Physical activity is beneficial for both physical and mental health. Despite
opportunities both at and outside of school, many adolescents are not
participating in regular physical activity. Some of the reasons for a lack of physical
activity by adolescents are outlined in this article.
Current recommendations
European recommendations state that children and adolescents aged 5–18 years should
accumulate at least 60 minutes of moderate to vigorous physical activity daily most days
of the week (activity that noticeably increases the heart rate and breathing rate).
1
However, the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study of
12.5–17.5 yearolds reported that under onethird of European girls and under twothirds
of boys achieve this.
2
In general, female adolescents participate in less physical activity
than males, with a greater decline in participation for girls as they age.
2,3
Numerous
factors that inhibit girls’ participation in physical activity have been cited.
3,4
Opportunities and barriers to physical exercise
Opportunities for adolescents to partake in physical activity exist both at, and outside of,
school. However, for adolescents a number of barriers to the enjoyment of, and
participation in physical activity have been identified.
At school
Physical education classes and organised sport aim to provide an opportunity to meet daily recommendations for physical
activity in a fun, supportive environment. However, body image and concerns over appearance may be barriers to physical
activity; many girls note that getting ‘sweaty’ and messedup hair and makeup limit their willingness to participate. Adolescents
are also concerned with stereotypes (sporty females perceived as more masculine), bullying or teasing from their peers, and
may lack sporting role models. A lack of confidence in their own ability and skill level can also inhibit participation and
enjoyment.
36
Outside of school
Activities outside of school include organised sport, active hobbies and family interaction. As the popularity of sedentary
behaviours, such as watching television, using the internet and video games increases, adolescents may spend more time on
them, as opposed to physical activity.
2,4,6
Other time constraints include homework or parttime work. Adolescents’ access to
physical activities may be limited by family structure and routine, parents’ safety concerns, lack of support or inability to
provide for travel, equipment purchases and club membership fees.
3,4,7
Enhancing enjoyment and participation
As the benefits of physical activity are clear, and attitudes are shaped early on, it is imperative that individuals are encouraged
to take part in, and enjoy, physical activity from a young age. The numerous reasons that inhibit participation must be
addressed, for example discussing with adolescents their attitudes towards sports clothing, body issues, stereotypes, and
factors which would increase their participation and enjoyment.
3
This may include revising school uniform codes and the option
to shower and dress in private.
5,6
Schools appear best placed to effect change. It has been recommended that physical education and sports in schools should
focus more on promoting the confidence and wellbeing of each individual, in addition to fitness and competitive sport.
3
Physical
education should be inclusive and staff should be supportive of all pupils, regardless of ability. It is important to provide
adolescents with opportunities to partake in novel activities that they enjoy, and inexpensive activities that do not require
specific skills or transportation. Adolescents could be motivated by developing skills in leadership, team work and organisation,
a positive body image, and improving academic performance. Girls are more likely to be motivated by social and health
benefits, whereas boys are more likely to be motivated by being part of a team. Girls’ enjoyment of physical activity may be
enhanced by participation with friends and in a girlsonly environment partly due to body image concerns. Adolescents should
be made aware of their physical activity levels e.g. by selfmonitoring with a step counter. Active transport to and from school
should be encouraged.
3,6,7
At home, families have a big influence on the activity levels of children, but this influence declines as children grow older. While
adolescents may be increasingly influenced by their peers, families can also act as role models by being active themselves.
3,8
References
1. World Health Organization, Physical activity and young people:
http://www.who.int/dietphysicalactivity/factsheet_young_people/en/index.html
2. Ruiz JR et al. (2011). Objectively measured physical activity and sedentary time in European adolescents: the HELENA
study. Am J Epidemiol 174(2):173–84.
3. Women’s Sport and Fitness Foundation (2012). Changing the game for girls. London: United Kingdom.
4. Dwyer JJM et al. (2006). Adolescent girls’ perceived barriers to participation in physical activity. Adolescence 41:75–89.
5. Stankov I et al. (2012). Overweight and obese adolescents: what turns them off physical activity? Int J Behav Nutr Phys
Act 9:53.
6. O’Dea JA. (2003). Why do kids eat healthful food? Perceived benefits of and barriers to healthful eating and physical
activity among children and adolescents. J Am Diet Assoc 103:497–501.
