Issues with feeding and nutritional deficiencies
As any parent knows, kids can often be picky eaters, and getting them to eat the food we know to be good for them can often be a challenging (if not messy) battle of wills. For the parent of a child with attention-deficit hyperactivity disorder (ADHD), mealtimes can be particularly distressing, often having to compromise by feeding what the child is willing to eat rather than what is nutritionally wholesome.
Eating habits and children
Eating should be considered to be a pleasurable experience and for toddlers and very young children meal times can be full of fun and adventure as they become exposed to new tastes, flavours and textures. As such, they should be encouraged to try a wide variety of nutritious foods, as it is well established that poor food choices can negatively impact on children’s growth and health. Unfortunately, young children rarely differentiate between foods that are nutritionally beneficial and those that are low-nutrient and high in calories; as parents, therefore, it is important to ensure that we provide nutritionally balanced meals. It is not uncommon for children to alternately refuse and then demand certain foods and children with ADHD can cause particular concern, often appearing to eat so little that parents fear that their child may not be properly nourished.
Appetite in ADHD
ADHD is a group of behavioural symptoms that include inattentiveness, hyperactivity and impulsiveness that become apparent in some children in the pre- and early school years. It is one of the most common childhood disorders and often continues through adolescence and into adulthood. Normally treated with behavioural therapy and stimulant medications, there is also increasing evidence that diet can play a significant role in reducing and managing symptoms in a majority of children. In addition, certain food groups and deficiencies in a variety of nutrients can exacerbate symptoms. The drug most frequently prescribed for ADHD is methylphenidate, and whilst many parents find that pharmaceuticals can have a calming effect on their children, one of the most frequently reported side effects with use of such medication is reduced appetite.
Consequences of reduced appetite
Establishing a good routine around meal times can be a key factor in establishing good eating habits, but having a child who simply isn’t hungry can cause immense issues. As a consequence of reduced food intake, children with ADHD may therefore have a low intake of highly important nutrients such as essential vitamins, minerals, proteins and fatty acids that are vital contributors to, or cofactors for, many of the metabolic processes involved in normal growth and development. Not surprisingly, some children can develop common deficiencies, which can in turn exacerbate some of the symptoms associated with the condition.
The importance of protein
Of the 23 or so amino acids that are the molecular building blocks of proteins, 9 are termed indispensable or ‘essential’, meaning that they must be supplied from some food or supplement source; the others, which used to be classified simply as nonessential, are based on the body’s ability to synthesise them from other amino acids. Many of the neurotransmitters involved in the development and progression of ADHD, such as serotonin and dopamine, are metabolically derived from the essential amino acids and there is evidence that levels of essential amino acids such as phenylalanine, tyrosine (considered conditionally essential, as the body can make it but if levels of its precursor are low it becomes an essential), tryptophan, and isoleucine may be lower in ADHD individuals when compared to individuals without the condition. 1
Highly processed meat products such as sausages, burgers and chicken nuggets are generally derived from cheap cuts of meat and can be high in components such as gristle. As gristle is made predominately of collagen, a protein low in essential amino acids, the nutritional value of the total protein in these foods is much lower than non-processed lean meat products. If children are not getting a good source of quality protein such as fresh fish, or lean meat such as chicken or beef, this can impact negatively on the amino acid pool from which these neurotransmitters are synthesised.
