Welcome to the latest and greatest wrinkle in the world of nutrition science: a recent study has suggested that saturated fat – long considered a primary culprit in the development of heart disease – is perhaps no more than an innocent bystander. The meta-analysis, published March 18th in the Annals of Internal Medicine, found no association between saturated fat intake and increased risk of heart attacks or other cardiac events.
To be clear, the researchers did find a link between trans fat intake and heart disease. But they found no evidence that saturated fat increased the risk of heart disease, or that unsaturated fats decreased the risk of heart disease. Does this mean that you can now inhale steak, butter, and whole milk with abandon? Or stop taking those expensive flaxseed and/or fish oil supplements? Well, it depends.
On one hand, some folks believe that this study demonstrates a need to more specifically analyze individual types of saturated and unsaturated fats (e.g., some saturated dairy fats are associated with a lower risk of heart disease, whereas some unsaturated vegetable fats are associated with a higher risk of heart disease).
On the other hand, some folks believe that this study demonstrates a need to stop focusing on nutrients altogether and start focusing on whole foods. For instance, Dr. Frank Hu, a professor of nutrition and epidemiology at the Harvard School of Public Health who was not involved with the study at hand opined that “The single macronutrient approach is outdated.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.”
Food for thought
The whole food approach is nothing new. For instance, take a look back at Jamie’s October blog post about the Mediterranean Diet. Or, for a more lengthy review, read Michael Pollan’s essay, Unhappy Meals, that was originally published in the January 2007 edition of the New York Times Magazine. Pollan’s take-home message is definitely good food for thought: Eat food. Not too much. Mostly plants.
What do you think? Should saturated fat be avoided like the plague? Or is it more complicated than that?… Or perhaps more simple?
Scenario: A 58 year-old man named Mike has just been diagnosed with prostate cancer. He is wondering how this could be since there is no family history of the disease, and he exercises regularly, is a vegan, and takes antioxidant supplements. Mike assumed that his healthy lifestyle would decrease his chances of developing cancer, but apparently not. After talking to his doctor, he wonders if the supplements played a causal role in his recent diagnosis.
Antioxidants are substances that protect against the detrimental effects of oxygen free-radicals. These radicals, with reactive, unpaired electrons, are produced during normal metabolism and can damage cell membranes and biological molecules such as protein or DNA. Diets high in fruits and vegetables are rich in antioxidants, such as vitamin C, vitamin E, β-carotene and selenium, which can neutralize these reactive oxygen species. Many people, however, do not consume adequate amounts of these foods. This explains why the dietary supplement industry promotes antioxidant supplements to consumers, with promises of decreasing aging and preventing cancer along with other health-promoting properties. This sounds great, of course, but is there any scientific proof to back up these claims?
According to the National Institutes of Health (NIH), supplements with high doses of β-carotene may increase the risk of lung cancer in smokers and vitamin E supplements may increase the risk of hemorrhagic stroke and prostate cancer. In 2011, a study of >35,000 men, known as The Selenium and Vitamin E Cancer Prevention Trial (SELECT), discovered that selenium and vitamin E supplements did not decrease the risk of prostate cancer, and that vitamin E supplements (taken alone) increased the risk by 17% (NCCAM Supplements). Multiple other studies echo these findings (Harvard University). Nonetheless, many people in the USA continue to regularly use antioxidant supplements, according to experts at Stanford University (Stanford University).
One possible reason for antioxidant supplements doing more harm than good relates to the fact that high levels of antioxidants can potentially convert to proxidants. Moreover, oxidant molecules are used in the body to get rid of damaged cells, including those that are precancerous or cancerous, so supplements could disrupt an important oxidant/antioxidant balance. So as the saying goes, more is not always better.
The best option for obtaining adequate amounts of antioxidants is adding fruits, vegetables, and whole grains to your diet. The typical American diet already provides 120% of the RDAs for many antioxidant nutrients (JNCI Paper), so supplementation should not be necessary for most healthy people. Furthermore, the health-promoting benefits of consuming antioxidant-rich foods may actually be caused by other substances present in the same foods, or relate to lifestyle choices of individuals who most often consume these foods.
Conclusion to Scenario: In the end, Mike realizes that not every claim about dietary supplements is true. Mike does not want what happened to him to also happen to his little brother. He thus intends to warn his little brother about the truth behind antioxidant supplementation. What will you do? We suggest you get the facts, and only the facts, before using any dietary supplement.
