60% Of Adults Can’t Digest Milk

This article from the USA Today is so good I am quoting all of it. The bolding is mine.

This may be significant, in my non-expert opinion, because some scientists believe that improperly digested lactose makes galactose build up in the blood, damaging the ovaries and may lead to ovarian cancer.

This is worse with cottage cheese and yogurt since these products contain more galactose. A 1989 study showed that women who ate a lot of dairy products, particularly yogurt and cottage cheese, had triple the risk for ovarian cancer.

The study was run by Dr. Cramer of Harvard, involved hundreds of women and a control group.

Cramer, D.W. and others, 1989. Galactose consumption and metabolism in
relation to the risk of ovarian cancer. Lancet 2, 66 – 71.

Got milk? If you do, take a moment to ponder the true oddness of being able to drink milk after you’re a baby.

No other species but humans can. And most humans can’t either.

The long lists of food allergies some people claim to have can make it seem as if they’re just finicky eaters trying to rationalize likes and dislikes. Not so. Eggs, peanuts, tree nuts, fish, shellfish soy and gluten all can wreak havoc on the immune system of allergic individuals, even causing a deadly reaction called anaphylaxis.

But those allergic reactions are relatively rare, affecting an estimated 4% of adults.

Milk’s different.

There are people who have true milk allergies that can cause deadly reactions. But most people who have bad reactions to milk aren’t actually allergic to it, in that it’s not their immune system that’s responding to the milk

Instead, people who are lactose intolerant can’t digest the main sugar —lactose— found in milk. In normal humans, the enzyme that does so —lactase— stops being produced when the person is between two and five years old. The undigested sugars end up in the colon, where they begin to ferment, producing gas that can cause cramping, bloating, nausea, flatulence and diarrhea.

If you’re American or European it’s hard to realize this, but being able to digest milk as an adult is one weird genetic adaptation.

It’s not normal. Somewhat less than 40% of people in the world retain the ability to digest lactose after childhood. The numbers are often given as close to 0% of Native Americans, 5% of Asians, 25% of African and Caribbean peoples, 50% of Mediterranean peoples and 90% of northern Europeans. Sweden has one of the world’s highest percentages of lactase tolerant people.

Being able to digest milk is so strange that scientists say we shouldn’t really call lactose intolerance a disease, because that presumes it’s abnormal. Instead, they call it lactase persistence, indicating what’s really weird is the ability to continue to drink milk.

There’s been a lot of research over the past decade looking at the genetic mutation that allows this subset of humanity to stay milk drinkers into adulthood.

A long-held theory was that the mutation showed up first in Northern Europe, where people got less vitamin D from the sun and therefore did better if they could also get the crucial hormone (it’s not really a vitamin at all) from milk.

But now a group at University College London has shown that the mutation actually appeared about 7,500 years ago in dairy farmers who lived in a region between the central Balkans and central Europe, in what was known as the Funnel Beaker culture.

The paper was published this week in PLoS Computational Biology.

The researchers used a computer to model the spread of lactase persistence, dairy farming, other food gathering practices and genes in Europe.

Today, the highest proportion of people with lactase persistence live in Northwest Europe, especially the Netherlands, Ireland and Scandinavia. But the computer model suggests that dairy farmers carrying this gene variant probably originated in central Europe and then spread more widely and rapidly than non-dairying groups.

Author Mark Thomas of University College London’s dept of Genetics, Evolution and Environment says: “In Europe, a single genetic change…is strongly associated with lactase persistence and appears to have given people with it a big survival advantage.”

The European mutation is different from several lactase persistence genes associated with small populations of African peoples who historically have been cattle herders.

Researchers at the University of Maryland identified one such mutation among Nilo-Saharan-speaking peoples in Kenya and Tanzania. That mutation seems to have arisen between 2,700 to 6,800 years ago. Two other mutations have been found among the Beja people of northeastern Sudan and tribes of the same language family in northern Kenya.

Calcium alone may not prevent osteoporosis

I’ve read several of Dr. Andrew Weil’s books. I don’t agree with everything he has to say, but I like to read his opinions as they seem less biased. Dr. Andrew Weil is a medical doctor (M.D.) and popular health writer with an interest in alternative medicine. Dr. Weil is just as likely to endorse a conventional medical treatment as give a positive ( or negative ) review of an alternative treatment.

Here is what he has to say about the possible under reporting of osteoporosis in Asia and why that shouldn’t be taken as indicator that much lowers calcium intakes aren’t safe.

