Nguyen-Hoang A, Dhadra M, Hughes J. The importance of plant-based omega-3 Alpha-Linolenic Acid (ALA) and its role in promoting the development of children’s brain: A Narrative Review. HPHR. 2023;64. 10.54111/0001/LLL1
The increasing global trend towards plant-based diets emphasizes the importance of incorporating nutrient-rich plant-based foods while reducing the consumption of animal products. Within this context, Alpha-Linolenic Acid (ALA), a plant-based omega-3 fatty acid, which plays a pivotal role in maintaining overall health. Its significance extends to supporting proper growth and development in infants and children, as well as facilitating brain development and function during childhood. ALA also contributes to other omega-3s and helps maintain a balanced ratio of omega-3 to omega-6 fatty acids. Despite its essential functions, the impact of plant-based omega-3 ALA on brain function is often overlooked. Thus, this narrative review aims to delve into the role of ALA in promoting brain health in children.
The growing global trend towards plant-based diets highlights the significance of consuming a diet rich in plant-based foods and reducing the consumption of animal products, as recognized by various health organizations including the World Health Organization (WHO).1-2 Such diets are abundant in fibre, vitamins, minerals, and other crucial nutrients, including omega-3 fatty acids. These nutrients play a vital role in maintaining heart health, brain function, and overall well-being.3-4 In recent years, the American College of Lifestyle Medicine recognizes the significance of a plant-based diet as a fundamental pillar of lifestyle medicine, emphasizing its crucial role in promoting overall health.5-6 Incorporating plant-based omega-3 Alpha-Linolenic Acid (ALA) into one’s diet can not only meet daily recommended intake levels of this vital nutrient but can also lower the risk of cardiovascular disease, lower blood pressure, and reduce cholesterol levels, according to a comprehensive systematic review of multiple studies.7 Plant-based omega-3 ALA is an essential fatty acid that has a critical role in maintaining good health. It helps to prevent chronic diseases such as cardiovascular diseases and stroke, while also slowing down cognitive function and memory decline in adults.8-9 ALA is essential for proper growth and development in infants and children and has been found to protect against obesity in childhood.10-11 Furthermore, ALA is a crucial precursor for the synthesis of other omega-3 fatty acids, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). However, despite its importance, the benefits of plant-based omega-3 ALA to brain function are often underestimated in practice.12 It is noteworthy that ALA is an essential fatty acid that cannot be produced by the human body and must be acquired through the diet or dietary supplements. Plant-based omega-3 ALA has been shown to promote balanced ratios of omega-3 and omega-6 fatty acids, which is supported by scientific research.13 Moreover, plant-based omega-3 ALA, plays a distinct role in supporting brain development in children and has antioxidant properties that provide neuroprotective effects.14-15 Several studies have suggested that adequate intake of ALA may have a beneficial effect on cognitive function and overall brain health in children.16-17 Therefore, this narrative review provides an overview of the role of ALA in children’s brain health.
