The dangers in our cooking fat

A tasty dish of fried bhajia and sausage. Over-consumption of cheap cooking fats, driven by their tasty flavour, poses a major public health crisis in Kenya. Photo/PETERSON GITHAIGA

What you need to know:

  • Cheap cooking fats contain high levels of trans fatty acids, increasing our risk of developing heart disease

Over-consumption of cheap cooking fats, driven by their tasty flavour, poses a major public health crisis in Kenya, the Saturday Nation has learned.

The looming catastrophe is worsened by the absence of regulation on the manufacture and labelling of cooking fats to guide consumers. The situation is compounded by an acute shortage of nutritionists, whose ratio to the population falls far below World Health Organisation (WHO) guidelines.

The cheap cooking fats contain high levels of trans fatty acids. The consumption of trans fats increases one’s risk of developing heart disease and stroke, and is also a factor in developing type 2 diabetes.

Riding on the crest of consumers’ blissful ignorance, manufacturers are running all the way to the bank, because the cheap hydrogenation process used in manufacturing popular cooking fats and margarines ensures longer shelf life. The products are also easier to ferry across vast expanses of land, compared to the more expensive liquid oils.

In an interview, the vice-chancellor of the Presbyterian University of Eastern Africa, Prof Kihumbu Thairu, warned that trans-fatty acids (TFAs), which are found in the popular brands of cooking fats and margarines, decrease the response of human cells to insulin, leading to maturity-onset (type 2) diabetes.

Weak immune system

The fats also predispose to cancer by inhibiting the action of enzymes that destroy toxic and carcinogenic (cancer-causing) chemicals in the body, says Prof Thairu, a neurophysiologist and chairman of the Commission for Higher Education. Trans fats, he says, also weaken the body’s immune system and increase vulnerability to infections.

Accumulation of fats in the lining of blood vessels, the professor says, hardens them, leading to high blood pressure, coronary heart disease and stroke — concerns the government chief nutritionist, Mrs Terry Wefwafwa, and Prof Paul Kioy, a neurologist and former student of Prof Thairu, share.

And, in a claim that should worry the growing pool of senior citizens (60 years plus), Prof Thairu associates trans fatty acids with Alzheimer’s disease — a condition that accelerates mental decline in older people.

Prof Thairu says many Africans carry the gene that predisposes to Alzheimer’s disease. “But only a few used to get the disease,” asserts Prof Thairu, who suspects that a traditional diet inhibits the disease. Yam, for instance, seems to have helped ward off the disease as indicated by comparative studies between Nigerians and African Americans.

A Google search found reference to a study published in the Archives of Neurology of February 2003, which showed that the intake of both trans fats and saturated fats promotes the development of Alzheimer’s disease.

It described the disease as “a truly terrible form of dementia, in which people of middle age and older are progressively stripped of their memories, identities, personalities and ultimately their lives.”

Although no study to firm up the link between trans fats and Alzheimer’s disease has been done in Kenya, Prof Thairu has observed that the disease is increasing among older Kenyans, and this, he suspects, could be due to high intake of trans fats.

Prof Kioy says the only study he knows of in Kenya was done in two locations of Nyeri, Central Province, but the sample was too small to extrapolate to the rest of the country.

Although there is no direct correlation between TFAs and Alzheimer’s disease, Prof Kioy mentions a Canadian ‘activist’ study, which showed that “there is a trend towards a higher rate of the disease” when you eat trans fats.

On the other hand, Prof Kioy says, “Trans polyunsaturated fats have been shown to protect against Alzheimer’s disease, and to slow it down where it had occurred,” even as he insists that “nobody really knows what causes AD. There are many suggestions but none has been linked with a cause and effect.”

Out of nine locally manufactured fats, which Prof Thairu and his students at Moi University — his last station before moving to the PCEA University in Kikuyu, examined — only two brands showed they had no trans fats.

So, why is Kenya Bureau of Standards (Kebs) not regulating the manufacture and labelling of cooking fats?

In an e-mailed response to Saturday Nation queries addressed to Kebs boss Joel Kioko, Ms Agneta Okoba and John Angila said it was up to the ministry responsible for public health to give them guidelines on which to base a standard, and to educate wananchi on the hazards of trans fats.

Mrs Wefwafwa said in an interview that the nutrition division has only recently come alert to the looming crisis, which she partly blames on the fast foods culture.

Although the nutrition boss says fats per se are not bad — “they protect the vital body organs” and that “deposited in the right places, they help us feel warm,” Kenyans are consuming far too much fat.

The average urbanite has tea with mandazi (a variant of doughnuts) for breakfast, chips and sausages for lunch and ugali with sukumawiki cooked with generous amounts of fat for supper. The result, Mrs Wefwafwa says, is fat intake well above the WHO limits.

