. Even if omega-3 intake is increased in the Western diet, we still need to make sure to reduce omega-6 intake. The balanced ratio of omega 6/omega 3 is crucial for good health and normal development, but also for the prevention and management of chronic diseases.