What is iron and what does it do?
Iron is involved in the formation of haemoglobin, which transports oxygen via the blood to every cell in the body.
While haemoglobin levels are ultimately lowered by iron deficiency, it is not the only type of iron that can be measured. A blood test requesting iron studies may also look at serum iron, transferrin (or iron binding capacity) or TIBC (the concentration of transferrin) and ferritin (iron storage). The first sign of iron deficiency is usually a drop in ferritin levels, followed by a fall in transferrin saturation and rise in transferrin.
We get two different types of iron from our diet haem/heme and non-haem/non-heme. The first is the most easy to absorb and use and is from animal sources, such as meat and seafood. Non-heam comes from plants such as vegetables, grains, legumes and nuts. Although non-heam iron often makes a larger amount of our daily intake (in a healthy diet), it is less bio-available.
Symptoms of iron deficiency anaemia
As iron is involved in transporting oxygen around the body, a deficiency can lead to shortness of breath, an increased heart rate, tiredness and changes in moods. It may also increase susceptibility to infections and cause a sore tongue, dizziness or even headaches. A bizarre, occasional symptom of iron deficiency is pica, which causes cravings to eat things not considered food such as soil or ice.
How do we become deficient in iron?
There are a number of reasons why iron is the most common nutritional deficiency.
The first part of the equation is the form and quantity of iron rich foods in our diet. While this is a large part of the anaemia story, it tends to get the most attention by many sources only focusing on the amount of iron in different foods. While much is made of the apparent difficulty for vegans and vegetarians to get enough iron in their diet from non-haem sources alone, it doesn’t explain why iron deficiency anaemia is also common in the carnivorous population (source).
A number of factors interfere with our absorption and utilization of dietary iron.
First we need vitamin C to help us absorb iron and a deficiency in this vitamin can result in low iron.
Other nutrients and substances can block proper uptake of iron including too much calcium and zinc, tannins (in tea and coffee), caffeine (tea, coffee, “energy drinks”), phytates (in many vegetable sources such as legumes and bran), oxalates (in spinach and rhubarb), phosvitin in egg yolk, polyphenols (in green tea, red grapes - their juice and wine) and some medicines (such as antacids and asprin).
When you look at this list of inhibitors it seems amazing we can absorb any iron at all! Zinc is abundant in some common iron rich foods such as red meat and oysters. While a vegetarian eating the cheese and spinach pie is hampered by oxalates and calcium.
The second part of the equation is how much iron our individual body needs, uses up or looses from other health issues. This is so often overlooked but is an important part of the picture in treating iron deficiency, after all why just pump more iron into the body if something is causing it to block the uptake or use up the iron too fast to replenish it?
Sometimes we just need a higher than usual amount of iron, compared to others. Endurance sport, increased physical work, growth spurts in children and teenagers, pregnancy and lactation all increase our demands on iron.
A common cause of iron loss, resulting in anaemia, is menstruation related. Periods that are heavy, long or too frequent need to be treated rather than focus on iron replenishment alone. In naturopathy we may look at hormonal normalization, uterine astringing and other nutritional deficiencies to correct the underlying problem.
Other forms of blood loss can contribute to anaemia. An internal bleed, such as in the bowel or other organs is a potentially serious problem and needs to be investigated.
Digestive problems, inhibiting iron uptake are also common. Bowel conditions like parasites such as hookworms, chronic diarrhoea, coeliac disease and Crohns can be an issue.
Other illnesses, such as hyperthyroid may contribute to anaemia.
Some drugs including antacids and other prescribed medication for treating ulcers and reflux may inhibit your uptake of iron.
How much iron do we need?
