by Marion Nestle

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Jun 18 2014

Time Magazine: “Eat Butter.” Maybe in moderation, please?

I love butter as much as the next person, but when I went to New York’s Food Fest yesterday, the butter makers were all proudly displaying Time Magazine’s provocative June 23 cover.

INTcover0623LR.jpg

The cover story is by Bryan Walsh.

It comes with an even more provacative video–one of those “everything you thought you knew about diet is wrong” things.

I’m quoted in his article, but I wish he had quoted more of my comments about context.

He says saturated fat consumption is down, but heart disease is still the number one killer of Americans.

Yes it is, but not nearly as much as it used to be (as I discussed in a previous post):

Americans must be doing something right.

The big problem is type-2 diabetes.  It’s going up in parallel with obesity: Fat calories and sugar calories contribute to obesity.

The dietary bottom line?  Eat your veggies, balance calories, and stay active.

Really, it’s not more complicated than that.

But that kind of advice will never make the cover of Time, alas.

Addition, June 20: David Katz on how easy it is to misinterpret studies of saturated fat (or sugars for that matter) and health.

Mar 19 2014

Is saturated fat a problem? Food for debate.

What is a poor eater to do?

The latest meta-analysis of the effects of saturated fat on heart disease finds—none.

This study, reported in the Annals of Internal Medicine (doi: 10.7326/M13-1788), examined the results of

  • 32 observational studies involving 530 525 participants
  • 17 observational studies involving 25 721 participants
  • 27 randomized controlled trials involving 103 052 participants

The result?

Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats. 

This meta-analysis follows an editorial in a Mayo Clinic publication (http://dx.doi.org/10.1016/j.mayocp.2013.11.006) by authors who argue that saturated fat is not the problem.  Carbohydrates (e.g., sugars) are the problem.  The authors argue:

  • Effects of saturated fat on blood cholesterol are weak and transient.
  • Meta-analyses have found a lack of an association between heart disease mortality and saturated fat intake.
  • Stroke studies find that patients with stroke had eaten less saturated fat.
  • Long-term studies find that people with the highest dairy consumption have the lowest mortality risk, and also low diabetes and heart disease.
  • Dietary trials find trivial or no benefit at all from decreasing saturated fat and/or increasing intake of polyunsaturated fat.

On this basis, they say that advice to reduce intake of saturated fat is irrational.

The New York Times asked several experts for comment on the meta-analysis, among them Dr. Frank Hu of Harvard:

The single macronutrient approach is outdated…I think future dietary guidelines will put more and more emphasis on real food rather than giving an absolute upper limit or cutoff point for certain macronutrients…people should try to eat foods that are typical of the Mediterranean diet, like nuts, fish, avocado, high-fiber grains and olive oil.

Dr. Hu was referring to a large clinical trial (not included in the meta-analysis), which concluded that a diet with more nuts and extra virgin olive oil reduced heart attacks and strokes when compared with a lower fat diet with more starches.

The Times story contained a reminder that the American Heart Association issued dietary guidelines last year to “restrict saturated fat to as little as 5 percent of their daily calories, or roughly two tablespoons of butter or two ounces of Cheddar cheese for the typical person eating about 2,000 calories a day.”

How to make sense of this?

I vote with Frank Hu that dietary advice should focus on food, not nutrients.

Focusing on one or another nutrient—fat, saturated fat, cholesterol, or sugar—takes foods out of their caloric as well as dietary context.

My guess: If you balance food intake with physical activity and are not overeating, the specific proportion of fat, carbohydrate, and protein won’t matter nearly as much.

While the arguments about fat v. sugar go on and on:  Eat your veggies, vary the foods you eat, don’t gorge, and enjoy what you eat.

Nov 28 2012

The Danish fat tax: reflections on its demise.

My latest publication is a commentary on the reversal of the Danish fat tax in New Scientist, November 26:

Fighting the flab means fighting makers of fatty foods

A YEAR ago in these pages, I congratulated the Danish government on its revolutionary experiment. It had just implemented a world-first fiscal and public health measure – a tax on food products containing more than 2.3 per cent saturated fat.

This experiment has now been dropped. Under intense pressure from the food industry in an already weak economy, the Danish government has repealed the fat tax and abandoned an impending tax on sugars.

