Tuesday, April 29, 2008

Those sneaky supermarkets!


There are about 320 000 food and beverage products available in the US and an average supermarket carries
30 000-40 000 of them!

According to Marion Nestle in her book, What to Eat, supermarkets want you to get confused by all this choice- it forces you to wander the aisle, picking up foods that aren't on your grocery list.

Brian Wansink, author of Mindless Eating, agrees: "The longer we end up lingering in a grocery store the more we end up buying".

This is why the the frozen foods are not at the entrance of the grocery store- if we bought them first, we'd rush through the rest of the grocery store and not buy as much.

As Nestle points out, supermarkets are businesses- not social service agencies providing food for the hungry.

Here are some other sneaky supermarket stunts:

Highest-selling products-preishables like meat, dairy, frozen foods- are generally against the back or side walls- no need to put them in front cause they know you'll seek them out. There's also the greatest traffic flow along the periphery.

Nearest the entrance are the high-profit articles- flowers, produce, freshly baked bread, sushi...

High-profit center-aisle foods are generally placed 60 inches above the floor, easily seen by adults. Products made to attract kids can be found at their eye level.

Store brands are generally placed to the right of high-traffic items since people read from left to right- that way the store brands get noticed.

Displays at the end of the aisles are generally saved for high-profit and heavily-advertised products- likely to be bought on impulse.

Aren't they sneaky?

Sources:

Nestle, M. What to Eat. North Point Press, 2006.
Wansink, B. Mindless Eating: Why we eat more than we think. Bantam: 2006.

Monday, April 28, 2008

Diet and Age-Related Macular Degeneration


A client asked for this information so thought I'd post it for you!

According to Dr. Max Snodderly, Ph.D., head of the laboratory at The Schepens Eye Research Institute in Boston, Massachusetts, an affiliate of Harvard Medical School, “Improved nutrition could help to retard the loss of visual sensitivity with age. Perhaps the gradual loss of vision in many older people is not an inevitable consequence of the aging process. ”

Age-related macular degeneration (AMD) is the leading cause of vision loss in people over the age of 55. Macular degeneration occurs when the macula (the central part of the retina responsible for sharp focus) is damaged. This damage causes permanent loss of central vision. Regular eye exams can detect the disease early on and laser treatments can slow down the central vision loss.

For most AMD cases, there’s no known cure or treatment. Symptoms of AMD include blurred or fuzzy vision, the illusion that straight lines, such as sentences on a page, are wavy and the appearance of a dark or empty area in the center of vision. Risk factors for the disease include cigarette smoking and family history of AMD. Exposure to sunlight, having light irises, and even being a woman seem to be additional risk factors.

Research shows that the consumption of fruits and vegetables containing two carotenoid (phytochemicals) pigments may be linked to a reduced risk for AMD. These carotenoids are lutein and zeaxanthin, primarily found in broccoli, corn and dark green vegetables like spinach and kale. Lutein and zeaxanthin are actually part of the retina of the eye. Increasing the concentration of these pigments in the eye may prevent vision loss.

Average lutein intake is 1-2 mg per day for American adults. Studies that have found improved visual function with lutein intake used a dosage of 10-15mg lutein. However, some researchers recommend lower levels, more in keeping with actual intakes, until the risks and benefits of these carotenoids are known. Studies done at Harvard University found that 6 mg per day of lutein lead to a 43% lower risk for macular degeneration.

Pharmaceutical companies have added the carotenoids to their dietary supplements but there is no definitive evidence about the safety and effectiveness of these supplements.

According to Linda Nebeling, Ph.D., R.D., of the National Cancer Institute, national data shows an overall decline in lutein & zeaxanthin intake, particularly in groups at greatest risk for age-related macular degeneration, as a result of a decrease in fruit and vegetable intake.

LUTEIN & ZEAXANTHIN CONCENTRATION IN FRUITS & VEGETABLES

Food

Per 100g

(mg)

Per Serving

(mg)

Serving size

Kale, raw

39.6

22.2

1 cup

Kale, cooked & drained

15.8

16.9

½ cup

Turnip greens, cooked & drained

8.4

9.0

½ cup

Collards, cooked & drained

8.0

8.7

½ cup

Spinach, cooked & drained

7.0

7.5

½ cup

Spinach, raw

11.9

6.7

1 cup

Broccoli, cooked & drained

2.2

1.7

½ cup

Corn, sweet, cooked & drained (not canned)

1.8

1.5

½ cup

Lettuce, Romaine, raw

2.6

1.5

1 cup

Peas, green, canned & drained

1.4

1.1

½ cup

Brussel sprouts, cooked & drained

1.3

1.0

½ cup

Corn, whole kernel, canned & drained

0.9

1.0

½ cup

Beans, snap green, cooked & drained

0.7

0.4

½ cup

Tangerine juice, fresh

0.2

0.3

¾ cup

Orange juice, unsweetened

0.1

0.3

¾ cup

Orange, Fresh

0.2

0.2

1 medium

The combination of antioxidants (vitamins C and E, and beta-carotene) and zinc, alone or with lutein, has also shown a modest benefit in reducing the risk for progression from moderate to advanced age-related macular degeneration and vision loss.

