Here’s What You Need to Know:
- Fruit juices are generally perceived as healthy by most people.
- Parents often choose fruit juices over whole fruits for their kids to get their daily fruit intake.
- Fruit juices and whole fruits are thought as being the same but this isn’t true. Fruit juice consumption in excess can negatively affect your health.
- Fruit juices lack fibre which contains antioxidants and feed beneficial bacteria in your gut. When you juicing you lose the fibre.
- Most commercial fruit juices contain added sugars, artificial colourants, flavourants and preservatives and should be consumed sparingly.
- Consume fresh whole fruits or blend the fruits so that you don’t lose the fibre.
The juicing of fruits is perceived as a healthy practice by consumers.
Most of us have felt tempted by the juicer infomercials that make juice making seem effortless, easier to get your kids to consume than whole fruits.
Proponents of juicing even go as far as saying that juicing unlocks the vitamins and minerals in the fruits.
Commercial fruit juices are very common as well. The latter eliminate the hassle of having to make the juice yourself and are almost always more delicious and attractive as home-made ones, don’t spoil as easily and often contain added vitamins.
Overall, fruit juices are perceived as being healthy.
Scientific studies, however, paint a different picture.
It has been found that a higher consumption of specific whole fruits, particularly blueberries, grapes, and apples, decreases your risk of getting type 2 diabetes, whereas greater consumption of fruit juice is associated with a higher risk (1).
A recent study reported that replacing blueberry juice with an equal amount of whole blueberries decreases the risk of developing type 2 diabetes by an astounding 33% (1).
Several studies reported similar findings (2, 3, 4)
What people fail to realise is that juicing isn’t a healthy practice.
The truth is that juicing eliminates a lot of the stuff that makes whole fruits healthy and alters the health properties of the latter.
What Makes Juices Less Healthy?
The main issue with juicing is the loss of the dietary fibre contained in fruits. This is the pulp that comes out on the other side of the juicing machine and that is often thrown away.
Dietary fibre is essential for reap the complete benefits of fruits. In fact, the consumption of fibre from fruits and other sources has been linked to health benefits like reduced coronary heart disease risk (5) and colorectal cancers (6).
It has been found that just a 10g/ day increase in fibre consumption can decrease the risk of all coronary events by 14%.
In a study at the University of Copenhagen (7), healthy people who ate 550g of whole apples a day (about 3 medium apples) for 4 weeks had their LDL (bad) cholesterol reduced by 6.7%. When the same people had 500ml of clear apple juice instead their LDL-cholesterol increased by an amazing 6.9%.
When they drank 500ml/ day of juice with a bit of the fibre added back (cloudy juice) their LDL-cholesterol increased by only 2.2%.
Obviously, fibre has a role to play in this.
Clearly, we need to rethink the notion that fibre is the indigestible material that just keeps you regular!
Fibre contains important antioxidants
Fruits have long been known to contain a class of nutrients called polyphenols.
Polyphenols are known to contribute to the prevention of cardiovascular diseases, cancers, osteoporosis and diabetes mellitus (8)
The surprising fact is that most of the polyphenols found in fruits are bound to dietary fibre.
These are known as non-extractable polyphenols (NEPPs). NEPPs have potential health-related properties, in particular in relation to gastrointestinal health, such as a reduction of intestinal tumor generation (9)
NEPPs are released from the fibre by the action of intestinal bacteria. Juicing fruits means that a lot of these antioxidants are lost.
Fibre feeds beneficial bacteria in your gut
Fibre is used as a source of food for bacteria preset in your intestines.
For example, intestinal bacteria ferment fibre to make short chain fatty acids like Butyrate (10). Butyrate is a source of fuel for cells that line our colon.
In other words, we feed them (intestinal bacteria) and they feed us in return.
The bacteria also thank us for feeding them fibre by fighting off harmful bacteria and improving mineral absorption (e.g. Calcium).
Other Reasons to choose Whole Fruits
Whole fruits are more filling than fruit juices and thus is is easier to over drink and ingest a lot of sugar in the process.
The fibre in whole fruits also slows down the release of sugar into the bloodstream. With fruit juice, massive amounts hit the bloodstream rapidly.
► Eat whole fruits and encourage your kids to do so.
► Choose blending over juicing. With blending you keep the fibre and there are many ways to make fruit blending fun, one of them is to make fruit smoothies.
► Consume moderately: small amounts of fruit juice are not likely to cause major problems if you are healthy, active and lean. However, they can be a disaster for people who are overweight or have diet-related metabolic problems.
