TKF Science Writing

I am currently writing an article on oxidation and free radicals and I thought I’d go over the basics for those interested in how it relates to food. I’ll give you one guess as to what element oxidation refers to. If you guessed boron that would be incorrect. The correct answer is of course oxygen. Free radicals and oxygen go hand in hand in biological reactions.

To give you a simple example of oxidation, take an apple and slice it in half. Leave it on the counter for a few minutes, watch it turn brown, and you have just witnessed the phenomenon of oxidation. By breaking the skin on an apple, you have just exposed the it’s cells to oxygen and have seen first hand the destruction of those cells.

Free radicals are compounds that are highly reactive due to the presence of a lone pair of electrons. Electrons do not enjoy being in pairs because of the instability factor. Much like the economy today, nothing really likes to be unstable. The same goes for the natural world. I harken back to the movie Titanic where a member of the crew shoots a gun in the air and says “maintain order here”. The same goes for electrons in that they want to be stable. Okay, movie tangent over, back to the food thing.

So, at a molecular level, we have electrons wanting to be in pairs when in walks these free radical types whose electrons have no dance partner or pair and are very unstable. What do they do? They walk around the dance floor like an overzealous teenage boy looking to pick up a dance partner. It could be the girl against the wall, the girl on the floor, the chaperone, or your buddies date. Free radicals don’t care, they just wants to become stable so they will grab anybody.

When this free radical steals someone else’s date, they have just created another free radical who is looking for a dance partner and the whole process starts again. The next thing you know the whole dance floor (our cells) becomes saturated with free radicals and chaos ensues. This chaos leads to mutated cells and loss of proper cell functioning.

Transfer that metaphor to your diet and cooking habits. Examples of the stag free radical stealing dates are:

cigarettes
smog
intense exercise
stress
alcohol
charred food
pesticides
UV light

In walks the savior of the dance known as anti-oxidants. They come in and help clear everything up. They protect against the free radicals by bonding with them. Essentially, they share their date (electron) with the free radical. Anti-oxidants are found in foods that contain:

Beta-carotene (carrots, sweet potatoes, cantaloupes, squash, mangoes)

Lutein - green leafy vegetables such as spinach, collard greens, and kale

Lycopene - tomatoes, watermelon, guava, papaya, apricots, pink grapefruits

Vitamin A - sweet potatoes and carrots

Vitamin C - apples, oranges, pineapples, strawberries, blueberries

Vitamin E - wheat germ, some oils (corn, safflower, soybean), green leafy vegetables, whole grains, avocadoes, almonds, olives, nuts, broccoli

If you start to include these anti-oxidants in your diet perhaps you won’t ever get stood up on the dance flood again. At least your dance floor (your cells) will be better protected from those lurking free radicals.

A researcher at the University of the Basque Country UPV/EHU has hypothesized that two glasses of red wine a day will help reduce fatty deposits in the liver. It has been in the media for a long while that two glasses of red wine were healthy, especially for middle aged men. It is thought that consuming red wine daily kept the heart from aging too rapidly.

The culprit of this phenomenom is a compound called reservatrol. Reservatrol has antioxidative properties and is found in the skins of red grapes, muscadines, red wine, natural grape juice, and tea. Similar to other antioxidents, reservatrol is thought to protect against certain forms of cancer, cardiovascular disease, and dementia.

Reservatrol is a polyphenol phyochemical. Polyphenols are long chains of phenol compounds strung together. In chemistry terms, a phenol is a six membered ring with a -OH (hydroxyl) group attached. In your mind’s eye, picture a stop sign as the basic structure and then attach an oxygen atom to one corner of the hexagon and then attach one hyrdrogen atom to the oxygen. Poly is a prefix meaning many so just string together a few of these structures and you end up with a polyphenolic compound.

Phytochemicals appear in plants and are considered to have disease fighting qualities. These are the compounds that are considered to have anti-oxidative benefits to humans. By helping to fight the damage to cells that oxygen creates, polyphenols fall into this class of compounds.

