Oatmeal, Traditional Diets & Longevity

Oatmeal, Traditional Diets & Longevity

the humble oat

Blue Zone

Scientists have been curious to uncover the dietary secrets of the world’s longest lived people from the so-called Blue Zones in various corners of the globe  But while distilling the evidence based common denominators they didn’t find commonalities in the specific foods they were eating, but rather Blue Zones all share quintessentially traditional ways of cooking meals that are rich in plants and minimally processed whole grains. Despite all the comforts of modern life, perhaps we are guilty of throwing out all the old in favour of the new.  But with lifestyle related diseases on the rise, perhaps we have thrown the baby out with the bathwater.  Incorporating those traditional staples back into our meals would probably serve us all well.  And one traditional dietary staple in Europe is the humble oat.

Studies demonstrate that people who eat two to three servings of whole grains per day reduced their risk of getting diabetes by 21 percent and also lowered their risk for inflammatory conditions like arthritis, gout, Crohn’s disease and neurodegenerative diseases, among others. A study of nurses also found that women who ate two to three servings of whole-grain products each day were 30 percent less likely to have a heart attack or die from heart disease than those who had less than one serving per week. The operative word here is “whole grain” — highly processed quick-cooking, sugar-laden packets don’t carry the same benefits as traditional, minimally processed oats, often referred to as steel-cut or old-fashioned oats.  Traditional processing means they also have less of their nutrients stripped away, retaining more gut loving fibre and having an overall lower GI, but also pack in more nutritional benefits without any need for additional porridge toppings. Of course, your destiny as a potential centenarian will also be determined by your DNA, upbringing, as well as how physically active you are and a host of other lifestyle factors.  But while arguing over which specific nutrients link to health has not got us very far in the nutritional sciences, the prevailing scientific evidence definitely weighs more heavily in favour of traditional dietary patterns and methods of processing.  But don’t take it from me, Guinness World Records' oldest man Jiroemon Kimura from near Kyoto, Japan, who died in 2018 age 116 attributed his health and longevity to porridge, miso soup and vegetables!

Forgotten Fibre & our ‘Old Friends’

The health benefits of oats are broad and attributed to their unique, yet well-balanced nutritional profile. They are a source of carbohydrates, contain quality, low-cost, plant-based protein (around 11-15%) with good amino acid composition.  Oats are also a good source of unsaturated (the good kind) fats, containing much higher levels than other cereals.  Micronutrients found in oats include vitamin E known to protect the body from damaging free radicals and play an important role in prevention of diseases such as cancer, arthritis, atherosclerosis.  Interestingly, a diet rich in vitamin E containing foods such as oats is associated with longevity, but vitamin E supplements repeatedly fail to show benefit in clinical trials and has even been linked to an increase in the risk of stroke, increased risk of prostate cancer.  The key message – aim for a food first approach and remember processing of the oat can impact degradation of vitamin E. Although often overlooked, fibre is actually one of the key nutrient players in our health. In general, positive effects of oats are associated with the fibre called β-glucan.  Which has proven beneficial effect on serum cholesterol levels and cardiovascular disease risk but did you know beta-glucan can also help you swerve the seasonal lurgies.  Many of the cells of our immune system are directly activated by b-glucan, enhancing their anti-microbial activities to fight infection. But oats contain significant amounts of different fibres including resistant starch, a particular type of fibre, often called functional fibre for its important role in digestive process and provides fermentable fuel for the gut microbes. As a result of bacterial fermentation, oats produce key immune regulating molecules called short chain fatty acids which lower unruly inflammation, prevent leaky gut which has been linked to poor health and recovery from antibiotics.  Oats contain significant amounts of resistant starch and other fibrous starches, but since this can be destroyed during processing, look for traditionally milled, wholegrains which can have four times the amount of fibre as refined grains.  The unique fact that oats contain β-glucan combined with these other resistant starches, give greater reduction in glucose and insulin concentrations than might have been expected with only one type of fibre in isolation.

Phytonutrients & the case for organic

Phytochemicals are biologically active chemical compounds found in plants. These natural plant products have been used to prevent and treat various diseases for thousands of years, in fact phytonutrients are now the subject of huge medical interest because studies show regular consumption can both reduce the risk of infections and lifestyle/ageing diseases. Currently phytonutrients are referred to as non-nutritive – meaning we don’t have a specific recommended daily intake or reference amount for deemed necessary for health – but the general message is to eat more! In terms of health benefits oats are best known for their fibre content, particularly beta-glucan as mentioned above. Less well known is that this humble grain contains a unique phytonutrient profile including a class of more than twenty polyphenols known as avenanthramides, not found in any other foods. Avenanthramides have a wide range of beneficial effects on our health attributed to their anti-oxidant and free-radical scavenging ability as well as being anti-inflammatory. Although there might not be much difference between the vitamin and mineral content of organic vs. regular plant-based produce, there are now numerous studies demonstrating that organic can have up to 100 times more phytonutrients than non-organic.   Processing can also have an impact on the bioavailability of these phytonutrients.  Concentrations of avenanthramides in oats are heavily influenced by geography and environmental stress (Emmons & Peterson, 2001; Peterson & Dimberg, 2008).  Organic oats don’t have the extra help of pesticides, so they must upregulate their phytonutrient content.   Processing can have an impact too.  One study investigating the effects of processing on oats found that the avenanthramides content was much reduced the highly processed – Key message: not all oats are created (grown/processed) equally.