TKF Science Writing

In a new study published in the Archives of Internal Medicine, scientists have hypothesized that increasing red meat intake leads to higher overall mortality.

The study included people aged 50-71 and were recruited from 6 states (California, Florida, New Jersey, North Carolina, and Pennsylvania).  Atlanta and Detroit were the two main metro areas studied from the above list.  For baseline purposes, the participants were asked to fill out a questionairre outlining the foods they normally ate over the last year. 

Sources of red meat included bacon, beef, cold cuts, ham, hamburger, hotdogs, liver, pork, sausage, steak, and meats in foods such as pizza, chili, lasagna, and stew.  White meat included chicken, fish, turkey, poultry cold cuts, canned tuna, as well as low fat sausages and hot dogs.  The scientists did point out that there was some overlap in the food items as there is red meat in some of the low fat options.  Their statistical models accounted for this fact as the data was analyzed.

High, medium, and low risk type diets were created based on the results of the questionairre.  Over 600,000 respondents returned the questionairre form and after excluding people for various reasons (moved away, incomplete forms, very high or very low intake of red meat), the scientists came back with almost 550,000 samples with a 60/40 ratio of men to women respectively.  The researchers found that the higher the intake of red meat, mortality rates would increase modestly.  Conversely, with a higher white meat diet, there was a small decrease in total mortality.

There were some interesting correlations that the scientists also found.  For example, they found a positive association between smokers, or former smokers, and the intake of processed meats, as it relates to cancer.  They hypothesized that it could be due to the N-nitroso compounds and carcinogens found in cigarettes. 

The N-Nitroso compounds, as you may have guessed, are derived from nitrogen and are found in bacon, fermented sausage, hot dogs, bologna, salami, corned beef, ham, and other smoked or cured meat, fish, and poultry.  They are formed from nitrogen compounds (amines and amides) as bacteria break off the acid portion of amino acid compounds.  In chemistry terms, this is known as decarboxylation.

Prior studies have shown that cooked red meat intake can create chemicals that are not present in raw meat.  These chemicals are carcinogens.  This is due to the presence of heterocyclic amines and polycyclic aromatic hydrocarbons.  Easy enough to understand right?   

Heterocyclic amines (HCAs) are found in muscle meats such as beef, pork, fowl, and fish.  These compounds are formed at high temperatures as amino acids react with creatine, a chemical found in animal muscle tissue.  Four factors come into play when dealing with heterocyclic amines; type of food, cooking method, temperature, and time.  Of the four, temperature is the most important factor.  When cooking meats, the highest temperatures occur when we barbecue on a grill, broil in the oven, or fry in oil.  Oven roasting and baking are done at lower temperatures so the formation of HCA’s is less  Cooking meats low and slow and as a friend told me, with its best days before it (instead of well done), may be the best bet for someone who is concerned about HCA formation.  Also, take it easy on the drippings on the bottom of the pan as that gravy contains substantial amounts of HCA’s as well.  

Polycyclic aromatic hydrocarbons (PAH’s) are found on the surface of meat after cooking it at high temperatures.  They are also present due to incomplete burning of coal, oil and gas, garbage, or other organic substances like tobacco.  These compounds are more prevalent when grilling whereas the heterocyclic amines usually form when pan fried.

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.

History and Origin

Gouda is a semi-soft cheese made primarily from cow’s milk and is named from the town of its origin in the South Holland region of the Netherlands.  In researching the origin of Gouda, some say that it dates back to 1697.  Farmers from the region would bring their cheese to the market and eventually, the cheese adopted the name from which it came.  

How Gouda is Made

The cow’s milk is cultured and heated until the curd is separated from the whey.  Curd is the part of milk that coagulates as seen when putting sour milk into a cup of coffee.  The whey or milk plasma is the liquid portion leftover after the curd has been strained.  The curd is then “washed” by adding hot water.  This separates out more whey from the curd.  The resulting mixture is pressed into circular moulds and soaked in a brine solution.  Eventually, a rind will form.  After soaking, the cheese is dried then coated to prevent dehydration and then allowed to ripen.

Taste

A very complex tasting cheese, Gouda meshes salty, sweet, sour, bitter, and umami (meaty or savory) flavors all in one tasty bite.  It also exhibits a fifth and not well-known flavor profile described as having mouthfullness, thickness, and a complex body.  This flabor profile is due to the presence of what are called Kokumi compounds.

Kokumi Sensation

Termed by the Japanese, Kokumi compounds generate the Kokumi sensation, which is a Japanese word used to describe deliciousness.  More succintly, it describes the continuity and roundness of a particular food.  Scientists in Munich, Germany, in a recent journal article from the Journal of Agricultural and Food Chemistry were seeking to unlock the flavor secrets of these compounds as it relates to Gouda cheese.

To start, the scientists chose two Gouda subjects of different ripeness; a 44-week and a 4-week cheese .  Their goal was to understand and apply biological principles that give rise to Gouda’s unique flavors by separating components and attempting to recombine them synthetically.  The results of the synthetically re-combined product was measured against the original components in natural Gouda.  They did this by focusing on the small-molecule metabolite profiles recognized by our taste sensors.

Senses

The four sensory tastes (bitterness, sweetness, sourness, and umami) were recognized previously in different studies of cheese.  Calcium and magnesium chloride were found to give rise to bitterness along with amino acids.  Lactic acid and hydrogen phosphate brought out a sour taste.  Sodium chloride and sodium phosphate were culpable for the salty sensation.  Lastly, Unami, the meaty or savory sensation was a result of monosodium L-glutamate and sodium lactate.

Results

The scientists found that tasters preferred and noticed a more pronounced mouthfullness, thickness, and a complex body in the natural 44-week subject more than the artificial re-combinant.  This lead scientists to believe that the Kokumi compounds and subsequent sensation are generated through the ripening process and that re-creating that taste may be a difficult endeavour.  In any event, to get the full Gouda flavor, for now, your best bet is to visit your local cheese shop.

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