Caveman diet proves healthy

But widely held diet-heart theory may be wrong

EATING like a caveman, or woman, proved to be a success strategy for obese postmenopausal women to lose weight, improve their cholesterol and lower their risk for diabetes and cardiovascular disease, a new study presented to the Endocrine Society in Boston has found.

In a statement released by the British Medical Journal, the lead author of the study, Caroline Blomquist, a doctoral student in the Department of Public Health and Clinical Medicine at Umeå University in Umeå, Sweden said: “A paleolithic-type diet, high in polyunsaturated fatty acids, may have long-term beneficial effects on obesity-related disorders, including reduced risk for diabetes and cardiovascular disease.”

During their research, Blomquist and her colleagues put 35 obese post-menopausal women, with normal insulin levels, on a paleo diet (30% protein, 30% carbohydrates and 40% fat), while the others ate a prudent “traditional” health diet, with 15% protein, 30% fat, and 55% carbohydrates.

Those on the paleo diet ate lean meat, fish, eggs, vegetables, fruit, nuts and berries and used olive oils and avocado oils as additional fat sources.

The diet excluded dairy products, cereals, added salt and refined fats and sugar.

The women were monitored over two years.

Researchers found that while women on both diets lost significant body weight, those on the paleo diet had significantly lower levels of fatty acids, normally associated with the development of diabetes.

“Obesity-related disorders have reached pandemic proportions, with significant economic burden on a global scale.

“It is of vital interest to find effective methods to improve metabolic balance,” Blomquist said.

Meanwhile, a study published in the British Medical Journal found that lowering cholesterol with vegetable oils might not curb heart disease risk or help you live longer.

The findings add to doubts around the widely held belief that vegetable oils, rich in linoleic acid, are good for heart health.

According to a statement published by the BMJ, the traditional “diet-heart hypothesis” predicts that replacing saturated fat with vegetable oils rich in linoleic acid will reduce cardiovascular deaths by lowering blood cholesterol levels.

Although many studies support this theory, this paradigm has never been causally demonstrated in a randomised controlled trial and thus has remained uncertain for more than 50 years. Furthermore, key findings from landmark trials on this topic were not published.

Now a team of US researchers, led by the National Institute of Health and University of North Carolina’s Christopher Ramsden, set out to re-examine this hypothesis by analysing recovered data from a large randomised, controlled trial that took place 45 years ago.

The project was called the Minnesota Coronary Experiment (MCE) and entailed researchers following 9 423 participants from state mental hospitals and a nursing home for up to 4½ years.

The control group ate a diet high in saturated fat.

As expected, the diet enriched with linoleic acid lowered cholesterol levels, but this did not translate to improved survival.

“In fact, participants who had greater reduction in blood cholesterol had higher, rather than lower, risk of death,” the researchers said.

In 2013, the researchers examined unpublished data from a similar trial – the Sydney Diet Heart Study – and found the risk of death from coronary heart disease was higher in those who replaced saturated fat with vegetable oil rich in linoleic acid.

The researchers found there was a growing body of evidence that the benefits of replacing saturated fat with vegetable oils, rich in linoleic acid, were over-emphasised in the past.

They also noted that although small amounts of linoleic acid were essential for health, high intakes were not natural to human diets, and preliminary evidence linked by-products of linoleic acid to chronic pain and other diseases.

University of Queensland senior lecturer Lennert Veerman said in the statement that his advice was to eat more fish, fruits, vegetables, and wholegrains.

“We should avoid salt, sugar, industrial trans fats, and avoid over-eating,” he said.