Health benefits of lactic acid bacteria in fermented milk

Lactic acid bacteria do more than just pre-digest lactose and produce yogurt. Back in the early 1900s, the Russian immunologist Ilya Metchnikov proposed that lactic acid bacteria in fermented milks help eliminate toxic microbes in our digestive system. To support Mr. Metchnikov’s prescient claim, research in recent decades suggests that Bifidobacteria, fostered in breast milk, colonizes the infant intestine and keep it healthy through acidification and production of antibacterial substances. Once the infant is weaned, the Bifidobacteria recede in favor of a mixed population of Streptococcus, Staphylococcus, E. coli, and yeasts.

Bacteria such as L. fermentum, L. casei, L. brevis, and L. acidophilus adhere to the human intestinal wall. Their presence shields it from other microbes by the secretion of antibacterial compounds, and by boosting the immune response to infection. Furthermore, research suggests that these bacteria also dismantle cholesterol and reduce the production of carcinogens.

The consumption of fermented milks for health purposes, however, is debatable. At the time of Mr. Metchnikov’s claim, milk fermentation involved a dozen or more microbes. Industrial versions nowadays usually limit it to two or three. This biological narrowing does not only affect flavor and consistency, but its health value as well. In addition, live cultures in industrial buttermilk and yogurt grow well in milk but cannot survive in the human body. Some manufacturers are adding "probiotic" Lactobacilli and Bifidobacteria to their cultured milk products in an attempt to mimic the original fermented milks. Such products are advertised for the health benefits afore noted.

Sugars and Health

Empty calories
The concentration of calories in sugar is only second to fats and oils. The cautionary advise against consuming too much sugar derives from ingesting too many calories and displacing nutritious food with "empty calories.". Refined sugars are devoid of vitamins, minerals, and other nutritients that are important in a healthy diet.

Tooth decay

Certain kinds of Streptococcus colonize the mouth. The bacteria convert sugars into "plaque" carbohydrates, which anchor them to the teeth and form a protective layer. In addition, they also produce defensive acids that damage tooth enamel and lead to tooth decay.

(Interestingly, phenolic compounds such as are found in chocolate and tea interfere with the adhesion of bacteria to the teeth.)

Blood glucose

The body uses glucose as its primary source of energy. However, glucose is a highly reactive molecule. In excessive quantities, it can damage the eyes, kidneys, and both nervous and circulatory systems. The body controls glucose by removing it promptly from the blood via insulin, which helps distribute it to tissues for energy or storage. Intake of sugar overload stresses the insulin system. Diabetes may result from such strain.

Glycemic Index

Food varies in its content of sugars. The glycemic index measures how much a given food raises glucose levels. The foods that raise blood glucose level the most are ones rich in glucose such as rice, potatoes, and other starchy foods. Table sugar has a slightly lower glycemic index as it is a combination of glucose and fructose. Foods containing fructose have much lower glycemic indeces because fructose has to metabolize through the liver before it becomes available as a source of energy.

Chocolate and Health

Cocoa beans are like other seeds in that they contain high amounts of saturated fats, used in the plant to support the embryo until it sprouts roots and leaves. However, the fat content can be compared to that of avocados or olive oil. Much of the fat in cocoa butter is stearic acid, which is quickly converted into oleic acid, an unsaturated fatty acid.

Chocolate consumption is believed to reduce the risk of heart disease in the way that red wine flavanols do. Cocoa particles are a rich source of antioxidant phenolic compounds, which prevent fat-like substances such as LDL (Low Density Lipoproteins) from oxidizing and clogging arteries. Added sugar or milk dilutes the cocoa solids and their phenolics. The dutching process also reduces phenolics in cocoa. Milk proteins bind phenolics and prevent us from absorbing them. Therefore, the type and quality of chocolate consumed matters in relation to its effects on heart health.

There is no link established for the consumption of chocolate and acne. Chocolate is not a causative agent for acne, nor does it have any effect on acne. It does not worsen a condition or make it better. Acne is more likely to be affected by stress level and hormones than diet.

Chocolate is not responsible for cavities. The high-sugar content in some chocolate is more likely to be the culprit than the cocoa parts. In fact, cocoa butter has been used to coat teeth and prevent plaque formation.

Eating chocolate may have some psychological benefits as discussed in the section Chocolate and the Brain.

