Blood donations and athletic performance

You ask for something... I deliver.
I got a question about the effects of blood donations on athletic performance (thanks James)... and here's what I found (it's another long one- sorry!)
BTW- I got all my info from legitimate web sources (ie physisicians'/medical sites, Canadian blood services website).

Giving blood is an incredible act of goodwill. Donated blood helps to save countless lives every year. According to one US source, fewer than 5% of the eligible donors in the US give whole blood.

According to Canadian Blood Services, it takes the following number of donations to help save the life of someone undergoing the following procedures:
Cancer treatment: up to 8 donations a week
Coronary artery bypass: 1-5 donations
Car accident/gunshot wounds: up to 50 donations
Liver transplant: up to 100 donations
Other organ transplants: up to 10 donations
Brain surgery: 4-10 donations
Fractured hip/joint replacement: 2-5 donations

Although very altuisitic, giving blood is not without consequences, especially for endurance athletes.

The average person has 10 pints of blood flowing through his or her body. There are four components in blood:

Red blood cells: 40-45% of your blood. Carry oxygen to the body's tissues and remove carbon dioxide. Most relevant for athletic performance. The more red blood cells you have in your blood, the more oxygen you’re able to carry to your muscles and the harder and longer your body can go while exercising.

White blood cells: Less than 1% of your blood. Immune system's main defence against infection.

Platelets: 5% of your blood. Cell fragments that clot, which helps to prevent and control bleeding.

Plasma: 55% of your blood. It is 90% water and vital to our survival. Provides the transportation system for blood cells. Without plasma, the cells would not be able to do their work. Plasma also carries microbe-fighting antibodies that fight diseases.

When you donate blood you will be giving one pint (2 cups or 10 percent of your total blood volume). In doing so, you will be decreasing the number of your red cells (oxygen carriers) by one-tenth as well.

The reduction in total blood volume lowers the body's ability to dissipate heat and regulate its temperature. However, the fluid (plasma) portion of the blood that has been lost can be replaced fairly quickly (within 24-48 hours) with proper hydration.

As this replacement is occurring, the remaining red blood cell concentration becomes diluted. It may take up to six weeks to bring the red blood cell count back to pre-donation levels. In fact, once you donate, you must wait 56 days before donating again- to let your red blood cell count return to pre-donation levels.

In the meantime, athletes report a detrimental drop in performance by up to 10 percent. This drop in performance is most visible among distance runners, who rely heavily on aerobic capacity.
In 1995 a study looked at the effects of blood donation in 10 competitive cyclists before and after donating one pint of blood. They measured performance at two hours, two days and seven days post-donation and found that sub-maximal performance was unaffected but maximal performance was decreased for at least one week after blood donation.

The reduction in red blood cell count reduces the body's ability to carry oxygen from the lungs to the muscles. Medical personnel advise donors to drink plenty of fluids, and to increase their intake of iron prior to and after
donation.

Coaches also report a higher incidence of illness among athletes who donate blood. They blame a blood donation on a lowering of white cell count and a reduction in the body's ability to fight infections. An intense training program may exacerbate the loss of immunity and lead to a breakdown. Therefore, many coaches are apprehensive toward blood donations during the competitive season, but encourage their athletes to donate blood between seasons.

The medical director for the Boston Marathon believes that for people who engage in light to moderate exercise, blood
donation should not be a concern. Another sport physician says that in an endurance athlete, blood donation should have virtually no effect on strength or short-burst activities. As a recovery strategy, this doctor recommends hydrating aggressively throughout the day after giving blood. He advises endurance athletes to think of the blood-donation day as a rest day and to tread cautiously the next day because hydration stores may not be replenished and can predispose one to fainting.

The body can detect when its red cell percentage is low, and it responds by initiating the production of more red blood cells in the bone marrow. This process can take a number of weeks. The molecule released by the kidneys to begin this process is called erythropoietin (the natural form of EPO).

An interesting hypothesis was presented a few years ago by Dr. Kamal Jabbour. He suggested that an athlete may actually be able to enhance his or her performance by giving blood. After red blood cells are removed from the body, a rejuvenation effort is initiated through the natural production of EPO, as described above. Often, however, this red blood cell production process may not shut off immediately upon reaching pre-donation levels. As a result, the red blood cell concentration may actually overshoot the baseline slightly before eventually returning to normal. Anecdotal evidence relates that this can vary anywhere from four to six weeks after blood donation.
If the above hypothesis holds true, it suggests that an athlete can safely donate blood, recover gradually without overtraining, then peak temporarily for a superior performance before returning to normal. Timing is critical and requires a lot of practice, much to the delight of the local blood banks.

