For around 10 years, the month of January for many people has been synonymous with removing foods of animal origin from the menu and following a vegan diet. Last year, for example, the English organization “Veganuary”, creator of the movement known as “Vegan January” in Brazil, received registrations from more than 700 thousand people.
Volunteers came from every country in the world, with the exception of the Vatican and North Korea. They register on the organization’s website to receive recipe tips, restaurant suggestions and other content that is part of the world without meat and meat products. But how does this change in diet for a month affect the human body?
That’s what researchers from the School of Biosciences at the University of Nottingham, in the United Kingdom, asked themselves. To find the answer, they conducted a study with a group of 159 participants, aged 18 to 60, recruited in two periods: at the end of 2019 and 2020.
Scientists compared those who signed up for “Vegan January” with others who maintained the same dietary pattern. The results of the work were published in the scientific journal Nutrients and showed the positive, and some negative, effects of the change.
Most prominently, the vegan diet led volunteers to record a significant reduction in cholesterol, estimated at 10-fold, and a decrease in saturated fat – both factors linked to lower risks of cardiovascular disease. On the other hand, however, a sharp drop in the levels of vitamin B12, a compound present mostly in items of animal origin, and iodine was observed among those who did not take dietary supplements.
“While we showed some clear health benefits of switching from meat and dairy to vegan, the study also highlighted the vitamins and minerals that people taking part in Veganuary need to pay special attention to, namely iodine and B12. Our advice to this year’s participants would be to check food labels carefully and try to ensure that alternative products have these added nutrients,” says Simon Welham, professor at the university and lead author of the study, in a statement.
Although an iodine deficiency is rarer – in Brazil, for example, salt is mandatory fortified with the nutrient – scientists highlight that the lack can be dangerous among pregnant women due to the fact that iodine is essential for brain development. of the fetus. B12 deficiency can lead to problems such as anemia as it is involved in the formation of red blood cells.
“’Vegan January’ can be done perfectly healthily if followed sensibly, and our study shows that there can be pros and cons to switching from a meat and dairy diet. For any major dietary change, it is important that people plan accordingly to ensure they are getting the nutrients they need,” says the researcher.
For Welham, the ideal would be for those people who eat meat and are going to join the challenge to seek advice from specialized professionals first. But he considers that just a closer look at food labels would help:
“Omnivores who commit to vegan campaigns could seek nutritional advice before changing their diet to ensure their nutrient intake is adequate. As this is unlikely for many in the absence of dietary consultation, there is a need for clear guidance that is visible to all those considering such a dietary change.”
Improved insulin and weight loss
Despite important warnings about the measures needed to avoid nutritional deficiencies, the new work adds to a body of evidence that has highlighted positive impacts on markers associated with heart health resulting from a vegan diet.
At the end of last year, researchers from Stanford University, in the United States, sought to evaluate this effect in the most faithful way possible – by following two identical twin brothers, in which one implemented a diet without items of animal origin, while the other followed the diet conventional.
The study, published in the scientific journal JAMA Network Open, followed 22 pairs, that is, 44 volunteers, for two months. Analyzing the results of blood tests before and after the study, the scientists observed that the vegan diet led to a significant drop in bad cholesterol, LDL, insulin levels and body weight.
At the beginning, those in the vegan group had an LDL of, on average, 110.7 mg/dL, which dropped to 95.5 mg/dL after the eight weeks. Among those who followed a conventional diet, the rate went from 118.5 mg/dL to 116.1 mg/dL. Ideally, the marker should be below 100 mg/dL.
The first group also showed a 20% reduction in fasting insulin and a drop of approximately 1.9 kg more in weight than that seen in participants who continued on the omnivorous diet.