Lack of exercise and poor diet have long been blamed for the rise in the nation’s diabetes rate. But a landmark new study suggests another factor may be at work: A growing epidemic of underactive thyroid.

The condition, called hypothyroidism, affects millions of Americans, according to Dr. Raphael Kellman, a leading expert on thyroid disease who runs the Kellman Center for Integrative and Functional Medicine in New York City. He says the findings confirm a link he’s highlighted for many years.

The American Thyroid Association estimates that 12 percent of the nation’s population have diseased thyroids, with many people unaware their thyroid glands may be responsible for other health problems.

This butterfly-shaped endocrine gland, generally found in the lower front of the neck, plays a critical role in keeping vital organs — including the brain and heart — working normally.

Restoring thyroid glands to normal function can help stall development of other diseases.

According to another expert on hypothyroidism, endocrinologist Dr. Minisha Sood, director of inpatient diabetes care at New York City’s Lenox Hill Hospital, evidence now confirms suspicions of a link between deficient thyroids and diabetes.

“Most endocrinologists now screen for thyroid disease in patients with pre-diabetes and diabetes,” she says, “because it’s known that thyroid disease is more prevalent in these populations.”

The latest study was conducted by Dutch researchers at Rotterdam’s Erasmus University Medical Center who tracked nearly 8,500 people over eight years. A team led by Dr. Layal Chaker found 1,100 study participants developed pre-diabetes — modestly raised blood sugar levels, but not high enough to be considered diabetes — before the study ended and 798 developed the chronic disease more seriously.

Overall, Chaker’s researchers found under-performing thyroid glands increased chances of developing diabetes by a worrying 13 percent.

“This finding suggests we should consider screening people with pre-diabetes for low thyroid function,” she comments.

The work was presented at a recent meeting in Boston of the Endocrine Society — which boasts 18,000 members in 122 countries — and will be published in a peer-reviewed medical journal.

While the study pinpointed the close relationship between underactive thyroid glands and diabetes, it didn’t shed any new light on why this link exists.

Symptoms of possible thyroid disease include depression, difficulty losing weight, fatigue, hair loss, inability to concentrate, and heightened sensitivity to cold, among others.

According Kellman, the first step for people suspecting they may have thyroid disease is having levels of hormones known as T3, T4, and TSH checked through simple blood tests. It’s essential to seek professional advice, he emphasizes.

While some doctors favor drugs to treat high blood sugar, Kellman leans heavily toward health supplements which have been successful in reinstating thyroid heath. His center’s treatments encompass evaluating patients’ physiology, environment, nutrition, and other factors that may impact on the thyroid’s failure to function normally.

“Vitamins and nutrients can help fight the underlying cause of thyroid disorders, such as autoimmune processes and inflammation, and help improve dysfunctional thyroids,” he says. 

Among treatments he has used successfully are selenium, (a mineral found in the soil), ashwagandha (a powerful herb long used by practitioners India’s traditional Ayurvedic medicine), compounded T3 and T4 hormone supplements and Armour thyroid (a natural medication made from pigs’ thyroids). Some patients are treated with more than one of these, depending on identified causes of hypothyroidism.

Kellman also stresses the importance of gut health, noting that the body’s bacteria are crucial in “creating byproducts that can help insulin sensitivity and protect against inflammation.”  

Other nutrients some doctors find effective include iodine, vitamins B and D (a strong association has been found between vitamin D deficiency and hypothyroidism), zinc, tyrosine, and probiotics.

“The microbiome [micro-organisms found in the body] in the gut play critical roles in many physiological processes, including thyroid function,” observes Kellman.”I don’t necessarily recommend the [probiotic] supplement with the highest number of bacteria — although that’s important — but supplements with the most diversity.”  

Beating hypothyroidism is an important step in preventing the onset of diabetes, he argues.