been said about the dietary factors that may contribute to the development of
type 2 diabetes. Now a lot of new research gives us a
clearer picture of the specific factors involved in this global health problem –
and it sure is interesting…
dietician Dr Ingrid van Heerden reports back on a talk by Prof Renée Blaauw,
presented at the South African Sugar Association’s Nutrition in Non-Communicable
Diseases Prevention Roadshow in 2015.
Type 2 diabetes is associated with chronic, low-grade inflammation,
particularly in fat tissue. Signals from the inflamed tissue interfere with the
working of insulin and promote insulin resistance – the forerunner of type 2
diabetes. When this type of inflammation occurs, thin and obese people react
produce macrophages, a type of white blood cell that engulfs and removes
harmful components in the body, and which have anti-inflammatory effects. The
fat tissue of overweight and obese people, on the other hand, produces
inflammatory cytokines – proteins that either regulate or interfere with cell
that cytokines can have either a positive or negative effect, particularly when
inflammation is present, has been linked to the development of insulin
resistance. If this isn’t counteracted by a healthy diet, weight loss and
exercise, it can progress to type 2 diabetes.
to reduce inflammation in the body include weight loss and eating plenty of
protective vegetables, fruits and whole grains.
Read: Inflammation and important factor in type 2 diabetes
intake and type 2 diabetes
Research shows that a high protein intake promotes weight loss which, in the
short term, improves glucose control. However, long-term studies show that a
high-protein intake could be risky.
In a 12-year
follow-up study with more than 27,000 participants, it was found that
high-protein diets caused an increased risk of type 2 diabetes. This result is
a direct contradiction of the message proposed by promoters of high-protein,
high-fat slimming diets who maintain that these diets will reduce the risk of type
study, conducted in Sweden among subjects between the ages of 45 and 74, dietary
data was collected in order to determine the macronutrient intake (i.e. the protein,
fat and carbohydrate intake) of the population.
subjects’ protein intake was increased, thus replacing fat or carbohydrate in
the diet, the risk of developing type 2 diabetes increased by 67% in the group
of people eating the most protein (mainly processed meats and eggs). Interestingly,
the study participants who ate more carbohydrates or fats didn’t show this
increased risk of type 2 diabetes.
also found that the subjects who ate more fibre-rich bread and cereals (grains)
were less likely to develop type 2 diabetes, which lead them to suggest the
following: “Replacing protein with carbohydrates may be favourable, especially
if fibre-rich breads and cereals are chosen as carbohydrate sources.”
recommendation was supported by a meta-analysis done by researchers in Norway
who consulted 16 studies that investigated the influence of various types of
grains on the risk of developing type 2 diabetes.
reduced risk of type 2 diabetes mellitus
In view of the positive findings reported by the Norwegian researchers, Prof
Blaauw identified another meta-analysis conducted in China that combined the
results of 17 other studies to determine if dietary fibre can help to protect
us against type 2 diabetes.
these combined study results showed that dietary fibre can decrease the risk of
developing type 2 diabetes by 19%, and that cereal fibre and insoluble fibre
(as found in unprocessed wheat, for example) can lower the risk by 23% and 25%,
co-workers identified what’s called a “dose-response effect” for dietary fibre.
This means that, as the dose of a beneficial compound (a food, a medication or
a nutrient) increases, so does the beneficial effect.
In the case
of the study by Yao et al., people eating 15g of dietary fibre a day had a 2%
reduced risk of developing type 2 diabetes, while people consuming 35g of
dietary fibre a day reduced their risk by 34%.
Read: Fibre-rich grains tied to lower diabetes risk
How can we
increase our dietary fibre intake?
This high level of fibre in the diet mirrors the dietary patterns of our
ancestors, and some rural people who still follow a diet rich in unprocessed
grains. A fibre-rich diet also contains very little animal protein. These
populations had/still have a low incidence of type 2 diabetes – something
that’s often been ascribed to their intake of unprocessed grains, wild
vegetables, roots, nuts and fruits.
While it may
not possible to return fully to the eating habits of our ancestors, we can make
a concerted effort to increase our dietary fibre intake by eating high-fibre
foods as often as possible. Try to select unprocessed foods that are rich in
dietary fibre, and low in fat and salt.
(beans, peas, lentils, soya and products made from soya beans), home-cooked
oats, quinoa, brown rice, unsifted wheat, sorghum, millet and maize, breads
with a high fibre content, and oat or wheat bran, should help you achieve an
intake of 35g of dietary fibre a day.
increase dietary fibre
It wouldn’t be wise to change from a typical Western diet (based on highly
processed “white” grains and cereals) to traditional grains overnight, as this
is guaranteed to cause digestive problems, which may put you off dietary fibre
slowly by introducing one item of high-fibre food to your diet a week, such as
1 teaspoon of wheat bran added to your breakfast cereal, fruit juice or
smoothie. Continue for 1 to 2 weeks until your digestive tract and its
population of microorganisms have adjusted to handle the extra 5g of daily
Now add a
bit more fibre to your diet. For example, add a small serving of legumes which,
when properly prepared, shouldn’t cause bloating. (Soak the legumes overnight
and discard the water. Boil in water and discard the water. Then boil again in
water until soft. Allow the legumes to soak up sufficient water with the second
cooking to be soft and digestible.)
adding fibre-rich foods to your diet over a period of 2 to 3 months, you’ll
reach the desired level of intake. In most cases, the transition will be relatively
develop symptoms of discomfort and bloating when you increase your dietary
fibre intake, despite a careful, gradual introduction, you may be intolerant or
allergic to soya or gluten. If this is the case, it’s important to have tests
done to confirm your allergy or intolerance. Consult a registered dietician to
assist you with a diet that avoids the offending foods without causing any
Extra virgin olive oil linked to lower blood sugar and cholesterol
Red meat tied to higher type 2 diabetes risk
Yoghurt and cheese tied to lower diabetes risk
1. Aune D et al, (2013). Whole grain and refined grain consumption and the risk
of type 2 diabetes: a systematic review and dose-response meta-analysis of
cohort studies. Eur J Epidemiol, 28(11): 845-58.
2. Blaauw R (2015). Dietary Factors for the Prevention of Diabetes Mellitus.
Lecture presented on 12 February 2015, at the SASA Nutrition in NCD Prevention
3. Ericson U et al, (2013). High intakes of protein and processed meat
associated with increased incidence of type 2 diabetes. Br J Nutr, 109(6):
4.Yao B et al, 2014. Dietary fibre intake and risk of type 2 diabetes: a
dose-response analysis of prospective studies. Eur J Epidemiol, 29(2):79-88.
Dr Ingrid van Heerden is a registered dietician and holds a doctoral degree in Nutrition and Biochemistry. She believes that "we are what we eat" and offers free nutrition and weight loss advice via her DietDoc service on Health24.com. Read more of her articles.