Author: hmr49592

Spices are a unique part of our diets. They are aromatic, dried, edible, rich in potent phytochemicals, often intensely colored, and have culinary and medical uses. Spices are used for preservation and for enjoyment by adding flavor to foods.

Dr. Mary Hardy recently gave a webinar about spices and health. I was interested in the topic because as a future dietitian I look forward to providing my clients with evidence-based advice about nutrition to help them improve their health. I believe that recommending the use of spices, both in general and for specific medical uses, has the potential to play a big role in the health of my clients.

Dr. Hardy talked about the use of ginger, turmeric, and cinnamon for use in specific medical contexts in detail, but I will focus this blog post on her discussion of general spice use.

There is research to support that eating spices in general is beneficial for human health. Epidemiological data from a 7-year study in 500,000 Chinese adults found that eating spices 6 to 7 times per week may increase longevity by reducing all-cause mortality by 14%. Other epidemiological data supports the of cooking at home to promote health due to the generally healthier diet (lower fat and sugar intake) of those who cook at home and their decreased risk for type 2 diabetes. *Important note- epidemiological data does not show cause and effect relationships. It only shows an observation.

Spices can improve adherence to healthy diets because they add flavor and make food increasingly palatable. There is evidence to support that teaching people to cook with spices improves adherence to a low sodium diet. In one study, a group taught to cook with spices ate 1000 mg/d less sodium than the control group after 20 weeks. Additionally, there is evidence that people have better acceptance of lower fat food when spices were added to the low-fat foods.

Recommending the use of spices and incorporating spice cooking lessons into nutrition therapy are promising techniques that dietitians can use to help clients maintain healthy diets and improve adherence to sodium restrictions. Cooking lessons have the potential to be positive, fun, and engaging, so client satisfaction will likely be high if that technique is used. Also, grocery store tours with a special focus on the spice isle may help clients gain confidence in selecting spices from the store for home use.

Dr. Amy Goss of the University of Alabama Birmingham studies the effects of macronutrient manipulation (or manipulations of the proportion of carbohydrate, fat, and protein in the diet) on body fat distribution and metabolic health in adults with obesity.

A quick note on body fat distribution: body fat can be distributed under the skin (subcutaneously), around the organs (viscerally), and in muscle (intermuscular). Visceral and intermuscular fat pose greater health concerns than subcutaneous fat. Dr. Goss’ work on many studies has shown that a reduced carbohydrate and higher fat diet results in a more optimal body composition and lower risk for type II diabetes in obese individuals.

When carbohydrates are ingested, the body secretes the hormone insulin. Insulin blocks fat burning and stimulates lipogenesis (fat synthesis) in the liver. Not all individuals produce the same amount of insulin in response to the same amount of carbohydrates, however. For example, African Americans secrete 2-3 times the insulin to the same amount of glucose as Caucasian individuals. Because some individuals are prone to excessive insulin secretion and subsequent fat accumulation, they may respond better to a lower carbohydrate diet.

Dr. Goss conducted a macronutrient manipulation diet study in women with polycystic ovary syndrome (PCOS). She used this population because patients with PCOS are at increased risk for visceral fat accumulation, which can cause resistance to insulin, and high insulin secretion. She tested a low carbohydrate high fat diet in these women and found that they had a selective depletion of their visceral and intermuscular fat without overall weight loss, retention of muscle mass, and improved metabolic outcomes for type II diabetes when compared to controls on a higher carbohydrate low fat diet.  The women also had improved blood lipid values from baseline on the low carbohydrate high fat diet.

The potential impact of these findings is a change in the dietary recommendations given to obese individuals with high levels of visceral fat. The evidence from Dr. Goss’ work suggest that a low carbohydrate high fat diet may have beneficial body fat redistribution effects that help patients lower their risk for insulin resistance and type II diabetes. Pending further corroboration, practitioners could use this information to adjust their recommendations for obese individuals to strive for a diet higher in healthy fats (such as olive oil, avocado, nuts) and lower in carbohydrates. The fascinating thing to me is how different people respond to carbohydrates and insulin in different ways. The findings of this study and others conducted by Dr. Goss point to the idea that blanket recommendations, such as the low fat recommendations from the Dietary  Guidelines for Americans, may not be ideal for everyone in the population.