Age mg iron
0-3 months 1.7
4-6 months 4.3
7-12 months 7.8
1-3 years 6.9
4-6 years 6.1
7-10 years 8.7
Men aged 11-18 11.3
Men aged 19 and over 8.7
Women aged 11-50 14.8
Pregnant women 27.0
Postmenopausal women 8.7
Dietary sources of iron
food (quantity) [approx iron content (mg)]
oysters (85 g) [13.2]
beef liver (100 g) [6.5 ]
prune juice (1/2 c) [5.2]
parsley (50g) [4.9]
spinach (100 g) [3.0]
canned sardines (120 g) [3.24]
lean beef (100g) [3.1]
cashew nuts (50 g) [2.5]
lean lamb (100 g) [2.5]
kidney beans (1/2 c) [2.1]
lean pork (100 g) [1.4]
canned tuna (100 g) [1.0]
chicken (100 g) [0.9]
(Sources Queensland Health and University of Maryland)
Supplementing iron
Many GP’s and dieticians in Australia will primarily recommend two sources of iron – dietary in the form of meat or a supplement of ferrous sulphate (produced by pharmaceutical companies). The averages GP gets very little nutritional education in their basic training and at times rely on pharmaceutical industry advice and information via dieticians and other associations. Meat and Livestock Australia are a sponsor of the Dieticians Association of Australia while that may not directly influence the Associations advice, it is a notable commercial partnership.
Ferrous sulphate (Fefol, Ferogradumet etc) commonly causes gut upsets like constipation, nausea, vomiting and dark coloured stools. Because of this naturopaths tend to recommend a more gentle form of iron supplementation such as ferrous fumerate, with added vitamin C, or liquid forms incorporating herbs and nutrients.
Note: Some antibiotics, like tetracycline should not be taken with an iron supplement or an iron rich meal as it may reduce the drug’s effectiveness.
Resources
Vegetarian Society fact sheets on iron and raising vegetarian children.
USA Government fact sheet.
Vegan resources
Listen to the podcast
Showing posts with label vegan. Show all posts
Showing posts with label vegan. Show all posts
Monday, January 19, 2009
Monday, August 25, 2008
radiothon with a mexican twist
Regular listeners of RRR need no reminder that it is radiothon time. I’ve written some extra posts in the past week as a special thank you to subscribers and clients. I hope you have enjoyed them.
Today I take you for a quick peek behind the scenes. Here is my wonderful host Nicole Findlay from the Long Grass Sessions in action. Each fortnight she asks me questions on an aspect of health, fields the calls for talkback and makes me feel right at home in the RRR studio.
Not only did she put this week's radiothon show together but found the time to make vegan Monte Carlo biscuits. Inspired by “Vegan Indulgence” published by a recent guest to her show Aduki press - these bikkies were an amazing treat.
My treat to keep Nicole and the wonderful volunteers going through the show was a thermos full of Mexican hot chocolate – dairy-free of course. Inspired by a couple of shows in the past year I wanted to marry a superfood with a super herb. At the tail end of winter a boost of lung warming cinnamon never goes astray. While chocolate, the real stuff without the milk and sugar, has rightful claim to some health giving antioxidant properties.
Hot chocolate with cinnamon
1-2 squares of 100% chocolate (I used Mexican chocolate which was a bargain from Casa Iberica in Fitzroy)
1 cup of rice milk
1 cinnamon stick
1/2 tsp palm sugar
a drop of pure vanilla extract
Warm the milk over low heat in a pot. Add the finely chopped chocolate, cinnamon, sugar and vanilla. Stir gently. Don’t let the mixture boil. When the chocolate has melted take off the heat and use a whisk to froth it up.
Drink straight away.
This is a potent brew, stick to a small serve.
Don’t add sugar if you are using regular, sweetened dark chocolate.
For an authentic twist consider adding a bit of chilli.
For this big batch I used 1 litre of rice milk with about 100 gm of chocolate.
Thanks for subscribing to RRR – it keeps shows like Health Trip on air, gives a much needed outlet for new independent and local music and adds to the rich tapestry that is Melbourne. As a result of money raised in recent radiothons the station is now streamed live over the net all over the world and segments like mine are podcast.
Monday, October 08, 2007
Helping children build healthy bones
The CSIRO has recently released a Wellbeing Plan For Healthy Kids with the aim that every primary school aged child will bring home information and a fridge magnet to teach their family how to eat and live well. While this is a wonderful initiative – looking at creating lifelong healthy habits like drinking lots of water, eating breakfast every day, upping the vegetable intake and being more active – the advice on creating strong bones tells a very limited and heavily biased story. Today’s Health Trip looks at the bigger picture about creating a lifetime of healthy bones.