Vegetable fats standards
According to Kebs, WHO recommends that a maximum of one per cent of the total calories consumed from diet may be from TFAs. The Kenya Standards for vegetable fats and oils have set a limit of 0.25 per cent for all free fatty acids.

Other parameters controlled by Kebs include the saturation level (by iodine value) and hence control of partial hydrogenation, the process linked to production of trans fats.

Kebs further states that Kenya has national standards for labelling of products as well as for nutrition and health claims (KS 40 & KS CAC/GL 23).

“These standards provide for minimum requirements that should go to a label,” Kebs says but adds: “It’s not a mandatory requirement for one to declare free fatty acid content.”

The standards watchdog absolves itself over this, saying “the ministry responsible for public health will be in a better position to provide this information as the primary government custodian of health matters.”

This regulatory lacuna could be responsible for the situation where, according to Prof Thairu, “many edible oil manufacturing companies in Kenya produce TFAs in shortenings and margarine (with) some products (having) up to 40 per cent trans fats.”

Shoppers, Prof Thairu says, prefer shortenings and margarines to liquid oils — the main reason being their low cost and tempting taste — what industry refers to as the “pleasing mouth feel”. Advertisers, the don says, also play a major role in popularising cheap fats.

And yet, barring reheating of vegetable oils — a process that unleashes TFAs — pure cooking oils such as sunflower, corn oil, peanut oil and palm oil, are healthier options than the potentially dangerous cooking fats. Prof Thairu considers sunflower oil “one of the best oils comparable to olive oil”.

Since 1977 when Kenyans began to consume margarine and shortenings, the incidence and prevalence of coronary heart disease in the country has shot up, the professor asserts. Quoting an editorial in a 2006 issue of the British Medical Journal, the don points out that, a two per cent increase in the total energy intake from TFAs is associated with 23 per cent increase in the incidence of coronary heart disease.

Because of this, various countries, starting with Denmark, which banned trans fatty acids in 2003, have moved to regulate their consumption.

The don is concerned that current labelling of edible fats and margarines is unhelpful to consumers.

A survey he conducted with students of Moi University “did not show any information on trans fats”.

The study examined a range of popular cooking fats, most of which declared “no cholesterol” but were silent on TFAs. Only two brands declared having “no trans fats”.

According to Prof Thairu, manufacturers and the government have the duty to work towards a national food policy, which should prohibit the sale of food and products with more than two per cent of total energy intake of trans fats — similar to UK regulation.

“The policy should also disqualify the usage of oils or fats with more than 2 per cent total energy intake of trans fats as an ingredient of foods,” he says.

Prof Thairu suggests that food manufacturers be obliged by law to state the amount of trans fats in their foods in the nutrition label, as is currently the case in the US and UK.

Manufacturing process

He also roots for “alternatives to TFA-containing products (to) be promoted nationally and used.”

Since popular fats are cheap to make, the don wants alternative manufacturing processes enforced. He says: “Increasing the temperature, pressure and duration of the process, reduces the amount of trans fats in the products — increasing costs a bit”. However, “chemical interesterification can be used since TFA-bearing products can be replaced without extra cost while retaining what the industry calls “pleasing mouth feel.””

Fats are mixtures of triacylglycerols consisting of various fatty acids esterified with glycerol. Interesterification is the result of heat treatment that causes an exchange of some of the fatty acids between the glycerol molecules and alters the properties of the fat. Lard, for example, is not a good creaming agent for baked products until it has been so treated. Good news, indeed, because according to the don, pork lard has no trans fats.

Not all trans fats are bad, according to Prof Thairu and Mrs Wefwafwa. The fats, they say, are found in natural form in meat and dairy products, with the don adding “quantities do not appear to be harmful to health”. Butter, he says, is safer than margarine.

The problem, they say, is artificial fats, whose process of manufacture, entailing partial hydrogenation of plant oils, makes them harmful.

For fans of fast foods, especially chips and sausages, Prof Thairu warns that re-heating cooking oils for more than 10 minutes, even if they might have been harmless before, heightens the risk of exposure to TFAs.

Nutrition division
Although the chief nutritionist said the prevalence of trans fats in Kenya has not been quantified, her division, together with the Nutritionists and Dieticians Institute, was working closely with Kebs to formulate a standard informed by WHO guidelines.

How soon? “Usually when we define a standard and start working with Kebs, in six months we are through,” she assures.

The nutrition division has not packaged information to educate wananchi on the dangers of TFAs because of acute staff shortage. The division, Mrs Wefwafwa says, has only 414 of Kenya’s estimated 1,200 nutritionists.

While WHO recommends one nutritionist/dietician for every 5,000 people, the current ratio of one public nutritionist for almost 100,000 Kenyans or a nutritionist for every 33,000 Kenyans (that is, all nutritionists combined) falls way below the requirement.

Pending formulation of a standard, Mrs Wefwafwa encourages use of liquid oils from sunflower, simsim and groundnuts.