What You Need to Know:
- Iron is an important mineral involved in many processes in the body, like oxygen transport.
- The body needs more iron during adolescence due to growth and the onset of menstruation.
- Physical activity and sports increase iron requirements.
- It is easy to become iron deficient if one is not careful about the diet.
- Here we cover some of the tricks to increase iron absorption from food.
- Iron supplements are not necessary and can be dangerous.
Adolescents need to get sufficient quantities of iron from their diet as it is a key nutrient for their growth and development.
During adolescence the body requires more iron because this is a phase of physical intense growth and development which requires a higher blood volume. The onset of menstruation in adolescent girls also means that more iron is needed.
Furthermore, physical activity increases the requirement of iron due to increased losses of iron from the body.
Iron deficiency, which can eventually lead to iron-deficiency anaemia is a common nutritional deficiency worldwide among adolescents. This is due to their higher needs coupled with the fact that many adolescents often consume monotonous and unbalanced diets that may negatively affect the intake of iron.
Unfortunately, preventing iron deficiency is not as easy as eating iron-rich foods and supplementing with an iron supplement.
There are a lot of dietary factors that affect the amount of iron from food that enters the circulation and care must be taken when planning diets.
Supplementation, especially in high doses, is problematic because of potential toxicity issues in the long run and, more acutely, gastrointestinal issues like constipation.
The South African department of health sets the daily requirement (Nutrient Reference Values-NRV) of iron at 18mg per day for individuals 4 years and older.
Iron Deficiency Symptoms
The common symptoms of iron deficiency are reduced memory, concentration and a reduced ability to learn new things.
In a study done in 5398 children aged 6-16 years in the United States, it was found that children with iron deficiency had greater than twice the risk of scoring below average in math than did children with normal iron status (1).
Fatigue is also among the most common symptoms as reduced iron levels mean that less haemoglobin is available in blood to carry oxygen. Tasks like climbing stairs, walking uphill or exercising become harder.
The heart also beats faster (higher pulse rate) in its attempt to maintain oxygen circulation.
To ascertain the iron levels blood tests are recommended that more accurately give you an idea of iron levels in the body.
However, keep in mind that iron deficiency can have causes that are not related to nutrition and the proper diagnosis conducted by a healthcare professional, is important.
Obtaining Iron from Food
It is recommended to obtain iron from food. Supplements may be considered only under recommendation by a healthcare professional.
Types of food Iron
There are two forms if iron in food, name haeme and non-haeme iron.
Haeme iron: found animal sources like meats, fish and shellfish.
Non-haeme iron: found in plant sources like dark-green leafy vegetables (e.g. Spinach), dried fruits and beans.
Ensuring efficient Iron absorption
In terms of absorption, haeme is much better absorbed than non-haeme iron.
This is because non-haeme iron is susceptible to inhibition by a number of dietary factors which reduce the bioavailability of non-haeme iron. These factors are:
□ Calcium: present in dairy products. Calcium competes against Iron for absorption at the intestines as they use the same transporter.
□ Phytates (present in cereals and grains) and Polyphenols (present in tea and coffee) that bind non-haeme iron making them unavailable for absorption.
All hope is not lost because your body can still absorb non-haeme iron if facilitators are taken in in the meal containing non-haeme iron. These facilitators are Vitamin C and Vitamin A.
Vitamin C is a powerful stimulator of non-haeme iron absorption. My honours thesis was on this very topic (thesis title, “Determinants of Bioavailability in Iron Nutrition: Vitamin C as a Knight in Shining Armour”)
Iron supplements are not recommended unless prescribed by a healthcare professional.
Self-administration of iron can be hazardous because long-term consumption can lead to accumulation of iron in body tissues like the liver.
Excessive iron intake can also cause constipation.
Iron is present in many foods as a fortificant (e.g. in flour and cereals) or in nutritional shakes and multivitamins. These are generally not reason for concern as they are present in small amounts.
Putting it all together
□ Consume animal sources: these supply haeme iron that are efficiently absorbed. This is a good way to reverse deficiency.
□ Eat a source of Vitamin C: vitamin C helps with iron absorption and can improve the absorption of non-haeme sources.
About the Author
MSc (Med) Exer. Sci (UCT) cum laude, BSc (Hons) Biology.
Veeraj is an exercise and nutritional scientist by training and profession. He is passion revolves around researching and developing nutritional products for optimal health and performance, with a particular interest in sports, child and diabetic nutrition products. Veeraj was previously a graduate student at the University of Cape Town, where he examined how exercise and nutrition influence the function of genes in muscle. His research was published in renowned scientific journals and medical textbooks on Diabetes and Exercise (PubMed listing). Veeraj keeps healthy by regularly lifting weights and takes daily walks.
