On Nutrition by Ed Blonz

Diabetes: Genetics and Environment Both Play a Role

DEAR DR. BLONZ: In doing a research paper on health issues faced by indigenous peoples, I came across the issue of the Pima American Indians in Arizona, who have a very high incidence of Type 2 diabetes. Is this a genetic issue, or a dietary and lifestyle issue? -- J.D., Casa Grande, Arizona

DEAR J.D.: It’s both. The Pima appear to have a genetic component that is not serving them well under the current style of eating in the United States. It is called a thrifty genotype, and it provides survival advantages when there is an irregular food supply by conferring maximum efficiency in the processing and utilization of dietary energy (calories).

Pima Indians live in northwest Mexico and the southwestern U.S., having migrated there from remote mountainous regions in Peru, where a good number remain. In these areas, there is an inconsistent food supply throughout the year. Over the millennia, the Pima in Peru and Mexico adapted to the sparse availability of food in these regions, and as a group, they tend to be slim and do not suffer from Type 2 diabetes.

The Pima who migrated to what is now the United States, however, no longer have to cope with an irregular food supply, and are now experiencing an epidemic of obesity and Type 2 diabetes attributable to this environmental change in their diet.

Insulin resistance and hyperinsulinemia have been identified in the Americanized Pima Indian population. Scientists from around the world continue to study this population because it offers a rare insight into the independent roles of genes and environment on the risk of disease. Studies continue to report on the critical roles of food selection and increased physical activity in helping reduce the risk of Type 2 diabetes in this population. There is an interesting discussion on this topic at b.link/pima85.

DEAR DR. BLONZ: I need to up my level of dietary fiber. I want something convenient, but I am seeking taste, not cardboard. What do you consider to be the best foods that are rich in fiber? -- N.F., San Jose, California

DEAR N.F.: Americans tend to eat rather low on the fiber scale, and population studies continually find that increased consumption of dietary fiber is associated with a range of health benefits.

In terms of convenience, there’s no better way to start the day than with a bowl of fiber-rich whole-grain cereal topped by some fresh or dried fruit. Setting the requisite time aside in the morning to have a healthful breakfast can be an important adjunct to your health.

With or without the cereal, dried fruits are on my list of excellent fiber-filled foods. They are an often-overlooked fiber source with a great variety of rich fruit flavors, and the fact that they are dried gives them an extended shelf life. Combining them with various nuts and seeds, even tossing in a few dark chocolate chips and coconut flakes, makes a healthful, fiber-rich snack or mini-meal that can be available throughout the day. This mix is also a great real-food option for your child’s lunchbox.

Next, we have vegetables, whole grains and legumes (beans), all of which have a high fiber content. No cardboard on that list. Fiber supplements can have a role, but first, focus on foods naturally high in fiber. They come with an assortment of other important nutrients and phytochemicals. For more, check the FDA’s fact sheet on dietary fiber at b.link/pdf34.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.