Food sources of Vitamin C include: broccoli, green and red peppers, collard greens, pineapple, strawberries, citrus fruits.

Food sources of Vitamin E include: Asparagus, avocado, nuts, olives, seeds, spinach and leafy greens, wheat germ, vegetable oils (corn, sunflower, soybean, cottonseed).

Food sources of beta-carotene include: Carrots, cantaloupe and other fruit and veggies with red, orange and yellow pigments.

Food sources of zinc include: Red meat, poultry, oysters, fortified cereals


Sources:

http://www.macular.org/nutrition/l_chart.html

Practice-Based Evidence in Nutrition http://www.dieteticsatwork.com/pen/

http://en.wikipedia.org/wiki/Macular_degeneration

http://www.hc-sc.gc.ca/iyh-vsv/life-vie/seniors-aines_vc-sv_e.html

http://jn.nutrition.org/cgi/content/full/136/10/2519

Friday, April 25, 2008

Are you a Locavore?


The New Oxford American Dictionnary 2007 Word of the Year was "Locavore".

What does it mean?

"A locavore is someone who seeks out locally produced food, usually for ecological reasons".

The term "localvore" is sometimes used.

The locavore movement encourages consumers to eat locally produced foods, sometimes within a specific radius of 50, 100, or 150 miles. It also encourages consumers to buy from farmers’ markets or even to grow their own food.

See blog post 'What's the 100-mile diet' 10 April 2008 for an example of a huge insipiration to many locavores.

Sources:



Wednesday, April 23, 2008

Fact or Fiction?


Fact or Fiction?

Wine is the only alcohol that's beneficial to heart health, helping to increase the good or "healthy" HDL cholesterol and helping to reduce the formation of blood clots that can cause heart attacks or strokes.


Fiction!


All alcohol, not just the alcohol in wine, has these benefits. Red or white wine, beer, hard alcohol, cordials all have the same effect on cardiovascular disease. Drinking pattern is actually more important than type of alcohol.


Men who have 1-2 alcoholic drinks a day were found to have a 30-40% lower risk of heart attacks compared to men who didn't drink at all. Although more than 2 drinks a day has been associated with further heart and stroke protection, it has also been associated with increased mortality due to accidents, liver disease and other causes and it's not recommended.


For women, it's trickier. Women benefit from alcohol's ability to increase the good HDL cholesterol and reduce the risk of heart attacks and stroke but data from the Nurse's Health Study found that women who drank 2 alcoholic drinks a day had a higher risk of breast cancer- 20-25% higher (so the current average risk of developing breast cancer in the US is 12 out of 100 women but was 14-15 out of 100 for women that drank more alcohol).


The research shows that the link between breast cancer and alcohol intake was seen in women who didn't get enough folic acid and other B vitamins from their diet.


So, if you don't drink alcohol now, you don't have to start (the same benefits can be achieved by exercising!) but if you're a man with a history of heart disease, you may benefit from 1-2 standard alcoholic drinks* a day (of any type of alcoholic beverage). If you're a woman, the benefits of alcohol may be offset by an increased risk of breast cancer. Make sure you get enough folic acid in your diet (whole grains, dark leafy greens, beans and lentils).


Always talk to your doctor about your alcohol intake.


*What's a standard drink?

5oz wine (12% alcohol), 1 12-oz (360mL) beer (5% alcohol), 1.5oz spirits (40% alcohol).


Sources:


Willett, WC. Eat, Drink and Be Healthy. Free Press 2005.
European Cancer Conference. "Alcohol Amount, Not Type -- Wine, Beer, Liquor -- Triggers Breast Cancer." ScienceDaily 28 September 2007. 23 April 2008 /releases/2007/09/070927083251.htm>.

You are what your mother eats

UK researchers have found that what a woman eats around the time of conception can influence whether she has a boy or a girl.

The researchers looked at the diets of 740 first-time moms who didn’t know the sex of their foetus. Nutritional data was collected 3 times during their pregnancies: at preconception, at around 16 weeks and later in the pregnancy at 16-28 weeks’ gestation.