ALA is an omega-3 fatty acid that found naturally in plant-based sources like nuts and plant oils like blackcurrant (known as Ribes nigrum) seed oil but is not present in animal sources such as fish. Insufficient dietary intake of alpha-linolenic acid (ALA) has been reported worldwide, especially in developing countries.18 Mean ALA intakes were found to be lower than the recommended adequate intake (AI) in children from Bangladesh, Gambia, South Africa, and Yunnan, China.19-20 In rural Bangladesh, 89.8% of children aged 24-35 months had ALA intakes below the Institute of Medicine’s AI of 700 mg/day for 1- to 3-year-old children.20
Inadequate dietary intake of ALA can lead to reduced DHA concentrations in various brain regions, including the hypophysis, frontal cortex, and striatum.23 Furthermore, deficiency of dietary ALA can also result in significant reductions in DHA in neural and retinal membranes, which are consistently associated with impaired learning, olfaction, audition, and vision.24 Although some studies have raised concerns about the limited metabolic conversion of ALA to DHA, recent systematic reviews in both humans and animals have demonstrated that DHA synthesis from ALA can provide sufficient levels of DHA for the brain and eye, particularly with adequate dietary ALA intake.21,25-26
Plant-based omega-3 ALA plays a crucial role in maintaining a balanced intake of omega-3 and omega-6 fatty acids for promoting healthy brain function in children. Both omega-3s and omega-6s are components of the human brain at early ages, comprising approximately 60% of fatty acids.27 However, excessive consumption of omega-6s can also contribute to inflammation in the body. Like ALA, omega-6 linolenic acid (LA) is an essential fatty acid that must be obtained from foods. LA is the precursor of other omega-6 fatty acids in the body. ALA and LA use the same metabolic pathway enzymes for the conversion to other omega-3s and omega-6s, respectively. Studies have shown that inadequate dietary ALA intake leads to an increase in cerebral 22:5 omega-6 and a reduction in DHA.24
A systematic review of randomized controlled trials (RCTs) highlighted that a balance of these fatty acids can support healthy brain function in children.28 An imbalance can lead to inflammation and oxidative stress, which can impair brain function. Thus, the ratio of omega-6 to omega-3 has become an important research topic. The optimal ratio of omega-3 to omega-6 for children’s brain function is still under investigation, but some studies suggest that a 4:1 ratio of omega-6 to omega-3 fatty acids is optimal for brain health in children due to its importance for the development of the hippocampus, cerebellum, and glial cell number in the developing brain.29-31 Further investigation is necessary to determine the optimal ratio of omega-6 to omega-3 fatty acids. While a consensus on the ideal ratio has yet to be reached, accumulating evidence suggests that maintaining a low omega-6 to omega-3 ratio of approximately 4:1 is crucial for promoting healthy brain development in children. It is important to note that the Western diet, which is commonly consumed by children, contains omega-6 fatty acids at levels 14 to 25 times higher than omega-3 fatty acids.32 This substantial imbalance has been associated with an increased risk of neurodevelopmental disorders.33-34 Studies demonstrated that excessively high omega-6/omega-3 ratios have been identified as a potential modifiable factor contributing to cognitive and behavioural challenges in children.35-36 Both commodity data-based studies and longitudinal studies have demonstrated that few children consume adequate amounts of omega-3s. Notably, ALA has been shown to have anti-inflammatory and neuroprotective effects, as highlighted in reviews, suggesting that it plays a critical role in neuronal maintenance, learning, and memory performance.14,37
The importance of ALA as an essential omega-3 fatty acid for the paediatric population has been widely acknowledged by health organizations worldwide. The European Food Safety Authority’s (EFSA) Scientific Panel has emphasized the significance of ALA in the growth and development of the nervous system, particularly during the early years of life when these systems are rapidly developing.38 The EFSA (2017) recommends that infants and children should consume 5% of their total energy intake from ALA.39 The United States Institute of Medicine (IOM) and Korea have established specific dietary recommendations for alpha-linolenic acid (ALA) based on age groups.40-41 Infants from birth to 12 months in the United States are recommended to consume 0.5g of ALA per day, while children aged 1-3 years and 4-8 years should consume 0.7 grams and 0.9 grams per day, respectively. In Korea, infants from 0-5 months of age should consume 0.6g of ALA per day, while those aged 6-11 months are recommended to consume 0.5g per day. Children aged 1-2 years and 3-5 years in Korea should consume 0.6g and 0.9g of ALA per day, respectively. These guidelines reflect differences in nutritional goals and aim to ensure that individuals receive sufficient ALA intake for optimal health and development. Despite disparities in the recommended daily intake of ALA across different nations, the consensus among health experts remains unwavering that ALA is an indispensable omega-3 fatty acid that must be incorporated into the diet from early infancy.