Clinical studies have shown a direct link between the severity of ADHD symptoms and several nutritional deficiencies, some of them derived from an overall unhealthy diet or simply through inadequate intake of foods rich in the essential nutrients – such as fresh fruit and vegetables, fish, and whole grain products. 2
The importance of fat
Similar to essential protein, there are certain groups of fat that the body simply cannot make, such as the omega-3 and omega-6 families of polyunsaturated fatty acids. These essential fats must therefore be provided through diet, where they play a crucial role in many aspects of brain performance including mood, memory and behaviour,3 especially the omega-3 fatty acid eicosapentaenoic acid (or EPA) that directly influences both serotonin and dopamine function. 4
Symptoms of essential fatty acid deficiency include hyperactivity in children and disorders of the nervous system, poor memory, fatigue, inflammatory conditions and hormonal imbalances, 5 with evidence suggesting that deficiencies could be related to ADHD. 6,7 Such deficiencies can arise from a reduction in dietary essential fatty acids intake, and/or the impaired capacity of the neurological system of individuals with ADHD to convert essential fatty acids to longer chain fatty acids EPA and gamma-linolenic acid (GLA). 8 Oily fish, such as sardines, salmon or mackerel, provides a rich source of the long-chain omega-3 EPA and is an ideal dietary source. Within the UK, cod (often in the form of fish and chips or fish fingers) and tinned tuna are general favourites, though their omega-3 levels do not compare well with those of oily fish,9 which may reflect the generally low intake of long-chain omega-3 within the UK.10 Indeed, data obtained from the latest National Diet and Nutrition Survey, showed that mean consumption of oily fish was well below the recommended one portion (140g) per week in all age groups. 1
Not surprisingly, the use of fish oil supplements to restore omega-3 deficiencies in ADHD is increasingly common. Although improvements have been documented with omega-3 fatty acids, and EPA in particular,12 combined omega-3 and omega-6 supplementation such as EPA and GLA appears to be superior to the use of omega-3 fatty acids alone. 13, 14
The importance of vitamins and minerals
Vitamins and minerals have numerous roles within the body and act as vital cofactors in the many metabolic pathways that support normal growth and development. Many vitamins and minerals have a synergistic action within the body, meaning that a deficiency in one of these nutrients may correlate with an imbalance of other nutrients. Recent statistics from the Department of Environment Food and Rural Affairs15 suggest that consumption of fruit and vegetables is decreasing, certainly for lower income households where there has been a 30% decline in purchases of fresh fruit and vegetables since 2006. Indeed, less than a third of adults, and only one in ten children, are currently eating their recommended ’five-a-day’ of fruit and vegetables, recent government figures suggest. 16
Given that fruit and vegetables provide a rich source of vitamins and minerals, children who do not consume adequate amounts may be susceptible to low levels of water-soluble nutrients. For the ADHD child this appears to be of particular importance. For example, magnesium is considered to be an ’anti-stress’ mineral and deficiencies may manifest as hyperactivity, insomnia, and restlessness. Zinc plays an important role in the activity of neurotransmitters, fatty acids and melatonin, which are connected with healthy behaviour and sleep. Deficiencies in both magnesium and zinc have been suggested to exacerbate the symptoms of ADHD, with significant numbers of children with ADHD being deficient. 17,18 Supplementation with zinc and magnesium has been shown to be extremely beneficial in alleviating the symptoms of ADHD, especially when combined with omega-3 fatty acids. 19
Meeting the nutritional needs of children with ADHD
Deficiencies commonly observed in the ADHD child can be modified through a combination of careful food planning and supplementation.
Offering a variety of different foods at meal times can help children feel less intimidated at the idea of eating what may appear large and overwhelming portions. Try, for example, serving 4-5 different types of vegetables rather than one large portion of carrots. Different vegetables contain different vitamins and minerals and your child is more likely to eat more and get a better, balanced intake of nutrients when faced with ‘choice’.
Provide a wide variety of nutritious foods at regular two- to three-hour intervals (usually three meals and two or three snacks each day) and allow your child to take some responsibility for how much of each food to eat and the order in which to eat them. If your child has finished eating, respect his or her wishes to stop and do not force or bribe children, as this can set a pattern of eating-related behaviour that can be difficult to break.
Ideally, where possible, all meals should be eaten together and at the table to avoid the distraction of television or toys and to encourage focus on routine. Children generally eat better when an adult sits and eats with them.
A child cannot eat a particular food that is not offered to them. Many parents do not consider purchasing or cooking foods that they do not like themselves. As such, many children are often not exposed to certain foods, such as fish or specific vegetables until they reach school or are fed by other adults. Data from the National Diet and Nutrition Survey indicates that many adults do not consume adequate amounts of fruit and vegetables and oily fish, for example, and it is therefore likely that this behaviour and food choice may be reflected in the eating behaviour of their children.
Heavily processed food, refined foods and junk foods lack many of the essential fats, proteins, vitamins and minerals needed for normal functioning. Evidence suggests that consuming these kinds of food depletes the body of essential nutrients and has profound negative effects on many metabolic processes. Avoiding these types of foods and choosing ‘whole’ foods such as lean meat, fish, whole grains with plenty of fruit and vegetables provides the body with the essential nutrients needed for normal function and for normal growth and development.
Remember that you are a role model and that your child learns from you. If you eat nutritionally wholesome food and avoid giving your child foods low in nutrients and high in saturated fat, sugars and salt, they are more likely to develop life-long good eating habits that they will continue with when they are old enough to choose their own food.
Finally, don’t be afraid to use supplements if you have concerns that your child may not be getting specific nutrients. If your child simply will not eat oily fish and refuses to eat their greens, use of a good quality EPA and vitamin and mineral supplement may be a prudent choice. Be aware that children’s tastes constantly evolve, however, and it is wise to consistently re-introduce foods that they may not have liked in previous months. Both you and your child may be pleasantly surprised!
Next month– part two: ADHD and the issue of dietary restrictions
NDNS (National Diet and Nutrition Survey) 2012
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11. NDNS (National Diet and Nutrition Survey) 2012
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