Barriers to adolescent enjoyment of and participation in physical activity
7. De Cocker K et al. (2012). Can differences in physical activity by socioeconomic status in European adolescents be
explained by differences in psychosocial correlates? A mediation analysis within the HELENA (Healthy Lifestyle in Europe
by Nutrition in Adolescence) Study. Public Health Nutr 12:1–10; doi:
8. Fitzgerald A et al. (2012). Do peers matter? A review of peer and/or friends’ influence on physical activity among
American adolescents. J Adolescence 35(4):941–58.
2
The term ‘superfood’ has become a popular buzzword in the language of food
and health. However, there is no technical definition of the word and the
scientific evidence for the health effects of these foods — while often positive —
does not necessarily apply to real diets. A diet based on a variety of nutritious
foods, including plenty of fruits and vegetables, remains the best way to ensure
a balanced nutrient intake for optimal health.
The origin of the superfood
The concept of the superfood is a popular one when it comes to food and health. The
media is full of reports of ultrahealthy foods, from blueberries and beetroot to cocoa
and salmon. These reports claim to reflect the latest scientific evidence, and assure us
that eating these foods will give our bodies the health kick they need to stave off illness
and aging. But is there any truth to such reports?
The current attention on superfoods has likely been encouraged by a growing public
interest in food and health, particularly in the developed world.
1
While the use of the
term has been recorded as far back as the beginning of the 20th century, it has only
recently become popular in mainstream language.
2
A simple internet search for the
word, superfood, reveals close to 10 million results — predominantly from health and nutrition blogs, online newspapers and
magazines, and providers of nutritional supplements.
Despite its ubiquity in the media, however, there is no official or legal definition of a superfood. The Oxford English dictionary,
for example, describes a superfood as “a nutrientrich food considered to be especially beneficial for health and wellbeing”,
while the MerriamWebster dictionary omits any reference to health and defines it as “a super nutrientdense food, loaded with
vitamins, minerals, fibre, antioxidants, and/or phytonutrients”.
3,4
Generally speaking, superfoods refer to foods — especially
fruits and vegetables — whose nutrient content confers a health benefit above that of other foods.
What is the evidence?
In order to distinguish the truth from the hype, it is important to look carefully at the scientific evidence behind the media’s
superfood claims. Blueberries are one of the more popular and wellknown superfoods, and have been studied frequently by
scientists curious about their health properties. The berries’ high concentrations of a group of antioxidant plant compounds,
especially those called anthocyanins, have been reported to inhibit the growth of cancerous human colon cells, as well as kill
them off.
5
Blueberries are also rich in other antioxidants, which have been shown to prevent and reverse agerelated memory
decline in rats.
6
Antioxidants are molecules which protect the cells in the body from harmful free radicals. These free radicals come from
sources such as cigarette smoke and alcohol, and are also produced naturally in the body during metabolism. Too many free
radicals in the body can result in oxidative stress which, in turn, causes cell damage that can lead to agerelated diseases like
cancer, diabetes, and heart disease.
7
Other fruits which have received superfood status include açaí berries and pomegranates. The fruit pulp of açaí berries has
been shown to have potent antioxidant properties, although any potential health benefits of this have yet to be confirmed in
humans.
8,9
Studies on pomegranate juice have suggested that it can lower blood pressure in the shortterm, as well as reduce
oxidative stress, in healthy people.
10,11
These are both significant risk factors for heart disease.
Like pomegranate juice, beetroot has been proposed as a hearthealthy superfood. Its high levels of nitrate are claimed to be
converted by the body into nitric oxide which, among other functions, has been shown to lower blood pressure and the
tendency for blood clotting in humans.
12
Cocoa has similarly been claimed to cut the risk of heart disease by lowering blood
pressure and increasing the elasticity of blood vessels. This is thought to be due to cocoa’s high content of compounds called
flavonoids.
13,14
Finally, salmon has frequently made it onto superfood lists amid growing evidence that the omega3 fatty acids
in salmon and other oily fish may prevent heart problems in people with a high cardiovascular risk, as well as alleviate joint
pain experienced by patients with rheumatoid arthritis.
1517
Looking closer
These are just a handful of the many studies that have looked at the health properties of foods. At first glance, they appear to
lend weight to the existence of certain superfoods — certainly, the nutrients in these foods have been shown to have several
healthpromoting properties. But a closer look reveals the difficulty in applying the results of these studies to real diets. This is
because the conditions under which foods are studied in the lab are often very different to the way these foods are normally
consumed by people in their everyday lives.