Carolina Cawthon, a PhD student in Foods and Nutrition department at the University of Georgia, recently gave a seminar on food addiction. Ms. Cawthon’s talk shed some light on the debate about whether or not food addiction is an actual addiction. During her talk, she covered how our brains make decisions about food, what addiction is, and the evidence we have concerning the addictive capabilities of foods in animals and humans. Understanding food addiction is important area in the arena of public health because it is a topic that is impacted by the design of our food system and the availability of “addictive” foods, as well as policy surrounding taxation of such foods.

Our food intake is regulated by many things, including stretch receptors in our stomachs (sense the amount of food that is being taken in) and hormones (send signals to our brains about hunger and fullness). The decision-making portion of our brain, which decides to eat or not eat a food, is influenced by both reasoning and reward areas of the brain. The reasoning areas operate by objectively analyzing how much we have eaten already and how hungry or full we feel. The reward areas of the brain send messages related to anticipation of how good it will feel to eat something.

Addiction is an illness in which an individual is dependent on a substance and seeks it out to avoid distress (withdrawals, anxiety, etc.). The individual continues to use the substance in spite of consequences and has a high level of motivation to obtain the substance. Use of the substance becomes a compulsion. In the physiologic state of dependence on a substance (like drugs or alcohol), the individual’s body adapts so that they need more of the substance to achieve the desired effects.

Scientists have used rats to study addiction related to food and drugs. They have found that rats become addicted to substances at rates comparable to humans and thus are useful in addiction studies. Researchers have found that rats with more impulsive traits are more likely to demonstrate addicted behaviors in relation to food intake, especially when offered a diet high in fat and sugar.

The Yale Food Addiction Scale is a tool used to measure food addiction traits in human subjects. Brain imaging data has revealed that individuals with higher scores using this scale (indicating food addiction) have higher anticipation for food and lower reward after receiving the anticipated food. This aligns with the classic attributes of addiction- heightened desire for a substance but lower satisfaction after receiving it. Researchers have used this scale to identify individuals with a greater risk for food addiction to be: women, overweight or obese, over 35 years of age, and with a previous history of disordered eating. Dopamine is a neurotransmitter involved in the brain’s reward system. Some research has shown that individuals with higher BMIs have lower densities of dopamine receptors, which support hypothesis overweight or obese individuals could feel less rewarded by food and thus eat more to compensate. So we have some data that points to the addictive capabilities of food. However, a complicating factor is that while alcohol and drug addicts can be advised to stop using the substances completely, people need food to live and thus could never be advised to stop eating.

Even though great strides are being made in food addiction research, it is not entirely clear whether food addiction is the same type of illness as drug or alcohol addiction. There is no consensus among professionals about the validity of food addiction yet. Given the rise of obesity in our nation and the detriment it is to health, a better understanding of food addiction and its characteristics will continue to be important to the success of public health efforts.

A popular media article from www.msn.com recently caught my eye. The headline that drew me in was, “The One Food That Can Make Your Bones 20 Percent Stronger (It’s Not Dairy).” I was shocked by such a dramatic claim (20% stronger bones!!) and clicked on the article to read further. It turns out the article was referencing a research study done in male mice on a specific type of bone loss due to radiation exposure. I found a handful of claims from the article to be misrepresentative of the information from the original research paper. Most of the issues with the claims from the media article stem from the important fact that the findings of animal studies are not directly translatable to humans. It may be insulting to your intelligence to say that mice are very different from humans. While animal research is vital to science, a major weakness is the lack of direct relatability to humans. Additionally, the title of the media article may confuse consumers by undercutting the vital role that adequate calcium plays in bone health.

The study compared an antioxidant cocktail, dihydrolipoic acid (DHLA), ibuprofen, and prunes. They found that mice on the prune diet exposed to radiation maintained levels of bone-related gene expression comparable to the control mice. In a second experiment comparing a control, DHLA, and prunes, the bone volume mice on the prune diet was preserved following a radiation treatment.

Among the inaccurate claims from the popular media article was the assertion that eating prunes makes “your” bones 20 percent stronger. The glaring issue with this statement is that just because and effect was seen in mice does not mean that same type of effect will be detected in humans. Additionally, even if the effect was seen in humans, it may not occur at the same magnitude (i.e. maybe x amount of prunes per day can help to make radiation damaged bones 5% stronger).

The mice in the prune group of the experiment were fed a diet that consisted of 25% prunes by weight. Often in animal studies researchers will use large doses of the independent variable they are studying to see an effect. This is not a bad thing, it can save time and money by showing the researcher if a topic is worth studying in greater detail. However, it is important to keep in mind what a high proportion of the experimental diet was prunes when interpreting the results.

