A gluten-free lifestyle has become one of the most popular diet trends in recent years, often under the pretense that this would improve health. Now, a new study show that heart health does not improve with the exclusion of gluten.
The claimed benefits of gluten avoidance are many, a calmer stomach, improved sleep, increased energy and even improved cardiovascular health. But there is still no scientific evidence to support the notion that excluding gluten would be a good choice for everyone.
Less gluten, increased risk of cardiovascular disease
A group of researchers from Columbia University Medical Center, Massachusetts General Hospital, and Harvard Medical School have analysed data from two large cohort studies with over 100,000 participants (Nurses Health Study and Health Professionals Follow-up Study). No participant had been given a celiac disease diagnosis.
These participants were asked to fill out detailed diet surveys every four years between 1986 and 2010. With more than 130 questions about how often a person consumed specified portions of certain foods and drinks.
During these 26 years of follow-up, 2,431 women and 4,098 men developed coronary heart disease. The researchers could see a small but statistically significant increased risk of cardiovascular disease among those who ate a gluten-free diet.
Those participants with the lowest intake of gluten had a coronary heart disease incidence rate of 352 per 100 000 person-years. Those at the highest level of intake had a rate of 277 events per 100 000 person years.
Causation is everything
The association between a gluten-free diet and an increased risk of cardiovascular disease wouldn’t necessary mean that eating gluten free food increase disease risks. It could instead be a choice resulting from already apprent health issues.
The researchers did compensate for a number of confounder values, however. Several of which that could be related to heart disease risk, including age, race, body mass index, history of diabetes, high blood pressure or high cholesterol, regular use of aspirin and non-steroidal anti-inflammatory drugs, current use of statins, current use of a multivitamin, smoking history, physical activity, parental history of heart attack, menopausal status, and menopausal hormone use. Other dietary factors such as alcohol, red and processed meats, polyunsaturated and trans fats, and fruit and vegetables.
Fibers and sugar
Many gluten-free products add more sugar and fat to compensate for the texture and taste difference that result from removing gluten. Gluten-free foods are often fiber-poor and fiber is a known factor to promote cardiovascular health.
“People who don’t have a true gluten allergy or sensitivity, avoiding gluten may result in reduced consumption of whole grains, which actually offer cardiovascular benefits”
– Andrew T. Chan, MD, of Massachusetts General Hospital and Harvard Medical School, and colleagues.
Naturally, those participants who ate the most amount of gluten also consume more of whole grains and refined grains. They also consumed less fat overall and ate less unprocessed red meat.
The researchers concluded that gluten-free diets should not be promoted for coronary heart disease prevention. But if you don’t need to avoid gluten for medical reasons, this study would suggests it may be beneficial to continue including whole grains in your diet for their cardiovascular benefits.
The study has been published in the British Medical Journal.
Benjamin Lebwohl et al. Long term gluten consumption in adults without celiac disease and risk of coronary heart disease: prospective cohort study. BMJ 2 maj 2017. DOI: 10.1136/bmj.j1892)