A recent study suggests that while folate intake is generally beneficial, particularly for the young, it might lead to metabolic issues in older individuals. Researchers from Texas A&M University’s AgriLife Research observed that lower folate levels, a form of vitamin B9, aided in the shift from sleep metabolism to waking metabolism in mice. During sleep, metabolism focuses on burning body fat, while waking metabolism shifts to burning carbohydrates for daily activities.
This study builds on previous research where folate restriction in yeast and worms led to increased longevity compared to controls. In the current study, 52-week-old middle-aged mice were either given a standard diet or a folate-deficient diet. Despite the lack of folate, the folate-deprived mice did not show signs of anemia or reduced body weight, and males actually weighed more than those on a standard diet. The study did not assess the impact of folate reduction on lifespan, as all mice were euthanized at 120 weeks. However, there was no significant difference in life expectancy between the two diet groups.
Senior author Michael Polymenis, a biochemistry and biophysics professor at Texas A&M, explained that aging impairs the body’s ability to quickly switch between different metabolic states. This adjustment is crucial for meeting the body’s changing energy needs. Michelle Routhenstein, a preventive cardiology dietitian, highlighted that the body’s use of carbohydrates during the day and fat at night is influenced by insulin levels and growth hormones.
Polymenis also raised an intriguing question about how folate-deprived mice maintained red blood cell levels without anemia. He suggested that the gut bacteria might provide a source of folate, as these mice still had 30-40% of the folate levels found in controls.
While the research suggests potential benefits of reducing folate for older adults, it has only been tested in mice. Polymenis advises against altering folate intake without further human studies, emphasizing the need for more research. Routhenstein maintains that folate is crucial for health, particularly cardiovascular health, and recommends continuing a diet rich in folate. She also suggests consulting a registered dietitian to stay updated on nutrition research. Polymenis envisions that future fortification practices could include folate-reducing additives for those who need it.