Evidence shows that calcium alone does not create healthy bones
While calcium is the major building block in bone formation, it is totally useless without Vitamin D. This vitamin basically promotes calcium absorption (from the blood) and regulates bone formation and loss. Focusing all our education about bone health on dietary calcium is immaterial is we can’t actually use it.
Vitamin D can be made by the body under the right conditions. It begins in the skin when exposed to UV. Some fatty fish (eg: sardines, tuna, mackeral, eel), egg yolks (though some commercial farming practices can alter this) and cod liver oil also give us Vitamin D. In such a sun drenched land like Australia you may be surprised to learn that a significant number of Aussies are deficient in Vitamin D. Though smog and dark skin can be a factor, the greatest reason for this is the successful education campaign around skin cancer prevention. While we are deligently covering up, slathering on the sun block and avoiding overt sun exposure we are decreasing our chance of developing a deadly melanoma but unfortunately becoming D-deficient and osteoporotic as a side effect. The link above gives some good recommendations on sun exposure for different cities in Australia and New Zealand as well as a good guide to supplementation for all ages.
A report in the EMJA published last year described vitamin D deficiency in Australian children as now being “a significant paediatric health issue”. Another recent study (looking at the higher incidence of Vitamin D deficiency in children with Type 1 diabetes) found that Vitamin D levels in blood samples of Queensland children and adolescents were lower overall than those found in the subjects of the Swedish study.
But don't forget, all the Vitamin D and calcium in the world won’t stop bone loss without adequate weight bearing exercise. Kids who become couch potatoes can’t grow healthy bones.
Other important nutrients for healthy bones
Aside from the Vitamin D issues, there is no debate around the need for adequate calcium intake for many aspects of good health. The debate centres around how much calcium we actually need, the most effective dietary sources and how other foods and substances impact on our calcium bioavailability. Here are some of the major players that are often overlooked in all the ‘official’ hype about calcium:
Sodium: The more salt in your diet the more calcium we pee out. While it is one thing to not have the salt shaker on the table at meal times don’t underestimate the amount of sodium added to processed foods (even some healthy looking breakfast cereals, let alone chips) and restaurant as well as takeaway foods. Raising children to not have a salt craving palate is a great addition to their healthy bone plan.
Phosphorous: This is another mineral essential to the calcium regulation and healthy bone story. Like sodium, this is a case of too much (and rarely, too little) upsetting the calcium applecart. Excess phosphorous gets into the diet from soft drinks, phosphate additives and in diets high in dairy, poultry and meat. We need equal amounts of phosphorous to calcium in our diet in order to use the calcium. The average diet has 2-4 x more phosphorous than calcium!
Magnesium: We need 1/2 as much magnesium to calcium, for the calcium to be used in our body for building strong bones. There are 2 major issues that contribute to magnesium deficiency becoming increasingly common. Firstly the best sources of magnesium tend to come from whole foods like unrefined grains and nuts. But most people eat refined plant foods such as flour and white rice which promotes magnesium deficiency. The other problem is excess calcium. While a cup of whole milk may contain 115 mg of calcium the magnesium content is around 10-15 mg. [Source: Tricky, R. "Women, Hormones and the Menstrual Cycle"]. The average calcium:magnesium ratio in dairy foods ranges from 8:1-12:1 versus the bio availability requirement of 2:1.
Vitamin K: This little talked about vitamin, rich in green, leafy vegetables is another important co-factor in the regulation of calcium in the body. Most Australian children do not get the recommended amount of fruit and vegetables in their diet, so we are likely to learn more about Vitamin K if this trend continues.
Protein: The more protein you eat, especially from animal sources such as meat, poultry and dairy, the more calcium you loose through your urine. For every gram of protein you eat, you loose 1 milligram of calcium. Most official dietary plans do not take this into account. While vegetarian, especially vegan, diets are criticized for an overall lower intake of calcium, it doesn’t take into account that a low animal protein diet causes less calcium loss. New evidence is emerging to show that a balanced vegan requires lower RDI of calcium
Phytates and oxylates: Plant foods however, can reduce calcium utilization. High fibre such as straight bran can reduce calcium absorption. If you had a bowl of 100% wheat bran, you would only be able to absorb half the amount of calcium from other foods eaten at that meal. However, it is rare for someone to eat just bran. Likewise oxylates in some foods such as spinach and beans can reduce calcium absorption. Soaking beans and cooking in fresh water reduces the oxylate content.