Nobody likes taxes, and the fat tax was especially unpopular among Danish consumers, who resented having to pay more for butter, dairy products and meats – foods naturally high in fat.

But the real reason for the repeal was to appease business interests. The ministry of taxation’s rationale was that the levy on fatty foods raised the costs of doing business, put Danish jobs at risk and drove customers to buy food in Sweden and Germany.

In June this year, a coalition of Danish food businesses organised a national repeal-the-tax campaign. The coalition said that fat and sugar taxes would cause the loss of 1300 jobs, generate high administrative costs and increase cross-border shopping – precisely the arguments cited by the government for its U-turn.

We can now ask the obvious questions. Did the tax achieve its aims? Was it good public policy? What should governments be doing to reduce dietary risk factors for obesity?

The purpose of food taxes is to reduce sales of the products concerned. In bringing in its fat tax, the Danish government also wanted to raise revenue, reduce costs associated with obesity-related diseases, and increase health and longevity. A year is hardly time to assess the impact on health, but the tax did bring in $216 million. Danes will now face higher income taxes to make up for the loss of the fat tax.

Business groups insist that the tax had no effect on the amount of fat that Danes ate, although they chose cheaper foods. In contrast, economists at the University of Copenhagen say Danish fat consumption fell by 10 to 20 per cent in the first three months after the tax went into effect. But it is not possible to know whether it fell, and cross-border shopping rose, because of the tax or because of the slump that hit the Danish economy.

A recent analysis in the BMJ suggests that 20 per cent is the minimum tax rate on food to produce a measurable improvement in public health. The price of Danish foods hit by the tax increased by up to 9 per cent, enough to cause a political firestorm but not to make much of a difference to health.

Is a saturated-fat tax good public policy? A tax on sugary drinks would be a better idea. To see why, recall that obesity is the result of an excess intake of calories over what we burn. Surplus calories, whether from carbohydrate, protein or fat, are stored as body fat. All food fats are a mix of unsaturated and saturated fatty acids; all provide the same number of calories per unit weight.

Saturated fats raise the risk of coronary heart disease, although not by much. Trans fats, banned in Denmark since 2003, are a greater risk factor. Because the different saturated fatty acids vary in their risk, imposing a single tax on them as if they are indistinguishable is difficult to support scientifically.

For these reasons, anti-obesity tax measures in other countries have tended to avoid targeting broad nutrient groups. Instead, they focus on processed foods, fast food or sugary drinks – all major sources of calories. Taxing them seems like a more promising strategy.

What else should governments be doing? That they have a role in addressing the health problems caused by obesity is beyond debate, not least because they bear much of the cost of dealing with such problems. In the US, economists estimate the cost of obesity-related healthcare and lost productivity at between $147 billion and $190 billion a year. The need to act is urgent. But how?

One lesson from Denmark is that small countries with open borders cannot raise the prices of food or anything else unless neighbouring countries also do so. But the greater lesson is that any attempt to encourage people to eat less will encounter fierce food-industry opposition. Eating less is bad for business.

In the US, state and city efforts to tax sugary drinks have met with overwhelming opposition from soft-drink companies. They have successfully spent tens of millions of dollars lobbying legislators and convincing the public that such measures deprive voters of their “right to choose” or, as in Denmark, can damage the economy.

What’s more, the poor cannot be expected to support measures that increase food costs, even though obesity-related problems are much more common among low-income groups.

If governments really want to reduce the costs of obesity-related chronic diseases, they will have to address the problem at its source: the production and marketing of unhealthy food products.

A review by the American Heart Association cites increasing evidence for the benefits of anti-obesity interventions: food taxes, subsidising healthy foods, media campaigns to promote exercise and good diet, restrictions on portion sizes, and restrictions on the marketing of unhealthy foods and their sale in schools.

Governments must decide whether they want to bear the political consequences of putting health before business interests. The Danish government cast a clear vote for business.

At some point, governments will need to find ways to make food firms responsible for the health problems their products cause. When they do, we are likely to see immediate improvements in food quality and health. Let’s hope this happens soon.

