International Study: Moderate Consumption of Fats and Carbohydrates Best for Health

Research with more than 135,000 people across five continents has shown that a diet which includes a moderate intake of fat and fruits and vegetables, and avoidance of high carbohydrates, is associated with lower risk of death.

To be specific about moderate, the lowest risk of death was in those people who consume three to four servings (or a total of 375 to 500 grams) of fruits, vegetables and legumes a day, with little additional benefit from more.

As well, contrary to popular belief, consuming a higher amount of fat (about 35 per cent of energy) is associated with a lower risk of death compared to lower intakes. However, a diet high in carbohydrates (of more than 60 per cent of energy) is related to higher mortality, although not with the risk of cardiovascular disease.

These are the top messages of two reports published Tuesday (Aug. 29) in The Lancet, both produced from a major global study led by researchers at the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences. The reports were also presented on Tuesday (Aug. 29) at the Congress of the European Society of Cardiology in Barcelona, Spain.

The data are from the Prospective Urban Rural Epidemiology (PURE) study which followed more than 135,000 people from 18 low-income, middle-income and high-income countries. The study asked people about their diet and followed them for an average of seven and half years.

The research on dietary fats found that they are not associated with major cardiovascular disease, but higher fat consumption was associated with lower mortality; this was seen for all major types of fats (saturated fats, polyunsaturated fats and mono unsaturated fats), with saturated fats being associated with lower stroke risk.

Total fat and individual types of fat were not associated with risk of heart attacks or death due to cardiovascular disease.

The researchers point out that, while this may appear surprising to some, these new results are consistent with several observational studies and randomized controlled trials conducted in Western countries during the last two decades.

The large new study, when viewed in the context of most previous studies, questions the conventional beliefs about dietary fats and clinical outcomes, says Mahshid Dehghan, the lead author for the study and an investigator at PHRI.

“A decrease in fat intake automatically led to an increase in carbohydrate consumption and our findings may explain why certain populations such as South Asians, who do not consume much fat but consume a lot of carbohydrates, have higher mortality rates,” she said.

Dehghan pointed out that dietary guidelines have focused for decades on reducing total fat to below 30 per cent of daily caloric intake and saturated fat to below 10 per cent of caloric intake. This is based on the idea that reducing saturated fat should reduce the risk of cardiovascular disease, but did not take into account how saturated fat is replaced in the diet.

She added that the current guidelines were developed about four decades ago using data from some Western countries where fat was more than 40 per cent or 45 per cent of caloric intake and saturated fat intakes were more than 20 per cent. The consumption of these are now much lower in North America and Europe (31 per cent and 11 per cent respectively).

The second paper from the PURE study assessed fruit, vegetable and legume consumption and related them to deaths, heart disease and strokes.

The study found current fruit, vegetable and legume intake globally is between three to four servings per day, but most dietary guidelines recommend a minimum of five daily servings. Given that fruits and vegetables are relatively expensive in most middle-income and low-income countries, this level of consumption is unaffordable for most people in many regions of the world such as South Asia, China, Southeast Asia and Africa, where the levels of their consumption is much lower than in Western countries.

“Our study found the lowest risk of death in those who consumed three to four servings or the equivalent to 375 to 500 grams of fruits, vegetables and legumes per day, with little additional benefit for intake beyond that range,” said Victoria Miller, a McMaster doctoral student and lead author of the paper. “Additionally, fruit intake was more strongly associated with benefit than vegetables.

“The PURE study includes populations from geographic regions which have not been studied before, and the diversity of populations adds considerable strength that these foods reduce disease risk.”

Previous research has shown that eating fruits, vegetables and legumes decrease the risk of cardiovascular disease and deaths, but most studies were conducted mainly in North America and Europe with a few from other parts of the world.

“Raw vegetable intake was more strongly associated with a lower risk of death compared to cooked vegetable intake, but raw vegetables are rarely eaten in South Asia, Africa and Southeast Asia,” Miller said. “Dietary guidelines do not differentiate between the benefits of raw versus cooked vegetables — our results indicate that recommendations should emphasize raw vegetable intake over cooked.”

Legumes include beans, black beans, lentils, peas, chickpeas and black-eyed peas and are frequently eaten as an alternative to meat or some grains and starches such as pasta and white bread.

“Legumes are commonly consumed by many populations in South Asia, Africa and Latin America. Eating even one serving per day decreases the risk of cardiovascular disease and death. Legumes are not commonly consumed outside these geographic regions, so increased consumption among populations in Europe or North America may be favourable,” said Miller.

In a third study, published concurrently by The Lancet Diabetes and Endocrinology, the same researchers looked at the impact of fats and carbohydrates on blood lipids and blood pressure.

They found that LDL (so-called ‘bad’ cholesterol) is not reliable in predicting effects of saturated fat on future cardiovascular events. Instead, the ratio of Apolipoprotein B (ApoB) and Apolipoprotein A1 (ApoA1), or organizing proteins in the blood, give the best indication of the impact of saturated fat on cardiovascular risk.

Andrew Mente, an investigator at PHRI and an associate professor of the Department of Health Research Methods, Evidence and Impact at McMaster, is an author on the three studies.

“The findings of these studies are robust, globally applicable and provide evidence to inform nutrition policies. This is relevant because in some parts of the world nutritional inadequacy is a problem, whereas in other parts of the world nutritional excesses may be the problem,” he said.

“Most people in the world consume three to four servings of fruits, vegetables and legumes a day. This target is likely more affordable and achievable, especially in low and middle-income countries where the costs of fruits and vegetables are relatively high.”

