Omega-3 deficiency: mostly pregnant women and children to suffer

Consumption of omega-3s often falls short of the amounts recommended by the World Health Organization, highlighting the need to promote their consumption especially in the most vulnerable groups of the population, such as children, women of childbearing age and the elderly. For example, among Americans, the amount of EPA and DHA consumed by pregnant women is five times less than the recommended 520 milligrams, and in children it reaches only 40 percent of the optimal dose.

These are the findings published in the journal Nutrients by researchers at the University of Nebraska Medical Center the Pennsylvania State University and the University of California Riverside (USA).

Proper omega-3 consumption is essential especially for pregnant women and children

The major omega-3 fatty acids, EPA and DHA, play key roles related to health and the development of certain diseases, and the benefits have been well established by numerous scientific studies.

In early childhood, omega-3s play an essential role in growth, particularly in vision and brain development. In children, in fact, these fatty acids are essential in maintenance and cell renewal throughout the body and have been shown to have a positive impact on brain activity, learning, and cognitive development.

Increased consumption of EPA and DHA during pregnancy has been associated with lower risk of maternal depression, lower intrauterine growth restriction and preterm delivery, and reduced allergies and asthma in children.

In adults, increased consumption of these fatty acids is associated with cardio-protective effects: anti-cholesterolemic, anti-thrombotic, anti-inflammatory, anti-hypertensive, and anti-arrhythmic. 

Regarding cardiovascular disease risk factors, there is strong evidence that EPA and DHA can positively modify blood lipids, inflammation, and endothelial function. In the elderly, omega-3s have also been shown to help modulate depression and cognitive decline. 

The mechanisms underlying these effects appear to be varied; for example, eicosanoids, and other bioactive lipid mediators derived from omega-3 metabolism, are signaling molecules that have a variety of functions in the cardiovascular, pulmonary, immune, and endocrine systems.

Consumption of fatty fish is the main source of EPA and DHA in the diet, and α-linolenic acid conversion serves as an additional but limited source. Supplementation with fish liver oil, krill and cod oil, as well as other products derived from algal sources, can also improve omega-3 fatty acid status.

In any case, consumption among populations following a typical Western diet rich in animal fats is grossly inadequate and poses a health risk, especially for women of childbearing age or pregnant women.

Based on the analysis of data from the 2003-2012 National Health and Nutrition Examination Survey (NHANES) study, it was found that the omega-3 consumption of pregnant women and women of childbearing age is lower than that of males of the same age. 

While a subsequent NHANES analysis using data collected from 2001 to 2014 found that 100 percent of childbearing and pregnant women did not meet the weekly fish consumption recommendation (at least two to three servings per week).

Referring to the 2015-2020 Dietary Guidelines for Americans, more than 95 percent of women in this age group do not reach the EPA and DHA intake recommendation of 250 milligrams per day.

The U.S. population consumes an insufficient amount of omega-3s.

In order to identify the segments of the U.S. population at greatest risk of omega-3 deficiency, the main objective of the study was to estimate EPA and DHA consumption in population subgroups and assess differences by age, sex, and pregnancy status, using data collected from the NHANES study as a nationally representative sample. 

The results showed that children and adolescents consumed lower doses of omega-3 than adults; and women lower amounts than men. 

In contrast, the small percentage of individuals taking EPA- and DHA-based supplements showed significantly higher levels than those who did not use them. 

One of the most alarming findings, was that the amount of EPA + DHA consumed by pregnant women was less than one-fifth of the recommendation of 520 milligrams per day, and that for children aged 1 to 8 years, only 40 percent of the intake of EPA + DHA recommended by the National Academy of Medicine was achieved.

Although these population groups are the "gentler" ones, the results also showed worrying evidence for adults and the elderly with omega-3 consumption below 60 percent of the recommendation.

In general, consumption of these important fatty acids was found to be insufficient in every age group, highlighting a condition that could increase the risk of health problems, particularly in vulnerable populations such as young people, children and pregnant women.

Regarding the consumption of omega-3 supplements, only 0.6 percent of women of childbearing age reported taking a supplement containing EPA and/or DHA and only 7.3 percent of pregnant women.

Since supplement use is associated with increased intake of polyunsaturated fatty acids, it could be an important source of EPA and DHA, particularly for pregnant women.

Some details of the study

Intakes of fish and EPA and DHA fatty acids were calculated for 45,347 people of all ages by analyzing data from the latest NHANES study.

In detail, the data showed that in children aged 1 to 5 years, the total intake of EPA + DHA (32.4 mg per day) represents less than a quarter of the World Health Organization's recommended amount of ~150 mg per day. Just as insufficient were the amounts of omega-3 consumed by children up to 11 years old.

Adolescents (12-19 years) also had low EPA + DHA intake at 59.2 mg per day, which is well below the WHO recommendation of 200-500 mg per day.

Average intakes in adults and the elderly were below the minimum recommended dose of 200 mg/day of EPA + DHA provided by many organizations, reaching only 16% and 21% of the recommended 325 mg per day per 1000 Kcal. 

Further studies are needed to define populations at risk for omega-3 deficiency

According to data reported by the researchers, omega-3 consumption among different segments of the U.S. population is below recommended intake levels, and is insufficient to ensure health status and to modulate risk factors for protection against chronic diseases.

Ellen Schutt, executive director of the Global Organization for EPA and DHA, said this study confirms the importance of increased omega-3 consumption in the United States.

Previous research had already shown, in fact, that 95 percent of the U.S. population was deficient in omega-3, and the present study further helps to define the at-risk groups, precisely those most vulnerable.

Source: M. Thompson et al. Omega-3 Fatty Acid Intake by Age, Gender, and Pregnancy Status in the United States: National Health and Nutrition Examination Survey 2003-2014," Nutrients.