Introduction
Most mothers-to-be are well aware of the added responsibility to eat healthy food and be healthy during pregnancy, for their sake and for the sake of the baby. Many mothers however, may not be aware that the baby’s brain development has specific nutritional needs during different stages of pregnancy. The rapid development of an unborn child’s brain is an amazing process, starting with one tiny cell in an embryo, and ending with a fully developed and operational brain nine months later. Some aspects of brain development are out of the control of the mother, such as a genetically inherited brain dysfunction or accidental injuries, but the mother to a large extent is in a position to contribute to the healthy brain development of her baby.
This blog focusses on the development of the brain only, not on the rest of the unborn baby’s body, and also only deals with the specific dietary needs of the brain during gestation.
The first trimester
Brain development – Brain development starts at the embryonic stage already (first 8 weeks), and continues at a rapid rate through the fetal stage until birth. The fetal nervous system, consisting of the brain and spinal cord, is one of the first systems to develop. About 16 days after fertilization the embryo forms the neural tube, which develops into the brain and spinal cord. The brain begins to form by week 3 and by week 4 the different brain sections (forebrain, midbrain and hindbrain) starts to develop. By week 6 the brain hemispheres starts to form, and by week 11 the spinal cord starts to sprout spinal nerves.
Dietary needs – this trimester is usually characterized with nausea and can be very stressful, food wise! Don’t be too concerned, as the baby initially lives off the yolk sack and is not too dependent on nutrients in the mother’s diet. The developing placenta’s health becomes more important, as the placenta will soon be the baby’s source of “food”. Protein and calories are important for the health of the placenta. Eating and nausea don’t go hand in hand, but try to eat small and frequent meals.
Folate is essential for fetal cell growth, tissue development and DNA formation. Eat folate rich foods such as leafy greens, avocados and whole grains, but also supplement with at least 400 micrograms of folic acid or take a vitamin B-complex daily.
The second trimester
Brain development – During this stage the fetal brain grows rapidly, and by the 20th week the forebrain starts to develop into left and right cerebral hemispheres. Up to this stage the fetal brain is smooth, but then the folding of the outer layer (cortex) of the brain starts, and is only completed when the child is about 18 months old. The folding process results in a “wrinkled” appearance and this development increases the surface of the cortex to about three times the size a smooth cortex would have been. A large cortex can then fit into a small volume (the skull), also resulting in the benefits of reduced neuronal wiring length and improved cognitive function. By the end of this trimester (24 weeks) the brain starts to regulate all body functions.
Dietary needs – During the second trimester optimal growth of the baby requires protein (meat, poultry, eggs, diary, nuts, seeds, whole grains) to assist with forming new tissue; carbohydrates (whole grains, fruit, vegetables) for energy and as sources of fiber; calcium to help build strong bones; iron to help form new red blood cells, and the most important nutrient for the baby’s brain – healthy fats. Healthy fats consist largely of unsaturated fat and in particular omega-3 fatty acids that are essential for brain development. Omega-3 fatty acids are found in fish such as salmon, trout, herring, anchovies, pilchards, sardines and also in soy and walnuts. Trans fats, found in processed foods, should be avoided.
The third trimester
Brain development – From week 26 the brain tissue starts to develop creases and fissures, (appearing grooved and indented) while brain tissues continues to develop at a fast rate. Soon afterwards the brain starts to monitor breathing and regulates body temperature. During the last 13 weeks the brain virtually triples in weight. The cerebellum (motor control) develops very fast now, and its surface increases 30-fold in the last 16 weeks of pregnancy. The cerebral cortex (thinking, remembering, feeling) develops throughout the pregnancy, but only starts to function when the baby is born.
The wonder of a single tiny cell in the embryo that started the whole process of forming the brain, has multiplied to around 100 billion brain cells by the time the baby is born.
Dietary needs – As the baby’s brain grows very fast during the third trimester, food rich in omega-3 fatty acids becomes even more important. A balanced, healthy diet throughout pregnancy, coupled to daily walking or some form of exercise, with no smoking or alcohol intake, will give your unborn baby the optimal environment to grow and develop in for the 9 months before entering the outside world!
Guidelines for a balanced healthy diet
- Vegetables – a balanced variety of colors, constituting two-thirds of the food on your plate.
- Fruit – lots of fresh fruit – rather have fruit for dessert than other sweets.
- Beans, nuts, seeds and legumes – these are great sources of fiber and protein.
- Herbs and spices – much healthier for flavoring than salt – many contain plant compounds, with antioxidants and anti-inflammatory effects.
- Healthy grains – whole grains are best.
- Fish and seafood – 3 times a week.
- Poultry 2 – 3 times a week. Lean red meat in small portions 1-2 times a week.
- Eggs – eat on average 5 – 7 eggs a week (preferably free range).
- Olive oil – extra virgin olive oil should be the principal fat, it replaces butter, margarine, other cooking oils and makes a lovely salad dressing. Eat lots of olives and avocado too.
- Dairy – low servings of dairy (1 cup of milk/yogurt per day). Use diary from cultured milk, such as kefir, Greek or plain yogurt, and fresh curd cheeses like ricotta.
Drinking – drink lots of water. Avoid alcohol during pregnancy, as alcohol enters the fetal bloodstream in the same concentrations that are present in the mother’s blood. The unborn baby however takes twice as long to eliminate alcohol from its