Women who consumed more calories around conception were more likely to give birth to a boy. Those that ate ~2,200 calories a day were 1.5 times more likely to have a boy than those that ate less than 1,850 calories a day. No association between the mother's weight and the baby’s gender was found and, in fact, the moms had similar weights. This could mean, although it was not reported, that the women with the higher caloric intake and therefore more likely to give birth to a boy, were more likely to be more active.

Eating breakfast cereals before and around the time of conception was also strongly associated with women giving birth to a baby boy. Women eating more breakfast cereals were 1.89 times more likely to have a boy than those who didn’t consume a lot of cereal and those that skipped breakfast.

Moreover, diets higher in a number of nutrients, including potassium, calcium and vitamins C, E and B12, were also linked to male births.

There was no association between smoking and caffeine intake with the baby’s gender.

Other studies have found that non-nutritional factors have been associated with gender allocation including temperature of the environment, hormonal variations in women at the time of conception and timing of insemination relative to ovulation. These factors may have confounded the results of this study.

This study showed a link between food intake and gender at preconception but intake during pregnancy was not associated with baby’s gender.

Alice Domar, an assistant professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School is worried that women will start skipping breakfast and eating less in the hopes of giving birth to a girl in light of this study. She cautions that its virtually impossible for a woman to change the sex of her baby and a woman's diet has a profound impact on the health of her baby- and that includes folate-fortified breakfast cereals!

Sources:

Mathews, F., Johnson, PJ., Neil, A. You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans. Proceedings of the Royal Society: Biological Sciences. April 22 2008.

http://www.medicalnewstoday.com/articles/105013.php

http://www.usnews.com/blogs/on-women/2008/4/23/can-diet-determine-a-babys-sex-poppycock.html

Tuesday, April 22, 2008

Eggs related to mortality, more so in diabetics


The Confusion

According to the Heart and Stroke Foundation of Canada, “Most people can eat eggs in moderation without concern for any harmful effects on blood cholesterol. However, those with high blood cholesterol, are advised to limit their intake of eggs to two per week”.

But wasn’t the recommendation to reduce egg intake to less than 4 a week? Or was it 2 a week? Or was it "an egg a day is ok"?

The egg recommendations keep changing and the research behind the effects of eggs on our health is as confusing.

Cholesterol in our Food and in our Blood

Eggs have more cholesterol than any other single food- all of it in its yolk. The white has no cholesterol. There's around ~210mg cholesterol per egg.

It’s true that saturated and trans fats increase blood cholesterol to a greater extent than cholesterol found in foods, but dietary cholesterol still plays an important role and shouldn’t be dismissed.

Our body makes cholesterol naturally, so we actually don’t need to get any from our diet. But we do. Foods from animal sources have cholesterol- like egg yolks, meat, poultry, milk, dairy products…

The Scientific committee behind the 2004 Dietary Guidelines for Americans said: “the relationship between cholesterol intake and cholesterol concentration is direct and progressive, increasing the risk of coronary heart disease”.

According to the American Heart Association, the average man consumes 337mg cholesterol a day and the average woman, 217mg. The American Heart Association and The Heart and Stroke Foundation of Canada recommends limiting cholesterol to less than 300mg.day, less than 200mg if you’ve had a heart attack or stroke, if you have diabetes and if you have high LDL (bad) cholesterol.

Now, it gets a bit confusing because the amount of cholesterol in your blood doesn’t necessarily reflect the amount of cholesterol you’re eating. Saturated and trans fats increase your blood cholesterol level more effectively than cholesterol in food. Moreover, unsaturated fats, fibre found in fruits, vegetables, lentils and whole grains help lower cholesterol levels. Exercise also helps lower your bad cholesterol (but helps increase your good HDL cholesterol). When researchers study the effect of eggs on blood cholesterol, they need to be taking all these other factors into account… not very easy to do!
On top of that, some people can eat a lot of cholesterol with no effect on their blood cholesterol- others are not so lucky!

The Research

A recent study published in the American Journal of Clinical Nutrition looked at egg intake of 21 327 men from the Physicians’ Health Study, excluding those that had a history of heart disease, heart attack, stroke, cancer and other serious health problems.
Egg intake was self-reported at baseline, 2 years, 4 years, 6 years. 8 years and 10 years.
Average egg consumption was 1 egg a week.
Egg consumption of up to 6 eggs a week was not associated with increased risk of death but, compared with those that ate eggs less than 1 time a week, those that at eggs more than 7 times a week had a 22% greater risk of death (excluding those that had diabetes and after adjusting for confounders).
Risk of death when diabetes was present was 100% (2 times) greater for those that ate more eggs!

