Low hemoglobin levels are beneficial for health

Finnish researchers have discovered that hemoglobin levels which are within the normal range, but at the lower end, may be beneficial for health, in particular for the glucose metabolism and cardiovascular health.

Hemoglobin is a vital protein present in red blood cells and its main function is to transport oxygen from the lungs to the different tissues of the body. According to reference values, normal hemoglobin levels are 12 to 16 g/l for women and 13 to 17 g/l for men.

“Therefore, the normal range is quite wide and previous studies have suggested that a hemoglobin level within normal reference values, but at the lower end of the range, may be beneficial for health,” he says. Jooa Norhapostdoctoral researcher at the University of Turku in Finland.

In the new study, researchers measured the hemoglobin levels of 64 adults and conducted a comprehensive assessment of their metabolism and cardiovascular health. “We found that lower hemoglobin levels were particularly associated with a better glucose metabolism, but also with the physical fitness, cardiovascular health and less liver fat”explains Norha.

Although the number of participants was limited, the researchers point out the reliability of the study, published in the journal ‘Annals of Medicine’. It is increased by its follow-up design and the rigorous imaging and laboratory tests performed on the participants.

“We measure the glucose metabolism, i.e. insulin sensitivitydelivering insulin and sugar directly into participants’ bloodstreams in a laboratory setting. This allowed us to study how the body reacts to insulin,” adds Norha.

Previous studies have shown similar results, since in Finnish data it has been observed that lower hemoglobin levels are associated with a lower overall mortality and lower cardiovascular mortality.

“The mechanisms that explain the impact we have observed are not entirely clear. It has been suggested that low hemoglobin levels, although still within the healthy range, trigger cellular protective mechanisms related to oxygen deprivation, which promote cellular metabolism,” explains the study’s principal investigator, Ilkka Heinonen.

However, the researchers do not recommend measuring hemoglobin unnecessarily in asymptomatic and generally healthy people. Abnormally low or high values ​​should be consulted with a doctor.