Brain development

Brain development continues at a rapid rate and continues developing until about 3 years of age. Myelination that started during gestation continues, helping the brain develop the flexibility needed for electrical impulses involved in neurotransmission. Neurotransmitter synthesis is active during this time and is involved in the development of baby’s reward centre in the brain which effects mood and behaviour. The hippocampus continues to develop improving baby’s recognition and memory [1,14].

During this time, DHA is a critical nutrient to ensure the foundations are laid down for optimal brain function throughout life. Breastmilk will supply DHA if mother’s omega-3 intake in sufficient, however in many western countries where omega-3 intake is low, DHA concentrations in breastmilk are low [2]. Dietary sources of omega-3 from fish should also be introduced.

Iron is a critical nutrient because it is needed for healthy red blood cells and the transfer of oxygen throughout the body. It is also an important cofactor for many metabolic and neurological functions involved in brain development. By about 6 months maternal iron stores become depleted, and the amount contained in breastmilk alone is no longer sufficient to meet the nutritional needs of babies beyond 6 months [3]. The RDI for babies aged 7-12 months of age is 11mg per day [4] which can be achieved by including iron rich foods such as red meat, spinach, legumes, and iron fortified cereals.

Key nutrients for brain development

RDI = Recommended Daily Intake

AI = Average Intake

Eye development

The eyes continue to develop and by 7-11 months of age baby is beginning to have depth perception which helps to judge distance. Peek-a-boo is likely to be a favourite game with lots of giggles and smiles [5].

Key nutrients for eye development found in breastmilk are dependent on mother’s dietary intake [8]. Eating a variety of fruits, vegetables and fish will help the breastfeeding mother to ensure healthy levels of vitamin A, lutein and DHA. These nutrients are required for the development of the retina for healthy vision.

During weaning, including a variety of brightly coloured fruits and vegetables will increase baby’s intake of essential carotenoids, beta-carotene and lutein, which are needed for healthy vision.

Key nutrients for eye development

Intestinal and gut microbiota development

Now that baby’s intestines are ‘closed’ it is safe to introduce solid foods. The gut microbiome continues to develop, and it is important to include both prebiotic and probiotic foods in the diet. Yoghurt is a good source of beneficial bacteria, and the smooth texture makes it an ideal choice for babies over the age of 6 months.

If breastfeeding, baby will be getting a good dose of beneficial bacteria and prebiotics from breastmilk. If using infant formula, look for one that contains prebiotics such as galacto-oligosaccharides (GOS). This will help colonize beneficial bacteria in baby’s digestive system which will improve digestive health and immune system development [9].

Constipation may occur when baby begins solids as the digestive system is still learning how to process new foods. Including fibre rich foods from wholegrains such as brown rice and fruit and vegetable purees with the skin on will help manage constipation [6].

Immune system development

Your baby may have experienced her first cold by now, and while seeing your baby unwell can be unsettling, this is how the immune system develops. By creating antibodies against a pathogen, baby’s immune system can step in and do its job the next time it encounters that particular bug. The process continues each time baby gets sick, building up a memory database defence system against common virus and bacteria.

To support baby’s immune system, include foods rich in vitamin C such as pear, apple, mango and kiwi fruit. Foods containing beta-glucan such as oats and baker’s yeast may also support immune health, as beta-glucan has been shown to improve immune system function in children [10-11].

Key nutrients for digestive and immune development

Bone and teeth development

By 6-12 months of age, baby’s first tooth will appear. The front teeth are usually the first to appear and it may begin with one tooth on the bottom, followed shortly by another lower tooth and two up the top.

Bones continue to grow and develop at a rapid rate, so much so that calcium requirements per kilogram of body weight are higher during infancy and childhood than other time of life.

Key nutrients for bone and tooth development

Kidney development

During infancy and childhood, renal function differs from that in adults with a lower glomerular filtration rate and reduced reabsorption of sodium and water. Babies under the age of 12 months do not have the capacity to process salt over the adequate intake which is 170mg/day for babies aged 7-12 months [3-4]. Excess sodium in baby’s diet during this time can have harmful effects on the developing kidneys and on blood pressure in later life [5].

Foods to avoid in babies under 12 months:

Salt

Never give salt to babies under the age of 12 months. It is important not to add salt to any cooking that you give your baby, and always read ingredient lists on packaged foods to ensure there is no added salt.

Honey

Honey can contain spores of a bacterium called Clostridium botulinum, which can germinate in a baby’s immature digestive system and cause infant botulism, a rare but potentially fatal illness.

Once baby is over 12 months old the digestive system is developed enough to keep the bacteria in honey from growing, thereby rendering the bacteria harmless [12].

Developmental milestones 6-12 months:

Gross motor skills: sits unsupported, stands with support, moves from tummy to sitting position, pull to standing using furniture.

Fine motor skills: Transfers objects from one hand to the other, puts objects into containers, points at things, uses hand and fingers to pick up small objects.

Self-help skills: holds own bottle, feeds self, finger foods using thumb and finger tips, begins to hold a spoon and attempts to feed self, drinks from a cup with a lid or small sips from open cup.

Cognitive skills: finds objects after watching them disappear, begins to use objects as tools after being shown how, handles toys in new ways: pulling, turning, poking, tearing [5].

References

1. Fox SE, et al. Child Development. 2010; 81:28–40.
2. Mosca F, et al. Pediatr Med Chir. 2017; Jun 28;39(2).
3. Domellöf et al. J Pediatri Gastro Nutr. 2014, Jan 58;1:119-129.
4. https://www.nrv.gov.au/nutrients
5. http://www.childrensmn.org/educationmaterials/childrensmn/article/15314/developmental-milestones-6-to-12-months-/
6. https://www1.racgp.org.au/ajgp/2018/may/paediatric-constipation
7. https://www.who.int/nutrition/topics/FFA_summary_rec_conclusion.pdf
8. Lipkie TE, et al. PLoS One. 2015; June 10(6)
9. Sierra et al. Eur J Nutr. 2015 Feb;54(1):89-99.
10. Hong F, et al. J Immunol. 2004 Jul 15;173(2):797-806.
11. Meng, J Nutr Food Sci. 2016, 6:4
12. http://www.kidshealth.org/en/parents/botulism
13. Huang HL, et al. Lipids Health Dis. 2013 Mar;12:27.
14. Cusick et al. J Pediatr . 2016 August; 175: 16–21.
15. Derbyshire E, Obeid R. Nutrients. 2020 Jun 10;12(6):1731.
16. Cerdó T, at al.Curr Opin Clin Nutr Metab Care. 2019 Nov;22(6):434-441.
17. Huang HL, et al. Lipids Health Dis. 2013 Mar;12:27.