Unfortunately, this study didn’t collect much dietary information, including intake of saturated fat, trans fats, fibre (fruits, veggies, whole grains), fish, unsaturated fats- all factors that could influence blood cholesterol levels and mortality.

However, this isn’t the first study to report an increased risk for diabetics that eat eggs.

Harvard investigators looked at egg consumption of 120 000 people and found that those that ate up to one egg a day had no increase in risk of heart disease or stroke. However, those with diabetes doubled their risk of heart disease with one or more egg/day.

A 1999 study published in JAMA showed a 2 time greater risk of heart disease with consumption of more than 1 egg a week compared to less than 1 egg a week in 37851 diabetic men from the Health Professionals Follow-up Study.

Explanation

It’s known that type 1 diabetics absorb more cholesterol but this has not yet been shown in type 2 diabetics. Nonetheless, it can be assumed that dietary cholesterol leads to a less favourable lipid profile in diabetics- meaning that when they eat foods that have cholesterol, it has more of an effect on their blood cholesterol, increasing their bad or "lousy" LDL cholesterol, than for non-diabetics.

Bottom line

If you must have eggs with the yolks, eat them in moderation, ideally less than 4 a week. If you do eat an egg a day, be careful to reduce your intake of other cholesterol-containing foods (foods made with eggs, meat, dairy, etc.)
If you have diabetes, limit your egg intake even more.

Sources:
http://ww1.heartandstroke.ca/Page.asp?PageID=1562&ArticleID=1363&Src=&From=SubCategory#what_if_high
http://www.americanheart.org/presenter.jhtml?identifier=4488
Djoussé, L; Gaziano, JM. Egg consumption in relation to cardiovascular disease and mortality: the Physicians Health Study. Am J Clin Nutr 2008. 87:964-69.
Eckel, RH. Egg consumption in relation to cardiovascular disease and mortality: the story gets more complex.
Nestle, M. What to Eat. North Point Press 2006.
Willett, WC. Eat, Drink and Be Healthy: The Harvard Medical School Guide to Healthy Eating. Free Press 2005.

Monday, April 21, 2008

Should you be watching your sodium intake?


Yes!

According to the World Health Organization, hypertension is the leading risk factor for death in the world and according to Blood Pressure
Canada, it's the leading risk factor for death in Canada, causing most of the strokes and heart disease. High sodium intake has also been linked to increased severity and frequency of asthma, osteoporosis, stomach cancer, kidney stones and worsening of symptoms and signs of congestive heart failure.

Excess dietary sodium is said to be the cause of hypertension in at least one million Canadians. In Canada today, 46% of women and 38% of men over 60 years of age are taking anti-hypertensive medications.

The average Canadian consumed 3100-3500 mg sodium a day. On average, men consume more sodium than women: 4000 mg/day compared to 2700mg/day (19-30 year olds).

Health Canada and the US National Academy of Sciences (Institute of Medicine) have determined that an adequate intake (an intake you should aim for) is 1200-1500 mg/day of sodium. The research shows that lowering sodium intake to this level could reduce the incidence of stroke and heart disease by as much as 30%.

As the Director of the Canadian Stroke Network points out: “if we discovered that a food additive was causing 30% of all cancers, something would be done right away”.

An intake of 1500mg/day allows for sodium loss in sweat for those that are moderately physically active. Very active people may require a sodium intake that’s a bit higher.

Sodium recommendation by age are:

Age

Sodium Intake per Day (mg)

0-6 months

120

7-12 months

370

1-3 years

1000

4-8 years

1200

9-50 years

1500

50-70 years

1300

>70 years

1200

Tips to help you reduce your sodium intake:

  • Read labels. Nutrition Facts table lists the amount of sodium (in milligrams) per one serving of the food. You can also refer to the % Daily Value which compares the amount of sodium in one serving of your product to 2400 milligrams. Generally, foods low in sodium have a % Daily Value of 5% or less.
  • Pay attention to serving size. Sodium numbers on a nutrition label are for the serving indicated!
  • Use herbs and spices instead of salt when cooking - try garlic, lemon juice, onion, vinegar and herbs. Remove the salt shaker from the table to break the habit of salting food at the table.
  • Limit your intake of processed meats such as bologna, ham, sausage, hot dogs, bacon, deli meats, and smoked salmon.
  • Limit your use of salty condiments such as bouillon cubes, soy sauce, Worcestershire sauce, soy sauce or bbq sauce.
  • Rely less on convenience foods such as canned soups, frozen dinners and packaged rice and pasta mixes.
  • Choose lower sodium products.
  • Be assertive when dining out. Request that salt not be added and order sauces and dressings on the side so you can control the amount you use.
  • Rinse canned food when possible (like canned vegetable, beans, tuna). Research done at Duke University has shown that rinsing vegetables for 1 minute reduced sodium content by 41% and rinsing tuna 1 minute reduced sodium by 76%.


