Is Nutrition Unbalanced If Only DHA Is Supplemented Without ARA?

Many people taking DHA have this question: "Advertisements constantly promote DHA as 'brain gold', so is ARA merely a redundant ingredient? If I only take DHA and skip ARA, will my nutrition become unbalanced?"

There is no universal answer - conclusions vary by population. For infants aged 0–3 years and pregnant/lactating women, DHA-only supplementation without ARA deviates from the nutritional pattern of breastmilk and carries risks of fatty acid imbalance. For adults and older children who regularly consume meat and eggs, dietary ARA is generally sufficient, so DHA-only supplementation rarely causes nutritional imbalance.

First: DHA and ARA Are Distinct Nutrients

DHA (Docosahexaenoic Acid) belongs to the omega-3 family; ARA (Arachidonic Acid) belongs to the omega-6 family. Both are long-chain polyunsaturated fatty acids (LCPUFAs) that participate in constructing the brain, retina and cell membranes, yet they undertake different functions:

• DHA: Highly concentrated in grey matter of the cerebral cortex and outer segments of retinal photoreceptors. It acts as the core structural nutrient for the brain and eyes, supporting synaptic integrity and visual acuity.
• ARA: Present in nearly all cell membranes (not only brain cells). The total amount of ARA accumulated in the infant brain exceeds DHA. It also serves as the precursor for prostaglandins, leukotrienes, resolvins and other signalling molecules that regulate immunity, inflammatory responses and vascular tension.

DHA and ARA share the same desaturation and elongation enzyme system (especially Δ6-desaturase), creating metabolic competition. Excess of one nutrient can obstruct the conversion pathway of the other. This means adequate DHA cannot automatically compensate for insufficient ARA, and ARA is not dispensable. A balanced ratio of both is required.

Breastmilk Sets the Benchmark: DHA and ARA Naturally Occur Together

A pooled analysis of 65 breastmilk studies covering 2,474 mothers shows mature breastmilk contains an average of 0.32% DHA and 0.47% ARA of total fatty acids, generating an ARA:DHA ratio of approximately 1.5:1 (DHA:ARA ≈ 1:1.5). Summary data of Chinese breastmilk samples shows an ARA/DHA ratio ranging from 1.14 to 2.73. The widely cited ratio "1:1.7 for Chinese breastmilk" falls perfectly within this range.

Key takeaway: Breastmilk never contains DHA alone; nature provides infants with DHA and ARA as a paired nutrient combination. Based on this evidence, EFSA sets adequate intake levels for infants aged 0–6 months: 100 mg/day DHA and 140 mg/day ARA. WHO/FAO also recommends an ARA:DHA ratio close to 2:1 based on body weight.

China's national standard GB 10765-2021 codifies this principle as a mandatory requirement: Stage 1 and Stage 2 infant formula containing added DHA must also include ARA, with ARA content no lower than DHA. This is not a suggestion, but a minimum compliance standard.

What Happens When Infants Receive DHA Only, No ARA?

Research repeatedly identifies several risks of DHA-only supplementation with zero preformed ARA for infants:

1. Declining ARA concentrations in red blood cell membranes When infant formula contains no preformed ARA, even though infants can synthesise small amounts of ARA from linoleic acid (LA), ARA levels in blood and brain cell membranes remain markedly lower than breastfed infants. Conversion efficiency is limited for two reasons: infant Δ6-desaturase activity is inherently weak; furthermore, certain FADS gene polymorphisms further reduce endogenous synthesis capacity.
2. High DHA combined with insufficient ARA hinders developmental outcomes A landmark randomised controlled trial separated full-term infants into four groups: no LCPUFA supplementation, 0.32% DHA, 0.64% DHA and 0.96% DHA, with ARA fixed at 0.64%. Groups with moderate DHA and balanced DHA:ARA ratios demonstrated favourable outcomes in language development, card sorting and cognitive assessments at age six. However, the highest-DHA group (0.96% DHA, pushing the ARA:DHA ratio down to 0.67) showed deteriorated cognitive performance. This proves higher DHA does not equal better development; DHA alone cannot support optimal neurodevelopment when ARA is lacking.
3. Stronger evidence of restricted growth in preterm infants Preterm infants miss the intrauterine accumulation phase of DHA and ARA. Multiple studies indicate formula providing high-dose DHA without supplementary ARA may impair weight and length gain in preterm babies.
4. Deficient foundation for immune and inflammatory regulation ARA acts as a precursor for prostaglandins and other mediators required to balance pro-inflammatory and anti-inflammatory responses. While not life-threatening for healthy adults, this deficiency creates an implicit disadvantage for infants building their immune systems.

Interim conclusion: Formula-fed infants aged 0–3 years consuming ARA-free formula, or receiving only standalone DHA algal oil without ARA-rich complementary food (especially during the all-milk phase before 6 months), experience relative ARA insufficiency. This deviates from breastmilk nutritional composition and constitutes a fatty acid imbalance. After 6 months of age, egg yolks and meat puree supply partial ARA. Nevertheless, ARA-free formula remains a disadvantage while milk serves as the primary food source.