Caffeine and smoking (which may include passive smoking) also disrupt the healthy bone story but we would hope kids are exposed to neither of these. Never give your children or teens cola or energy drinks, as the combination of phosphorous and caffeine is a surefire recipe for osteoporosis.
Calcium
While calcium is considered an important building block for healthy bones, the literature repeatedly demonstrates that calcium alone does not build stronger bones in children. Nor does having your RDI of calcium in the form of dairy prevent bone fractures in adults.
Dairy foods are repeatedly promoted as the “best” sources of calcium. Other than supplements, it is true that gram for gram (perhaps with the exception of unhulled sesame seeds and kelp) dairy products contain more calcium than any other food. However, whether these are the best foods to grow healthy bones is debatable considering the issues of phosphorous, magnesium and protein, as discussed above.
Another factor to consider is dairy intolerances and allergies, either to lactose (which is even higher in low fat dairy foods) or the dairy protein. Some indications that your baby or child is negatively reacting to dairy products may include: skin rashes, digestive upsets (like wind, colic, diarhhoea or constipation), mood changes and atopic allergies (such as asthma, eczema or hayfever). Naturopathically we tend to find children who have recurrent ear, nose and throat issues potentially have a higher rate of dairy intolerance.
If your child does have an inflammatory bowel condition, whether caused by a food allergy or common conditions such as Crohns disease, very little of their food sources of calcium may be utilized when loose bowels are involved.
The official rate of dairy allergies in Australia is 1:50 children, however this only includes children who have had immunological testing (not every child with a food allergy is referred for testing) and doesn't include dairy intolerance, meaning the actual occurrence of children not tolerating all or some dairy foods is much higher. Certain ethnicity's, such as children with an Asian background, have a very high risk of dairy allergy and I would advise them to avoid dairy completely. Interesting to note is that approximately 1:4 children with a dairy allergy will also be allergic to soy foods.
How much calcium do we need?
According to the Victorian government the RDI’s for children and teens are as follows:
Babies – 0 to 6 months (breastfed) recommended dietary intake (RDI) 300mg
Babies – 0 to 6 months (formula-fed) RDI 500mg
Babies – 7 to 12 months RDI 550mg
Children – 1 to 3 years RDI 700mg
Children – 4 to 7 years RDI 800mg
Children – 8 to 11 years (girls) RDI 900mg, (boys) RDI 800mg
Children and teenagers – 12 to 15 years (girls) RDI 1000mg, (boys) RDI 1200mg
Teenagers – 16 to 18 years (girls) RDI 800mg, (boys) RDI 1000mg.
The UK Vegan Society has some good resources on non-animal sources of calcium.
Keep in mind these figures assume that there are adequate amounts of co-nutrients and no other factors interfering with the bio availability. Compulsory reading for anyone interested in the whole debate is this excellent article from the Harvard School of Public Health “Calcium and Milk: What’s Best For Your Bones”. Their conclusions are drawn from long term studies (minimum 12 years) of over 100,000 men and women, which makes them the most credible source currently available on the subject. While they question conventional assumptions as to the the amount of calcium required (they suspect it is actually lower than the official recommendations) on the issue of dairy for strong bones they conclude:
What else can stop a child growing healthy bones?
As if the average Aussie diet, lack of UV and not doing adequate amounts of weight bearing exercise wasn’t enough to complicate the healthy bone picture, the use of steroids (such as cortisone used in asthma and eczema) and the increase rate of eating disorders from a young age also has a detrimental impact on the development of healthy bones.
So you can see, healthy bones is not all about having 3 cups of milk a day after all.
* (My emphasis). Along with the concerns that the Harvard studies mentioned around dairy intake and an increase in ovarian and prostate cancers, other studies show a link between drinking milk and developing Type 1 diabetes and the issue of Low fat dairy foods and infertility
Evidence shows that calcium alone does not create healthy bones
While calcium is the major building block in bone formation, it is totally useless without Vitamin D. This vitamin basically promotes calcium absorption (from the blood) and regulates bone formation and loss. Focusing all our education about bone health on dietary calcium is immaterial is we can’t actually use it.