Marion Nestle is the author of Food Politics and What to Eat and is the Paulette Goddard professor of nutrition, food studies, and public health at New York University

Nov 21 2012

Mon dieu. The French “Nutella tax.”

Not to worry.  This is just a proposal.

A French Senator wants the country to impose a 300% increase in the tax on palm oil imports, thereby raising the price of products containing it—like Nutella, the chocolate-hazelnut spread beloved by European children (and adults).

Of course they love it.  The first ingredient is sugar.

But the second ingredient is palm oil, high in saturated fats.  Palm oil production, again alas, is strongly linked to deforestation and other environmental problems in Malasia and Indonesia.

The proposed tax distresses Malasian palm oil producers:

The action…to propose onerous new burdens on palm oil producers, is irresponsible, badly-informed and ignores the primary source of saturated fats in the French diet [referring to trans fats].

The proposed tax also distresses the makers of Nutella, as well it should.  Most Nutella eaters probably think they are eating hazelnuts and chocolate.  It must come as an unpleasant surprise to learn that the first two ingredients are sugar and palm oil.

At a meeting in Boston this week, Joe O’Toole, the president of Lucullus, a French specialty food company, brought me the November 16 edition of Le Figaro.  He knew I’d want to see the two-page ad defending Nutella’s use of palm oil.

My rather loose translation:

Nutella, you are delicious but why do you have palm oil?

Let’s talk about palm oil.

For 50 years, the French have trusted us to be an important brand.  This is an important responsibility.  This is why we have always made responsible choices in our selection of ingredients.

Today, Nutella finds itself in an unjust position at the heart of a debate about palm oil….Palm oil gives smoothness (“l’onctuosité”) and stability to the recipe.

…Contrary to certain ideas and opportunistic communications…palm oil is not dangerous to health. Nutritionists say…Nutella contains less saturated fat than most snacks or breakfasts.

At the bottom of both pages, the ad says: “For your health, eat at least five fruits and vegetables per day.”

Oh.  OK. [It turns out that the French government requires this statement on all food ads.]

Nutella’s website has a Q and A.  For example:

How can Nutella® help moms at breakfast time?

It can be difficult to persuade children to eat breakfast. When used in moderation with complementary foods, Nutella® is a quick and easy tool to encourage kids to eat whole grains, such as whole wheat toast, English muffins, toaster waffles and bagels.

The chocolate milk argument!  It sounds better in French, no doubt.

Update, November 23: Thanks to Lucie for finding this annotated, alternative version of the ad.

 

 

 

 

 

 

 

 

 

Aug 5 2012

Low carb or low fat: Do calories count?

Here’s my once a month on the first Sunday Food Matters column for the San Francisco Chronicle, out today:

Nutrition and public policy expert Marion Nestle answers readers’ questions in this column written exclusively for The Chronicle. E-mail your questions to food@sfchronicle.com, with “Marion Nestle” in the subject line.

Q: I’m confused about calories. If I cut calories to lose weight, does it matter what foods I eat? Or are all calories the same?

A: As the co-author of “Why Calories Count: From Science to Politics,” I hear this question all the time.

The short answer: Calories matter for weight. The choice of foods that provide the calories matters a lot for health and may make it easier for you to diet successfully.

To lose weight, reducing calorie intake below expenditure works every time.

To prove this point, a professor at Kansas State University lost 27 pounds in 10 weeks on the Twinkies diet – one Twinkies every three hours with occasional snacks of chips, sugary cereals and cookies. Even so, he cut his usual calorie intake by 800 a day. Anyone would lose weight doing that.

Only four dietary components provide calories: fat (9 per gram), carbohydrate and protein (4 per gram each) – and alcohol (7 per gram).

Does the particular mix of these components make any difference to weight loss? Yes, say proponents of diets low in carbohydrate, especially rapidly absorbable sugars and refined starches.

Low-carbohydrate diets are necessarily high in fat, and somewhat higher in protein. Do people lose weight on them because of the effects of carbohydrates on insulin levels or because low-carbohydrate diets help reduce calories?

This question does not have an easy answer, but not for lack of trying. Weight-loss studies are hard to do. Estimating calorie intake is notoriously inaccurate, and measuring calories is difficult and expensive.

