Sometimes people use this reasoning for not changing to a plant-based diet. Someone may know a family member who lived a long healthy life and ate meat and dairy every day. Let me explain why this argument falls down under closer inspections.
As much as science and the medical community tries to understand the human body and why some people get diseases and others don’t, there is never any absolutes. Even heavy smokers sometimes outlive their friends who never touched a cigarette. I once knew a man dying of emphysema, and he had never smoked, or had any exposure to anything that could have triggered the disease. Well, we don’t now say I can smoke all I want because I knew someone who lived to be 100 that smoked because we know that the vast majority of people will eventually suffer adverse effects if they continue to smoke. There is a generalization that smokers suffer more debilitating diseases than non-smokers. The opposite is true as well. The 20 year China-Cornell-Oxford Project, known more commonly as The China Study was conducted by the Chinese Academy of Preventive Medicine, Cornell University, and the University of Oxford. In this study they determined that people of rural China who did not suffer from Heart Disease, Cancer, and other common diseases in the United States was due to their common trait of eating a plant-based diet, so we can conclude that generally speaking one will be more likely to avoid these diseases by changing their diet, and like my friend with emphysema, there will be exceptions to this as well. So one way to increase the likelihood of not developing these diseases is to change our eating habits.
The other issue that our generation now faces is the changes in our environment. We are exposed to far greater levels of chemicals, radiation, electromagnetic fields especially those in the microwave range (cell phones). In addition to this, the food we eat has many more chemicals, and the meat and dairy industry has completely changed the way that most of these foods are produced. Hormones are now used in animal confinement areas that our 100 year old grandma was never exposed to, or if she was not for a prolonged period that we have been. Even if you are now only eating free range meat and poultry, if you’re like me for many years you bought the cheap beef, or stopped at a fast food restaurants before we realized what was happening. And then there is the genetically modified organisms (GMOs) that our ancestors could’t even dream of. These GMOs, still not allowed in most European countries are in an estimated 80% of what is sold in a grocery store in the US.
With these two points combined, I see a much stronger reason to eat a plant-based diet, then I do to hang on to a thought that I might happen to be as lucky as my great aunt.