Sources:

Press Releases - Reductions needed in the sodium added to foods http://ww2.heartandstroke.ca/Page.asp?PageID=1613&ContentID=27085&ContentTypeID=1 Oct 25 2007

Sodium Policy – Blood Pressure Canada & Collaborating Organizations ttp://www.dietitians.ca/news/highlights_positions.asp Oct 25 2007

http://www.lesliebeck.com/page.php?id=2437&type=art

Brody, Jane. The Good Food Book: Living the High-Carbohydrate Way. Bantam: 1987.

The promotion of thinness is criminal



"Today I am fasting. No exceptions! I hope not eating does not affect my medication. Oh well, I refuse to eat because I am just too disgusted with myself. I felt like an absolute pig at prom. I will probably fast tomorrow as well. Any one have any fasting tips to keep up the energy?"


"I've been eating 300 cals a day for the past week, I've put a ban on fasting... I have like 60cals for breakfast, 70 for lunch then a 170cal dinner... but I feel like I'm eating sooo much. I don't want to go any lower because I don't want my metabolism to get shitty... It's driving me crazy, I could easily just have a 70 cal dinner and do 200cals a day, but I'm worried I'll start losing weight slower. Does anyone else eat only 200cals a day and lose at a steady rate?"

These are examples of entries that can be found on "pro-anorexia", aka "pro-ana" sites that give advice on how to lose weight,, how to hide eating disorders from family members and doctors, what foods are easier to throw up etc.

France has passed a pioneering bill that aims to criminalize websites like these that encourage girls to starve themselves. The bill would also affect fashion houses, magazines and advertisers that promote thinness. If the bill is passed by the French Senate, offenders would face a fine of 45 000 euros and 3 years in jail.

This follows other efforts to stop the promotion of an unhealthy body-ideal in the media:

In 2006, Spain required models to have a minimum BMI of 18 to be allowed to walk the runway. This occurred shortly after 2 models dies of anorexia-related causes.

In 2007, Italy banned an ad campaign for the fashion label Nolita (pictured in this blog) that showed a naked anorexic woman. The Publicity Control Institute rules that the image was in breach of their code of conduct that states that advertising must be honest, truthful and accurate and must respect human dignity in all its forms.

Dr. Hany Bissada, of Ottawa's Regional Centre for the Treatment of Eating Disorders supports the French bill and agrees that women with a BMI below 18 should not be allowed to model.
"I think it's a step in the right direction," he said. "It's not legislating weight; it's putting a minimum level of health for people to be able to participate in this industry."

Anna Wintour , Vogue Editor, encouraged designers to "consider athleticism and vitality" in the April issue of the magazine.

However, most of the fashion industry is not jumping on this bandwagon and remain skeptic about this new law and is even angry that they're being blamed for eating disorders.

Designer Jean-Paul Gauthier was quoted as saying: "This kind of problem cannot be resolved with laws".

Jeanne Beker, host of the Canadian Fashion Television, said: "I find it very strange that people are trying to legislate an aesthetic. We don't want to promote unhealthy images, but who's to say what's really healthy? How would it look if people over a certain weight couldn't be shown?"

She also says that this French law would be a form of censorship and points out that the images of models "are not to be taken literally" since fashion is supposed to depict fantasy, not reality.

The message is clear from the fashion industry- fashion is a business and it would not be profitable to have "average-weight" women selling their products.

Our society does have a preoccupation with weight. In Canada, at any given time, 70% of women and 35% of men are dieting. A 1993 Statistics Canada survey reported that of women 15- 25 years old, 1-2% have anorexia and 3-5% have bulimia. Eating disorders have the highest mortality rate of all mental illnesses, with 10% to 20% eventually dying from complications.

And regardless of what the fashion industry says, it's my opinion that the media's role in portraying a certain body image that many women (and men) go to great efforts to achieve, to the detriment of their health, is undeniable. It's very sad.

Sources:

Friday, April 18, 2008

Did you know...


Did you know that the average American drinks 25 gallons (~95 litres) of milk per year?

If you currently drink 2 cups 2% milk a day, did you know that if you switched to 1%, you would lose 4 lbs a year?

And that if you switched to skim milk, you would lose just under 8lbs a year?

I'd say that's a pretty easy way to lose some weight...

Sources:
Brault-Dubuc, M; Caron-Lahaie, L. Nutritive Value of Foods 2nd ed. 1994.

Thursday, April 17, 2008

Vitamin supplements can kill you!


