In a study published in the journal Life Science Alliance, Texas A&M AgriLife Research scientists found that lower folate intake can promote healthier metabolism in aging animal models, disproving the conventional assumption that high folate consumption generally benefits health. The study was led by Dr. Michael Polymenis, professor and associate director of graduate programs in the Texas A&M College of Agriculture and Life Sciences, Department of Biochemistry and Biophysics. This is the latest study by the researchers in their ongoing investigation of the effects of folic acid in biological models.
Optimal Folate Intake Varies
Folate, a B vitamin essential for cell growth and development, is widely recognized for its role in preventing birth defects. It occurs naturally in foods such as leafy greens and avocado. The synthetic version of folate, folic acid, is often added after grains have been refined. The word is derived from folio, which has the same root as foliage, as it is abundant in some leafy vegetables. Despite its widespread use, the long-term health effects of a lifetime consumption of high levels of folate are unclear. By restricting folate in animal models, the researchers observed a decrease in processes related to the growth and formation of new cells, but improved metabolic flexibility, which could lead to healthier aging, according to Polymenis.
According to the researchers, the optimal folate intake can vary depending on the age of the individual. While higher folate intake in the early years of life is critical for growth and development, lower intake later in life may benefit metabolic health and longevity. The study supports the concept of precision nutrition, which advocates personalized nutritional recommendations. According to Polymenis, further research is needed to explore the mechanisms behind this phenomenon and to develop safe and effective therapeutic interventions to promote healthy ageing.
Folate-Restricted Diet And its Benefits
Folate is an essential dietary component used in the body to form red blood cells as well as DNA, RNA and proteins. According to Polymenis, it is especially important for children, young adults and pregnant women because of its role in growth processes. He and the other Texas A&M AgriLife researchers wanted to determine the effects in less-studied age groups. To simulate the effects in older adults, the researchers removed folate from the diets of animal models at an age roughly equivalent to middle age in humans. A comparison group was raised in the same way, but continued to receive a typical diet containing folate. The researchers found that the female models with restricted folate intake were able to switch between carbohydrate and fat metabolism faster at night and during the day than women who received a normal diet.
With age, it takes longer to switch between fat-burning and carbohydrate-burning states, but this metabolic plasticity appears to be better preserved in animal models on a folate-restricted diet. In the male animals fed a folate-restricted diet, the overall metabolic rate increased during active periods, possibly helping them to maintain their energy levels and physical activity, and the folate-restricted group was able to maintain their weight and body fat into old age, unlike the control group. And despite the importance of folate for red blood cell production, the folate-deficient models showed no signs of anemia or other negative health consequences.
The research team began their work several years ago by using methotrexate to reduce folate uptake in yeast cells and then in the worm C. elegans. In both cases, the reduction in folate resulted in the models living longer. The team’s next step will be to repeat the experiment in more genetically diverse models that simulate human genetic diversity. The researchers will also expand their study of novel supplements to limit folate intake, which could later be incorporated into clinical trials.
Drugs to Limit Dietary Folate Intake
It has been shown that including nutrients in commonly consumed foods – vitamin D in milk, calcium in fruit juices – can help solve public health problems. For example, thyroid problems in the US in the early 20th century were a result of widespread iodine deficiency, which was remedied by adding iodine to table salt. In 1998, the U.S. mandated that staple foods, especially cereals, be “fortified” with folic acid and other B vitamins after the refining process. While this is helpful for some age groups, it could do more harm than good for older adults.
According to the scientists, this research may open a new avenue for the development of drugs that limit dietary intake of folic acid for people who don’t need as much of it, rather than reducing foods that contain folic acid, the synthetic version that is often added to foods and supplements. In the meantime, the researchers do not advise avoiding folic acid altogether. During pregnancy and breastfeeding, a targeted selection of foods with a high folate content is required to achieve the increased reference value. Regardless of dietary folate intake, women who want to or could become pregnant and pregnant women in the first trimester are recommended to take a folic acid supplement containing 400 µg of folic acid every day to prevent neural tube defects in the child.