It’s also imperative to acknowledge that the practicality of adhering to these recommendations can vary. While these guidelines are constructed with specific nutritional intentions, they may pose challenges for populations with limited access to ALA-rich foods due to factors such as geographic location or economic constraints.42 Notably, low parental education and awareness regarding the importance of ALA and its sources can influence their ability to make well-informed dietary decisions for their children.43-44 Further research could assess the effectiveness of educational campaigns targeting parents to increase their understanding of ALA’s importance and sources. Moreover, research could delve into the relationship between socioeconomic conditions and ALA consumption. Policymakers could establish educational programs for parents on nutrient-rich foods, as well as develop initiatives to educate and empower them to make healthier dietary choices within budget constraints.
The popularity of embracing a plant-based diet is steadily rising as a well-regarded and healthy dietary choice, endorsed by various health organizations for its significant role in promoting good health and overall well-being. Within this dietary approach, plant-based omega-3 fatty acid known as Alpha-Linolenic Acid (ALA) plays a crucial role. ALA is essential for supporting brain development and function during childhood. Moreover, plant-based omega-3 ALA also contributes to the biosynthesis of other omega-3 fatty acids, such as DHA and EPA, within the body. Insufficient dietary intake of ALA has been reported worldwide, especially in developing countries, and inadequate intake can lead to reduced DHA concentrations in various brain regions, which can lead to impaired learning, olfaction, audition, and vision. ALA is also necessary for maintaining a balanced intake of omega-3 and omega-6 fatty acids, which can support healthy brain function in children. Although the optimal ratio of omega-6 to omega-3 for children’s brain function is still under investigation, maintaining a low omega-6 to omega-3 ratio of approximately 4:1 is essential for supporting healthy brain development in children. Thus, incorporating plant-based sources of omega-3s, particularly ALA, into children’s diets is critical for their cognitive development and overall health. While different countries recommend varying daily amounts of ALA, it unanimously agrees that ALA is an essential nutrient that should be included in children’s diets from birth. The practicality of following these recommendations can be influenced by factors like not having enough ALA-rich foods available or parents not knowing about the importance of ALA. Further research is essential to explore what affects people’s ability to meet the recommended ALA levels.
Mona Dhadra, a full-qualified nutritional therapy practitioner and a registered Five-Element acupuncturist in Birmingham, United Kingdom. As a member of the British Acupuncture Council, all her treatments adhere to the highest standards of safety and competency. She has a keen interest in natural health. She qualified as a nutritional therapist from the University of Worcester and has since gone on to receive her degree equivalent qualification in Traditional Chinese medicine and five element acupuncture from The Acupuncture Academy. Mona operates a clinic in Oldbury, England, where she specializes in providing acupuncture treatments. Her practice interests are mental health and chronic pain.
Jessica Hughes, a neuroscientist with a Cambridge medical background. Beyond her work, she actively promotes community health by offering cooking tutorials, emphasizing plant-based nutrition to enhance her patients’ well-being.
Anh Nguyen-Hoang, a Registered Nutrition Therapy Practitioner and Genomic Medicine Consultant based in the UK, graduated from Harvard Medical School with rigorous training as a global Clinician-Scientist. During his time at Harvard, he spearheaded a ground-breaking collaboration initiative among Harvard Asian scholars, promoting tailored lifestyle medicine for Asians with a focus on improving the health of women and children. Dr Nguyen is a Senior Fellow of the British Association for Nutrition and Lifestyle Medicine (BANT) and an Ambassadorial Scholar of the UK Genetics Society.
Outside of his professional endeavors, he serves as a Guest Speaker at The Economist, engaging in workshop series covering nutrition, health, genomics, and mindfulness for policymakers, healthcare CEOs, and thought leaders across the globe. Furthermore, he contributes as a panel speaker at the Asia Summit Global Health 2021, a significant event addressing public health concerns in Asia, organized by The Hong Kong Trade Development Council. He has regularly received invitations to speak at conferences hosted by prestigious organizations such as the European Society for Paediatric Research, the European Society of Human Genetics, and The European Society of Clinical Nutrition and Metabolism.