Dairy Products Not Linked to Weight Loss Despite Lengthy Ad Campaign

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The National Dairy Council will soon end its advertising campaign

claiming that the consumption of dairy products is associated with

weight loss, the New York Times reported on May 11.

According to the Federal Trade Commission's Bureau of Consumer

Protection, the campaign will be suspended " until further research

provides stronger, more conclusive evidence of an association between

dairy consumption and weight loss. "

Indeed, the advertised claims made by the Dairy Council that three

servings of milk and other dairy products each day can lead to weight

loss are not supported by published, peer-reviewed research.

Last year, the British Journal of Nutrition reported a systematic

review and meta-analysis of the effects of calcium supplementation

and dairy consumption on body weight. The authors examined all

randomized controlled trials from several different scientific

databases dating from the earliest record in 1800 to May 2004. They

included studies that lasted 12 or more weeks with non-pregnant, non-

lactating individuals over 18 years old in which body weight was

measured at the end of the follow-up period.

The authors only included studies where the participants received

adequate calcium intake, to avoid possible confounding by calcium

deficiency in control groups. They also excluded studies of

populations with severe diseases that may have different calcium

needs than the average population. Ultimately the study included

thirteen trials that were then pooled and analyzed by calcium source

(either calcium supplementation, dairy or control).

After the initial analysis, calcium supplementation showed a positive

association with weight loss. Dairy sources showed no correlation

with weight loss. Interestingly, however, the association between

calcium supplementation and weight loss was eliminated when the

authors controlled for initial body weight. The authors suggest that

there could be a systematic problem with randomization procedures in

trials where calcium supplementation is used as an intervention.

In other words, people who were given calcium supplementation weighed

less than people who did not receive supplementation before the study

even started. After appropriate adjustments were made, no association

was found between calcium from any source (including dairy) and

weight loss.

The authors conclude that calcium supplementation and dairy provide

no additional benefits for individuals trying to lose weight. These

findings agree with a less extensive review that was completed in

2003.

It is important to note that the authors make the assumption that

adequate calcium levels are necessary for proper health, which should

always be maintained. Moreover, a study published this month in the

American Journal of Clinical Nutrition states that most Americans are

not meeting the current FDA recommendation of 1,000 mg of calcium per

day. This suggests that consuming calcium from dairy sources may be

beneficial to many people, but not necessarily for weight loss.

Adequate calcium intake is indeed important for many aspects of

personal health, especially bone mineral density. Controversy only

arises when extra calcium or dairy is advocated.

Other claims about the value of dairy made by the National Dairy

Council are also contentious, including the role of dairy in

controlling hypertension, kidney stones and colon cancer. And though

their Web site prominently advertises these benefits, it notably

ignores the potential link between high calcium levels and prostate

cancer, which is still debated in the scientific community but would

strongly argue against excessive dairy consumption, particularly by

men.

The safest bet at this point is to make sure your calcium intake is

adequate, but not excessive. The primary benefit of receiving your

calcium in the form of dairy is that it also contains vitamin D,

which is essential for calcium absorption. Non-dairy calcium

supplementation that includes vitamin D is an acceptable substitute

for those who cannot or prefer not to eat dairy.

Remember that the dairy industry has a vested interest in convincing

you to consume their products. While some of their claims may be

true, their primary motivation is to make a profit, not to make you

healthy. Always check with an impartial source for information about

the health value of any food or supplement.