(Written with the creative assistance of Nehemie Laguerre, a University of Florida undergraduate student)
A recent proposal by the U.S. Food and Drug Administration (FDA) to revamp food labels on packaged food for the first time in twenty years is welcome news. The new design promises to be easier to read and potentially more effective at communicating important health information to consumers. However, could the FDA do even better? For instance, Great Britain encourages front-of-package “traffic light” labels on processed foods (see Figure 1). Despite strong resistance from food industry groups, the British National Health Service believes that such labels are quite useful for consumers.
Indeed, a recent study (Thorndike et al, 2014) conducted in the United States suggests that traffic light labels might be an effective intervention for obesity. Using the cafeteria at Massachusetts General Hospital as their study site, researchers reported that sales of “red” foods decreased from 24% of food sales at the start to 20% at two years; red beverages went from 26% of beverage sales to 17% at two years. Green foods sales grew from 41% to 46%, and green beverages from 52% to 60%. The researchers concluded that, “These results suggest that simple food environment interventions can play a major role in public health policies to reduce obesity”.
What information is important to you?
What information do you feel is important to consider when purchasing food? In addition to the typical energy and nutrient content present on current food labels, what other information would you like to see? Think beyond the typical quantities represented on food labels and consider more complex food qualities. Back in 2011 the University of California, Berkeley, School of Journalism, asked this very same question in an open label design contest. Take a look at some of the contest submissions below.
Food for thought
Which of the above label designs do you like most? What unique bits of information or methods of communication do you think are most important and effective? Is there any other information that you imagine would helpful for consumers to be aware of? If so, help the FDA out and come up with a better label design!
You have probably heard about detox diets and fasting approaches for weight loss. One very popular version of such is the Master Cleanse diet, which is based upon a book entitled The Master Cleanser (by Stanley Burroughs; published over 50 years ago). The book claims that the diet will ‘cleanse’ the body of toxins, produce rapid weight loss, and provide relief of chronic conditions such as arthritis. Sounds too good to be true! So, what exactly is the Master Cleanse diet? Is this approach to weight loss safe and effective? Is it recommended by nutrition experts? Let’s take a closer look at the benefits and risks of the Master Cleanse.
The Master Cleanse is a strict diet that requires participants to consume 4 cups of salt water, 1 cup of herbal laxative tea, and 6-12 cups of a lemonade concoction (containing fresh lemon juice, maple sugar, cayenne pepper, and water). Participants are urged to follow the diet for at least 10 days. Those following the diet are warned of side effects associated with “detox”, including: cravings, fatigue, irritability, aches & pains, nausea, vomiting and burning sensations during bowel movements. The Master Cleanse diet has been touted by celebrities and you can find dozens of testimonials on the web proclaiming the benefits of such a dietary pattern (see for example: Master Cleanse).
So, what does nutrition science have to say about such an approach to weight loss? First off, there is no scientific evidence that the Master Cleanse rids the body of toxins (US News). This is the job of the liver; if your liver is functioning properly, it will rid the body of various toxins. Many have reported rapid weight loss on the Master Cleanse (which calls for consuming ~650 kcals/day). This is not surprising, as any form of starvation will lead to rapid weight loss. But, what is being lost during the cleanse? Experts say most of what is lost is water weight and moreover, that muscle and bone tissue can also decrease (Web MD). Doesn’t sound so positive, does it?
Slowing of the metabolism also occurs during starvation, which makes it difficult to maintain the weight loss after stopping the cleanse. Nutrition experts also warn about negative effects on the kidneys and heart, and the lack of many essential nutrients (e.g. fat, protein, vitamins, minerals, fiber) in the Lemonade Diet. This dietary pattern can also adversely affect the microorganisms that reside in our large intestine; recent studies are showing that the so called ‘gut microbiota’ play important roles in the development of chronic disease.
Nutrition experts recommend reducing calorie intake by perhaps 20-25%, while following the basic dietary recommendations for the macro- and micro-nutrients for successful weight loss. This should be coupled with increased physical activity. Experts tell us that this is probably the only way to lose weight and keep it off in the long run. So while diets like the Master Cleanse may produce rapid weight loss, there are many associated risks and long term success is unlikely. The choice then is yours: rapid unsustainable weigh loss associated with adverse metabolic perturbations or healthy, nutrition-science recommended approaches to maintain body weight. What will you do?
(Written with the creative assistance of Emily Richter, a University of Florida undergraduate student)