Pregnant & Lactating Women: DHA-only supplementation is acceptable with dietary precautions

It is safe for pregnant women to consume pure DHA algal oil (200 mg DHA daily). Meat and eggs in the maternal diet supply adequate ARA, supported by endogenous fatty acid conversion. One critical reminder: maternal omega-3 intake transfers to the foetus via the placenta and to infants through breastmilk. If the mother follows an extremely vegan diet with negligible ARA sources, breastmilk ARA concentrations will decrease, indirectly affecting the infant. DHA-only supplementation is viable during pregnancy only if the diet is not strictly vegan.

Older Children & Adults: DHA-only supplementation generally does NOT create imbalance

This group is frequently misled by parenting marketing rhetoric. For children above 3 years old, adolescents and adults, Δ6-desaturase activity is fully mature. Ordinary diets including pork, beef, chicken and offal contain substantial ARA (hundreds of milligrams per 100 g meat).

The common nutritional challenge in modern diets is excess omega-6 and insufficient omega-3 - meaning ARA intake is usually adequate or excessive, while DHA is deficient. For adults:

DHA-only supplementation will not cause ARA deficiency, thanks to dietary sources.

Additional combined DHA+ARA adult supplements may further elevate omega-6 burden and offer no benefit.

Recommended practice: Eat oily fish 2–3 times weekly to boost DHA; prioritise vegetable oils over frying fats to avoid extreme distortion of the DHA:ARA balance.

The Chinese Dietary Reference Intakes (2023 Edition) from the Chinese Nutrition Society only specifies optimal DHA:ARA ranges for early life to support brain and visual development. For adults, it establishes an adequate intake level for DHA alone, without mandatory ARA supplementation.

Self-Check: When Should You Avoid DHA-only Supplementation?

• Infants aged 0–6 months on exclusive formula: Formula with zero ARA or ARA content lower than DHA → Suboptimal; switch formula or consult a paediatrician regarding ARA sources. As a general guideline, parents are not advised to purchase standalone ARA drops independently; formula adjustment is preferred.
• Toddlers aged 6–36 months: ARA-free formula paired with daily egg yolk/meat intake → Acceptable. Severe picky eating with no animal products → DHA-only supplementation is insufficient; adjust diet or select combined DHA+ARA emulsions with a ratio of 1:1 ~ 1:2.
• Pregnant/lactating women: Low-EPA pure DHA algal oil (200 mg/day) plus regular meat and egg intake → Suitable. Strict vegan diet → Consider testing red blood cell membrane fatty acids; do not assume DHA alone meets all requirements.
• Healthy children over 3 years & adults: DHA-only supplementation is fully appropriate; ARA requirements are met through regular meals.

Concise Answer to the Title Question

Will nutrition be unbalanced if you take only DHA without ARA? For infants and pregnant/lactating women: Likely yes. Single-source DHA breaks the balanced DHA+ARA pairing found in breastmilk; a high-DHA, low-ARA profile may negatively impact cognition and growth. For people aged above 3 years who eat meat and eggs: Generally no. Conventional diets provide sufficient ARA. DHA-only supplementation merely addresses the typical dietary gap without creating new deficiencies.

Do not overemphasise DHA based on one-sided advertising, nor succumb to anxiety that missing ARA automatically harms children. Decisions should be based on age, daily diet and formula labelling, rather than debating whether ARA supplementation is compulsory.

Core Rule for Purchasing & Supplementation

For children aged 0–2 years, select formula or supplements with a DHA:ARA ratio between 1:1 and 1:2, and ensure ARA content is not lower than DHA (aligned with GB 10765-2021 and breastmilk reference ranges). Adults can choose pure DHA algal oil without needing to pay extra for ARA-containing formulations.

Primary References

1. Koletzko B et al. Should Infant Formula Provide Both Omega-3 DHA and Omega-6 Arachidonic Acid? Ann Nutr Metab, 2015; pooled analysis of 65 breastmilk studies showing average 0.32% DHA / 0.47% ARA; EFSA AI: 100 mg/d DHA +140 mg/d ARA; RCT evidence of impaired cognition under high-DHA low-ARA conditions
2. GB 10765-2021 National Food Safety Standard: Infant Formula – DHA addition requires ARA with ARA ≥ DHA
3. Chinese Nutrition Society, Chinese Dietary Reference Intakes (2023 Edition): 100 mg/d DHA AI for infants 0–6 months; DHA:ARA ratio 1.4:1–2:1 benefits brain and visual development
4. Su Yixiang, Child Nutrition and Related Diseases: Summary of breastmilk DHA/ARA levels; improved cognitive and visual outcomes at 18 months for infants receiving paired DHA+ARA matching breastmilk
5. Feihe Systematic Review of Chinese Breastmilk (2,585 samples across 17 provinces): Average DHA:ARA ≈1:1.7 in mature breastmilk
6. EU Delegated Regulation (EU) 2016/127: Academic consensus that endogenous ARA synthesis in infants is insufficient; safety of DHA-only formula remains unvalidated