The popular media article contained a recommendation for the public to eat 4-5 prunes per day for bone strengthening benefits. While prunes are a healthy food and provide many important nutrients, the findings from this particular study in no way support a specific recommendation for humans. The protective effect of prunes in the mice was specific to bone loss from radiation, which is mainly applicable to astronauts, cancer patients undergoing radiation, radiation workers, and victims of nuclear accidents. The public is largely not at risk for bone loss due to radiation exposure.

Another inaccurate claim from the article was that prunes have an “unknown superpower” to help bones. There is a large body of research surrounding prunes and bone health. Researchers have been aware of the beneficial effects prunes have on bones for years.

A more honest (but perhaps not as eye-catching) headline for this media article would be: One study finds a diet high in prunes to benefit the bone integrity of male mice exposed to radiation. This revised headline emphasizes that these are results from ONE study (which should never be accepted as truth- we need repetition for validation), the study was done in male animals (mice, not humans), and informs the reader of the specific type of bone loss that the experiment found prunes to prevent (radiation-induced bone loss).

Study source:

Schreurs, A-s; Shirazi-fard, Y; Shahnazari, MAuthor; Alwood, J S; Truong, T A; et al. Dried plum diet protects from bone loss caused by ionizing radiation. Scientific Reports (Nature Publisher Group); London6 (Feb 2016): 21343.

Popular media article:

https://www.msn.com/en-us/health/nutrition/the-one-food-that-can-make-your-bones-20-percent-stronger-it%E2%80%99s-not-dairy/ar-AAsuIb6?ocid=iehp

Do you want another reason to add green leafy vegetables into your diet? How does, ‘having a more efficient central nervous system and better visual function’ sound?

Dr. Billy R. Hammond recently gave a seminar to the University of Georgia Foods and Nutrition department, entitled “The influence of the macular carotenoids on the central nervous system.” Dr. Hammond works with carotenoids, which are pigments (color compounds) found in colorful fruits and vegetables.

What do carotenoids do?

Carotenoids are important antioxidant compounds. They can be found in high concentrations in the retina (the part of the central nervous system directly behind the eye) and in the brain. Both the brain and retina use a lot of energy, and because of this, are vulnerable to damage by dangerously reactive forms of oxygen. These reactive forms of oxygen are products created by normal cellular processes. Our bodies handle these destructive forms of oxygen by using antioxidants (such as vitamin E, vitamin C, and carotenoids) to cancel them out. Having carotenoids to work as antioxidants in these active parts of our bodies protects us from damage.

In addition to preventing damage, carotenoids help our central nervous system by improving the communication between nervous system cells (neurons). Because carotenoids improve the communication between neurons, then they, in theory, would make our central nervous system more efficient (or faster). A faster central nervous system could result in improved reaction time. Dr. Hammond has conducted several studies evaluating if carotenoid supplements make the central nervous system faster.

Do carotenoids make our central nervous system more efficient?

Using two types of carotenoids, lutein and zeaxanthin, Dr. Hammond has studied the effects of supplemental carotenoids on vision and cognition in multiple groups of people. In a study of UGA baseball players, a population for which rapid visual processing is very important, the researchers found that lutein and zeaxanthin supplements improved visual processing and speed.

In other studies of both college-age students and adolescents, Dr. Hammond’s research team has found that lutein and zeaxanthin supplementation improved cognitive function and neural activity.

What does this information mean for you?

The standard American diet is very low in fruits and vegetables. When we don’t eat a variety of fruits and vegetables or take a supplement, we don’t get the carotenoids we need for efficient functioning of our central nervous system and vision. I think it is important for findings such as these not to be misinterpreted or blown out of proportion. The findings of Dr. Hammond’s work do not mean that Americans should eat carotenoids to become super smart humans with super hero vision. The findings do indicate that the carotenoids lutein and zeaxanthin play important roles in vision and cognition, and are worth including in your daily diet to support an efficient central nervous system.

You can increase your intake of lutein and zeaxanthin by incorporating leafy greens such as kale, spinach, swiss chard, mustard greens, turnip greens, or collards into your diet.

One of my favorite ways to eat kale is in  kale apple salad. Here is a link to a recipe you can try: https://cooking.nytimes.com/recipes/1013732-kale-salad-with-apples-and-cheddar

Enjoy!