By Yucatan Times on December 17, 2020 Share Paleo, Vegan, Gluten-Free or Keto... There is no one right diet for everyone; there's the good, the bad and the ugly with all of these, depending upon the individual. The benefits and problems of paleo, vegan, gluten-free and keto are determined by a complexity of genetic/cultural/environmental factors. There is no one right diet for everyone; there’s the good, the bad and the ugly with all of these, depending upon the individual. For example, going gluten-free is innocuous even if you are not allergic or sensitive to gluten, but going vegan could be deadly, especially if you are a biological carnivore like my Inuit patients. A vegan diet is devoid of vitamin B-12 which is crucial for cognitive function. Cognitive decline in people over 50 has resulted from a lack of B-12 in their diet.