Relation between dairy food intake and cognitive function: The Maine-Syracuse Longitudinal Study

• G.E. Crichton 
• M.F. Elias 
• G.A. Dore 
• M.A. Robbins 
• a Nutritional Physiology Research Centre, University of South Australia, Adelaide 5001, Australia
• b Department of Psychology, University of Maine, Orono, ME, USA
• c Graduate School of Biomedical Sciences, University of Maine, Orono, ME, USA

Volume 22, Issue 1, January 2012, Pages 15–23

http://www.sciencedirect.com/science/article/pii/S0958694611001956 

 Serenoa, thanks.  I hadn't made the connection between dairy products and glycine.  The list of high-glycine foods that I'd looked at hadn't listed milk, but I now see you're right that dairy products do contain glycine:

http://wholefoodcatalog.info/nutrient/glycine/milks/ 

And here's the glycine content of a variety of other foods.  Gelatin, by the way, is said to be unusually high in glycine:

http://wholefoodcatalog.info/nutrient/glycine/foods/ 

The studies on milk (and other dairy products) and Alzheimer's disease are all over the place.  Omega 3 fatty acids, vitamin B12, and glycine in milk may help explain the beneficial aspects, while methionine (which increases homocysteine levels) may largely explain the negative aspects. 

https://docs.google.com/viewer?a=v&q=cache:6QvyQp4s6d8J:www.gordonwaynewatts.com/theology/HEALTH-DIET-Folder/zzzzz-Milk-And-Alzheimers.doc+milk+alzheimer's+disease&hl=en&gl=us&pid=bl&srcid=ADGEESjLtXbt8Wr-nfZjd7YS1zBI0-ejuCn7nB1DR-K9Gq4MjLIiauQ_jyqm8nyCO70rQrIDRmgI0FUnsC4KbJrzJVqL-vLLCNMK1LfSW7LI2DwszuokxuaUgHJRNITpXqFJiN95dGTb&sig=AHIEtbSEr1Cn2ZicFBwu3UE3KtZC4jSmmQ 

As usual, more studies are necessary. 

 Thanks for the input, Lane.

I suspect that the Vitamin D content of milk may play a significant role.

Higher Vitamin D Dietary Intake Is Associated With Lower Risk of Alzheimer’s Disease: A 7-Year Follow-up

http://biomedgerontology.oxfordjournals.org/content/early/2012/04/13/gerona.gls107.short 

And - the possibly beneficial effects of low-fat dairy vs. the possibly harmful effects of high-fat dairy may help to explain some of the varying results in the dairy studies.  Here are a couple of quotes that might help our understanding:

"Poorer cognitive function and an increased risk of vascular dementia (VaD) were found to be associated with a lower consumption of milk or dairy products. However, the consumption of whole-fat dairy products may be associated with cognitive decline in the elderly."

http://www.expert-reviews.com/doi/abs/10.1586/ern.11.56?journalCode=ern

 

Breakthroughs in Alzheimer Research

... Scientists at ICAD 2009 reported that following the Dietary Approaches to Stop Hypertension diet – or DASH diet – was associated with higher scores for cognitive functioning. The researchers found that four food categories from the diet plan – whole grains, vegetables, low-fat dairy foods, and nuts and beans – may offer benefits for cognition in late life. We need more research before we can confidently say how much of these foods to include in one’s diet to experience some benefit.

http://www.alz.org/pa/documents/alz-annualreport09.pdf 

I think you are right, Onward.  Vitamin D in milk also would help explain the beneficial aspects of milk in reducing the risk for Alzheimer's disease.  I think that I have posted this information about Vitamin D before, but it is worth posting here again. 

Sunshine and Vitamin-D helps to Eliminate Mercury

Accumulating data have provided evidence that vitamin D is involved in brain function. Vitamin D can inhibit the synthesis of inducible nitric oxide synthase and increase glutathione levels, suggesting a role for the hormone in brain detoxification.