Some other possible benefits of blood donations:

Some research has shown that donating blood may reduce the risk of heart disease for men and

stimulate the generation of red blood cells. They say that differences between men and women in heart attack risk may be due to circulating iron levels which are reduced in women by menstruation. Donating blood may reduce men's risk to that of women's, but the link has not been firmly established.

Weight loss a goal? A donor effectively burns about 650 calories by donating one pint of blood.

Can blood donation cause anemia?

Blood donation results in a drop in hemoglobin of approximately 10 g/L, depending on the size of the donor. Normal, healthy donors produce new red blood cells to replace those that were donated, within about 56 days. However, iron is an essential mineral necessary to produce new red blood cells. It is therefore very important for blood donors to have an adequate amount of iron in their diet. This is especially important for female donors, who have lower iron reserves due to loss of iron in menstrual periods and reduced iron reserves.

Hemoglobin levels are measured before a blood donation. In order to be able to donate, both men and women must have a minimum hemoglobin level of 125 g/L (12.5 g/dL).

Approximately 10% of female donors do not meet minimum hemoglobin criteria on a given donation. If your hemoglobin level is below 110 g/L (11.0 g/dL) you should see your physician to have further testing to confirm if anemia is present and determine the underlying cause. If anemia is present, you should not return to donate until the cause of the low hemoglobin has been identified and corrected.
It is quite rare for male donors to have a hemoglobin level below the minimum blood donor criteria. Male donors with a hemoglobin level below the acceptable level of 125 g/L (12.5 g/dL) are likely to be anemic. If your hemoglobin was below the acceptable level, further testing should be done by your physician to confirm if anemia is present and what is the underlying cause.

Criteria for donating:

Canadian Blood Services and Héma-Québec have the sole responsibility for collecting blood and administering the blood supply in Canada. They have established basic criteria that blood donors must meet before they can give blood. They include that you must:

• Be between 17 and 71 years old to be a regular donor (17 to 61 to be a first-time donor).
• Weigh at least 110 pounds.
• Be in general good health and feeling well when you donate.
• Complete a screening questionnaire.
• Meet minimum haemoglobin requirements (test done at clinic). Since blood donation results in the loss of iron and hemoglobin, individuals with inadequate iron stores who require iron supplementation are not good candidates for donation.

Certain people are not allowed to donate. they include:

• People who lived in Cameroon, Central African Republic, Chad, Congo, Equatorial Guinea, Gabon, Niger and Nigeria who may have been exposed to a new strain of HIV.
• People who received a blood transfusion while visiting those countries or who have had sex with someone who lived there.
• People who spent three months or more in Britain or France between 1980 and 1996. They may have been exposed to variant Creutzfeldt-Jakob disease (CJD).
• All men who have had sex with another man, even once, since 1977. Statistics show they are at greater risk for HIV/AIDS infection than other people. This one was under review in 2006 but no word yet as to any changes to it.
• Anyone who has taken illegal drugs intravenously.
  If you've recently had part of your body tattooed or pierced, you're also excluded as a blood or bone marrow donor — but for six months only.
  

Blood types:

The eight major types of blood (and the percentage of the population that have them) are:
- O positive (about 38%)
· O negative (about 7%)
· A positive (about 34%)
· A negative (about 6%)
· B positive (about 9%)
· B negative (about 2%)
· AB positive (about 3%)
· AB negative (about 1%)
People who are O negative can donate blood to anyone. People who are AB positive can receive blood from anyone.

Blood Donation Facts:

• Over 80 million units of blood are donated every year around the world.
• Only 38% is collected in developing countries where 82% of the global population live.
• Half a million women die every year from complications related to pregnancy and childbirth worldwide — 99% of them are in developing countries. Hemorrhage, which accounts for 25% of the complications, is the most common cause of maternal death.
• Up to 70% of all blood transfusions in Africa are given to children with severe anemia due to malaria, which accounts for about one in five of all childhood deaths in Africa.
• According to the World Health Organization, at least 65 countries do not test all donated blood for HIV, hepatitis B, hepatitis C and syphilis. Tainted blood still accounts for as much as five per cent of HIV infections in Africa. The WHO estimates that six million tests that should be done for infections in donated blood are not carried out.
• Since November 1985, all blood collected in Canada has been screened for HIV and other communicable diseases. It's estimated that the risk of contracting HIV from donated blood is now 1 in 2.1 million. In the mid-1980s, that risk was 1 in 16,000. The risk of contracting hepatitis C is estimated at 1 in 1.9 million.

