Want to live a longer and healthier life? Load up on brown rice, oatmeal, and millet, says new research from Harvard School of Public Health.

This new long-term study found that eating more whole grains decreased people’s risk of death by up to 15%, particularly from cardiovascular disease. This is likely thanks to the grain’s bran, the hard outer-layer that is rich in fiber, essential fatty acids, vitamins, and minerals. Increasing bran intake lowered the risk of death by up to 6% and the risk of cardiovascular disease by up to 20%.

Although government nutritional guidelines have long encouraged the consumption of whole grains, these findings challenge the tenets of Paleo and low-carb diets, which have taken the wellness world by storm.

According to proponents of the Paleo diet, modern humans thrive when they eat the way our ancestors did before the advent of agriculture – without grains and processed foods. Our ancestors spent eons hunting and foraging meats, nuts, vegetables and fruit, and only 10,000 years ago did we begin to farm wheat, corn, and other grains that are now staples of the modern diet.

According to Integrative Nutrition visiting teacher Mark Sisson, the Agricultural Revolution was disastrous for our health. He says, grains wreak havoc on our insulin response, cause inflammation, strain the digestive system, and contain damaging toxins such as lectins and phytates. He and other proponents of a “caveman” way of life advocate a low-carb diet that is entirely free of grains.

Sisson’s views are rapidly growing in popularity, and many followers of the Paleo diet find that they feel best – energetic, clear-headed, slimmer, and free of digestive woes and bloating – when they avoid grains.

What, then, do we make of the study’s most controversial finding? The Harvard researchers found that swapping out one serving of red meat for whole grains lowered the risk of cardiovascular disease-related deaths by a whopping 20%. This finding seemingly turns the Paleo movement on its head.

So are grains a healthy choice or not? It depends on who you ask. The debate only further proves that nutrition is a fledgling science where diametrically opposed viewpoints can both be proven.

That’s why at Integrative Nutrition, we cover a spectrum of over 100 different dietary theories – Paleo, veganism, Ayurveda, gluten-free, macrobiotics, and the Zone, just to name a few – and encourage students to experiment with different ways of eating. There’s no one-size-fits-all diet, and one person’s food may be another person’s poison. This is the core of what we call bio-individuality – it’s up to each person to find the foods and lifestyle that make them feel their best.

So what about you – do you eat grains? Or do you prefer a Paleo diet? Share with us in the comments below!