I’m not a fan of supplements. I find it odd that while we have a clear over-abundance of food, we’re a nation that over-supplements! We can get all the nutrients we need from food, there’s no need to take any kind of supplement- not even a multivitamin.

Of course, there are some cases where it’s recommended- someone who has a weak appetite or an inability to absorb or digest certain foods, for example. However, it’s my opinion that healthy individuals should not be taking pills to get their nutrients. Who knows what the long term effects will be?!

Antioxidant supplements like beta-carotene, vitamins E and C have long been peddled as being able to get rid of dangerous ‘free radicals’ in our bodies that have been linked to everything from cancer to heart disease.
However, a recent review of 67 studies, appearing in the Cochrane Library, involving a total of 233000 healthy adults and adults with medical conditions under control has found that people that took antioxidant supplements did not live longer and, in fact, some supplements increased mortality!


The researchers linked vitamin A supplements to a 16% increased risk of dying, beta-carotene to a 7% increased risk and vitamin E to a 4% increased risk. Cause of death was not tracked.

The antioxidants also appeared to offer no benefit to people with gastrointestinal, heart, neurological, eye, skin, rheumatoid, kidney and endocrine diseases, according to the authors.

Critics, including a supplement-industry trade group, argue that the review only included studies that included deaths. The researchers defend themselves saying that most of the trials that had no deaths were not “proper preventative trials” .

As Dr. Walter Willett (Harvard School of Public Health) points out:


“Pills that contain 1 or 2 or 10 substances made by plants just won’t do. Why not? Plants make a seemingly endless cornucopia of compounds that have biological activity in the human body…The vast majority of these phytochemicals have yet to be discovered”.

The benefits we get from fruits, vegetables and other foods not only come from the different substances they contain but possibly from the interactions between them.

Sources:
Retrieved April 17, 2008, from http://www.sciencedaily.com­ /releases/2008/04/080415194233.htm
www.whattoeatbook.com
http://news.bbc.co.uk/2/hi/health/7349980.stm
Willett, WC. Eat, Drink, and Be Healthy- The Harvard Medical School Guide to Healthy Eating. 2005. http://www.cbc.ca/health/story/2008/04/16/antioxidants-study.html

The Glycemic Index and the Glycemic Load


What happens when we eat carbs?

Some foods make our blood sugars spike really quickly and others, not so much. The foods that have an effect on blood glucose contain carbohydrates. When you eat foods containing carbs they break down to their basic component, glucose or sugar, in the intestine and glucose gets into the bloodstream. As a result, your blood glucose goes up. In response, your pancreas secretes a hormone called insulin that helps sugar get out of the blood and into your body cells that need sugar. Glucose is actually the main fuel for your brain and muscles.

However, when lots of glucose comes in at the same time, your pancreas secretes a lot of insulin at once resulting in a quick drop of your blood glucose. When your blood glucose goes down that quickly, you feel hungry and, as a result, eat again, leading to potential weight gain. Another thing that happens when there’s too much glucose that comes in at once is that your muscle cells start to resist storing the extra glucose. This extra sugar gets stored as fat and also contributes to weight gain.

There are carbohydrates that break down really quickly into glucose- so eating too much of those types of carbohydrates quickly causes your blood glucose to spike quickly, causing all this havoc.

David Jenkins and colleagues from the University of Toronto created a system that ranks carbohydrate foods based on how quickly they break down to sugar. This is known as the Glycemic Index. They compared the impact of different foods on blood glucose to the impact of standard foods like pure sugar on blood glucose. Pure sugar was given a Glycemic Index (GI) of 100.

Foods that have a GI of less than 55 are considered to have a low GI or low impact on blood glucose, 55-69 is a moderate GI and a GI of greater than 70 is considered high.

For example, black beans have a GI of 30. This means that they boost blood sugar 30% as much as pure glucose.

Although GI offers some useful information, it’s not the whole picture. For example, carrots have a GI of over 70. Carrots do have sugar that’s highly absorbable but the total amount of sugar is very small and therefore has very little effect on blood glucose. Luckily, there’s something called the Glycemic Load.

The Glycemic Load (GL) was developed by Walter Willett and colleagues at the Harvard School of Public Health and considers the total amount of carbs in a food as well as the GI. A GL of less than 10 is low, 11-19 is medium and more than 20 is high.

The Glycemic Load of carrots is 5.

Although most health experts, including Marion Nestle and Walter Willett, call GL and GI useful tools, they caution to not build your diet around it. Marion Nestle says she ignores the long lists of foods and their GI and GL values (I included one of those lists below) because not only do the numbers vary depending on the source, but they also vary depending on preparation and cooking methods. It all gets very confusing.