The author of the thesis is Ms Elizabeth Hijona Muruamendiaraz and her report is found in ScienceDaily’s website published May 13th, 2009. The aim of the study was to determine whether the compound reservatrol reduced esteatosis (fatty liver) in rats. Three groups of rats were used:

· Group 1 had access to food and water.

· Group 2 was affected by esteatosis and was fed a high carbohydrate/fat free diet along with a period of fasting.

· Group 3 also had estatosis and had the same diet as group 2 but was also given a daily 10mg dose of reservratrol.

What Ms. Muruamendiaraz found was that members of group 3 had fewer cells with fatty liver deposits than group 2 members. She also found that group 3 had less naturally occuring oxidative substances than those in group 2. Furthermore, due to the fact that there were less oxidative substances in the reservratrol group, the livers from the rats of that group were able to conserve some of their anti-oxidants. She went on to conclude that reservratrol is beneficial in maintaining the balance between oxidative and anti-oxidative substances.

Other scientists and doctors remain sceptical of the results however and advise against drinking 14 glasses of wine a week. Some say that the build up of concentrated fructose in wine will cause fatty deposits in the liver. The jury may still be out and I’m sure more long term testing is underway about the health benefits of red wine.

In the meantime, reservratol sure does taste good.

Losing weight is on the minds of many as the warmer months start rolling around.  Whether it is to fit into a prom dress, look good on the beach, or just get a bit more healthy, the weight loss fight continues.

Scientists may have found a breakthrough in calcium, the most abundant mineral in the body.  In a study published in the British Journal of Nutrition, a diet that boosted calcium intake led to more significant weight loss than its control group.  The study took a sample of obese women and through a 15-week period, had them on a diet of  no more than 600 mg of calcium per day.  The recommended daily allowance of calcium is 1000 mg more or less as depending on age (1,000 mg for 19-50 years old, 1,200 for 51+ years).  In terms of food rich in calcium, the list includes:

•    milk = 1 cup = 300 mg

•    yogurt = 1 cup = 415 mg

•    cheese = 1.5 oz = 300 mg

•    broccoli = 1 cup cooked = 94 mg

•    spinach = 1/2 cup cooked from frozen = 139 mg

•    almonds = 1 oz = 75 mg

In addition to the low calorie diet, the subjects of the weight loss study also consumed two calcium supplements per day equiling 1,200 mg.  The control group were given a placebo and the results were then monitored.  The group that took the calcium supplements lost 13.2 lbs while the control group lost 2.2 lbs. 

One caveat to point out where that the test subjects had a diet that was already calcium deficient so this study does not delve into an already calcium rich diet.

Angelo Tremblay, holder of the Canada Research Chair in Environment and Energy Balance hypothesized that the brain seems to detect a lack of calcium in the body.  This can lead to the desire to eat more stifling weight loss. 

Professor Tremblay’s first foray into the relationship between calcium and weight loss occured in 2003.  He found that women’s diets that were poor in calcium led to more body fat, bigger waistelines, and higher bad cholesterol levels than their higher level counterparts.  Along the same lines, in 2007 Professor Tremblay found a direct correlation between calcium and a lower heart disease risk.

I’ve always thought of eggs as a super food.  It is one of those foods that nutrition gurus across the world say we should eat.  In the past, due to their high cholesterol content, experts advised that eggs were best eaten sparingly.  Interestingly enough, many claim that there is no correlation between eggs and heart disease, the number one cause of death in North America.  Researchers now are saying that the egg can also help reduce high blood pressure.  Another benefit from our famed superhero, the egg.  The study was reported in the Journal of Agricultural Food Chemistry.

Eggs consist of 75% water, 12% proteins, 12% lipids (fats), and 1% vitamins, minerals, and carbohydrates.  Rich in bioactive proteins and peptides (short polymers formed from the linking of amino acids), eggs are a vehicle used to lower high blood pressure.  Scientists at the University of Alberta, Edmonton have found that the process of cooking eggs leads to more of these helpful proteins and peptides.

During digestion, the peptides are either absorbed through the intestine or locally through the gastrointestinal tract.  Antimicrobrial, anticancer, antihypertensive peptides and protease inhibitors all have been reported present in eggs.  One particular enzyme known as ACE (Angiotensin converting enzyme) was of particular interest to the researchers at the univeristy.