One major characteristic of research in this area is that very high levels of nutrients tend to be used. These are usually not
realistically attainable in the context of a normal diet. On top of this, the physiological effects of many of these foods are often
shortterm.
12,13
This means people would need to consume them often in order to reap their health benefits. This could be
counterproductive, especially for certain foods: frequently consuming cocoa in the form of chocolate, for example, would
boost intakes not only of cocoa’s healthpromoting flavonoids but also of other nutrients of which we are recommended to
consume less.
Perhaps an even greater consideration when looking at these studies is that many of them tend to use either animal models
such as rats, or in vitro experiments using isolated batches of human cells. These types of studies are useful for giving
scientists an idea of what the health properties and physiological mechanisms of certain food components could be, but there is
no guarantee that these components will have the same effects in people when consumed in the diet. Investigating effects in
humans is a complex task: our diets, genes, and lifestyles vary from person to person, making it difficult to study the impact of
nutrients on health. This means that, in contrast to cell culture and animal studies, a different approach is needed when
exploring effects in humans that ideally includes both intervention studies (where researchers manipulate the diet to determine
the effect of a food or nutrient) and observational studies (where researchers observe the effects of natural differences in
people’s diets).
The science behind superfoods: are they really super?
3
A final point to consider when looking at studies on the ‘healthfulness’ of foods is that many researchers study foods in
isolation. Given that people normally consume combinations of foods, picking out a single one to study does not reflect real
human consumption. What’s more, there is evidence to suggest that in some cases coconsumption of foods can actually
increase the body’s ability to absorb nutrients. The betacarotene in carrots and spinach, for instance, is more readily absorbed
when eaten together with a source of fat such as salad dressing.
18
This hints at the merits of a diet based on a variety of
nutritious foods as opposed to a diet based solely on one or a handful of superfoods.
The bottom line
The idea of foods having exceptional health benefits is an attractive one, and has surely fuelled the public interest in
superfoods. Indeed, the science in this area has demonstrated that certain components of foods and drinks may be particularly
good for you. This is also reflected in the existence of approved health claims, for which the European Food Safety Authority
has found the scientific evidence base to be sufficiently convincing.
19
At the same time, it is unrealistic to expect a narrow
range of ‘superfoods’ to significantly improve our wellbeing. When looking at the evidence behind superfoods, we need to be
realistic about how this translates into real diets.
Labelling some foods as ‘super’ in the media may also give the impression that other foods in our diets are not as healthy
when, in reality, these foods often provide nutrients just as valuable as those found in superfoods. Carrots, apples and onions,
for example, are packed with healthpromoting nutrients such as betacarotene, fibre, and the flavonoid quercetin.
20
Wholegrain varieties of cerealbased starchy foods such as bread, rice and pasta are also high in dietary fibre. In adults,
dietary fibre intake should be at least 25 g per day.
21
These foods often have the added benefit of being cheap and readily
available. This means we can easily consume them in large enough quantities and on a regular basis to get the most from their
nutrient content. Given that most people in Europe are not eating enough fruit and vegetables to meet dietary
recommendations, upping our daily intakes of a variety of fruits and vegetables will go a long way towards generally improving
our wellbeing.
22
Conclusion
When it comes to ensuring a balanced nutrient intake for good health, we need to increase the range of nutritious foods in our
diets rather than focusing solely on a handful of foods claimed to be ‘super’. Importantly, this should include a greater quantity
and variety of fruits and vegetables. Many European countries provide foodbased dietary guidelines to help people reach this
goal.
23
References
1. European Commission (2010). Functional foods. DG Research. Brussels: Belgium.
2. The Gleaner (1915). Kingston, Jamaica, 24 June 18/2.
3. Oxford English Dictionary, online edition, entry superfood,
. Accessed on 24 April
2012.
4. MerriamWebster Dictionary, online edition, entry superfood,
. Accessed on 24 April
2012.
5. Yi W et al. (2005). Phenolic compounds from blueberries can inhibit colon cancer cell proliferation and induce apoptosis.
Agric Food Chem 53(18):7320–9.
6. Malin DH et al. (2011). Shortterm blueberryenriched diet prevents and reverses object recognition memory loss in
aging rats. Nutrition 27(3):338–42.