Vitamin D can be made by the body under the right conditions. It begins in the skin when exposed to UV. Some fatty fish (eg: sardines, tuna, mackeral, eel), egg yolks (though some commercial farming practices can alter this) and cod liver oil also give us Vitamin D. In such a sun drenched land like Australia you may be surprised to learn that a significant number of Aussies are deficient in Vitamin D. Though smog and dark skin can be a factor, the greatest reason for this is the successful education campaign around skin cancer prevention. While we are deligently covering up, slathering on the sun block and avoiding overt sun exposure we are decreasing our chance of developing a deadly melanoma but unfortunately becoming D-deficient and osteoporotic as a side effect. The link above gives some good recommendations on sun exposure for different cities in Australia and New Zealand as well as a good guide to supplementation for all ages.
A report in the EMJA published last year described vitamin D deficiency in Australian children as now being “a significant paediatric health issue”. Another recent study (looking at the higher incidence of Vitamin D deficiency in children with Type 1 diabetes) found that Vitamin D levels in blood samples of Queensland children and adolescents were lower overall than those found in the subjects of the Swedish study.
But don't forget, all the Vitamin D and calcium in the world won’t stop bone loss without adequate weight bearing exercise. Kids who become couch potatoes can’t grow healthy bones.
Other important nutrients for healthy bones
Aside from the Vitamin D issues, there is no debate around the need for adequate calcium intake for many aspects of good health. The debate centres around how much calcium we actually need, the most effective dietary sources and how other foods and substances impact on our calcium bioavailability. Here are some of the major players that are often overlooked in all the ‘official’ hype about calcium:
Sodium: The more salt in your diet the more calcium we pee out. While it is one thing to not have the salt shaker on the table at meal times don’t underestimate the amount of sodium added to processed foods (even some healthy looking breakfast cereals, let alone chips) and restaurant as well as takeaway foods. Raising children to not have a salt craving palate is a great addition to their healthy bone plan.
Phosphorous: This is another mineral essential to the calcium regulation and healthy bone story. Like sodium, this is a case of too much (and rarely, too little) upsetting the calcium applecart. Excess phosphorous gets into the diet from soft drinks, phosphate additives and in diets high in dairy, poultry and meat. We need equal amounts of phosphorous to calcium in our diet in order to use the calcium. The average diet has 2-4 x more phosphorous than calcium!
Magnesium: We need 1/2 as much magnesium to calcium, for the calcium to be used in our body for building strong bones. There are 2 major issues that contribute to magnesium deficiency becoming increasingly common. Firstly the best sources of magnesium tend to come from whole foods like unrefined grains and nuts. But most people eat refined plant foods such as flour and white rice which promotes magnesium deficiency. The other problem is excess calcium. While a cup of whole milk may contain 115 mg of calcium the magnesium content is around 10-15 mg. [Source: Tricky, R. "Women, Hormones and the Menstrual Cycle"]. The average calcium:magnesium ratio in dairy foods ranges from 8:1-12:1 versus the bio availability requirement of 2:1.
Vitamin K: This little talked about vitamin, rich in green, leafy vegetables is another important co-factor in the regulation of calcium in the body. Most Australian children do not get the recommended amount of fruit and vegetables in their diet, so we are likely to learn more about Vitamin K if this trend continues.
Protein: The more protein you eat, especially from animal sources such as meat, poultry and dairy, the more calcium you loose through your urine. For every gram of protein you eat, you loose 1 milligram of calcium. Most official dietary plans do not take this into account. While vegetarian, especially vegan, diets are criticized for an overall lower intake of calcium, it doesn’t take into account that a low animal protein diet causes less calcium loss. New evidence is emerging to show that a balanced vegan requires lower RDI of calcium
Phytates and oxylates: Plant foods however, can reduce calcium utilization. High fibre such as straight bran can reduce calcium absorption. If you had a bowl of 100% wheat bran, you would only be able to absorb half the amount of calcium from other foods eaten at that meal. However, it is rare for someone to eat just bran. Likewise oxylates in some foods such as spinach and beans can reduce calcium absorption. Soaking beans and cooking in fresh water reduces the oxylate content.