Chocolate toxicity in dogs - theobromine

Theobromine is the compound in chocolate responsible for chocolate toxicity in dogs. Dogs metabolize theobromine very slowly in comparison to humans. The half life of theobromine is 17.5 hrs in dogs compared to 3 hrs in humans. Lethal toxicity in dogs is noted as 100-150 mg of theobromine per kg of body weight in dogs, though its toxic effects can be observed at much lower concentrations.

There are variables to take into account when dealing with chocolate/theobromine toxicity.

The weight of the dog.

Smaller dogs are many times more susceptible to toxicity. The ratio of mg/kg is much higher. Dogs are gorgers. Small dogs may have less body mass and weight, but can consume high amounts of chocolate if readily available.

The theobromine content in the chocolate eaten

The same amount of baker's chocolate is potentially more lethal than milk chocolate due to the content of cocoa solids. The more diluted the cocoa content in a chocolate product, the lesser the threat. This does not mean that it is ok to give dogs small amounts of chocolate. Even small amounts can lead to toxicity, even if it is not lethal. Dogs will suffer vomiting and diarreah after eating small amounts of chocolate as their body attempts to prevent further theobromine absorbtion. White chocolate is not dangerous since it does not contain theobromine. 

Beware of cocoa shell mulches used in landscaping. Cocoa shells naturally contain theobromine. Manufacturers often strip theobromine from the mulch, but not always. Check for content if your pet likes to eat the mulch.

So what happens when a dog consumes chocolate?

Theobromine stimulates the Central Nervous System (CNS). The dog shows signs of hyperactivity and restlessness, increased urine output, and irregular heartbeat. According to the Merck Veterinary Manual, Methylxanthines like theobromine increase intracellular calcium levels that lead to increased strength and contractility of skeletal and cardiac muscle. They compete for receptors in the CNS and inhibit esterases that result in increased cyclic AMP levels. They also increase circulating levels of epinephrine and norepinephrine. In severe cases, these chemical changes cause dogs to have tremors and seizures, hypertension, increased body temperature, and difficulty breathing. Coma and death may also result.

Other species are also susceptible to theobromine including cats and rabbits. However, other species are less prone to consume chocolate. Seek veterinary care immediately if you suspect your pet has ingested chocolate.

Chocolate and the Brain

Eating chocolate has long been associated with a feeling of well-being, alertness, and satisfaction. Researchers have identified some key components in chocolate that account for the emotions of eating chocolate.

Anandamide

Anandamide is a naturally-occurring neurotransmitter molecule synthesized in areas of the human brain important in enforcing and breaking short term neural connections. Its role is important in memory, higher thought processes, movement control, and forgetfulness. Anandamide binds to the so-called "bliss" receptor. Its effects include dulling pain and inducing an overall feeling of well-being. Unfortunately for humans, anandamide is a fragile molecule which breaks down easily.

Researchers have isolated at least three compounds in chocolate that strongly resemble anandamide. Those compounds are able to bind to the bliss receptor and produce effects similar to those of anandamide. Furthermore, they have also found in chocolate numerous other compounds that inhibit anandamide breakdown. According to the research of Daniele Piomelli and Emmanuelle diTomaso, chocolate has "pharmalogically-active substances that...may be responsible for certain drug-induced psychoses associated with chocolate craving."

Theobromine

According to xocoatl.org, the often-quoted caffeine content of chocolate is a myth. The stimulant effects often attributed to caffeine, are in fact, the effects of theobromine, which makes up about 1-2% of cocoa by weight.  Like caffeine, theobromine increases the activity of neurotransmitters responsible for increased attention and alertness. But unlike caffeine, theobromine is a much milder stimulant to the central nervous system and is not physiologically addictive. Theobromine also increases a sense of well-being as a mild anti-depressant. It is proven to be a cause of physical and mental relaxation. It stimulates the cardiovascular and  muscular systems. All in all, theobromine may be responsible for giving chocolate its aphrodisiac charactersitics.

Though chocolate contains trace amounts of cannabinoid and phenylethylamine chemicals, research has shown that there are no chemical properties that would cause a physical dependency. Craving chocolate and satisfying the crave has more to do with the sensory experience of consuming chocolate than meeting a  physiological need.

The following websites are good sources for more information on chocolate and its compounds:
http://antoine.frostburg.edu/chem/senese/101/features/anandamide.shtml
http://www.xocoatl.org/