ACE is an enzyme responsible for regulating blood pressure.  It is part of the rennin-angiotensin system which which helps maintain stable cardiovascular functions.  ACE catalyzes the formation of angiotensin II (from angioetensin I), a potent vaso constrictor chemical which causes muscles to narrow blood vessels.  This results in the increasing of vascular resistance, decreasing blood flow, and ultimately to high blood pressure.  The compounds in the egg work to inhibit the formation of ACE.

Pharmaceutical companies have also guided efforts for antihypertensive drug development.  These drugs, aptly named ACE inhibitors, slow the activity of ACE.  Captopril, Benazepril, and Enapril are a few that belong to this category.  Often prescribed by doctors, these drugs are based on the same essential concept which is to inhibit ACE.  Side effects do occur for certain people and it is best to let a physician handle those issues.

Considering that table consumption accounts for 70% of total egg consumption in North America, differing cooking methods were addressed by the researchers.  The eggs were cooked two ways:

•  Boiling for 10 minutes, cooling for 5 under cold water, and then peeling.

•  Frying  after separating whites and yolk (each fried separately).

After cooking, they were frozen immediately and then subjected to varying scientific and metabolic processes such as changing pH and introducing pancreatic digestive enzymes.  This was done to mimic the metabolic actions in the gut.

The results showed that the fried egg had the strongest inhibitory factor.  Researchers hypothesized that this may be due to the fried egg having been cooked at a higher internal temperature (170 °C ) than the boiled egg (100 °C), which may have affected the release of bioactive peptides.

Be it fried eggs, egg salad, egg drop soup, or eggs Benedict, it seems that our superhero still belongs to the super food hall of fame.

Reference

J. Agric. Food Chem., 2009, 57 (2), pp 471–477

Other than keeping vampires away, I thought that the benefits of garlic were an urban myth.  Findings posted in the January 2009 issue of of the international chemistry journal Angewandte Chemie apparently have proven me wrong.  The study was conducted by researchers at the Queens University in Ontario.

The organic compound Allicin, which gives garlic its aroma and flavor is thought to be the prime mover.  The sulfenic acid formed  when Allicin decomposition starts reacts rapidly with free radicals which have been known to be responsible for the aging process.  Scientists produced synthetic allicin and the reaction between the acid and radicals resulted in a very potent anti-oxidant.

More specifically, it is peroxyl radicals that are the garlics main target.  Peroxyl radicals belong to to a group called free radicals which are highly  reactive oxygen molecules that have lost an electron.  This loss of an electron make these molecules unstable or in chemical terms, reactive.  To recover this lost electron, a free radical might steal an electron from a neighboring healthy cell.  As a result, vital cellular mechanisms could be compromised.  It is ironic that an essential element can have such a deleterious effect on the human body.  This constant attack on the body is known as oxidative stress and have been linked to diseases such as stroke, cancer, and heart disease. 

Free radicals are derived from basic metabolic processes as well as exposure to X-rays, smoking, air pollutants, ozone, and industrial chemicals.  The role of the anti-oxidant is to take away the harmful properties associated with free radicals.

There is a caveat to this study in that allicin is not found in fresh garlic and the reaction can only take place when the garlic is crushed.  Lots of recipes call for crushed garlic so this should not be a problem.  One technique to use is with the side of a chefs knife smash the garlic down.  This serves two purposes in that you have yourself some crushed garlic and the peeling of the outer skin becomes much easier.

Many people like to buy organic foods believing in the notion that it is a better product.  Unfortunately, this ”superior” product can cost three times as much as non-organically grown foods.  A study published in August of 2008 in the Journal of the Science of Food and Agriculture suggests that buying organically grown food for nutritional value could be a waste of money.