Caffeine and smoking (which may include passive smoking) also disrupt the healthy bone story but we would hope kids are exposed to neither of these. Never give your children or teens cola or energy drinks, as the combination of phosphorous and caffeine is a surefire recipe for osteoporosis.
Calcium
While calcium is considered an important building block for healthy bones, the literature repeatedly demonstrates that calcium alone does not build stronger bones in children. Nor does having your RDI of calcium in the form of dairy prevent bone fractures in adults.
Dairy foods are repeatedly promoted as the “best” sources of calcium. Other than supplements, it is true that gram for gram (perhaps with the exception of unhulled sesame seeds and kelp) dairy products contain more calcium than any other food. However, whether these are the best foods to grow healthy bones is debatable considering the issues of phosphorous, magnesium and protein, as discussed above.
Another factor to consider is dairy intolerances and allergies, either to lactose (which is even higher in low fat dairy foods) or the dairy protein. Some indications that your baby or child is negatively reacting to dairy products may include: skin rashes, digestive upsets (like wind, colic, diarhhoea or constipation), mood changes and atopic allergies (such as asthma, eczema or hayfever). Naturopathically we tend to find children who have recurrent ear, nose and throat issues potentially have a higher rate of dairy intolerance.
If your child does have an inflammatory bowel condition, whether caused by a food allergy or common conditions such as Crohns disease, very little of their food sources of calcium may be utilized when loose bowels are involved.
The official rate of dairy allergies in Australia is 1:50 children, however this only includes children who have had immunological testing (not every child with a food allergy is referred for testing) and doesn't include dairy intolerance, meaning the actual occurrence of children not tolerating all or some dairy foods is much higher. Certain ethnicity's, such as children with an Asian background, have a very high risk of dairy allergy and I would advise them to avoid dairy completely. Interesting to note is that approximately 1:4 children with a dairy allergy will also be allergic to soy foods.
How much calcium do we need?
According to the Victorian government the RDI’s for children and teens are as follows:
Babies – 0 to 6 months (breastfed) recommended dietary intake (RDI) 300mg
Babies – 0 to 6 months (formula-fed) RDI 500mg
Babies – 7 to 12 months RDI 550mg
Children – 1 to 3 years RDI 700mg
Children – 4 to 7 years RDI 800mg
Children – 8 to 11 years (girls) RDI 900mg, (boys) RDI 800mg
Children and teenagers – 12 to 15 years (girls) RDI 1000mg, (boys) RDI 1200mg
Teenagers – 16 to 18 years (girls) RDI 800mg, (boys) RDI 1000mg.
The UK Vegan Society has some good resources on non-animal sources of calcium.
Keep in mind these figures assume that there are adequate amounts of co-nutrients and no other factors interfering with the bio availability. Compulsory reading for anyone interested in the whole debate is this excellent article from the Harvard School of Public Health “Calcium and Milk: What’s Best For Your Bones”. Their conclusions are drawn from long term studies (minimum 12 years) of over 100,000 men and women, which makes them the most credible source currently available on the subject. While they question conventional assumptions as to the the amount of calcium required (they suspect it is actually lower than the official recommendations) on the issue of dairy for strong bones they conclude:
Currently, there's no good evidence that consuming more than one serving of milk per day in addition to a reasonable diet (which typically provides about 300 milligrams of calcium per day from nondairy sources) will reduce fracture risk. Because of unresolved concerns about the risk of ovarian and prostate cancer, it may be prudent to avoid higher intakes of dairy products.*
What else can stop a child growing healthy bones?
As if the average Aussie diet, lack of UV and not doing adequate amounts of weight bearing exercise wasn’t enough to complicate the healthy bone picture, the use of steroids (such as cortisone used in asthma and eczema) and the increase rate of eating disorders from a young age also has a detrimental impact on the development of healthy bones.
So you can see, healthy bones is not all about having 3 cups of milk a day after all.
* (My emphasis). Along with the concerns that the Harvard studies mentioned around dairy intake and an increase in ovarian and prostate cancers, other studies show a link between drinking milk and developing Type 1 diabetes and the issue of Low fat dairy foods and infertility
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