Possible Link Between Alzheimer’s Disease and High Carb Diets

A recent article from USA Today discusses a study conducted by researchers at the Mayo Clinic, in which 1,230 adults, ages 70 to 89, were tracked to determine how dietary choices might play a role in MCI (mild cognitive impairment). Subjects were asked to provide information on their diets from the previous year. Of that group, 940 were shown to have no current impairment and were asked to return for a 15 month follow-up. Four years into the study 200 of the 940 remaining began to show signs of MCI, outside the norm for this age group, including problems with thinking, memory, language, and judgment.

Lead author Rosebud Roberts, a professor in the department of epidemiology at the Mayo Clinic in Rochester, MN, stated that Alzheimer’s Disease affects 5.2 million Americans, and that number is expected to rise, maybe even triple, by 2050. While MCI doesn’t always mean a definite sentence of dementia or Alzheimer’s, many with MCI do go on to develop these diseases.

Researchers, including those at the Mayo Clinic, are trying to understand the causes of these life-changing diseases, but have yet to make a definitive link. However, they do suspect sugars and carbohydrates play a role in Alzheimer’s Disease and dementia. From USA Today:

“Sugars also played a role in the development of MCI, often a precursor to Alzheimer’s disease, according to the report in the Journal of Alzheimer’s Disease. Eating more proteins and fats offer some protection from MCI.”

They’ve gone as far as saying that elderly people who “load their plates with carbohydrates” have almost four times the risk of developing MCI.

An article from the Mayo Clinic proclaims the subjects whose diets were highest in fat, had a 42 percent less risk of developing cognitive issues. Subjects with the highest protein consumption were a close second, with a 41 percent decreased risk. This is certainly a boon to high fat diets, such as Atkins. Another quote from USA Today:

“This (study) is consistent with what we’ve seen in past published research on how a lower carbohydrate diet can help to reduce the risk of Alzheimer’s,” says Colette Heimowitz, vice president of Nutrition and Education for Atkins Nutritionals Inc.

While not completely in contrast, Dr. Roberts does state this shows the need to balance proteins, carbohydrates and fats. Some low carb proponents might disagree, depending on the source of said carbohydrates.

In the interest of objectivity I have to disclose that, from what I can tell, this is merely an observational study, which is hardly conclusive. Subjects were asked to self-report food intake, and that’s usually a spotty thing to rely on, at best. Do you remember exactly what you ate a year ago, or even a month ago? That being said, we do know that too much sugar is bad for the brain, and it certainly isn’t a stretch to suspect that a higher carbohydrate diet is less than helpful, since excess carbohydrates convert to sugar in the bloodstream, as is pointed out in the Mayo Clinic quote below:

“A high carbohydrate intake could be bad for you because carbohydrates impact your glucose and insulin metabolism,” Dr. Roberts says. “Sugar fuels the brain — so moderate intake is good. However, high levels of sugar may actually prevent the brain from using the sugar — similar to what we see with type 2 diabetes.”