7. Dröge W. (2002). Free radicals in the physiological control of cell function. Physiol Rev 82(1):47–95.
8. Lichtenthäler R et al. (2005). Total oxidant scavenging capacities of Euterpe oleracea Mart. (Açaí) fruits. Int J Food Sci
Nutr 56(1):53–64.
9. Hassimotto NMA et al. (2005). Antioxidant activity of dietary fruits, vegetables, and commercial frozen fruit pulps. J
Agric Food Chem 53:2928–35.
10. Lynn A et al. (2012). Effects of pomegranate juice supplementation on pulse wave velocity and blood pressure in
healthy young and middleaged men and women. Plant Foods Hum Nutr 67(3):309–14.
11. Aviram M et al. (2000). Pomegranate juice consumption reduces oxidative stress, atherogenic modifications to LDL, and
platelet aggregation: studies in humans and in atherosclerotic apolipoprotein E–deficient mice. Am J Clin Nutr 71
(5):1062–76.
12. Webb AJ et al. (2008). Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via
bioconversion to nitrite. Hypertension 51:784–90.
13. KrisEtherton PM & Keen CL. (2002). Evidence that the antioxidant flavonoids in tea and cocoa are beneficial for
cardiovascular health. Curr Opin Lipidol 13:41–9.
14. Hooper L et al. (2008). Flavonoids, flavonoidrich foods, and cardiovascular risk: a metaanalysis of randomized
controlled trials. Am J Clin Nutr 88(1):38–50.
15. KrisEtherton PM et al. (2003). Fish consumption, fish oil, omega3 fatty acids, and cardiovascular disease. Arterioscler
Thromb Vasc Biol 23:e20–e30.
16. DelgadoLista J et al. (2012). Long chain omega3 fatty acids and cardiovascular disease: a systematic review. Br J Nutr
107(Suppl 2):S201–13.
17. Goldberg RJ & Katz J. (2007). A metaanalysis of the analgesic effects of omega3 polyunsaturated fatty acid
supplementation for inflammatory joint pain. Pain 129(1–2):210–23.
18. Brown MJ et al. (2004). Carotenoid bioavailability is higher from salads ingested with fullfat than with fatreduced salad
dressings as measured with electrochemical detection. Am J Clin Nutr 80:396–403.
19. EU Register on nutrition and health claims:
http://ec.europa.eu/nuhclaims/
20. Crozier A et al. (1997). Quantitative analysis of the flavonoid content of commercial tomatoes, onions, lettuce, and
celery. J Agric Food Chem 45(3):590–5.
21. EFSA panel on dietetic products, nutrition and allergies (2010). Scientific opinion on dietary reference values for
carbohydrates and dietary fibre. EFSA Journal 8(3):1462. Available at:
http://www.efsa.europa.eu/en/efsajournal/pub/1462.htm
22. EUFIC Review (2012). Fruit and vegetable consumption in Europe – do Europeans get enough?
http://www.eufic.org/article/en/expid/FruitvegetableconsumptionEurope/
23. EUFIC Review (2009). Foodbased dietary guidelines in Europe.
http://www.eufic.org/article/en/expid/food
baseddietaryguidelinesineurope/
4
Coeliac disease is a gutdamaging condition that can develop at any time
throughout life. Following a glutenfree diet is currently the only effective
treatment.
What is coeliac disease?
Coeliac disease is an autoimmune disorder in which the immune system reacts to gluten, a
collective name for a type of protein in wheat, rye and barley. Some people also react to
oats. The lining of the small intestine becomes damaged which causes malabsorption of
nutrients, increasing the risk of nutrient deficiencies, anaemia and osteoporosis. Symptoms
vary considerably, ranging from digestive complaints to poor growth, skin rashes or
infertility.
1
Increasing prevalence but underdiagnosed
In Europe an estimated 1% of adults and children have the disease.
2
The prevalence
varies widely; for ages 30–64 years, it is eight times higher in Finland (2.4%) than in
Germany (0.3%), perhaps relating to both genetic and environmental factors. In Finland,
the prevalence has doubled over 20 years which cannot be explained by better detection
rates.
3
Undetected or misdiagnosed coeliac disease is common and may result in ongoing health risks.
4
Symptoms can be absent or
nonspecific, and are often mistaken for irritable bowel syndrome. This is perpetuated by a misconception that coeliac patients
are underweight, whereas in fact many are normal or overweight.
