I have several pounds of brown rice that are 2 to 4 years old. I was about to cook some when I read that it should discarded after one year. I was born near the end of the Depression, grew up during WW2 and have an almost DNA level reluctance to waste food. So my question is: "To eat or not to eat!"? I also have some red lentils that have hanging around for over 3 years.
All recommendations I am familiar with say to use brown rice in less than a year, 6 months if possible because of the likelihood of the oils in the germ becoming rancid. Air-tight packaging and storing it in the refrigerator or freezer extends the shelf-life some. The rancidity gives the rice a bitter, acrid taste. We do know that as oils become rancid, or react with oxygen, the nutritive value is destroyed and the taste becomes increasingly unpalatable. There is ongoing research into the effects of consuming rancid oils and fats in foods. There is not yet complete understanding of what health impacts they can have over time, so we suggest people be cautious. and try to limit the amount of rancid oils they consume. While there may not be immediate health concerns, they may have long-term impacts.
Milled rice (white rice) that has the germ removed can be stored for years if kept dry. So can the lentils. They may not absorb moisture quite as well when you cook them, and may not be quite as nutritious as they were originally, but they are safe.