A summer holiday is only complete with a visit to the beach. It is a true Australian summer tradition. Sand between you toes, swimming in the ocean, building sandcastles, sun, surf and sand. Aah, summer!
Although this paints a very pretty picture, there are potential hazards with sun exposure, one of which is dehydration.
It is important to adopt particular behaviours to ensure adequate hydration is maintained.
Children are more vulnerable to heat illness than adults as they have a greater surface area-to-body mass ratio, a lower rate of sweating, different thirst sensitivities and slower rate of acclimatisation to heat.
Why is dehydration dangerous?
Dehydration can range from mild to severe, depending on the degree of fluid loss. There is reduced blood volume, increased heart rate, increased perception of effort, reduced exercise and movement performance, headache, hot flushes and nausea.
Dehydration also promotes secretion of the stress hormone cortisol.
Mild dehydration is characterised by a loss of 1 per cent to 2 per cent body fluid. Even at this level, cognition, short-term memory and attention can be impacted. Children may also become irritable and unhappy. Fatigue and slowed metabolism may also result in mild dehydration.
In severe dehydration there may be a loss of consciousness, and research suggests death could occur in extreme cases.
You can see now that dehydration is very serious. It impacts the thermoregulatory system, which regulates core body temperature. It also compromises cardiovascular health and the blood-brain barrier, making it extremely difficult for nutrients and messages to be transported around the body.
It is important to note that if you suspect your child is suffering heat illness or dehydration, seek expert attention as soon as possible.
Rapid rehydration with copious amounts of water may cause a hurried influx of water to the brain. This may be detrimental and is therefore not recommended.
Unfortunately, there is no gold standard to measure hydration status in children. Urinary volume alone is a poor measure.
However, the colour of urine is a suitable indicator. Normal urine colour is a clear to straw colour. Evidence of mild dehydration may be deduced if urine is very dark and resembling the colour of concentrated apple juice.
The best and most efficient method to prevent dehydration in children at the beach is to monitor hydration status.
Food and drink suggestions for hydrating
Australia does not have a recommended guideline suggesting how much water children should consume to remain hydrated. However, with the inclusion of high-moisture foods, it is possible to prevent dehydration.
See the list below for the water content of foods commonly consumed at the beach. A high-moisture food contains at least 90 per cent water. However, increasing consumption of foods containing at least 80 per cent water is beneficial.
Foods and their water percentage
90-99% Fat-free milk, cantaloupe, strawberries, watermelon, lettuce, celery, spinach;
80-89% Fruit juice, yoghurt, apples, grapes, oranges, carrots, pears, pineapple;
70-79% Bananas, avocados, cottage cheese, ricotta cheese, corn;
60-69% Ice-cream, pasta, salmon, chicken breast;
30-39% Bread, bagels, rolls
Eight simple hydration tips for the beach
1 Do not wait until your child is thirsty. Thirst is an early indicator of mild dehydration. It is recommended to consume fluid regularly to prevent thirst;
2 Encourage children to drink water. Plain water is good;
3 Other liquids such as diluted fruit juice are also good options. Too much fruit juice may promote dental caries. However, in moderation, such fluids may promote greater water absorption in the small intestine and more rapid hydration than water alone;
4 Beach visits are an ideal time for consuming high water-containing fruits. Pack a snack box for children containing grapes, watermelon, cantaloupe, honeydew melon, strawberries, blueberries, mango, peaches and nectarines. These fruits contain beneficial nutrients and they will assist in maintaining a hydrated state. For something different, try freezing a mix of berries to serve at the beach;
5 Vegetables such as cucumber, celery, tomatoes, mixed leaves, capsicum and carrot are good for snacking at the beach. They provide beneficial nutrients but will also assist in maintaining hydration because of their water content. Pack a combination of dips such as tzatziki, humous and beetroot dip for dipping vegetables;
6 Monitor and/or limit processed foods such as the sweet and salty snack variety. These foods contain high amounts of unnecessary sugars and salt. Such ingredients combined with sun exposure may promote dehydration and thirst;
7 Do not give cola and other caffeinated beverages to children. Caffeine is a diuretic that enhances urinary output and fluid loss from the body. Caffeine is also a stimulant that is not appropriate for the young; and
8 Include good-quality carbohydrate-containing foods such as multigrain or sourdough breads. Carbohydrates accelerate and promote water absorption by stimulating water movement. Pack sandwiches with chicken or cheese for added nutrients. Remember to pack food and drink in a cooler bag to prevent premature perishing.
Don’t forget safe sun exposure
Recommendations for remaining hydrated at the beach cannot be made without alluding to general sun safety. In Australia, the sun is exceptionally strong. Safe practices such as avoiding sun exposure during peak sun hours, sitting under shade, applying sun protection lotion, wearing a hat and sunglasses are important for preventing dehydration and to reduce the risk of skin cancer.
» Sharon Brooks is a registered nutritionist and food scientist. She operates Sharon’s Nutrition, a nutrition consultation business specialising in proactive health and optimal well-being.