Health Guidelines

Dairy Consumption, Obesity, and Insulin Resistance Syndrome

A new risk condition getting much attention lately is insulin resistance syndrome (IRS). It is characterized by high blood insulin levels and is linked to obesity, high blood pressure, low HDL levels, high blood triglycerides or blood fats, high blood sugar levels, and high risk for diabetes and heart disease.

Recent studies indicate that 24% of the adult population exhibits IRS resulting in major health problems. Factors that increase the risk for this problem are excess body weight, inactivity, smoking, and poor dietary habits; especially a low fiber intake and a high intake of refined carbohydrates (a high glycemic load).

New research indicates that milk may be protective against IRS. A large prospective study looking at heart disease in young adults (18-30 years old), called the CARDIA Study, was used to study milk consumption and risk of IRS. They looked at lifestyle factors, body weight, and eating habits for 10 years in 3157 young adults, both blacks and whites, and men and women.

Here is what they found. There was a consistent decrease in risk of IRS for each increase in the level of milk products eaten in those persons who were overweight (BMI of 25+) but not in lean people. When you compare the highest intake of milk products eaten (top 20%) to the lowest intake of milk products eaten (bottom 20%) the risk of IRS dropped by a significant 72% in the overweight group. This protective relationship remains even when adjusting for race, gender, other dietary factors, activity level, and other possible confounders.

It's been known for some time that fiber is also protective against IRS. People who ate the least milk products and the lowest fiber intake had seven time the rate of IRS compared to those who had a high intake of both dietary fiber and milk.

The authors point out that trends in eating in the past few decades include a decrease in milk consumption, an increase in drinking soda pop, and an increase in snacking and refined foods. This is certainly not a healthy trend, especially in our children. At the same time, obesity and insulin resistance have been increasing. The food guide pyramid recommends two servings of milk products daily, preferably low fat choices.

In summary, researchers observed that overweight people with a higher intake of milk and milk products (such as yogurt and cottage cheese) had a significantly lower rate of:

• Obesity

• High blood sugar levels

• Abnormal blood lipids (low HDL or high triglycerides)

• Elevated blood pressure

• Insulin resistance syndrome

The authors conclude by saying, "Our study suggests that increased dairy consumption may protect overweight individuals from the development of obesity and insulin resistance syndrome, two key risk factors for the development of type 2 diabetes and cardiovascular disease." These are two of our nations leading causes of death.

Comments: Keep in mind that if you are lean (BMI < 25) milk had no added protective benefit against IRS. Other things you can do to prevent IRS are: exercise regularly, stay lean, avoid smoking, eat a diet high in dietary fiber (in this study fiber was even more protective than milk), and limit highly refined carbohydrates (foods with a high glycemic index such as white bread, soda pop, white rice, sweets, etc.).

Reference

Mark A. Pereira, et al, Dairy consumption, obesity, and the insulin resistance syndrome in young adults, JAMA 287:2081-2089, April 24, 2002

Making Healthy Choices articles are written by Don Hall, DrPH, CHES president of LifeLong Health with contributions from associated health professionals. Content is general health information from evidence based research. It's purpose is not to treat disease or take the place of advice by your doctor but to promote healthy lifestyles. Persons with health problems should contact their physician for specific guidance.

Content reviewed 5-9-02 DRH.  Copyrighted 2002 by PrevMedix LLC. All rights reserved.