1
Currently, testing is recommended for symptomatic
individuals (including associated conditions such as osteoporosis or irondeficiency anaemia) and those with increased risk of
coeliac disease including people with existing autoimmune disease (e.g., type 1 diabetes, autoimmune hypothyroidism) or with
firstdegree relatives with coeliac disease.
5
Before eliminating gluten from the diet, diagnosis uses blood testing and usually
smallbowel biopsy.
The challenge of a lifelong glutenfree diet
A strict, lifelong glutenfree (GF) diet allows the small intestine to recover. Obvious sources of gluten are bread, many
breakfast cereals, pasta, pizza, cakes and biscuits. Gluten may also be used to give structure to food products such as
sausages, stock cubes, soups and sauces. Naturally GF foods include meat, fish, eggs, fruit, vegetables, dairy products, beans,
potatoes, rice, maize, quinoa and buckwheat. Substitute foods such as speciallymade GF bread, flour, pasta, and crackers,
have increased in variety in recent years and are available on prescription in some countries.
1
Inadvertent gluten consumption may occur, for example by crosscontamination; GF foods should be prepared with separate
utensils e.g. toaster.
1
People with coeliac disease vary in their sensitivity to trace amounts of gluten.
6
There has been confusion about whether oats can be included in a GF diet. During milling oats often come into contact with
wheat, rye or barley. Pure uncontaminated oats, labelled ‘glutenfree’, are considered safe for most. However, a small
proportion of people may (also) have an immune response to avenin, a protein similar to gluten that is found in oats. Those
newly diagnosed with coeliac disease should avoid oats until the disease is well controlled by a GF diet, when GF oats can be
gradually introduced whilst monitoring for adverse effects.
7
Qualified dietitians can help ensure the diet is balanced and contains enough dietary fibre and micronutrients including calcium.
Official coeliac societies across Europe also provide support.
1
Food labelling
If a glutencontaining ingredient is used in the production of a foodstuff, then the gluten source must be on the label. Labelling
rules in force late 2014 will require glutencontaining cereals to be highlighted in the list of ingredients. This requirement will
also extend to nonprepacked foods sold loose, e.g. in restaurants. Foods labelled ‘glutenfree’ must not contain more than 20
mg of gluten per 1 kg. Specialist products containing between 20 and 100 mg of gluten per 1 kg can be labelled ‘very low
gluten’.
6
Manufacturers must implement procedures to prevent crosscontamination. A Crossed Grain trademark symbol,
recognised worldwide by people with coeliac disease, is available to manufacturers and retailers to help consumers choose
safe products.
1
Prevention and new therapies
A recent study suggests the gradual introduction of glutencontaining foods into an infant’s diet after four months but before
seven months, whilst continuing breastfeeding, may help to protect against the development or delay the onset of the disease.
8
New therapies being researched for easier GF living in the future, include genetically altering wheat to remove gluten and
drugs or vaccines that could prevent gluten damaging the gut.
9
References
1. Association of European Coeliac Societies:
2. Mustalahti K et al. (2010). The prevalence of celiac disease in Europe: results of a centralized, international mass
screening project. Ann Med 42:587–95.
3. Lohi S et al. (2007). Increasing prevalence of coeliac disease over time. Aliment Pharmacol Ther 26(9):1217–25.
4. Evans KE et al. (2011). Is it time to screen for adult coeliac disease? Eur J Gastroenterol Hepatol 23:833–8.
5. Husby S et al. (2012). European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the
diagnosis of coeliac disease. J Pediatr Gastroenterol Nutr 54(1):136–60.
6. Commission Regulation (EC) No 41/2009 concerning the composition and labelling of foodstuffs suitable for people
intolerant to gluten:
http://eurlex.europa.eu/LexUriServ/LexUriServ.do?
uri=OJ:L:2009:016:0003:0005:EN:PDF
7. Ellis HJ & Ciclitira PJ. (2008). Should coeliac sufferers be allowed their oats? Eur J Gastroenterol Hepatol 20:492–3.
8. Szajewska H et al. (2012). Systematic review: early infant feeding and coeliac disease prevention. Aliment Pharmacol
Ther 36(7):607–18.
9. Lerner A et al. (2010). New therapeutic strategies for celiac disease. Autoimmunity Reviews 9:144–7.
Coeliac disease on the rise in Europe
5