The first measurement study I know of took place in 1964. Investigators from the Oakland Institute for Medical Research studied weight loss in five obese patients in a hospital metabolic ward. They calculated the number of calories needed to induce rapid weight loss in each patient, and fed each of them a liquid formula diet containing that number every day. Every few weeks, they changed the formula to vary the proportions of protein (ranging from 14 percent to 36 percent of calories), fat (12 percent to 83 percent), and carbohydrate (3 percent to 64 percent).

Regardless of the proportions, all patients lost weight at a constant rate. The investigators titled their study “Calories Do Count.”

This study was conducted under rigidly controlled conditions of hospitalization and involved actual measurements – not estimations – of calorie intake and body weight.

But what about weight-loss studies involving people who are not incarcerated? Since the early 2000s, numerous clinical trials have shown low-carbohydrate diets to produce greater weight loss than low-fat diets. Some also have observed improvements in blood pressure, blood glucose levels and blood lipids.

But it is so inaccurate to estimate calorie intake in such studies that most didn’t bother to try. This means they can’t say whether the weight loss was due to composition of the diet or to calorie reduction.

It’s possible that low-carbohydrate, high-fat diets make people less hungry, but the evidence for this is mixed. Most studies of extreme diets of any type report high dropout rates or failure to stick to the diet for more than six months or so. And even though initial weight loss is rapid on low-carbohydrate diets because of water loss, these diets are low in fiber and some vitamins.

One problem with losing weight is that it takes fewer calories to maintain smaller bodies. Dieting also reduces energy expenditure.

One recent study of that problem involved taking detailed measurements for several years, and illustrates the difficulties of obtaining definitive answers to questions about diet composition and energy balance.

The researchers wanted to know whether diet composition affected energy expenditure in very obese people who had just dieted off up to 15 percent of their weight. They found that a low-carbohydrate diet did not slow down energy expenditure nearly as much as a low-fat diet, meaning that low-carbohydrate diets might make it easier for people to maintain weight loss.

On this basis, the investigators said, “The results of our study challenge the notion that a calorie is a calorie from a metabolic perspective.”

Perhaps, but study subjects were fed prepared calorie-controlled diets for only four weeks, and lost and maintained weight under highly controlled conditions. Does diet composition matter for weight maintenance in the real world? Longer-term studies by other investigators show that diet composition makes little difference in the ability to maintain weight loss.

Most reviews of the subject conclude that any diet will lead to weight loss if it cuts calories sufficiently.

Obviously, some diets are better for health than others.

Face it. The greatest challenge in dieting is to figure out how to eat less – and to eat healthfully on a regular basis – in the midst of today’s “eat more” food environment. And that’s a much more important research problem than whether low-carbohydrate or low-fat diets work better for weight loss.

Marion Nestle is an author and a professor in the nutrition, food studies and public health department at New York University. She blogs at foodpolitics.com. E-mail: food@sfchronicle.com

 

 

Oct 24 2011

On Denmark’s “fat tax”

I have a commentary in the October 23 issue of New Scientist (UK):

Cover of 22 October 2011 issue of New Scientist magazine

World’s first fat tax: what will it achieve?

Enviably healthy Denmark is leading the way in taxing unhealthy food. Why are they doing it, and will it work

THE Danish government’s now infamous “fat tax” has caused an international uproar, applauded by public health advocates on the one hand and dismissed on the other as nanny-state social engineering gone berserk.

I see it as one country’s attempt to stave off rising obesity rates, and its associated medical conditions, when other options seem less feasible. But the policies appear confusing. Why Denmark of all places? Why particular foods? Will such taxes really change eating behaviour? And aren’t there better ways to halt or reverse rising rates of diet-related chronic disease?

Before getting to these questions, let’s look at what Denmark has done. In 2009, its government announced a major tax overhaul aimed at cushioning the shock of the global economic crisis, promoting renewable energy, protecting the environment, discouraging climate change, and improving health – all while maintaining revenues, of course.

The tax reforms make it more expensive to produce products likely to harm the environment and to consume products potentially harmful to health, specifically tobacco, ice cream, chocolate, candy, sugar-sweetened soft drinks, and foods containing saturated fats.