“Moderation in most aspects of diet is to be preferred, as opposed to very low or very high intakes of most nutrients,” said Salim Yusuf, principal investigator of the study and the director of the PHRI.

Source: McMaster University


Today’s Comic

Researcher Finds Fats and Oils Help Unlock Full Nutritional Benefits of Veggies

The song says a spoonful of sugar helps the medicine go down, but an Iowa State University scientist has published new research suggesting a spoonful of oil makes vegetables more nutritious.

A new study led by Wendy White, an associate professor of food science and human nutrition, shows that eating salad with added fat in the form of soybean oil promotes the absorption of eight different micronutrients that promote human health. Conversely, eating the same salad without the added oil lessens the likelihood that the body will absorb the nutrients.

The study appeared recently in the peer-reviewed American Journal of Clinical Nutrition, and the results may ease the guilt of countless dieters who fret about adding dressing to their salads.

White’s study found added oil aided in the absorption of seven different micronutrients in salad vegetables. Those nutrients include four carotenoids – alpha and beta carotene, lutein and lycopene – two forms of vitamin E and vitamin K. The oil also promoted the absorption of vitamin A, the eighth micronutrient tracked in the study, which formed in the intestine from the alpha and beta carotene. The new study builds on previous research from White’s group that focused on alpha and beta carotene and lycopene.

White said better absorption of the nutrients promotes a range of health benefits, including cancer prevention and eyesight preservation.

The study also found that the amount of oil added to the vegetables had a proportional relationship with the amount of nutrient absorption. That is, more oil means more absorption.

“The best way to explain it would be to say that adding twice the amount of salad dressing leads to twice the nutrient absorption,” White said.

That doesn’t give salad eaters license to drench their greens in dressing, she cautioned. But she said consumers should be perfectly comfortable with the U.S. dietary recommendation of about two tablespoons of oil per day.

The study included 12 college-age women who consumed salads with various levels of soybean oil, a common ingredient in commercial salad dressings. The subjects then had their blood tested to measure the absorption of nutrients. Women were chosen for the trial due to differences in the speed with which men and women metabolize the nutrients in question.

The results showed maximal nutrient absorption occurred at around 32 grams of oil, which was the highest amount studied, or a little more than two tablespoons. However, White said she found some variability among the subjects.

“For most people, the oil is going to benefit nutrient absorption,” she said. “The average trend, which was statistically significant, was for increased absorption.”

Research collaborators include Yang Zhou, a former ISU postdoctoral researcher; Agatha Agustiana Crane, a former graduate research assistant in food science and human nutrition; Philip Dixon, a University Professor of Statistics, and Frits Quadt of Quadt Consultancy, among others.

Unilever, a global food company, provided funding for the research. The company had no input in the publication of the study.

So a spoonful or two of salad dressing may indeed help you derive the optimal nutritional benefit from your veggies. The relationship between a spoonful of sugar and the medicine going down, however, remains outside the scope of White’s research.

Source: Iowa State University of Science and Technology


Today’s Comic

Infographic: The Good, the Bad and the Ugly Fats


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Source: American Heart Association

The Fat Content of Red Meat

Contrary to popular belief, lean red meat does not contain high levels of fat or saturated fat. The total fat content of red meat has been considerably reduced over the last 40 years and the amount of fat in red meat is actually much lower than most people think.

The application of improved animal breeding and butchery techniques means that fully trimmed lean red meat typically contain between 4g – 10g of fat per 100g. Despite common reference to animal fats as being ‘saturated’, red meat contains both saturated and unsaturated fats. Indeed, lean beef and pork contain more unsaturated fat than saturated fat. Red meat also contains small amounts of omega-3 polyunsaturates, which help keep the heart healthy, especially in people who’ve already had a heart attack.

Saturated Fat

Originally, all saturated fats were thought to be associated with increased blood cholesterol, but it has become apparent that individual saturated fatty acids differ in their effect. One of the main saturated fatty acids present in red meat is called stearic acid and there is evidence that this fatty acid has no adverse effects on cholesterol levels in the blood.

A food is defined as ‘high’ in saturated fat if it contains 5g (or more) saturated fat per 100g. A food is defined as ‘low’ in saturated fat if it contains 1.5g (or less) saturated fat or less per 100g. Most lean red meats are, therefore, not high in saturated fat and contain only moderate amounts (see table below).

Saturated fat content, per 100g, lean cooked red meat

Red meat cut
Saturated fat
Lean beef rump steak, grilled 2.5g
Lean beef topside 2.1g
Lean stewing beef 2.3g
Lean lamb loin chops, grilled 4.9g
Lean leg of lamb, roasted 3.8g
Lean stewing lamb 6.5g
Lean diced cubed pork 1.6g
Lean loin chops, grilled 2.2g
Lean pork leg, roasted 1.9g

Source: Meat and Health

Cooking Fats and Oils


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All cooking fats and oils are made up of saturated, polyunsaturated and monounsaturated fatty acids in different proportions.

Generally, oils and fats with a high proportion of saturated fat are less healthy than those with higher poly and mono unsaturated fats.

Polyunsaturated fats can help lower cholesterol, omega-3 polyunsaturates may help protect against heart disease and omega-6 fatty acids may help with growth and brain function.

Monounsaturated fats can also help lower cholesterol if they replace saturated fats. Monounsaturated fats may also help decrease the risk of breast cancer and rheumatoid arthritis pain.

Read more . . . . .


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