Here’s What You Need to Know:
- Artificial food colourants (AFCs) are derived from petroleum and are used to improve the colour and appearance of food and beverages.
- AFCs have been implicated in hyperactive behaviours in children. Tartrazine is one such food colourant.
- Benzoate, a common food preservative, may worsen the effects of AFCs.
- Studies show that some children are more affected than others.
- Although AFCs are allowed in foods, regulatory bodies in some countries have taken proactive measures to have food manufacturers using the six artificial food colours (listed in this article) give a warning that the latter “may cause hyperactive behaviours in children”.
- It is best to minimise exposure to AFCs by reading labels carefully and choose products that use natural food colourants and no benzoates.
Finding Artificial Food Colourants on food labels.
There are many artificial food colourants used today but there are six, listed below, that are the most commonly used.
The use of the six colourants is regulated by the two major food regulatory authorities, namely the European Food Safety Authority (EFSA) and the US Food and Drug Administration (FDA).
These colourants are as follows:
□ Allura Red (E 129): cherry-red: used in soft drinks, candy, children’s medications and ice cream.
□ Brilliant Blue (E133): blue colouring used in candies and beverage mixes.
□ Sunset Yellow (E110): Yellow colouring: used in candy, desserts, snacks and sauces.
□ Tartrazine (E102): lemon-yellow dye found in soft drinks, candy and cereals.
□ Indigo Carmine (E132): blue dye used in candy, ice-cream and cereals.
□ Erythrosine (E127): A cherry-red coloring commonly used in candy, popsicles and cake-decorating gels.
In America these colourants are often listed by their names while in Europe they are listed by an “E-number”. South Africa follows the European system.
Evidence for AFCs causing hyperactivity
Interest in the effects of AFCs on hyperactive behaviours and learning difficulties in children dates from the early 70s when a diet that eliminates AFCs and preservatives began to be recommended to children with attention deficit hyperactivity disorder (ADHD) (1).
It must be noted that AFCs do not cause ADHD but studies have shown a small but significant negative effect of AFCs on children’s behaviour, regardless of whether or not they have ADHD.
A number of studies found an improvement in behaviours when AFCs, along with the popular preservative Benzoate, were eliminated from the diet of children with ADHD (2).
Another study found that food dyes, along with sodium benzoate, increased hyperactivity in both 3-year-olds and a group of 8- and 9-year-olds (3). However, because these study participants received a mixture of ingredients, it is difficult to determine what caused the hyperactivity.
It is probable that both benzoates and AFCs influence behaviour and foods containing them should be limited or eliminated.
Tartrazine, a very popular AFC, has been associated with behavioural changes like irritability, restlessness, depression and difficulty with sleeping (4). The good news is that many manufacturers have taken the initiative to stop using Tartrazine in food products, hence the recent explosion of “Tartrazine-free” products on the market.
Not all kids respond the same way
It appears that not all children react the same way to AFCs. Researchers at Southampton University found a genetic component that determines how food dyes affect a child (5).
While effects from AFCs have been observed in children with and without ADHD, some children seem much more sensitive to dyes than others (6).
The Authorities’ Ruling on AFCs
The position of both the FDA and the EFSA is that there is currently a lack of evidence to conclude that AFCs are unsafe.
However, in spite of the small number of studies conducted on the topic, there is definitely enough evidence to raise concern.
Interestingly, in 2009 the British government began encouraging food manufacturers to find alternative substances to color food. As of 2010, in the UK the following warning is required on the label of any food that contains artificial food dyes (7):
‘may have an adverse effect on activity and attention in children’.
□ Check the colour of the product: if a manufactured food product is brightly coloured then chances are that it contains AFCs. Proceed to read the label to spot the AFCs listed above.
□ Choose plant-derived colourants: read product labels to spot plant-based colourants like
a. Beta-carotene (from carrots-orange/ yellow)
b. Betanin (from beetroot-red),
c. Lycopene (from tomato-red)
d. Chlorophyllin (from algae-green)
e. Curcumin (from turmeric-orange)
□ Avoid benzoates: check labels for benzoates in the ingredients list. Avoid products containing benzoates as far as possible.
□ The dose makes the poison: many health products like medication and vitamins contains AFCs. However, the level of use of AFCs in these products and the amounts you would usually ingest are quite low compared to, let’s say, an AFC-coloured fruit juice. So don’t sweat over it.
