Metabolic complications w such as type 2 diabetes and obesity are partly the result of a high intake of calories and lack of exercise. However, chemical substances found in our environment may also impact our metabolic health.. This is shown in a study conducted on mice by PhD candidate Brecht Attema (Human Nutrition and Health). She obtained her PhD degree last week.
Brecht Attema’s dissertation cover features a fisherman who has cast his line in a liver-shaped pond. The artery in the liver springs from a factory enshrouded by dark clouds. ‘I studied the role of chemical substances in our environment and how they impact the liver in terms of metabolic complications such as type 2 diabetes and fatty liver’, Attema explains. ‘We know that PFAS accumulates in the environment and in the human body. It was only last month that high levels of PFAS were found in eggs of privately owned hens in the area near Dordrecht. We still have limited knowledge on the effects that these substances have on the human body.’
Attema studied the metabolic profile of mice that had been exposed to the PFAS variant PFOA and the more recently produced GenX, which is a substitute for PFOA. She also exposed mice to the fungicide propiconazole, which is one of the ingredients of pesticides used on wheat, rye and stone fruit such as cherries and peaches.
Fatty liver
‘The effects of these chemical substances are best measured when metabolism is under pressure. Hence, the mice were given a diet high in fat. This caused them to develop obesity and fatty liver. We then exposed the mice to chemical substances to see how these substances affect their – already strained- metabolism.’
Contrary to expectations, the chemical substances sometimes showed positive effects. ‘PFOA lowered the cholesterol and triglyceride (lipids found in the bloodstream, red.) levels in the blood plasma. This is interesting because some people use medication to achieve precisely this effect. The mechanism behind the effects of these chemical substances is identical to certain medication we use, the so-called fibrates. Exposure to PFOA and GenX also had adverse effects: it increased the accumulation of lipids in the liver, causing fatty liver.’
‘Higher dosages of the fungicide propiconazole also reduced body weight as well as the cholesterol and triglyceride levels in obese mice.’ Although this may sound positive, Attema also saw a considerable increase in fatty liver and signs of inflammation and scar tissue in the liver.
Caution
‘The fact that these chemical substances appear to positively impact the metabolic health of mice does not mean we can exercise less caution. The substances have a negative effect on liver health, after all,’ Attema cautions. ‘And although some substances deploy mechanisms similar to certain medication or exert the same effect, there is still a considerable difference between consciously taking medication versus unconsciously ingesting unknown levels of certain chemical substances.’