Monthly Archives: July 2018

Too Little of a Good Thing: Carbohydrates

I was in charge of refreshments at a reception held for a guest lecturer and, aware of some of the attendees’ dietary limitations, selected gluten-free, sugar-free, dairy-free, and vegan cookies, as well as a large bowl of seasonal fruits.

“I am on the keto diet,” several of the guests told me as they avoided the cookies and fruit.

Where had I been?

I did not realize that the ketogenic diet had reappeared with such popularity, although I knew it never had really gone away since the days of Dr. Atkins. A few minutes on the internet made apparent the ubiquity of a diet that forces the body to switch from using glucose to fatty acids for energy. The diet seems to appeal to those who believe that total abstinence from sweet and starchy foods is the only way to control calorie intake. It also appeals to those who feel that carbohydrates are the source of physical and cognitive distress.

That adherence to such a diet has side effects ranging from unpleasant to worrisome is a small price to pay for those who follow a carbohydrate-free eating plan. Who cares about bad breath, constipation, “keto brain” (inability to concentrate and remember), difficulty sustaining strenuous exercise, and dangerously low electrolyte levels? As long as the weight comes off, it is worth it. Or so the thinking goes.

What happens after the diet ends can be dealt with after the diet ends, and if it seems impossible to maintain weight loss, well, why not go right back on the carbohydrate-free diet? Long-term effects? No one knows, so it could be good (or bad).

When someone is in ketosis, the body uses fat as a back-up energy system. Normally and naturally the body depends on glucose for all its energy needs. The glucose comes into the body as the end product of digestion of all carbohydrates, whether sucrose or brown rice, and is converted through a series of biochemical reactions into energy. In ketosis, the body uses fatty acids as its energy source. Once the body adapts to this alternate source of energy, it seems to run more or less the same (except for muscles which work longer and harder when using glucoose, the natural source of energy.) Exercise physiologists tell us that there is so little stored glucose in muscle on a carbohydrate-free diet, that muscles may fail to sustain strenuous movement after a few minutes of intense exercise. This means muscles used to sprint after a dog darting into the street, or a toddler about to climb up the rungs of a bookcase, will run out of energy reserves very quickly.

However, the body has a way of getting around the lack of carbohydrates for its glucose source by making its own. Certain amino acids in the protein we eat are converted to glucose in a process call gluconeogenesis. This occurs in the liver and kidneys and, according to advice given to wannabe ketotics, must be prevented. According to one Internet site, “Perfect Keto,” one should eat a specific ratio of fat to protein, because if too much protein and too little fat are consumed, the body will use the amino acids in protein as a source of self-made glucose. To prevent this, one should eat a very high fat diet, and only moderate amounts of protein, namely 75% fat, 20% protein, and a tiny amount of carbohydrate, 5%.

You will know whether or not you have achieved your goal of ketosis by testing levels of ketone bodies in your urine, blood or breath. Ketone bodies are three substances (acetoacetate, beta-hydroxybutyrate, and acetone) that the liver produces from fatty acids during periods of fasting, starvation, and very low or zero carbohydrate diets.

Although we tend to associate a carbohydrate-free or extremely low carbohydrate diet with dieting, it has long been seen as an effective treatment for controlling intractable pediatric epilepsy. Indeed, it is so important that the epileptic child not deviate from this diet that nutritional products have been developed containing flavored protein/fat liquid supplements that function as meal substitutes.

Moreover, avoiding carbohydrates used to be, prior to the availability of insulin, the only way someone with diabetes could handle this disease. And minimizing carbohydrate intake not only from sugary foods, but vegetables such as winter squash, corn on the cob, and carrots may help maintain a normal fasting blood sugar level.

Is it worth putting the body through a major physiological readjustment in order to lose weight?  What about the effect of carbohydrate deprivation on mood? Will there be any rebound eating of carbohydrates once the diet is switched back to including some carbohydrates? A definitive study comparing weight loss among 609 participants who were on a low carbohydrate or low-fat diet over a 12 month period was published this past winter in the Journal of the American Medical Association. The study did not support claims that avoiding carbohydrate produces a better weight-loss outcome. The difference in weight loss between the two groups was about l ½ pounds.

But perhaps the low carbohydrate diet is better for mood. Certainly anecdotal reports of the benefits of eliminating or drastically reducing carbohydrate intake would have you believe that clearer, sharper, focused, energetic minds result.  Here, also, the claim was not borne out by results of another twelve month study comparing  a low-fat and low-carbohydrate diet.

That moods improve among those in the study not denied carbohydrate is not surprising, assuming that some of the mood effects such as energy, focus, calmness and a sense of well-being are associated with normal serotonin activity. The absence of carbohydrate over prolonged periods of time prevents the amino acid tryptophan from entering the brain where it is converted to serotonin. The result: a decrease in serotonin levels and the risk of mood changes associated with too little of this neurotransmitter.