“All things are poison, and nothing is without poison, the dosage alone makes it so a thing is not a poison.”-—Paracelsus (Father of Modern Toxicology)
MSc (Med) Exer. Sci (UCT) cum laude,
BSc (Hons) Biology-Human Nutrition
Veeraj’s passion revolves around researching and developing nutritional products for optimal health and performance, with a particular interest in sports, child and diabetic nutrition products. Veeraj was previously a graduate student at the University of Cape Town, where he examined the effect of exercise and nutrition on the function of genes in muscle. His research was published in renowned scientific journals and medical textbooks on Diabetes and Exercise (PubMed listing). Veeraj keeps healthy by regularly lifting weights and taking daily walks.
Fitness training for youth has traditionally been based mainly on aerobic exercise rather than strength training. The latter type of training is usually postponed at the end of the growth age, usually at the age of 18, even among those who are actively participating in sports.
It is believed that strength training carries a high risk of injury, can get children musclebound, and interfere with their physiology and normal growth.
However, this approach has no scientific evidence to support it. In fact, both the American College of Sports Medicine (ACSM) and American Academy of Pediatrics (AAP) endorse strength training as a safe and effective activity for this age group, provided that the programs properly designed and competently supervised.
What is Strength Training?
It is important to highlight that strength-training is a specialized form of physical conditioning that is distinct from the competitive sports of weightlifting and powerlifting in which the goal is to lift maximum amounts of weights in competition. Strength training programs may include the use of free weights, weight machines, elastic tubing, or an athlete’s own body weight (freehand exercises).
Let’s Bust The Myths
Strength Training Can Cause Injury and Stunt Growth
Well, any sport or recreational activity carries an inherent risk. Strength training, under supervision, is no more dangerous than other forms of activity (Faigenbaum). The key is to conduct a supervised strength training program that is well designed to include the appropriate exercises, proper loads, repetitions and sets. Another common concern is the possibility of arrested growth due to damaged epiphyseal growth plates, which are vital structures that determine the shape and final length of bones. There have been rare case reports of growth plate fractures but these are attributed to equipment misuse, excessive weights and improper technique, reiterating the need to have qualified adult supervision (Caine). In fact, there is a greater risk in sports that involve repetitive impact, like gymnastics and baseball (Cahill, 1999).
Strength Training Makes You Musclebound and Slow You Down.
Strength Training Can Lead To Steroid Use
The Many Benefits of Resistance Training
Weight-bearing exercises are well known in their ability to increase bone mineral density, thereby decreasing the risk of developing osteoporosis later in life. Bone mineral density is a measure of calcium and other minerals in bone and is an important predictor of bone health and risk of bone fractures. Numerous scientific studies have investigated the effect of resistance training on bone mineral density. Scientists from Cologne Sports University in Germany (ref) In 1994, Welton and colleagues showed the skeleton is most responsive to strength training benefits during growth. This means strength training is most beneficial for young women before the age of 16 and young men before the age of 18. Evidently, the benefits acquired are long term. Post-menopausal women suffered fewer hip fractures if they had engaged in weight-bearing activity as young girls. In addition to decreasing the risk of osteoporosis, strength training: * strengthens ligaments and tendons * readies soft tissues to produce the forces associated with play, making them more pliable and resistant to external forces * improves motor fitness skills, such as jumping and sprinting, which are often required in sports performance. In addition to decreasing the risk of osteoporosis, strength training: * strengthens ligaments and tendons * readies soft tissues to produce the forces associated with play, making them more pliable and resistant to external forces * improves motor fitness skills, such as jumping and sprinting, which are often required in sports performance. Strength Training May Also Work as Medicine Getting Started References Faigenbaum AD, Kraemer WJ, Cahill, et al. Youth resistance training: Position statement paper and literature review. J Strength Cond Res. 1996;18:62 Caine D, DiFiori J, Maffulli N. Physeal injuries in children’s and youth sports: reasons for concern? Br J Sports Med. 2006 Sep; 40(9):749-60.
About The Author
Veeraj Goyaram, BSc (Hons), MSc Exer. Sci (UCT)
Nutrition is my passion. That is why I traded the sun, sand and sea of my native Mauritius island for the research laboratory at the University of Cape Town’s Exercise Science and Sports Medicine Unit. I conducted research on how exercise and nutrition interact to influence the expression of genes. I always felt like there was a disconnect between science and the layperson. Scientists don’t often explain things in a language that the common person can understand and apply for the betterment of his health. That is how BodyandScience.com was born. To keep healthy I lift weights in the gym and taking walks on a daily basis. Find more about me on my Linked In profile.