While not all dietary approaches are applicable or beneficial to everyone, there are some, I think, that generally hold true. Here’s one: if you want a long and healthy life, do what you can to ensure stability in blood sugar and insulin levels. What this means usually means in practice is the regular eating of foods which tend not to disrupt blood sugar (and therefore insulin) levels such as meat, fish, eggs, green vegetables, certain fruits (e.g. apples, berries) beans, lentils nuts and seeds.
What this diet is generally devoid of, you may notice, is foods containing refined sugar and starchy carbs such as bread, potatoes, rice, pasta and breakfast cereals. The quite ‘primal’ diet above is often dubbed a ‘low carb’ diet, on the basis that it contains considerably less carbohydrate compared than the starch-rich diet so often advocated (and eaten) these days. Some people even recommend this sort of diet for diabetics, even though carbohydrate is the specific dietary element that diabetics have difficulty handling. For more on this specific issue and the nonsensical nature of advice so often metered out to diabetics, see here and here.
Part of the rationale for a carb-controlled diet in diabetics comes from the fact that the carb one eats, the lower the blood sugar level will tend to be. And at the risk of stating the obvious, this is of clear merit for diabetics whose prime ambition might be to keep blood sugar levels under control.
However, another important part of the rationale for eating a low or lower carbohydrate diet is that it demands less insulin to be secreted by the body’s pancreas. Generally speaking, the less insulin someone secretes, the less likely they are to sufferer from ‘insulin resistance’ (when the body’s ability to respond to insulin’s blood sugar lowering effects is blunted). Also, less insulin means less likelihood that the cells in the pancreas responsible for secreting insulin ” the so-called ‘beta’ cells ” will ‘exhaust’.
Basically, the more insulin someone secretes over time, the more likely they are to suffer from a lack of insulin and/or an inability to respond to it appropriately. This is a situation many type 2 diabetics can find themselves in, particularly, logic dictates, if they eat a diet replete with carbohydrates including starchy ones.
Of course this concept of controlling carb intake is not just relevant for diabetics, but also for those who would prefer not to develop diabetes. I was therefore interested to read a recent study which tested the effects of low-carb and low fat (and higher carb) diets in a group of obese adolescents aged 12-18. This 12-week long study that these diets performed similarly well with regard to changes in measures such as body mass index and body fat percentage.
On the other hand, the low carbohydrate diet out-performed the low fat one in two critical areas. Firstly, insulin levels were lower in those eating a lower carb diet. The researchers also used an assessment known as the homeostatic model assessment (HOMA) which is used to measure the extent to which an individual is suffering from insulin resistance and beta-cell exhaustion. Here too, the low-carbers faired better.
In short, after just 3 months on a lower carb diet, adolescents saw improvements in their biochemistry which would, generally speaking, put them at reduced risk of developing type 2 diabetes over time. This evidence is in line with other research which has found that the consumption of blood sugar-disruptive disruptive carbohydrate is associated with an increased risk of diabetes.
Demol S, et al. Low-carbohydrate (low & high-fat) versus high-carbohydrate low-fat diets in the treatment of obesity in adolescents. Acta Paediatr. 2008 Sep 29. [Epub ahead of print]