The All-Important Omega-3s
Omega-3s are once again a hot topic in the media and market shelves are full of omega-3 products. Is that justified? Is it really that important for pregnant women, children and adults to eat fish, omega-3s or DHA? And what’s the difference? For consumers, it does not seem easy to make a decision.
Let’s take a closer look at the ‘Omega-3 story’. Since the 1970s, scientists all over the world have taken a keen interest in the role of omega-3 fatty acids in human health. These nutrients are now among the most studied. Research has largely reported that omega-3s are of high importance for the human body—all cells depend on them throughout life. It starts with the conception phase, pregnancy and childhood, and continues until old age, where they are required for the development and maintenance of body functions.
While the brain and eyes are particularly dependent on a sufficient supply of omega-3s, consuming enough of these nutrients also helps to prevent and/or ameliorate common diseases such as cardiovascular disease, metabolic diseases, cognitive and psychological disorders, inflammatory diseases and even infertility.
Deep Diving Into The Omega-3s
There are three major omega-3 fatty acids in the diet that are involved in human physiology—alpha-linolenic acid (ALA), the longer-chain omega-3s eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
ALA is an essential nutrient and the human body depends on dietary intake, e.g. from plant oils. ALA is the precursor to EPA and DHA formation in humans. However, since human production of EPA and DHA is inefficient and dependent on diet composition, intake of preformed EPA and DHA has become crucial. These two do only occur in marine foods like salmon, other fatty fish or seafood.
Fatty acids usually serve as a source of energy and as building blocks for the body’s fat stores. However, EPA and DHA are unique as they have specific functions within the body. They are components of cell membranes where they have bioactive functions, are required for cellular signalling pathways and gene activation and they modulate anti-inflammatory cascades.
In short, omega-3s influence the proper functioning of every single cell in the human body and consequently have a major impact on development, health and diseases.
The average intake of omega-3s varies across cultures, countries and regions of countries, depending on the diet and amount of marine foods consumed. The recommendations for omega-3 intake tend to vary as well. For example, the American Academy of Nutrition and Dietetics recommends an intake of 500 mg of EPA and DHA combined per day, while the Japanese Ministry of Health, Labour and Welfare recommends at least 1,000 mg per day, but ideally 1,800 mg for women and 2200 mg of EPA and DHA combined per day for men in the general adult population. Scientists and authorities including the Food and Agriculture Organisation of the United Nations, World Health Organisation and the American Heart Association have also strongly advised consuming omega-3s.
For the management of cardiovascular risk factors in patients, such as lowering high triglyceride levels, intake of 2,000 mg up to 4,000 mg of EPA and DHA combined per day has become a medical practice.
Getting The Balance Right
Consuming less omega-6 fatty acids and more omega-3 fatty acids is a common guideline because it is important to keep the right balance of these antagonistic players in the human body. An excessively high ratio of omega-6s versus omega-3s, as found in a typical Western diet, promotes the development of diseases, whereas a low omega-6s versus omega-3s ratio has beneficial effects.
High consumption of common vegetable oils and meats (rich in omega-6s) and low intake of marine foods (rich in omega-3s) increases the ratio, which should ideally be kept to a maximum of 1:5. Nations that consume a lot of fish and seafood, like Japan, are able to achieve this. Western diets have been shown to contain as much as 10 to 30 times more omega-6s than omega-3s, thus throwing the ideal ratio off balance and allowing more omega-6s to crowd out omega-3s in our cells.
Benefits: EPA Versus DHA
Consuming DHA and EPA, either from marine foods, dietary supplements or DHA-fortified foods, has been advised for good reasons. EPA is important for heart function, as it helps regulate blood pressure and heart rate. It is also vital for the brain where it influences serotonin release and thereby mood control. Most prominently, EPA is a key inhibitor of inflammation, ameliorating eczema, arthritis, asthma and chronic obstructive pulmonary disease.
DHA is the building block of cell membranes and helping them maintain their functionability. The brain and eye particularly accumulate DHA where it influences the production of neuro-transmitters and thereby safeguards cognitive and visual function.
For example, DHA controls serotonin action in the brain and together with EPA, regulates mood and related disorders like depression, anxiety and impulsive behaviour. DHA also improves cognitive function throughout life—in a child’s brain development phase, during adulthood and in seniors where it lowers the risk of dementia and Alzheimer’s disease.
Pregnancy And Preformed DHA
Pregnant women should take good care of their DHA intake as. DHA accumulates in the brain before and after birth. Maternal stores provide the developing baby with the DHA necessary for brain development and, after birth, they continue to consume DHA from their mother via breast milk.
If the mother does not have enough DHA stores and does not consume adequate amounts of preformed DHA in her diet, the baby will not get enough for proper development and both mother and child will be malnourished.
Apart from better child development, good DHA status during pregnancy has also been associated with reduced preterm births, a lower risk of anxiety disorders during pregnancy as well as postpartum depression.
Pregnant women are usually advised to avoid eating fish that may contain elevated levels of mercury and other pollutants. Therefore, pregnant women are likely to avoid eating fish altogether with the good intention of providing the best nutrition for their growing offspring. It is precisely during this period in the baby’s life that getting enough DHA is of utmost importance.
Quality Makes A Difference
Selecting a high quality omega-3 source and preserving freshness is critical to ensure that uncompromised omega-3 reaches the consumer. In a recent article published by Scientific Reports, researchers found that fish oil supplements in New Zealand were highly oxidised and most did not meet the label content of omega-3s.
Only three out of 32 fish oil supplements surveyed contained the quantities of EPA and DHA that were equal to or higher than the labelled content, with most of the products tested containing less than 67 percent.
To ensure optimal freshness, fresh raw material with minimum odour and oxidation needs to be carefully selected. Proper handling must be applied to avoid oxidation later on in the production process. The finished product should also be dried in low light and packed in light-impermeable final packaging to ensure that freshness is preserved from start to finish.
For dietary supplements, it would be ideal to have reduced saturated fat of less than one percent in the finished product, compared to standard natural fish oil which comprises nearly 30 percent saturated fat. What this means for the consumer is simply this—better quality fish oils lead to less unwanted fats and better taste, while also allowing higher dosages, thus requiring fewer capsules to be consumed. Smaller capsules make ease of swallowing an added convenience for consumers.
Making Decisions Based On Science
With this knowledge, finding the right omega-3 product is easy. Firstly, it should contain DHA and EPA. Secondly, it should come from a high quality source and from a trustworthy supplier and finally, DHA and EPA should be as high in concentration as possible.
The message to consumers is clear—the scientific evidence regarding the health benefits of omega-3s is overwhelming. The right product can ensure better health.