LACTOSE INTOLERANCE: A CONDITION WHERE SOME OF US CANNOT DIGEST MILK PROPERLY

INTRODUCTION

In the society we live in, basically every food contains milk, albeit, at varying amounts. A great percentage of us love milk too. We take it in our coffees, our milks, our cereals and we even love to drink it on its own on a daily basis.

Unfortunately, just as a great percent of us like milk, a great percentage of us cannot properly digest milk either. At this point, you may go like duhhh who takes even milk for proper digestive purposes but how do you think those regular stomach disturbances like diarrhea, flatulence (farting) and bloating occur ? could it be your veggies or your red met diets ? well, no. It is your precious milk and I’m about to show you how.

Lactose is a sugar, a dissaccharide to say the least (Disaccharides are sugars composed of two simple sugars or monosaccharides), that is present majorly in milk. The body utilizes sugars in their simplest forms. The commonest simple sugars are; Glucose, fructose and galactose. For some reason, the body prefers to utilize sugars in the form of glucose. This implies that every carbohydrate has to be broken down or/and converted to glucose by one way or the other. Like I earlier said if you have been following closely, lactose is made up of two sugars and so what does that imply ? Yes you got it. It needs to be broken down.

Breakdown of sugars does not just occur by abracadabra or uttering magical words like “break sesame” (you see what I did there). This is where vital biological components known as “enzymes” come in. Enzymes are basically proteins (not entirely correct but I would choose not to complicate this) that help in speeding up chemical reactions and also remain unchanged at the end of these reactions. For lactose, an enzyme “lactase” is required to break it down to its monosaccharide components (glucose and galactose).

WHAT EXACTLY IS LACTOSE INTOLERANCE (LI) AND WHAT CAUSES IT ?

Lactose intolerance is a condition where the body cannot properly utilize milk due to its inability to breakdown lactose, a sugar present in milk. The primary cause of lactose intolerance is deficiency of an enzyme known as lactase. Lactase aids in the breakdown of lactose to glucose and galactose for easy utilization by the body. Individuals who lack this enzyme experience gastrointestinal complications after ingesting milk. Complications vary in individuals as some may just feel it slightly while others would wish they were rather dead.

PATHOPHYSIOLOGY OF LACTOSE INTOLERANCE:

The importance of proteins in the body cannot be overemphasised. It is particularly interesting to note that while other biomolecules (carbohydrates, lipids, nucleic acids) are produced by special pathways controlled by enzymes (which are proteins), proteins are produced by passage of information directly from DNA to RNA and finally, to the protein of intent.

What this means is that a silent mutation in a gene that controls an enzyme (say hexokinase) necessary for the glycolytic pathway (pathway necsassary for glucose production) may not really have a huge effect on glucose itself as glucose production will still continue anyway albeit through alternative pathways, but the enzyme which is glucokinase is affected largely and thus its function is altered. Pregnant pause, I should abort this mission with all these jargons but you’ll find this interesting soon.

A gene known as the LCT gene controls the production of lactase. This gene has a regulator (like an off/on switch) known as the MCM6 (not ManCrushMonday please but mini-michrosome maintenace) gene that determines when the LCT gene is on and off. When the LCT gene is on, lactase (the enzyme necessary for breaking down lactose) is produced and the reverse is the case when it is off.

The LCT gene is supposed to go off regularly when lactase requirement has been met but in recent years, through a process of natural selection, some individuals have developed a mutant form of the MCM6 gene which always causes the LCT gene to stay on at all times and these individuals stay producing lactase. These individuals are considered lactase persistent. In lactose intolerant individuals, the LCT gene stays off so lactase isn’t produced and lactose isn’t broken down.

LACTOSE INTOLERANCE MAY OCCUR DUE TO A NUMBER OF REASONS
Lactose intolerance differs quite much in individuals. Certain individuals may have never synthesised lactase from birth (Congenital lactose intolerance), some may have stopped producing lactase at late childhood or early adulthood (Primary lactose intolerance) and finally, some may be due to complications (ulcerative colitis, celiac disease etc) to the small intestine where lactase is produced and thus, leading to a lactase deficiency.

HOW DO YOU KNOW YOU ARE LACTOSE INTOLERANT ?

This is not so easy to know but a handful of symptoms present in cases of lactose intolerance. Diarrhoea is seen to occur. Vomiting and flatulence are also major symptoms. Bloating and nausea are also less common symptoms. The symptoms highlighted above could be due to anything so you cannot conclusively say one has lactose intolerance even after milk digestion just because they started vomiting profusely. More specific diagnostic tests are required. Ill simply highlight them below and also tell you why those tests are possible.

1. Breath Test:
   This is the most popular test for lactose intolerance and basically measures the amount of hydrogen in your breath. Pure lactose is ingested and this test is carried out not less than 30 minutes after. The hydrogen in breath will occur due to the utilization of lactose by bacteria in the colon (long intestine). Lactose will only get to the colon if it is not utilized in the small intestine. Colonic bacteria utilize lactose and produce hydrogen as well as other gases in exchange.

2. Testing of the blood:
   Your blood glucose level is taken before and after ingestion of a lactose meal. If your blood glucose level stays the same, it means lactose has not been broken down and well, your guess is as good as mine.

3. Stool test:
   Colonic bacteria as I earlier stated produces certain gases on utilizing lactose. One of such gases is methane and can be tested for in stool. Individuals with lactose intolerance tend to have more acidic stools due to the presence of methane and hydrogen which are acidic gases.
   The above are the three most common means of diagnosis. The less common ones can be see here

HOW CAN THIS BE MANAGED ?

Sadly, like almost any other disease out there, Lactose intolerance has no cure but it can be properly managed. Avoiding milk is the first option in managing this but milk is a rich source of certain vitamins and calcium so one might be scared of getting deficiencies. Alternative sources for these vitamins can be explored and used like broccoli, collard greens, bone marrow meals, egg yolks. These foods can serve as an alternative source of vitamins and calcium in individuals who need to avoid dairy products. Lactose-free milk can also be consumed. Lactase supplements are on the radar of recent though not being approved yet but it offers serious prospects in the management of lactose intolerance.

CONCLUSION

Lactose intolerance has a global prevalence of 75 to 90% 1 so its literally everyone’s problem. Maintaining a healthy lifestyle by dieting most especially can help in reducing the complications associated with this condition.

What are your thoughts on lactose intolerance ? Could you live with avoiding dairy products totally if you someday found out you were lactose intolerant ? Please feel free to make my comment box an avenue for healthy discussions.

THANKS A LOT FOR READING !!!!

REFERENCES
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IMAGE SOURCES
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