Just as the Academy Awards celebrate 'superstars', nutritionists and health enthusiasts everywhere celebrate 'superfoods' - those stars of the food world that are packed with nutritional value. The latest addition to superfood status is a national British breakfast favourite - oats.
You may be aware that eating a bowl of oats is good for your heart, but what exactly is it about these clever little grains that has elevated them to 'superfood' status? Are they really worth the effort or is it media hype?
The answer exists in their fibre content. Much of the fibre in oats is classified by scientists as insoluble; this is the bran-like fibre that is good for the gut and for digestive health. But within the oat grain there is also another type of soluble fibre called oat "beta-glucan."
Simply put, beta-glucans are not hype. They are one of nature's ingredients for a healthy heart. Un-simply put, oat beta-glucans are non-digestible polysaccharides (long chains of glucose molecules) that provide a number of health benefits. They have a potent cholesterol lowering effect that can lower the risk of heart disease and slow the absorption of sugars into the bloodstream which, in turn, can help regulate blood sugar levels and assist with weight control. While beta-glucans are found in various foods such as barley, mushrooms and yeasts, they have the highest concentration in oats.
Beta-glucans seem to lower cholesterol by acting a bit like wallpaper paste. Once they are ingested into the gut, they dissolve and form a thick gel. This gel then works in three different ways to reduce cholesterol. First, it is able to entrap cholesterol from foods and prevent it from being absorbed into the bloodstream. Food, as you may know, provides about 20% of our dietary cholesterol intake.
Second, it can prevent the absorption of bile acids, which enable the absorption of digested fat into the bloodstream. When these bile acids can't be reabsorbed they are excreted, meaning that the body has to make new bile acids. What does it use to make these new acids? Cholesterol from within your body! As such, this causes a reduction in existing cholesterol levels, clever huh? Last but not least, these bile acids, which are bound with fat, are ultimately excreted, thus leading to a further loss of fat and cholesterol throughout the body.
The really good news about the cholesterol lowering effect of beta-glucans is that they lower what is commonly termed 'bad' cholesterol (otherwise known as LDL cholesterol). It is raised levels of LDL that are particularly associated with increased risk of heart disease.
Much of the research into the cholesterol lowering effects of beta-glucans has centered on oats, as they are a good food source. In scientific studies a reduction of 5% in LDL levels can be seen within 4 weeks of starting to include oat based products. So strong is the evidence that both the US and the EU allow products containing at least 0.75g of oat beta-glucans in a typical portion to make a heart health claim.
Their effect appears to be a dose dependent, in other words the higher the intake of oat beta-glucan the greater the reduction in LDL cholesterol. An optimal intake is considered to be 3g or more of oat beta-glucan per day. This can be achieved by eating 90g of oats per day. In practical terms this equals 2-4 portions of oat based products e.g. porridge, breakfast cereals, breads and crackers. However, for those that are not inclined to eat 2-4 daily portions of oats, I would highly advise to seek foods and food supplements with added oat beta-glucans. It is important, however, that such foods and supplements be approved by EFSA in Europe or the FDA in the US - to ensure maximum efficacy.
So, the next time someone asks about your favourite super-food, I hope you will think of the powerful medicinal value of oats. I've included some tips below for how you can include oat beta-glucans into your daily diet:
Attaining Superfood Status: Eat Your Heart Oat!
• Choose porridge or an oat based cereal for breakfast.
• Swap wheat based crackers for oatcakes and top with a variety of topping such as hummus, smoked salmon or soft cheese.
• Add oats or granola to Greek yoghurt and leave over night to soften, sweeten if desired with honey or berries for as healthy snack or dessert the next day.
• Add finely milled oats to fruit smoothies to take before exercise.
• When baking muffins, brownies or scones use half wheat flour and half oatmeal flour.
• Add oats to crumble toppings, meatloaf, to coat fish or potato rissoles.
• Look for foods or supplements that call out oat beta-glucan on the labels.