What happens if and when carbohydrates are added back into the diet? Diminished serotonin levels may make the dieter vulnerable to overeating this food group.

Next time I am asked to bring refreshments, I will be sure to include some pork rinds.

References

“Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion,”  The DIETFITS Randomized Clinical Trial,  Gardner, C., Trepanowski, J., DelGobbo, L., et al,  JAMA 2018; 319:667-679

Long-term effects of a Very Low-Carbohydrate Diet and a Low-Fat Diet on Mood and Cognitive  Function .Brinkeworth, G, Buckley J, Noakes, M,  Arch Intern Med 2009 :169; 1880-1873

“Influence of tryptophan and serotonin on mood and cognition with a possible role of the gut-brain axis,” Jenkins. T., Nguyen, J., Polglaze, K.,, et al, Nutrients 2016 8(1): 56.

The Most Overlooked Benefit of Exercise: The Ability to Get from Point A to Point B

A friend who just returned from Seattle was recounting the unexpected steepness of the city streets. ”Nothing is flat,” she told me. “You are either going up or down.” She was not young and had been worried about spending time exploring the city with a relative at least 10 years her junior. The younger woman was athletic and her favorite leisure activity was going on very long walks.“One day we walked up hills so steep I wondered how cars could drive up them! She took me up flight after flight of outdoor steps to get into certain neighborhoods. But I kept up with her and I don’t think I was puffing anymore than she was…“

My friend ascribed her stamina to her favorite gym activities: either walking on an elevated treadmill that mimicked walking uphill, or the elliptical climber which required a motion similar to climbing a shallow set of steps.

“I exercise because it is a habit,” she said as we discussed her unexpected physical prowess. “If I skip more than a day or two, I don’t feel right and have trouble sleeping. And of course it is good for my bones, especially since my mother suffered from osteoporosis and fractured her hip. But it never occurred to me that it would improve my, I guess I would call it, functionality.”

“You mean your ability to move better, longer, more efficiently and with less fatigue?” I asked.

“Yes, all of the above,” she laughed, “almost like a real athlete.”

Her experience of finding herself able to handle the demands on her body of trudging up hills because she exercised regularly should not have been a surprise. This, after all, is the point of training for competitive athletes or people setting off to climb mountains in the Himalayas or bike ride across the continental U.S. But those of us who are not planning on competing in athletic events and prefer to watch mountain climbing on a National Geographic special forget the most basic benefit of exercise: It prepares our body to engage in physical activity that may at times become demanding and strenuous.

The converse is painfully obvious. Someone who is unfit because of a voluntary disregard for any type of regular physical activity will have trouble climbing the steps out of a subway station or walking down a seemingly endless airport terminal corridor on the way to a gate or exit. Breathing becomes labored, muscles begin to ache and there may even be the feeling that unless help in the form of an escalator or one of the airport moving people carriers comes along, the goal of getting out of the subway or to the departure gate will not be achievable.

Of course, there are many who would, but cannot, exercise because of physical limitations. For example, a painfully bad back or severe asthma are obstacles to physical activity that may be difficult to overcome. And there are many whose lifestyle severely limits time to go on a long walk, work out at a gym or have time on a day off to engage in recreational sports. Convincing those who could, but don’t exercise, usually relies on listing the benefits to one’s weight, skeletal infrastructure, digestive system, sleep, cognition, mood, vulnerability to diseases like diabetes or high blood pressure, and life span. For example, there are some studies claiming that weight loss can be achieved through exercise alone without dieting, and that exercise is important in decreasing stress and depression.

But why do we ignore the obvious? If we rely only on vehicular transportation, we will diminish our stamina, endurance, the ability to oxygenate muscle cells sufficiently for prolonged contractions, and our muscle mass.

In short, we will find it more and more difficult to go from point A to point B.

It is possible to go through adult life with minimal need to engage in physical activity to arrive at a destination. Cars that sit in a garage next to the kitchen, or in a parking space a few steps from the elevator in the office building, reduce the need to walk. Malls that allow parking in front of a store or restaurant, or valet services that bring the car back to where you are standing on a sidewalk, also eliminate the need to move very much. One can even find scooters in supermarkets so walking can be avoided, and ordering groceries on line eliminates the need to even go to the market.

However, there are consequences to a lifetime of little voluntary physical activity beyond the obvious ones of physical well-being. It means not being able to explore a new city or museum or zoo on foot. It means not being able to walk through the woods, around a lake, or a botanical garden. It means a casual stroll with a child or friend or spouse is not pleasurable because fatigue and muscle pain quickly limit distance and enjoyment.

