Friday, November 28, 2008

Organic milk doesn't contain hormones.

A commonly-heard reason for buying organic or rbST-free milk is that it 'doesn't contain hormones'... or does it?

It's a commonly-heard perception, but one that's simply not accurate.

Firstly, all milk contains hormones. That applies whether it's from a cow, goat, sheep or even a human; whether the animal has been raised conventionally, on pasture or organically; and regardless of whether the animal has been given supplemental hormones (e.g. recombinant bovine somatotropin or rbST). Even soy 'milk' contains plant-based hormones.

Secondly, milk in the US is fortified with vitamin D to (very successfully) prevent rickets. Vitamin D is a steroid hormone that is absorbed in the small intestine.

Thirdly, there is no evidence to show that cows given supplemental rbST have an increased concentration of either naturally-occurring or recombinant bST in milk. rbST was approved by the FDA in 1993 as being safe both for animal use and for human consumption of the resulting dairy products, and has been available for producers to use since 1994. rbST is a protein hormone and is therefore digested in the stomach, producing amino acids that are absorbed in the small intestine. This means that it has no biological activity in humans. Furthermore, there is no test available to show whether bST in milk originated from the cow herself or from supplementation, and the levels of bST in milk samples is often too low to detect in the lab.

Finally, I refer you to a recent study by Vicini et al. (2008, Journal of the American Dietetic Association, vol 108) that investigated the nutritional and hormonal composition of milk from the 48 contiguous states labeled as conventional, rbST-free or organically produced. All milks sampled had similar nutritional contents (fat, protein, lactose etc) and both organic and conventional milks had the same bST content. Furthermore, estradiol contents were actually higher in organic and rbST-free milk than conventional milk.

Myth: Organic/rbST-free milk doesn't contain any hormones. BUSTED!

By Jude L. Capper

References: Vicini et al., 2008. JADA; 108: 1198-1203.

NEXT MYTH: Watch this space...

Sunday, November 23, 2008

Are dairy products bad for your health?

The American Medical Association and American Dietetic Association have both stated that saturated fat consumption leads to increased cholesterol levels and heart disease. Based on this, consumption of dairy products predisposes us to coronary heart disease.

Premature death from cardiovascular disease has fallen since the mid-1970s in the US and UK. However, saturated fatty acid intake has not changed. How can this be? We’ve been told that saturated fat consumption predisposes us to coronary heart disease (CHD).

The recommendations to reduce the amount of saturated fat consumptions are based on the relationship between dietary intake of saturated fat and their potential to increase cholesterol levels. But does saturated fat increase cholesterol? In a meta-analysis of 60 trials,saturated fat increased total cholesterol, LDL-cholesterol (the “bad” cholesterol) and HDL-cholesterol (the “good” cholesterol). However, the ratio of total cholesterol to HDL-cholesterol has been suggested to be one o f the best indicators of CHD risk; and this ratio was slightly elevated with saturated fat consumption. Thus, consumption of saturated fats increases the good cholesterol, which counteracts the bad cholesterol, resulting in no overall negative effect.

What about dairy products though?

Cow’s milk is 3 to 4% fat, which is 60% saturated fat, 25% cis-monounsaturated fat, 2% trans-monounsaturated fat, and the remainder is poly-unsaturated fat. The National Health and Nutrition Examination Survey (NHANES) looked at the effect of dairy consumption on blood lipids in adults. There was no effect of the number of servings of dairy products consumed per day (ranging from less than 1 to greater than 4.5) on total cholesterol, LDL-cholesterol (the “bad” cholesterol), HDL-cholesterol (the “good” cholesterol) or triglycerides. Additionally, in the meta-analysis mentioned above, cis-monounsaturated fat significantly decreased the ratio of total cholesterol to HDL-cholesterol, suggesting decreased CHD risk. All of the evidence shows that dairy products do not predispose us to heart disease.

Myth: Consumption of dairy products predisposes us to coronary heart disease. BUSTED!

By Robin R. Rastani

References: Mensink et al., 2003. Am. J. Clin. Nutr.; NHANES, 1999-2002.

NEXT MYTH: Organic milk doesn't contain hormones.... or does it?

Sunday, November 9, 2008

Should we all be vegans?

Activist groups like PETA often promote the message that we should all be vegan and that farm animals would be more healthy and happy if they were allowed to wander unfettered through sun-lit pastures rather than being farmed. Is this really the future that we want to see?

Ok. Let’s think about this from an animal welfare point-of-view. Leaving aside the increased risk of predation (coyotes killing sheep, foxes killing lambs, chickens as road-kill), there’s no doubt that animal health can be at risk in such an environment. Investigation of the recent avian flu outbreaks showed that the spread and prevalence of the disease was widespread among outdoor and backyard chicken flocks, with no disease found on farms where chickens were housed in barns. Allowing animals to wander free totally negates biosecurity, putting the entire US herd or flock at risk, especially when notifiable diseases such as avian flu or foot-and-mouth occur. While it’s nice to imagine ‘happy’ Holstein cows peacefully grazing lush spring pastures, what happens when that pasture is buried under 48 inches of snow, or is bare and brown after only 1 inch of rain has fallen in the past four months? More to the point, where’s this pasture going to come from? If a producer doesn’t need to use their land to produce animal feed, how long will it be before it’s covered with concrete and houses?

However, this brings me to my main point, the one that the idealistic vegans seem to miss: if we all went vegan tomorrow, there would be no farm animals. No cute little chickens for the kids to hand feed, no baby lambs to pet at farm days, no doe-eyed Jerseys for 4-H kids to raise and take care of… just a big pile of 9.2 million slaughtered dairy cows.

Welfare-friendly? I think not.

Myth..... BUSTED!

By Jude L. Capper

NEXT MYTH: The American Medical Association and American Dietetic Association have both stated that saturated fat consumption leads to increased cholesterol levels and heart disease. Does consumption of dairy products predispose us to heart disease?