The study shows that vitamin D helps remove mercury from your body safely by radically increasing the amount of intracellular glutathione.

Neuroprotective and immunomodulatory effects of this hormone have also been described in several experimental models, indicating the potential value of vitamin D in helping neurodegenerative and neuroimmune diseases. In addition, vitamin D induces glioma cell death, making the hormone of potential interest in the management of brain tumors.

These results reveal previously unsuspected roles for vitamin D in brain function and suggest possible areas of future research.
Sources:

* Trends in Endocrinology and Metabolism April 2002,Volume 13, Issue 3, 1, Pages
100-105 

http://www.healthysavannah.com/VitD.html 

Good point, too, about the value of low-fat dairy products. 

"There are two sources of vitamin D, it is made in the skin by exposure to sunlight and there are a few dietary sources, such as oily fish, eggs, and fortified foods including margarine (which is required by law to contain vitamin D), some yogurts and breakfast cereals. There is very little vitamin D in milk and in fact only trace amounts and in the UK milk is not fortified with vitamin D."

http://www.milk.co.uk/page.aspx?intPageID=71 

Vitamin D (Cholecalciferol) is produced photochemically in the skin from 7-dehydrocholesterol.

This vitamin is responsible for absorption of calcium and phosphate. Calcium and phosphate level is also regulated by parathyroid hormone (PTH), parathormone or parathyrin (takes calcium from bones when vitamin D level is low – osteoporosis, osteomalacia). 

 Hi, Tom(ek).  You're certainly right that milk usually doesn't have a whole lot of vitamin D.  But still, since vitamin D is so hard to find in foods, and since most people seldom eat the few foods with the most vit. D, fortified milk is usually listed as one of the better sources, I think.

Just checked the 2 different kinds of milk we have in our refrigerator.  Per cup, each has just 25% of the daily recommended value of vit. D.  Which is not much.  Not nearly enough, I agree.

The top 6 food sources of Vit. D, according to one chart I saw, are:

cod liver oil
swordfish
salmon
tuna

fortified orange juice
fortified milk

Hi Onward, I'm not sure what is the daily recommended amount of vitamin D3 now but you can tell me how many micrograms or IU is that 25%.

IU - International Unit

1000 IU  - 25 micrograms
400 IU - 10 micrograms

"The new recommended daily allowance (RDA), as set in 2010, is based on age, as follows: for those 1-70 years of age, 600 IU daily; for those 71 years and older, 800 IU daily; and for pregnant and lactating women, 600 IU daily."

http://www.mayoclinic.com/health/vitamin-d/NS_patient-vitamind/DSECTION=dosing

Tom(ek), thanks for all the information.

I wish that the milk cartons would list exactly how much of each nutrient is in each serving of milk.  Instead they just tell you what percent of the recommended daily value is in each serving.  Yet the recommended daily values vary according to age group, as you pointed out.  So it's a bit confusing. 

Here's what one website says:

The Vitamin D content of foods rich in Vitamin D is below. All are in IU.

• Milk
  • Human milk – 22/L
  • Infant formula – 62/100 kcal, usually 5 ounces
  • Cow’s milk, fortified – 100/8 ounces
  • Soy milk – may or may not be Vitamin D fortified, usually 100/8 ounces
  • Rice milk – may or may not be Vitamin D fortified, usually 100/8 ounces
  • Other foods made with milk or soy may or may not be fortified such as yogurt, pudding, tofu, etc.
   
• Cereals, fortified – 40-50/8 ounces
• Egg yolk – 21
• Fish and Shellfish (3 ounces)
  • Catfish – 425
  • Halibut – 510
  • Herring – 1383
  • Oyster – 272
  • Mackerel – 213
  • Pink salmon – 530
  • Sardine – 231
  • Shrimp – 129
  • Tuna – 200
   
• Cod liver oil – 450 / teaspoon
• Shiitake mushrooms – 249 per 4
• Orange juice, fortified -100/8 ounces