Chocolate and weak bones for Valentine's Day?

Happy Valentine's Day!

A study looked at the chocolate intake of 1000 older women (70-85 years old) by asking them how often they ate chocolate: less than 1 a week, 1 to 6 times a week or more than 1 time a day.

They found that the higher consumption of chocolate intake was linearly associated with a lower bone density: The women who ate chocolate >1 time/day had 3.1% lower whole body bone density than the ones that ate chocolate < 1 time a week.

You have to be careful how you interpret these results, just as you have to be careful how you interpret the results of any study done on the health effects of single foods or nutrients.

In this case, maybe the women who ate more chocolate were less physically active or maybe they ate less healthfully- both would affect bone density.

So, rest assured that chocolate on its own does not cause weak bones!

14 chocolate fun facts!

1. Cacao or chocolate beans were used as currency by Aztec and Maya tribes.

2. The Mexican nuns were the first to solidify chocolate in the 1700s- they created and exported the first chocolate product as a fund raiser for their convent.

3. Chocolate comes in over 500 flavours.

4. Experiments conducted at the University of Pennsylvania and the U.S. Naval Academy found that consumption of chocolate, even frequent daily dietary intake, had no effect on the incidence of acne. Professional dermatologists today do not link acne with diet.

5. The gory scenes in Alfred Hitchcock's 'Psycho' was all chocolate syrup. Although the scene finishes in 45 seconds, it took 7 days to get the shot perfect!

6. Chocolate can be lethal to dogs. Theobromine, an ingredient that stimulates the cardiac muscle and the central nervous system, causes chocolate's toxicity. About two ounces of milk chocolate can be poisonous for a 10-lb puppy.

7. Chocolate was re-born in 1879 when Daniel Peter and Henre Nestle introduced milk chocolate to the world. In the same year Rudolphe Lindt introduced the conching process which makes chocolate smooth and soft.

8. Napoleon took chocolate along with him during his military campaign.

9. US Consumers spend more than $7 billion a year on chocolate.

10. US consumers eat 2.8 billion pounds of chocolate annually, representing nearly half of the world's supply.

11. Annual US per capita consumption of chocolate is 12 pounds per person.

12. American chocolate manufacturers use about 1.5 billion pounds of milk- only surpassed by the cheese and ice cream industries.

13. Most Americans prefer milk chocolate, approximately 92 percent, but dark chocolate's popularity is growing rapidly.

14. Although chocolate is not an aphrodisiac, as the ancient Aztecs believed, chocolate contains phenylethylamine (PEA), a natural substance that is reputed to stimulate the same reaction in the body as falling in love.

Hope you were able to enjoy some chocolate on Valentine's Day!

Sweeteners

So lots of stuff about sweeteners in the news so I'm going to talk about them some more...

The study everyone's talking about is one that fed 1 group rats a liquid sweetened with normal sugar and the other group with a liquid sweetened with saccharin.
After 10 days of exposure, the rats were allowed to eat a high-calories chocolate-flavoured snack. The saccharin group ate more and gained significantly more weight than the sugar group.

They also found that rats that were accustomed to eating the sweetener didn't have a temperature change after eating- normally, body temperature should rise after eating.
They suspect that that could mean that the rats' appetite control mechanism was disrupted as a result of consuming sweetener, possibly leading to them overeating.

Their theories/interpretations of their results, in a nutshell, are:

1. Artificial sweeteners may disrupt the body's natural ability to 'count' calories based on the food's sweetness. Early in life, our bodies learn that sweet foods and dense foods have more calories. It's
a Pavlovian type of behaviour. Sweeteners impair this natural relationship. The body may be fooled into thinking a product sweetened with sugar has no calories. As a result, people become unable to regulate their food intake... and therefore, their weight.

2. Liquids, diet or not, are not as satisfying as solid food.

Challengers of this study (like the Calorie Control Council that represents companies that sell artificial sweeteners!), say the research oversimplifies the complex issues that contribute to obesity in humans and lots of studies have shown that artificial sweeteners can help with weight loss.
The researchers point out that the increase consumption of artificial sweeteners is not the sole cause of obesity, but it can be a contributing factor.

Other challengers say that the study was done on rats, not humans. True. However, other studies done on humans have shown a link between artificial sweeteners and weight (see previous blog). The researchers do point out that the results need to be replicated on humans. They also want to look at whether age and gender are contributing factors...
I would like to point out though that in 1958, in the US, Congress passed the Delaney amendment to the food and drug laws which required the FDA to ban any substance from the food supply shown to cause cancer- in people or animals and even rats.