In a number of countries, including Japan, India, and Peru, the average daily calcium intake is very low, only 300 mg. That’s considerably less than the daily total of 1,000 mg recommended for adults between the ages of 19 and 50 and 1,200 mg recommended for those over 50 in the U.S., yet the incidence of bone fractures in these countries reportedly has been very low. The difference has been attributed to the level of physical activity people perform as well as the amount of incident sunlight in those countries. However, it is also believed that osteoporosis has been under-diagnosed and under-treated in Asia, which may explain why this condition appears to occur so much less frequently in these populations than in the U.S. and other western nations. That may be changing. The International Osteoporosis Foundation (IOF) projects that by 2050 about 50 percent of all osteoporotic hip fractures will occur in Asia.

In the article Dr. Weil goes on to describe the other things that need to be done to prevent osteoporosis too.  These includes exercise, reducing excessive caffeine intake, getting enough vitamin D, getting enough vitamin K, and getting enough vitamin A.   It is not just about calcium only.  Dr. Weil does recommend calcium supplements.

Get your levels tested, get outside in the sun, eat orange vegetables and eat the proper green vegetables !

 

Absorbing Calcium

Chinese Flower Cabbage aka “Choy Sum” aka Brassica rapa var. The leafy green with the most calcium.

Many vegetables are actually better for preventing bone loss than cow’s milk. Preventing osteoporosis is about more than calcium intake. It is also about calcium absorption and the calcium in many vegetables is more absorbable than calcium from cow’s milk. A number of vegetables also have more calcium per calorie than dairy milk and vegetables have other nutrients for bone health that dairy milk does not.

Brenda Davis RD, is a coauthor of the American Dietetic Association’s Position Paper On Vegetarianism. She is also a vegan and a nutrition book author. Her revised edition of “Becoming Vegetarian” has an excellent chart of calcium from various foods and how much you can expect to absorb. Note. Davis’ chart listed the rates of absorption for vegetables per half cup. The rates may not be the same in different amounts. Highlights from page 103:

Cow’s Milk
1 cup – 300 mg – 32% absorbed, 96 mg net

Chinese Cabbage Flower Leaves, cooked
( aka “choy sum”, Brassica rapa var. parachinensis)
1 cup – 478 mg – 40% absorbed, 192 mg net

*Chinese* Mustard Greens, cooked
1 cup – 424 mg – 40% absorbed, 170 net

Turnip Greens, cooked
1 cup – 198 mg – 52% absorbed, 102 mg net

Bok Choy, cooked
1 cup – 158 mg – 53% absorbed, 84 mg net

Mustard Greens, cooked
1 cup – 128 mg – 58% absorbed, 74 mg net

Kale, cooked ( scotch kale has much more )
1 cup – 122 mg – 49% absorbed, 60 mg net

White Beans, cooked
1 cup – 226 mg – 22% absorbed, 50 mg net

Broccoli, cooked
1 cup – 70 mg – 61% absorbed, 42 mg net

Sesame seeds, without hulls
1 ounce – 37 mg – 21% absorbed, 8 mg net

Tofu, made with a calcium based coagulant
1 cup – 516 mg – 31% absorbed, 160 mg net

Warning: not all vegetables are a good sources of calcium.

Some vegetables have a lot of calcium, but also a lot of oxalic acid which binds up the calcium so people can’t absorb it. Vegetables that are healthy to eat, but that are poor calcium sources are spinach, rhubarb, swiss chard and beet greens.

Spinach, cooked
1 cup 230 mg – 5% absorbed, 12 mg net

Rhubarb, cooked
1 cup 348 mg – 8.5% absorbed, 30 mg net

Lettuce too. Lettuce is low in oxalic acid and has a lot of nutrition per calorie but lettuce is so low calorie the amount you would have to eat to get a significant amount of nutrition is impractical.

1 cup of shredded raw romaine lettuce will only provides 15 mg of calcium gross, without taking amount absorbed into consideration.

I couldn’t find any information about absorbability for collard greens. The USDA online nutrition database lists that 1 cup of cooked, chopped collard greens has 266 mgs of calcium.

Krause’s Food, Nutrition, & Diet Therapy textbook (2000) lists the following amount of oxalates per 100 g:

Spinach (boiled) 750 mg
Collards 74 mg
Kale 13 mg

In other words, without a figure for the absorbability of the calcium in collard greens and assuming that oxalates are the only impediment it looks like collard greens are still a decent calcium source.

I couldn’t find any information about the absorbability of calcium from butternut squash, but that squash does have 84 mg of calcium per 1 cooked cup.