Why do we choose yellow maizemeal?

Why do we choose yellow maizemeal? It's a very important question for diabetics and those suffering from hypertension. In Europe it is known as polenta and grits in the USA.

We mill and consume unsifted yellow maize, with no separation of the three streams of meal, bran and germ; daily through the colder months. Other than the grinding it is completely unprocessed. In summer we choose rather green mealies from our garden when the vervets allow it. They too know that "corn" is a choice food.

Stone milled 100% whole corn and cream

So why do we choose yellow maize over the more traditional white?

In the first instance it is substantially cheaper. According to "SAFEX Feeds" white maize traded between 4700 and 5400 rand on 28th February, 2025 per ton; but yellow around R4300.

The difference was even greater until this season when farmers planted more white and less yellow maize; to our detriment.

If you have a mill, your breakfast will cost around 20c per generous helping of maizemeal; at R4.50/kg. Tasteless cornflakes will set you back about 70 rand per kilogramme.

Secondly we just find the yellow porridge tastier. That is probably because coloured foods generally have more of the phytochemicals that give our meals their flavour; and of course many other important nutrients too.

Thirdly there is the question as to why farmers never feed their poultry, pigs and cattle on white maize? It’s not just because it is more expensive. But what are the facts about the nutrient content of these different varieties?

Research comparing yellow and white maize

First of two passes through a stone mill

Interesting research^[1] reveals that scientists have discovered staggering differences between the nutrient content of three varieties of commercial sifted white meal as compared to unrefined yellow maize, similar to what we eat.

In some countries commercial yellow maizemeal is known as polenta but it comes with differing degrees of sifting; refinement to extract the bran and germ.

Protein content

The protein content of unrefined yellow maize was substantially higher than the three commercial brands of the sifted white variety; from 10 - 100% more.

The bran and germ also contain some of the more important essential amino acids which would have been extracted from the white maizemeal.

Fibre content

Unsifted yellow maize contains between 50 - 300% more fibre than the white meal; which is not surprising as commercial millers extract most or all of the bran.

This is important for large intestine health and in particular the microbiome, those friendly bugs in the gut that contribute so much to wellness; they are wholly dependent on the fibre in our food.

Fibre gives carbs their satiety; without it we are inclined to overindulge with obvious consequences. South Africans, in particular the women are amongst the most obese in the whole world.

Fat content

Compared with two of the three white maize brands, the unsifted yellow contains between 30 - 50% more of the important fatty acids located in the germ.

Let us recall that 60% of the brain is made up of fat.

But interestingly the third white maize brand actually had more fat. Whilst the bran had been extracted, the germ which is where these lipids are located was left intact.

That is most unusual as rancidity begins as soon as the grain is cracked. Wholemeal should be consumed within a week of being milled; or frozen.

Carbohydrate content

Commercial white maizemeal contains up to one third more starch than the unsifted yellow porridge that we enjoy. It contributes to what is known as Excessive Refined Carbohydrate Consumption, obesity and diabetes.

Minerals

I will comment only on four of the minerals; herein lies some very important information for those suffering from high blood pressure and the risk of heart disease.

Magnesium and zinc

Unrefined yellow maizemeal contains 15 times more magnesium and 5x extra zinc. These two elements are involved in a host of very important chemical reactions going on continuously in the body, far too many to mention here. But both are absolutely essential for the rapid degradation of homocysteine, a toxic breakdown product of protein metabolism. High levels in the blood are associated with numerous serious diseases.

• The H factor
  

Sodium and potassium

White maizemeal contains 50% more sodium and astonishingly 1/26th of the potassium.

There is very strong research associating hypertension with too much salt (sodium) and not enough potassium. That means that white commercial porridge and putu are a massive 50 times more likely to contribute to blood pressure than their unsifted yellow cousins; apart from the glycemic carbs which fuel metabolic syndrome.

Put differently yellow maizemeal would be at least 50 times more effective in helping to lower blood pressure.

Vitamin A

The yellow colour of maize is the rich source of beta-carotene which is two vitamin A molecules joined together. A typical 150 g serving of the porridge contains nearly 50% of the recommended daily allowance for preschool children. But the white variety has none.

Half a million children go blind every year in sub-Saharan Africa due to a vitamin A deficiency; 42 die daily in SA^[2].

Macular degeneration

Yellow maize is a rich source of lutein and zeaxanthin, carotenoids essential for the prevention of adult-onset macular degeneration; a deficiency is the most common cause of blindness in the elderly.

• Zeaxanthin macular degeneration
  

Flavour

The flavour of a food is dependent on phytonutrients specific to each plant. So the capsaicin in chilies would give them a very different taste as compared with the curcumin in turmeric or the allicin in garlic. The fat in the germ of wholegrain also increases the mouthfeel by dissolving these substances more effectively for our taste buds.

Both white and yellow refined maizemeal have little flavour as these taste-nutrients have been extracted.

Consequently the commercial brands used to make putu, porridge and pap are almost completely tasteless. Excessive salt and sugar have to be added to make them palatable; and often tomato-based sauces which in themselves also have large amounts of chemical flavouring.

In short refined white maizemeal makes a substantial contribution in various ways to hypertension; or to put it differently the unprocessed yellow grain would give very significant protection.

Too much salt is a key driver of hypertension; up to 30% of adult South Africans are affected. Diets high in sodium and low in potassium are central to this affliction. As a nation we consume on average 2 - 3 times the recommended amount of 5g (1 teaspoon) per day; mostly because of our tasteless ultra-refined foods.

Why do we choose yellow maizemeal? It's better in every way.

Obesity

• 7% of men born in the 1960s were obese by the age of 25 years.
• 16% born in the 1990s were obese by the age of 25 years.
• 25% of those born in 2015 are projected to be obese by 2040^[3].

For women it's even worse.

Refined grains are at the heart of this pandemic. Coupled with sugar and ultra-processed inflammatory seed oils added to tasteless starches, it is indeed a profound tragedy; one of early pain, disability and ultimately death from type 2 diabetes-related conditions.

Take home

To put it bluntly, commercial ultra-processed white maizemeal is expensive, low in protein and rich in particularly glycemic carbohydrate. It is one of the chief contributors to the poor health experienced by so many South Africans; and the permanent stunting of more than a quarter of our children by the age of 5.

You can occasionally find unrefined maizemeal at some farmers’ markets. Soak the "grits" overnight before cooking the next day, as you would do with dried beans for example.

Why do we choose yellow maizemeal?

Why do we choose yellow maizemeal? Its ratio of sodium to potassium means that it gives 50 times better protection against hypertension than the white grain; unsifted it has a much lower GI, more fibre and protein.