Challengers also point out that saccharin is banned in Canada. True. However, researchers say that the results would apply to other artificial sweeteners .
Supposedly, Canadian officials are reviewing the restriction on saccharin in light of new research showing it may not be harmful to humans... not sure about that one though. In 1977, saccharin was banned in the US because it was shown to cause bladder cancers in mice and rats. However, the Calorie Control Council launched a huge publicity 'freedom of choice' campaign and, Congress allowed saccharin back on the market. Interestingly, it cost 6% less to sweeten cola with saccharin versus sugar at that time... hmmm.

These are the sweeteners that Health Canada has approved for use and some comments:

1. Aspartame (Equal, NutraSweet, Sugar Twin, Sweet n' Low, also added to foods). According to Health Canada, safe for use in pregnancy. Acceptable Daily Intake (ADI): 40mg/kg body weight per day. One can diet pop= 200mg. So, a 110lbs person can safely have 2000mg a day= 10 cans Diet Coke/day. Flavour may change when heated.

2. Acesulfame-K (Added in packaged foods and beverages). Safe in pregnancy. ADI= 15mg/kg body weight/day. One can diet pop sweetened with acesulfame-K=42mg. A 110lbs person can safely have 750mg per day = 18 cans Diet Coke/day.

3. Cyclamate (Sugar Twin, Sweet n'Low, Sucaryl). Avoid when pregnant. ADI= 11mg/kg body weight/day. One packet Sugar Twin=264mg. A 110lbs person can safely have 550mg per day = 2 packets/day.

4. Saccharin (not allowed to be added to foods and beverages but available in tablets as Hermesetas). Avoid when pregnant. ADI= 5 mg/kg body weight per day. One tablet Hermesetas has 12 mg saccharin.

5. Sucralose (Splenda, also added to foods and beverages). Can be used for baking or cooking. Safe in pregnancy. ADI= 9mg/kg body weight per day. One packet of Splenda contains 12mg and 1 cup Splenda has ~250mg. A 110lbs person can safely have 450mg sucralose per day. Interestingly, Whole Foods Market refuse to sell products containing sucralose since it's not metabolized in the body and could be potentially unsafe. The products goes against the company's philosophy of selling "the highest quality natural and organic products available".

Bottom line: A healthy diet should not rely on soft drinks- diet or not- or sweeteners.

I'll have a burger, fries, a diet soda and a heart attack, please

Researchers have found another reason to cut back on red meat, fried foods and diet soda. Wait, diet soda?!

The Atherosclerosis Risk in Communities (ARIC) study, funded by the National Heart, Lung and Blood Institute, studied the food intake (using a 66-item food frequency questionnaires) of 9514 people aged 45-64 years old for at least 9 years.

In general, a Western-diet that was heavy on refined grains, processed meats, fried food, red meat, eggs and soda and light on fish, fruit, vegetables and whole grains, was associated with an 18% increased risk for metabolic syndrome, even after adjusting for smoking, physical activity and caloric intake.

Metabolic syndrome is a cluster of heart disease risk factors that include:
a high waist circumference, high blood pressure, high triglycerides, low "Healthy" HDL cholesterol and high fasting blood glucose levels. Having 3 or more of these risk factors increases greatly your risk of developing heart disease and diabetes.

The adults who ate 2 or more servings of meat a day increased their risk of developing metabolic syndrome by 25% compared to those that ate meat twice a week or less.

Fried food was also associated with a higher rate of metabolic syndrome, as was diet soda. Risk of developing metabolic syndrome was 34% higher among those that drank one can diet soda a day compared to those that didn't drink any.

Interestingly, other studies have found a link between diet soda intake, metabolic syndrome and obesity. For example, the Framingham Heart Study- a huge cardiovascular study based in Framingham, Massachusetts that started in 1948 with 5209 participants and is now on its 3rd generation participants and has taught us most of what we know about heart disease- recently released that they found that people who drank one or more 12-oz soda- diet or regular- had a higher risk of developing metabolic syndrome and of being obese. We know regular soda is associated with increased obesity rates and metabolic syndrome, but why diet soda?

Marion Nesltle points out in her book What to Eat that rates of overweight and obesity have risen in parallel with the increase in use of artificial sweetener. Coincidence? Probably not. Although sweeteners can help some people to reduce caloric intake and therefore, their weight, it seems that most people over-compensate and make up the calories saved, and a lot more!

Another theory, that needs to be researched further, states that because sweetener is very sweet, it signals the body that sugar is coming. Because sweeteners have no calories, we end up craving the calories that were promised but not delivered.