Not only that but if you add butter and cheese on top of a potato, the Glycemic Index will be lower (fat and proteins have no GI because they have no carbs) but calories and saturated fats increase. So just because a food or a meal has a low GI or a low GL, doesn’t mean it’s necessarily a good choice!

What you should focus on is how much food you’re eating and choosing less processed starchy foods (that usually have high GI and GLs anyway).

Health Benefits of choosing low Glycemic Index and Glycemic Load foods

In both the large Nurse’s Health Study and Health Professionals Follow-up Study, it was found that people who ate low fibre cereals and high Glycemic Load foods more than doubled their risk of type 2 diabetes.

Other research has shown that the excess sugar and insulin that comes from eating high GI and GL foods contribute to other chronic conditions like heart disease, breast cancer, colon cancer and polycystic ovarian syndrome.

Now, I haven’t read any of these studies (yet) but just summarizing from Willett’s book. However, it seems to me that people who eat higher fibre and lower GI and GL foods (like whole grains, legumes, vegetables) are those that are most likely to have healthier lifestyles- eat healthier, exercise more, don’t smoke, not overweight etc. than those that are eating low fibre and high GI/GL foods. So is it just the higher intake of high GL/GI foods that are contributing to these health conditions or is it a less healthy lifestyle?

Mike- hope this answers some of your questions. There'll be more to follow.

Glycemic Index and Load of foods: http://www.ajcn.org/cgi/reprint/76/1/5

Sources:


Nestle, Marion. What to Eat. 2006

Willett, WC. Eat, Drink, and Be Healthy- The Harvard Medical School Guide to Healthy Eating. Free Press 2005.

Wednesday, April 16, 2008

This is not a balanced meal...





















http://cupcakestakethecake.blogspot.com/

BPA Update!


Yesterday the Globe and Mail reported that Health Canada was going to make a statement any day now that Bisphenol-A (BPA) is a dangerous substance. If they do make this statement, they would be the first regulatory body in the world to do so. The US assessment proces is only at a preliminary stage right now.


Please click on the BPA label below to read my previous blog on BPA (Goodbye pink Nalgene bottle- April 7) for more information. Generally, it’s found in polycarbonate hard plastic products (like Nalgene bottles, baby bottles ) and in the lining of cans.

According to the article, US tests have found that more than 90% of the population carries trace residues of BPA in their bodies, the majority of which comes from BPA leached into our foods and drinks.

Independent studies have linked BPA exposure in animals to cancer, early puberty, schizophrenia, attention-deficit disorder and developmental delays. However, industry-funded studies have not been able to confirm these results.

Today, as a result of yesterday’s article, companies and stores are already starting to voluntarily pull plastic water bottles and storage containers containing BPA off their shelves. These companies include Forzani Group Ltd (which has 500 stores across Canada including Sport Check, Athlete’s World and Coast Mountain Sports), Hudson’s Bay Co. (which includes the Bay and Zellers), Canadian Tire, Mark’s Work Wearhouse and PartSources stores.
According to Forzani’s CEO, the Globe and Mail article “was sufficient cause to take the high road and get it off the shelf. We are doing this out of an overabundance of caution”.

Stay tuned for the government’s statement!
Thanks Nicole and James for the article links!
Sources:

Monday, April 14, 2008

I want to get high.


I’ve run on average 5 days a week for the last few years now. Have run a couple of marathons and other races and yet the runner’s high has remained elusive to me. Sure, running helps get rid of some of my anxiety or nervousness, but I wouldn’t call that a high or a euphoria.

Turns out something’s wrong with me cause after 30 years of speculation, they determined that the runner’s high does exist!

A German study sought to unravel the mechanism of the runner’s high and identify the relationship to perceived euphoria. 10 athletes were PET scanned on 2 separate occasions at rest and after 2 hour endurance runs (21.5 ±4.7km) in a random order. They also completed questionnaires to rate their moods at rest and after their run.

The researchers found that during the run, endorphins were produced, attaching themselves to areas of the brain associated with mood and this was correlated with a more euphoric mood.

Interestingly, according to lead researcher Dr. Boecker, the same areas of the brain that are activated during a run are also activated when people are involved in romantic love affairs!

The study was small- only 10 participants- and the level of athleticism wasn’t very high (21.5 km in 2 hours)- so although interesting, the study should be repeated on a greater number of people of varying athletic levels, in my opinion. I'd also be interested to find out if the same high is experienced by other types of athletes, including weight lifters.

In a follow-up study, Dr. Boecker is investigating if running affects pain perception. We've all heard stories of athletes running through passing of kidney stones or stress fractures, so the results should be interesting. They've recruited 20 marathon runners and a similar number of nonathletes and are studying the perception of pain after a run, and whether they are related changes in brain scans. He is also having the subjects walk to see whether the effects, if any, are because of the intensity of the exercise.

