Category Archives: Dairy

Does Calcium Consumption Help Prevent Brittle Bones in Older Women?

Posted on September 25, 2019 | 3 comments

Waste of money and effort?

Due to a lack of milk products, paleo diets may not meet the Recommended Daily Intake of calcium. Your blood must have a certain amount of calcium, and if that level is too low, your bones donate calcium to the bloodstream.

Many physicians worry that inadequate calcium consumption causes or contributes to thin, brittle, easily breakable bones in postmenopausal women. A recent study suggests that calcium intake doesn’t matter.

Abstract

CONTEXT:

Calcium intakes are commonly lower than the recommended levels, and increasing calcium intake is often recommended for bone health.

OBJECTIVE:To determine the relationship between dietary calcium intake and rate of bone loss in older postmenopausal women.

PARTICIPANTS:

Analysis of observational data collected from a randomized controlled trial. Participants were osteopenic (hip T-scores between -1.0 and -2.5) women, aged >65 years, not receiving therapy for osteoporosis nor taking calcium supplements. Women from the total cohort (n = 1994) contributed data to the analysis of calcium intake and bone mineral density (BMD) at baseline, and women from the placebo group (n = 698) contributed data to the analysis of calcium intake and change in BMD. BMD and bone mineral content (BMC) of the spine, total hip, femoral neck, and total body were measured three times over 6 years.

RESULTS:

Mean calcium intake was 886 mg/day. Baseline BMDs were not related to quintile of calcium intake at any site, before or after adjustment for baseline age, height, weight, physical activity, alcohol intake, smoking status, and past hormone replacement use. There was no relationship between bone loss and quintile of calcium intake at any site, with or without adjustment for covariables. Total body bone balance (i.e., change in BMC) was unrelated to an individuals’ calcium intake (P = 0.99).

CONCLUSIONS:

Postmenopausal bone loss is unrelated to dietary calcium intake. This suggests that strategies to increase calcium intake are unlikely to impact the prevalence of and morbidity from postmenopausal osteoporosis.

Source: Dietary Calcium Intake and Bone Loss Over 6 Years in Osteopenic Postmenopausal Women. – PubMed – NCBI

Steve Parker, M.D.

PS: Elderly men get osteoporosis, too. But when the Emergency Department calls me to admit an older patient with a hip fracture, it’s a woman 9 out of 10 times.

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Posted in Dairy, Paleo Diet, Supplements

How Fast Are Humans Evolving?

Posted on April 28, 2015 | Comments Off on How Fast Are Humans Evolving?
paleo diet, Steve Parker MD,calcium, osteoporosis

I’m guessing she’s northern European, perhaps Irish

Most paleo lifestyle proponents think that, genetically speaking, those of us living today are pretty much the same as our ancestors living 50,000 or even 200,000 thousand years ago. That may not be the case.

Conventional Wisdom

The traditional view of the rate of human evolution’s is articulated by Artemis P. Simopoulos, who was with The Center for Genetics, Nutrition and Health in 2009 when he wrote: “The spontaneous mutation rate for nuclear DNA is estimated at 0.5% per million years. Therefore, over the past 10,000 years there has been time for very little change in our genes, perhaps 0.005%. In fact, our genes today are very similar to the genes of our ancestors during the Paleolithic period 40,000 years ago, at which time our genetic profile was established.”

Evolving Thought

 

On the other hand, the experts are debating now whether the pace of human evolution has accelerated over the last 10,000 years. The iconoclasts say it has. For example, remember that most mammals lose the ability to digest milk after they’ve been weaned off the teat in early life: they lose the lactase enzyme that allowed them to digest milk sugar (lactose). That’s why lactose intolerance is so common among adult humans—only a third of us worldwide can digest milk. Five or 10,000 years ago, a genetic mutation occurred that allowed those possessing the gene to consume and digest milk. So a whole new source of food for adults opened up: dairy cattle. Would that have conferred a survival advantage? You bet. We have evidence that the milk-digesting mutation spread fairly quickly since its appearance. But it hasn’t spread across the globe uniformly. The ability to digest milk in adulthood—called lactase persistence—is less than 40% in Greece and Turkey, but higher than 90% in the UK and Scandinavia.

Another oft-cited example of rapid and recent human evolution is the appearance and spread of blue eyes starting six to 10,000 years ago. Everyone with blue eyes today apparently has a common ancestor that had a gene mutation back then, when everybody had brown eyes.

For more information on the “rapid evolution” idea, check out the writings of Gregory Cochran, Henry Harpending, and John Hawks. Also consider a new book by Nicholas Wade, “A Troublesome Inheritance: Genes, Race, and Human History.” Wade is a science writer for the New York Times.

Steve Parker, M.D.

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Posted in Dairy, Evolution

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Only a Third of the World’s Adults Can Digest Milk

Posted on August 4, 2013 | 3 comments

Nature has in interesting article on Neolithic dairying, lactose intolerance, cheese, yogurt, and the spread of genes that allow for lactose digestion. The ability to digest milk in adulthood—called lactase persistence—is less than 40% in Greece and Turky, but higher than 90% in the UK and Scandinavia.

During the most recent ice age, milk was essentially a toxin to adults because — unlike children — they could not produce the lactase enzyme required to break down lactose, the main sugar in milk. But as farming started to replace hunting and gathering in the Middle East around 11,000 years ago, cattle herders learned how to reduce lactose in dairy products to tolerable levels by fermenting milk to make cheese or yogurt. Several thousand years later, a genetic mutation spread through Europe that gave people the ability to produce lactase — and drink milk — throughout their lives. That adaptation opened up a rich new source of nutrition that could have sustained communities when harvests failed.

Read the rest.

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Natural Selection and the Origin of Cheeses

Posted on October 20, 2011 | 1 comment

Vitruvius at The Sagacious Iconoclast explains why cheese is an unlikely Paleolithic (Old Stone Age) food:

I was recently involved in a discussion in which some folks were attempting to distinguish between what they were calling “processed” cheese and other (presumably non-processed) cheese, without defining what they mean by “processed” cheese. As I think that’s a less than optimal approach, I’d like to take a moment to sketch out why that is so; perhaps increasing, in the process, your enjoyment of cheese forever.

Neolithic Cheese

Vitruvius suggests one way prehistoric man could make cheese: “transport milk in mammal stomach vessels containing natural rennet, in the heat, thousands of years ago, and voila: curds and whey.”

It’s a moderately lengthy article, but well worth it for the amusement and erudition.  You’ll learn how cheese is made, starting with the photons.

Steve Parker, M.D.

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