Many humans are lactose-intolerant...?

Question

Many humans are lactose-intolerant, meaning they cannot digest milk products containing the disaccharide lactose. Hypothesize the reason behind lactose intolerance.

Answer 1

martians too.

Answer 2

The better question is how did some humans become lactose tolerant. Too be able to tolerate lactose as adults is a very recent evolutionary adaptation. When people moved to colder climates where food was hard to come by in winter, they developed a tolerance for milk from their animals. People who are not of Northern European descent tend to be lactose intolerant. The exception is the Masai who live in Kenya and Zimbabwe and use a lot of milk from their cattle.

Answer 3

Milk is not natural at all. Especially cow's milk. We might as well drink milk from dogs or monkeys, because they are more related to us, better yet other humans--it sounds gross only because it is different. We only drink cow milk because they make alot of it and I have read somewhere that its really not even that good of a source of calcium.

I became Lactose in tolerant about 2 weeks ago. I am 16, but I am wondering if the fact that I was kind of disgusted by milk after I read into how its bad, made me lactose in tolerant. All I know is that my stomach was hurting, and when I did number 2, it was like diarehea so I think the milk just came right out. I felt sick.

Anyways, I think it isnt natural for us in the first place to drink milk and I dont know why those that can drink milk can.... there body probably never stopped producing the enzymes, but I guess my body did..

I feel that lactose intolerance is natural because we were only meant to drink milk from our mothers and milk from cows is only drunk because they produce alot of it. I understand eating meat, but drinking another animals or species milk which is not very related at all is pretty unnatural and gross.

Answer 4

Check out http://en.wikipedia.org/wiki/Lactose_intolerance . This article suggests that it's normal for children to stop producing the enzyme to digest lactose as they grow, and that the ability to digest lactose well into adulthood may be a recent genetic change in some Europeans and other groups.

So, you can think about why it might be a beneficial trait for humans to continue to tolerate milk , especially once we started farming milk-producing animals.

Answer 5

Some causes of lactose intolerance are well known. Primary lactase deficiency is a condition that develops over time. After about age 2 the body begins to produce less lactase, though most people will not notice symptoms until they are much older.

Secondary lactase deficiency occurs when injury to the small intestine or certain digestive diseases reduce the amount of lactase a person produces. These diseases include celiac disease, inflammatory bowel disease, and Crohn’s disease.

Researchers have identified a genetic link for lactose intolerance. Some people are born with a likelihood of developing primary lactase deficiency because it has been passed to them genetically (inherited from their parents). This discovery may be useful in developing a diagnostic test to identify people with the condition.

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Who is at risk for lactose intolerance?
Between 30 and 50 million Americans are lactose intolerant and certain ethnic and racial populations are more affected than others. Up to 80 percent of African Americans, 80 to 100 percent of American Indians, and 90 to 100 percent of Asian Americans are lactose intolerant. The condition is least common among people of northern European descent.

Babies that are born prematurely are also more likely to be lactose intolerant, because lactase levels do not increase until the third trimester of a woman’s pregnancy.

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How is lactose intolerance treated?
Lactose intolerance is easy to treat. No treatment can improve the body’s ability to produce lactase, but symptoms can be controlled through diet.

Young children and infants with lactase deficiency should not consume lactose-containing formulas or foods until they are able to tolerate lactose digestion. Most older children and adults do not have to avoid lactose completely, but people differ in the amounts and types of foods they can handle. For example, one person may have symptoms after drinking a small glass of milk, while another can drink one glass but not two. Others may be able to manage ice cream and aged cheeses, such as cheddar and Swiss, but not other dairy products. People can also tolerate more lactose by having smaller amounts of it at one time. The level of dietary control needed with lactose intolerance depends on how much lactose a person’s body can handle.

For those who react to very small amounts of lactose or have trouble limiting their intake of foods that contain it, the lactase enzyme is available without a prescription to help people digest foods that contain lactose. The tablets are taken with the first bite of dairy food. Lactase enzyme is also available as a liquid. Adding a few drops of the enzyme makes lactose more digestible for people with lactose intolerance.

Lactose-reduced milk and other products are available at most supermarkets. The milk contains all of the nutrients found in regular milk and remains fresh for about the same length of time, or longer if it is super-pasteurized.

Answer 6

The gene for lactose intolerancy is not harmful in any way to the human population since dairy products are not necessary for our survival. By conincience, the gene became more and more popular and spread among the human population, causing no harm. This can happen with many other gene types too.

Answer 7

A hypothesis is just an idea that could explain the fact. So, any logical statement that might explain why many humans are lactose intolerate is a hypothesis. In science, you test a hypothesis. If it stands up to testing then it becomes a theory, else the hypothesis is rejected.

Answer 8

Rent the movie Snatch with Brad Pitt and that Transporter dude.

There is a scene toward the end of the movie where " Tommy" explains it.

Answer 9

we were never suppose to drink another mammal's milk..
its for baby cows not humans.