Perhaps running in shorts for the first time in a while this week will give me some of that elusive high... I’ll keep you posted!

Thanks to Leandra (via Ingy's facebook) for this study!

Sources:

http://cercor.oxfordjournals.org/cgi/content/abstract/bhn013v1 http://www.nytimes.com/2008/03/27/health/nutrition/27best.html?_r=1&ei=5070&en=0a52a8acd148ab80&ex=1207540800&adxnnl=1&oref=slogin&emc=eta1&adxnnlx=1208224808-0P5KJzV5o7GLU98R5darsg

Rice-a-rific!


Rice is a staple food for at least 2/3 of the world's population. However, there are so many different types of rice that it could get a bit confusing.

Here’s a bit of an overview.


Rice is a member of the grass family. The plant is native to tropical and subtropical southern Asia and Southeastern Africa.


There are different types of rice, categorized based on processing, size and variety.


Processing


Brown rice undergoes the least amount of processing. The first step in milling of the rice plant is the removal of the outer husk and the product after this step is brown rice. The bran stays intact therefore brown rice contains more nutrients and 4 times the fibre found in white rice.

The Glycemic Index (GI) is a scale that ranks foods by how much they raise blood glucose compared to a standard food. A glycemic index off 55 or below is considered low and 70 or above is high. Brown rice falls in between with a GI of ~66.


Converted or Parboiled rice has been soaked and then steamed under pressure before milling. This actually forces some of the nutrients into the remaining portion of the grain so that some are retained during processing. As a result, this rice falls between brown and white rice in terms of nutrient content but actually has the lowest GI with a GI of 48.


Enriched rice has had the B vitamins (thiamin, niacin) and iron added after milling to replace some of the nutrients lost when the bran layer is removed.


Instant white rice has been milled and polished, fully cooked and then dehydrated. It is usually enriched but does not have the superior taste and texture of regular rice.


Size


Long-grain rice is four to five times longer than it is wide. When cooked the grains are fluffy and dry and stay separated. It’s ideal for salads. Long-grain rice (unconverted) has a medium GI of ~57.


Medium-grain rice is about twice as long as it is wide and cooks up moister and more tender than long-grain. It is popular in some Asian and Latin American cultures, and is the type of rice most commonly processed to make cold cereals.


Short-grain rice is oval or round in shape. Of the three types of rice, it has the most starch that makes it sticky, or clump together, when cooked. It is ideal for dishes such as sushi. Short grain rice has a high GI of >70.


Variety


Arborio: A starchy white rice, almost round in shape. Traditionally used for cooking Italian risotto. It also works well for paella and rice pudding. Arborio absorbs up to five times its weight in liquid that results in grains of a creamy consistency. This type of rice has a high GI of ~70.


Aromatic rice: Primarily long-grain varieties that have a toasty, nutty fragrance


Basmati: The most famous aromatic rice is grown in India and Pakistan. The grains elongate much more than they plump as they cook. Can be substituted for regular white rice in any recipe. You can also purchase brown basmati rice. Basmati rice is a long-grain variety. Basmati rice has a medium GI of 58.


Glutinous, sticky or sweet rice: Long-grain rice with a very high starch content. Suitable for Chinese dishes of shaped rice, such as rice balls or sticky rice cakes. This type of rice has a very high GI of ~98.


Jasmine, perfumed or Thai fragrant: A traditional long-grain white rice grown in Thailand. It has a soft texture and is similar in flavour to basmati rice. It is also grown in the United States where it is available in both white and brown forms. Jasmine rice has a very high GI of ~109.


Sources:

http://www.lesliebeck.com/ingredient_index.php?featured_food=18
http://en.wikipedia.org/wiki/Rice
http://freecookbooks.a1nethost.com/001/04/25.htm
http://images.google.ca/imgres?imgurl=http://www.bernas.com.my/images/ricegrain.jpg&imgrefurl=http://www.bernas.com.my/process.htm&h=282&w=360&sz=84&hl=en&start=4&um=1&tbnid=6VQ17F4VyxtItM:&tbnh=95&tbnw=121&prev=/images%3Fq%3Drice%2Bgrain%26um%3D1%26hl%3Den%26sa%3DN

Foster-Powell, K; Holt, S; Brand-Miller, JC. International table of glycemic index and glycemic load values. American Journal of Clinical Nutrition. 76(1) 2002. http://www.diabetes.ca/files/Diabetes_GL_FINAL2_CPG03.pdf
http://www.abingredients.com/products/rice_starch/images/rice_varieties.jpg