In the study, researchers at the University of Copenhagen have stated that there is no clear evidence to suggest that organically grown food is more nutritious than food grown with pesticides and other chemicals.  The study looked at the retention of minerals and trace elements in animals fed with a vegetable diet from three different cultivation techniques:

1.  low nutrient soil using animal manure and virtually no pesticides

2.  low nutrient soil using anmial manure and pesticides

3.  high nutrient soil using mineral fertilizers and pesticides

All crops experienced the same weather conditions and all were harvested at the same time.  The results showed that in all three cases, no differences in the percentage of trace minerals were seen in the crops.  The harvested produce (carrots, kale, peas, apples, and potatoes) was then fed to animals over a two year period and the uptake, if any, of these trace minerals in animal tissues was measured.  The results showed that no differences were seen in mineral retention based on the three cultivation techniques above.

The scientists go on to state that organic crops are more of a lifestyle choice for the people that can afford to purchase them.

I’m in the process of following a low carb diet called TNT (Targeted Nutrition Tactics), a high fat/high protein diet.  It really isn’t a diet but more of a long-term lifestyle choice.  The basic philosophy of this way of eating is to limit carbohydrate intake, which helps to retain and build lean muscle mass while losing fat.

In science terms, a carbohydrate includes sugars, starches, saccharides, polysaccharides, and cellulose.  These products are a result of the process called photosynthesis.  In chemistry terms, a carbohydrate is a molecule of carbon atoms surrounded by hydrogen (H) and hydroxyl groups (OH).  The general chemical formula for a carbohydrate is C(H2O).   The simplest carbohydrate is a monosaccharide.  Glucose, also known as a simple sugar and fructose, the sugar found in fruits, are common examples of a monosaccharide.  By combining two molecules of a monosaccharide (glucose and fructose), a disaccharide is formed.  Table sugar is the prime example in this category.  Polysaccharides are combinations of monosaccharides strung together.  These strings can be as long as 10,000 monosaccharides long.  These are plentiful in nature with starch and glycogen being two common examples.  Starches are found in stems, roots, and seeds of plants while glycogen is found primarily in the muscle and liver tissues of animals.  Our bodies are able to break down these long complex chains into glucose, which is used as an energy source.

Carbohydrates spike insulin, a hormone that causes our cells to take up glucose from the blood eventually storing it as the polysaccharide glycogen.  Glycogen is readily converted into glucose when the body needs it.  The strategy of a low carb lifestyle is to essentially force our bodies to use something else for energy.  That source is now fat.  One of the benefits of this type of high fat/high protein lifestyle is that it is now much easier to feel satiated without having to knock down a second plate of pasta.  You end up consuming fewer calories, which in turn can lead to weight loss.

This lifestyle also challenges the notion that all vegetables are good vegetables.  To examine this notion further, we should talk about a concept called the glycemic index.  This index was created to measure how readily our blood sugar is raised as it relates to the foods we eat.  For example, white rice, has a GI of anywhere from 50-70 (depending on origin).  On the other hand, carrots GI are 92.  Therefore, by eating carrots, you are raising your body’s blood sugar rather quickly signaling a rapid release of insulin which lowers your blood sugar rapidly.  Carrots and other high GI carbs (pasta, potatoes, bread) do not leave a feeling of satiation as compared to consuming a high fat food.  Often times, this can lead a  person to want to take eat more. 

Something that hasn’t been discussed yet is serving size.  A tool to measure this is called the Glycemic Load (GL).  The GL measures serving size and is the GI multiplied by the number of carbohydrate grams in a portion of food divided by 100.  The tenet behind this number is that a small portion of a high glycemic index food would give a similar result as a larger portion of a lower glycemic index food.  This should give a more accurate result of what kind of an effect a serving size of a particular food will have on actual glucose levels in the blood.

The beauty of this ”diet” is that there is no need to count calories or have to carry around a card with point systems on it.  The simplicity seems to work for me.  Eat high protein/fat foods with carbohydrates mixed in around workouts (carbohydrates help shuttle protein to muscles) and try not to combine carbohydrates and fats during the same meal.  I eat until I am satisfied but not stuffed and I have small meals throughout the day.  I have noticed that my jeans are a little bit baggier and that a need to tighten the belt a few more notches.  My energy levels are good and my latest blood work has my total cholesterol down and my triglycerides way down.  Who would have thought that this would be possible by eating bacon, eggs, and cheese every day.