My friend concluded her description of her tramp through the city with an ecstatic description of the flagship Starbucks restaurant that sits on top of a steep hill. The restaurant, part museum, part coffee grinding factory and mostly a place where the city folk gather to drink coffee and eat incredible pastries from Italy was the treat her relative had planned for her. “She told me parking is impossible around that neighborhood, and she hoped I was going to be able to get there on foot. My days of exercising really paid off.”

Is It Safe to Eat Food This Summer? Or Ever?

If you want to feel paranoid about eating in restaurants, or buying packaged fruits and vegetables that may be also be pre-cut, and cooking chicken and eggs, then don’t look up current food-borne illnesses on the Internet. I have a relative who gets alerts from the CDC about the latest source of food poisoning, and immediately passes the information on to me before I read about it in the newspapers. She told me to avoid Del Monte packages of cut-up vegetables as they contain a microscopic parasite, and also to dodge Cyclosporai via pre-cut melon because of a multi-state salmonella outbreak, and a few months ago, she alerted me not to buy Romaine lettuce in the supermarket or eat salads containing this leafy vegetable at restaurants because it was contaminated with E.coli. Thankfully, it is now again safe to have salads with this lettuce.

My food contamination alerts decreased temporarily when she went on vacation, so I decided to find out for myself what other aggressive pathogens might be lurking in my food supply. A quick scan of websites devoted to reports of food-borne illnesses uncovered a report about Kellogg’s breakfast cereal Sugar Smacks linked to a Salmonella outbreak across 31 states, Canadian restaurant workers in danger of Salmonella if they handle raw or frozen uncooked chicken, and one horrifying story in the British press about a man who nearly died after he ate a chicken liver parfait (we would call it a mousse) at a dinner at which he got an award from his employer. His situation sounds like something out of an Agatha Christie novel: disgruntled employee kills co-worker who received an award.  But actually many of the 500 people who attended the event got sick as well. However, this individual spent seven weeks in intensive care because he was unable to move his arms and legs and could neither talk nor blink. His eyes remained opened and he could not sleep. This ghastly set of symptoms was due to the Campylobacter bacteria. According to the report, the chicken liver “parfait” should have been heated to a much higher temperature than it was in order to kill off the bacteria lurking within.

How was the awardee, or any of the others who attended the catered dinner, supposed to know this?

And this is the problem. It is all very well to read about the outbreaks and then check the refrigerator to see whether the contaminated item is there. But obviously we know about the problem only after people become ill. In the back of our minds we may find ourselves thinking, maybe I will be the one getting sick from the next contaminated food outbreak. When the Romaine lettuce recall occurred a few months ago, and people shared information about this with their family and friends, I saw more than a few horrified expressions that seemed to say, “Didn’t I just have a salad at a restaurant or homemade with Romaine lettuce?”

The same thing is true of food poisoning from restaurants. There is a website, “I was poisoned.com”, on which victims of contaminated restaurant food write about the unpleasant aftermath of the meals they ate at a particular restaurant. I suspect that fewer people check that website before going out to eat than looking up the menu options in a restaurant they are considering visiting. But maybe one should start on the website first.

It is disheartening to realize that all of us are in jeopardy. Even if you never eat in a restaurant, unless you grow your own fruits and vegetables, raise chickens for eggs and baked chicken breasts, and also make your own bread from your hand-milled flour (flour from certain mills was contaminated last year), you could be next.

Of course, we can and should use precaution in our own food preparation: cooking foods at a high enough temperature to kill the pathogens, refrigerate foods as quickly as possible, keep counters and sponges clean, wash our hands after handling raw eggs and poultry, and prevent what is called cross-contamination. This means not wiping the counter with the sponge you used to mop up raw chicken juice (ugh) or making a salad with hands not washed after touching same chicken.  Perhaps decreasing the number of meals we eat away from home might also help. Preparing your own container of cut-up fruit or chicken salad or smoothie rather than buying these items eliminates the uncertainty of where the food comes from and the whether it was prepared under strict sanitary conditions. Avoid eating foods at catered buffets that look as if they could shelter bacteria. A mousse of chicken liver , assuming one likes chicken liver, should be consumed with caution if only because unless it is kept cold, one doesn’t know whether it is a culture medium for bacteria.

But how does one protect oneself against an outbreak of food-borne illness if the food is something as unprocessed as lettuce or cantaloupe? Or how is the consumer to know that Kellogg had another company manufacture the cereal that was contaminated?

A start would be to stop being complacent about food safety. Rather, perhaps a bit of paranoia is worth having when reading a restaurant menu, checking out the cleanliness of a restaurant rest- room  (where unwashed restaurant workers’ hands may cause hepatitis A outbreaks) and taking a peak at the “I was poisoned” website.

Just don’t look at it after you eat.