Regardless, the ARIC study results are clear: too much meat, fried foods and diet soda do not add up to a healthy diet or life.

You say tomato, I say...

In 1893, the Nix vs. Hedden case was brought to the US Supreme Court to address whether a tomato was a fruit or a vegetable.

The case was filed by the Nix family against Edward Hedden a collector of the port of New York. The Nix family wanted to get back duties that were paid under protest. At that time, according to the Tariff Act of 1883, tax was required to be paid on imported vegetables, not fruit.

Botanically, a tomato is a fruit because it develops from the ovary in the base of the flower, and contains the seeds of the plant. However, in 1893, the court ruled unanimously in favour of the defendant- they ruled that tomatoes were a vegetable. This decision was made because the ‘common language of the people’ refers to tomatoes as vegetables and this was the definition used in the Tariff Act.

So… next time someone tries to trick you and asks you whether a tomato is a fruit or a vegetable- you tell them:
Although botanically a fruit, tomatoes are "vegetables" and not "fruit" within the meaning of the Tariff Act of 1883 based on the common meaning of those words.

In fact, in 2005, supporters in the New Jersey legislature cited Nix as a basis for a bill designating the tomato as the official state vegetable.

Similar law suits include:
Carrot: defined to be a fruit in European Community law, for the purpose of jam classification
Toy Biz v. United States: decided that action figures of certain superheroes are legally toys, not dolls.

Aren't fun food facts fun?! :)

Is organic better?

Simple answer is: Yes.

No product can carry a "Certified Organic" label without first being inspected. The product has to meet a comprehensive set of rules overseen by the Canadian General Standards Board.

To qualify as certified organic, a field of corn, for example, would have to: be free of commercial fertilizers for three years, be free of herbicides for three years, the seed would not be from genetically modified seed and there has to be a buffer zone between organic plants and non-organic plants.

The opponents of organics- mainly the agencies that gain from conventional agriculture- work hard to make people doubt the reliability of oganic certification. They say things like: organic farming reduces productivity, is a hazard to our health, organic foods are not healthier...

Firstly, a review of studies done in 1981 showed that farmers who converted from conventional to organic methods reported only small declines in yields and that loss in income was offset by lower fuel costs.

A more recent study confirmed the results, finding that organic farms are only slightly less productive, leave soils healthier and use energy more efficiently.

Organic opponents claim that pesticides are safe...well... then why does the government regulate them?!

Scientists are not able to quantify the degree of harm caused by pesticides yet but it's known that pesticides accumulate in your body. In 2003, researchers compared the levels of pesticide "excretion products" in the urine of preschoolers who were fed conventional or organic foods. The urine of those fed conventional foods contained 6 times as many pesticide residues as the kids who ate organic.

It's common sense (but has also been shown in the research): If the crop is grown pesticide-free, fewer pesticides get into the soil and water, foods contain less of them and people that eat organic have less pesticides in their bodies!

Critics also say that because organic production uses composted manure instead of chemical fertilizers, they're exposed to more potentially dangerous microbes and are riskier.

Not true. To be certified organic, farmers have to follow strict rules to destroy dangerous microbes in manure... and are inspected whereas there are no rules for conventional growers.

Now... is organic healthier?

The mineral content of a plant food depends on how much is in the soil and organic foods are grown in a more mineral-rich healthy soil therefore, as shown in the research, organically-grown produce have a higher mineral content.

However, vitamin and phytochemical content of plant foods are more likely a product of genetic strain and post harvest processing rather than growing.

Marion Neslte, PhD and Professor of Nutition, Food Studies and Public Health at NYU, points out in her book What to Eat,

"I have no trouble thinking of several reasons why (organically grown foods) might have more (nutrients), but so what? I doubt the slight increase would be enough to make a measurable difference to health".

And even if it did, it would be near impossible to measure the effect on humans given the many foods different people eat in a day.

The former head of the nutriton dept at Columbia, Joan Gussow, said:

"Shouldn't we hope that people will choose organic foods on grounds more reliable than whether they contain a little more carotene or zinc? Isn't the most important story that organic production conserves natural resources, solves rather than creates environmental problems, and reduces the pollution of air, water, soil...and food?"

When you choose organic foods, you choose a planet with fewer pesticides, richer soil and a cleaner water supply.

If you want to take the extra step, choosing locally produced foods means you'll also be choosing to conserve fuel resources and to support the economic viability of local communities.

So, despite the slightly higher cost of organically-grown foods, choosing them is always a good idea!

Source: What to Eat by Marion Nestle