Some of these taxes took effect last July. The current fuss is over the introduction this month of a tax on foods containing at least 2.3 per cent saturated fat, a category that includes margarine, salad and cooking oils, animal fats, and dairy products, but not – thanks to effective lobbying from the dairy industry – fluid milk.

Copenhagen is the home of René Redzepi’s Noma, voted the world’s best restaurant for the past two years. To Americans, “Danish” means highly calorific fruit – and cheese-filled breakfast pastries. Despite such culinary riches, the Nordic nation reports enviable health statistics and a social support system beyond the wildest imagination of inhabitants of many countries. Danish citizens are entitled to free or very low-cost childcare, education and healthcare. Cycle lanes and high taxes on cars make bicycles the preferred method for getting to school or work, even by 63 per cent of members of the Danish parliament, the Folketing.

Taxes pay for this through policies that maintain a relatively narrow gap between the incomes of rich and poor. The Danish population is literate and educated. Its adult smoking rate is 19 per cent. Its obesity rate is 13.4 per cent, below the European average of 15 per cent and a level not seen in the US since the 1970s. Denmark has long used the tax system to achieve health goals. It has taxed candy for nearly 90 years, and was the first country to ban trans-fats in 2003.

Because its level of income disparity is relatively low, the effects of health taxes are less hard on the poor than in many other countries. But the Danes want their health to be better. Obesity rates may be low by US standards, but they used to be lower – 9.5 per cent in 2000. Life expectancy in Denmark is 79 years, at least two years below that in Japan or Iceland. The stated goal of the tax policies is to increase life expectancy as well as to reduce the burden and cost of illness from diet-related diseases.

Like all taxes, the “health” taxes are supposed to raise revenue: 2.75 billion Danish kroner annually ($470 million). The tax on saturated fat is expected to account for more than one-third of that. Since all food fats – no exceptions – are mixtures of saturated, unsaturated, and polyunsaturated fatty acids, the tax will have to be worked out food by food. Producers must do this, pay the tax, and pass the cost on to consumers.

Taxes on cigarettes are set high enough to discourage use, especially among young people. But the food taxes are low, 0.34 kroner on a litre of soft drinks, for example. The “fat” tax is 16 kroner per kilogram of saturated fat. In dollars, the taxes will add 12 cents to a bag of crisps and 40 cents to the price of a burger. Whether these amounts will discourage purchases remains to be seen.

Other countries are playing “me too” or waiting to see the results of Denmark’s experiment. Hungary has imposed a small tax on sweets, salty snacks, and sugary and caffeinated drinks and intends to use the revenues to offset healthcare costs. Romania and Iceland had such taxes but dropped them, whereas Finland and Ireland are considering them. Surprisingly, given his party’s anti-nanny state platform, UK prime minister David Cameron is suggesting food taxes to counter the nation’s burgeoning obesity crisis. The US has resisted calls for taxes on sugar-sweetened beverages, not least because the soft drink companies spent millions of dollars on defeating such proposals.

Leaving aside the usual criticisms, such as the impact on poorer people, I have a different reason for being troubled by tax interventions. They aim to change individual behaviour, but do little to change the behaviour of corporations that make and market unhealthful products, spending vast fortunes to make them available, desirable and socially acceptable.

Today, more and more evidence demonstrates the importance of food environment factors, such as processing, cost and marketing, in influencing food choices (The Lancet, DOI: 10.1016/S0140-6736(11)60813-1). Raising taxes is one way to change that environment by influencing the cost to the consumer. But governments seriously concerned about reducing rates of chronic disease should also consider ways to regulate production of unhealthy products, along with the ways they are marketed.

In the meantime, let us congratulate Denmark on what could be viewed as a revolutionary experiment. I can’t wait to see the results.

Marion Nestle is the author of Food Politics and What To Eat and is the Paulette Goddard Professor of Nutrition, Food Studies, and Public Health at New York University

Aug 16 2011

The fuss over saturated fat

I keep getting questions about saturated fat.  Does it really pose a health risk?  If so, how serious a risk?  And isn’t eating real food OK even if it contains saturated fat?  Good questions.  Here are a couple of recent examples:

Reader #1: I think that the idea that saturated fats in meat and dairy are unhealthful is errant, based on correlative – not causative – scientific studies…I propose that instead of demonizing one nutrient over another, we favor whole, high-quality foods of both animal and plant origin…designed by nature (and thousands of years of trial and error) to meet the needs of their respective populations. What do you say?

