Norwegian cheese variant may keep bone weakening at bay

Consuming Jarlsberg cheese – a type of Norwegian cheese that contains long-chained vitamin K₂ and DHNA* – may help fend off bone weakening, a study from Norway has shown. What’s more, it appears to do so without adversely affecting lipid levels, even extending its benefit to glycated haemoglobin levels.

“[T]he effect of cheese consumption on bone health has, to the best of our knowledge, never been investigated in human controlled clinical trials,” said the researchers. “Because of its high vitamin K₂ content, Jarlsberg appears to be a good candidate for such studies.”

Sixty-six healthy premenopausal women (mean age 33.6 years, mean BMI 24.3 kg/m²) were recruited. By skewed randomization (3:2), 41 participants consumed Jarlsberg cheese 57 g (daily optimal efficiency dose) while the rest consumed camembert cheese 50 g daily for 6 weeks. Following which, those consuming camembert transitioned to Jarlsberg for 6 more weeks. Participants were instructed not to alter their typical diet but to avoid consuming other cheese variants during the trial. [BMJ Nutr Prev Health 2022;doi:10.1136/bmjnph-2022-000424]

At 6 weeks, the Jarlsberg arm had significant increases in tOC** and cOC** (mean, 4.4 and 4.1 ng/mL, respectively; p<0.01 for both). Conversely, these variables were reduced in the camembert arm (mean, –2.0 and –1.2 ng/mL). Following the switch to Jarlsberg, the levels increased again (mean, 3.8 and 4.2 ng/mL). According to the investigators, these findings underscore the significant stimulatory effect of Jarlsberg on OC.

There was also a marked increase in PINP*** following Jarlsberg intake (mean, 8.1 ng/mL; p<0.01), which was met with a corresponding reduction in the camembert arm (mean,–1.3 ng/mL). PINP is used as a bone turnover marker (BTM) that could predict BMD^# changes within 1–3 months. [Osteoporos Int 2014;25:2159-2171; Clinica Chimica Acta 2017;467:4-7] “[This finding thus suggests] that daily consumption of 57 g Jarlsberg during a period of at least 6 weeks may increase BMD,” the researchers noted.

 

Other improved variables

Both Jarlsberg and camembert arms had slight increases in triglycerides (mean, 0.1 and 0.2 mmol/L, respectively), LDL-C (mean, 0.2 mmol/L for both arms), total cholesterol (mean, 0.2 mmol/L [both]), and LDL-C/HDL-C^## (mean, 0.1 mmol/L [both]) at 6 weeks.

Following the switch to Jarlsberg in the camembert arm, the lipid levels dropped, but only total cholesterol and LDL-C achieved statistical significance (mean, –0.4 and –0.3 mmol/L, respectively; p<0.01 for both).

The lack of blood lipid reduction during the first 6 weeks appears to digress from a study showing significant blood lipid reductions with Jarlsberg intake. [Int J Clin Trials 2020;7:55-65] However, the researchers noted that considering the reductions in the ensuing 6 weeks, the initial effect may have been temporary, perhaps owing to the lifestyle changes brought about by the COVID-19 restrictions. [J Transl Med 2020;18:229-244]

HbA_1c also dropped with Jarlsberg vs camembert (mean, –1.0 vs 0.7 mmol/L; p<0.01), which remained after the switch to Jarlsberg (mean, –1.0 mmol/L; p<0.01). “[This effect] suggests that daily intake of Jarlsberg can be an aid in controlling major lifestyle-related diseases,” said the researchers.

 

Could it be the vitamin K₂?

The study compared two cheese variants with similar fat and protein content but different vitamin K₂ content (the camembert cheese used does not contain vitamin K) to determine whether the effect was driven by vitamin K_2.

Despite the increase in the sum of vitamin K₂ vitamer^### levels – both during the first 6 weeks of Jarlsberg consumption and the switch period – the findings deviated from those seen in a study showing increasing vitamin K₂ levels, but falling tOC and cOC trends, as cheese dose increased beyond 57 g. [Int J Clin Trials 2020;7:55-65] “This should not be the case if vitamin K₂ was the only factor that increases tOC. Thus, the increase in tOC cannot solely be ascribed to the vitamin K₂ content of Jarlsberg,” the researchers explained.

 

Or is it DHNA?

The DHNA in Jarlsberg reportedly has anti-osteoporotic properties and increases BMD. [J Oral Maxillofac Surg Med Pathol 2016;28:66-72] “This might explain the increase in tOC [and cOC], and it has been suggested that DHNA could be used in the treatment of post-menopausal osteoporosis,” the researchers explained.

“[Hence,] the bone anabolic effects of daily Jarlsberg intake are more possibly caused by its [DHNA content] with stronger osteoblast stimulation compared with vitamin K₂,” they said. “DHNA is the possible key to the tOC-stimulatory effect of Jarlsberg.”

A myriad of health benefits

“[Our findings show that] daily Jarlsberg cheese consumption has a positive effect on OC, other BTMs, glycated haemoglobin, and lipids,” said the researchers. “[Our results] reflect increased bone anabolism and a possible reduced risk of adverse metabolic outcomes … [These suggest] that Jarlsberg cheese might have prophylactic effects on osteopenia and metabolic diseases.”

“Further research may reveal the possibility of recommending Jarlsberg cheese as prophylactic treatment or even an addition to antiresorptive treatment in osteoporosis,” the researchers concluded.

“The effect of daily Jarlsberg intake on increased [tOC] level is not a general cheese effect … If the raise [in] tOC and cOC levels is … a Jarlsberg effect, further studies on Jarlsberg as prophylaxis are even more relevant,” they added.