Reader #2: I wonder how the government can be so focused on low-fat milk. Is that really such a huge problem? Isn’t the bigger problem that the state of NY is telling people pretzels make a healthy snack? Isn’t it soda and cheese doodles and eating every dinner from a box that is the problem? Whole milk, really? I’d appreciate your clarity on this… we are full fat milk and cheese people, and all of this perplexes me.

I can understand why anyone might be confused about saturated fat.  Food fats are complicated and it helps to be a biochemist (as I once was) to sort out the issues related to degree of saturation and whether the omegas are 3, 6, or 9 (I explain all this in the chapter on fats and in an appendix to What to Eat).

And yes, the science is complex and sometimes seems contradictory but scientific committees for the past 50 years have concluded one after another that substituting other kinds of fatty acids for saturated fatty acids would reduce levels of blood cholesterol and the risk for coronary heart disease.

And no, those scientists cannot have all be delusional or paid off by the meat or dairy industries.  They—like scientists today—mostly call the science the way they see it.

What makes the research especially hard to sort out is that all food fats—no exceptions—are mixtures of saturated, unsaturated, and polyunsaturated fatty acids (just the proportions differ), that some saturated fatty acids raise blood cholesterol levels more than others do, and that one kind—stearic acid—seems neutral with respect to blood cholesterol.

But overall, the vast majority of expert committees typically conclude that we would reduce our heart disease risks if we kept intake of saturated fat below 10% of calories, and preferably at or below 7%.   On average, Americans consume 11-12% of calories from saturated fat, which doesn’t sound too far off but the average means that many people consume much more.

As is often the case with studies of single nutrients, research sometimes comes to different conclusions.  Several studies—all quite well done—have appeared just in the last year or so.

One of these is a meta-analysis (a review of multiple studies). It concludes:

…there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD [coronary heart disease] or CVD [cardiovascular disease]. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat [my emphasis].

What saturated fat gets replaced with is the subject of three other well conducted studies that come to a different—the mainstream—conclusion.  One, another recent meta-analysis, confirms decades of previous observations (sorry about the annoying abbreviations):

These findings provide evidence that consuming PUFA [polyunsaturated fatty acids] in place of SFA [saturated fatty acids] reduces CHD events in RCTs [randomized clinical trials]. This suggests that rather than trying to lower PUFA consumption, a shift toward greater population PUFA consumption in place of SFA would significantly reduce rates of CHD.

Translation: replacing saturated fats with polyunsaturated fats would be healthier.

Another meta-analysis comes to the same conclusion:

The associations suggest that replacing SFAs with PUFAs rather than MUFAs [monounsaturated fatty acids] or carbohydrates prevents CHD over a wide range of intakes.

A very recent consensus statement concludes:

the evidence from epidemiologic, clinical, and mechanistic studies is consistent in finding that the risk of CHD is reduced when SFAs are replaced with polyunsaturated fatty acids (PUFAs). In populations who consume a Western diet, the replacement of 1% of energy from SFAs with PUFAs lowers LDL cholesterol [the “bad” kind] and is likely to produce a reduction in CHD incidence of ≥2–3%. No clear benefit of substituting carbohydrates for SFAs has been shown, although there might be a benefit if the carbohydrate is unrefined and has a low glycemic index.

The advisory committee to the 2010 Dietary Guidelines for Americans reviewed this and other research relating saturated fatty acids to heart disease risk and concluded:

Cholesterol-raising SFAs, considered SFA minus stearic acid…down-regulate the low density lipoprotein (LDL) receptor by increasing intracellular cholesterol pools and decreasing LDL cholesterol uptake by the liver.

The committee’s research review addressed the question, “What is the Effect of Saturated Fat Intake on Increased Risk of Cardiovascular Disease or Type 2 Diabetes, Including Effects on Intermediate Markers such as Serum Lipid and Lipoprotein Levels?”  It judged the evidence strong

that intake of dietary SFA is positively associated with intermediate markers and end point health outcomes for two distinct metabolic pathways:

1) increased serum total and LDL cholesterol and increased risk of CVD and

2) increased markers of insulin resistance and increased risk of T2D [type-2 diabetes]. Conversely, decreased SFA intake improves measures of both CVD and T2D risk.

The evidence shows that 5 percent energy decrease in SFA, replaced by MUFA or PUFA, decreases risk of CVD and T2D in healthy adults and improves insulin responsiveness in insulin resistant and T2D individuals.

How much saturated fat might increase the risk of heart disease or type-2 diabetes depends on how much you eat as well as what you eat.

What to do to reduce your dietary risks for heart disease?  Take a look at the top 15 sources of saturated fats in U.S. diets:

  • Regular cheese
  • Pizza
  • Grain-based desserts (cakes, cookies, pies, pop-tarts, donuts, etc)
  • Dairy desserts
  • Chicken and chicken mixed dishes (e.g. fingers)
  • Sausage, franks, bacon, and ribs
  • Burgers
  • Mexican mixed dishes
  • Beef and beef mixed dishes
  • Reduced fat (not skim) milk
  • Pasta and pasta dishes
  • Whole milk
  • Eggs and egg mixed dishes
  • Candy
  • Butter
  • Potato/corn/other chips
  • Nuts/seeds and nut/seed mixed dishes
  • Fried white potatoes

Explanation: These foods do not necessarily have the most saturated fat.  If the list surprises you, recall that all food fats have some saturated fats.  These foods are leading sources because they contain some saturated fat and many Americans eat them.

It is surely no coincidence that these foods are also among the leading sources of calories in U.S. diets.  The health effects of diets, let me repeat, have to do with quantity as well as quality.

If you do not habitually eat most of the foods on this list, and are not gaining weight, saturated fatty acids are much less likely to be a problem for you.

And just because saturated fats raise the risk of heart disease does not mean they are poisons.   Eat fats.  Just not too much.

 

 

 

Mar 22 2010

Saturated fat vs. heart disease: current state of the science

Despite recent publications finding no correlation between intake of saturated fat and coronary heart disease (CHD) – see, for example, the recent meta-analysis in the American Journal of Clinical Nutrition – the debates over the role of saturated fat continue.

In that same issue of the Journal, another study says that reducing saturated fat only works if you replace it with something better.  If you replace saturated fat with carbohydrates, the effects on heart disease will be worse.

The fat story is not simple (in What to Eat, I explain the biochemistry of food fats in the chapter on fats and oils and in an appendix).  The main reason for the complexity is that different kinds of fats do not occur separately in foods.

Without exception, food fats are mixtures of  three kinds of fatty acids: saturated (no double bonds and solid at room temperature), monounsaturated (one double bond), and polyunsaturated (two or more double bonds and liquid at room temperature).  Food fats just differ in proportions of the three kinds.

Meat, dairy, and egg fats generally are more saturated.  Plant fats and oils are generally more unsaturated.

How to make sense of the saturated fat story? An expert panel from WHO and FAO just produced a new review of the evidence.  The panel evaluated CHD morbidity and mortality data from epidemiological studies and controlled clinical trials.  It found:

  • Convincing evidence that replacing saturated fat with polyunsaturated decreases the risk of CHD.
  • Probable evidence that replacing saturated fat with largely refined carbohydrates (starch and sugar) has no benefit and even may increase the risk of CHD.
  • Insufficient evidence relating to the effect on the risk of CHD of replacing saturated fat with monounsaturated fats or whole grain carbohydrates, but a trend suggesting that these might decrease CHD risk.
  • Possible positive relationship between saturated fat and increased risk of diabetes.
  • Insufficient evidence for establishing any relationship of saturated fat with cancer.

The panel’s recommendations:  (1) Replace saturated fat with polyunsaturated fats (omega-3 and omega-6) in the diet, and (2) Limit saturated fat to 10% of daily calories or less.

Translation: Eat less animal fat and replace it with vegetable fats.

Historical note: These are precisely the same recommendations that have been standard in the U.S. for at least fifty years.  This was good advice in the late 1950s.  It is still good advice.

UPDATE, March 22,2011:  Another major review has just come to precisely the same conclusions, this one from an international expert panel.  It also suggests areas for future research.  See American Journal of Clinical Nutrition 2011;93:684-88.

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