Holding on to brain function through nutrition

By the year 2050, the number of people in the world over 80 years old will reach 370 million. About 50 percent of adults currently 85 and older have Alzheimer’s disease. The statistics are sobering and warn of a growing and serious epidemic. A high prevalence of Alzheimer’s disease, which is a debilitating and costly disease, can severely impact the population.

With this perspective, the American Society for Nutrition hosted a symposium on the nutritional prevention of cognitive decline on Wednesday at Experimental Biology in San Diego. At the event, speakers presented a comprehensive overview of epidemiological, animal, and clinical trials regarding the role of B vitamins, omega-3s, vitamin D, and caffeinated beverages such as coffee and tea in the prevention and treatment of cognitive impairment.

Martha Morris, Ph.D., an epidemiologist at Tufts University, discussed the relationship of folic acid, B12, and homocysteine to age-related cognitive decline, dementia, and Alzheimer’s disease. In summary, she said, the evidence suggests that sufficient B12 intake could protect against cognitive decline related to elevated levels of homocysteine. However, once B12 status was replete, there was no further protection.

The next speaker to follow was Lenore Arab, Ph.D., nutritional epidemiologist at University of California, Los Angeles, who presented on the effects of caffeinated beverages coffee and tea. The popular drinks, of which many in attendance wished for during the early morning talk, showed promise in helping to slow cognitive decline according to evidence from observational, animal, and clinical data.

Tommy Cederholm, M.D., Ph.D., of Uppsala Universitet, Sweden, discussed the large amount of epidemiological studies and human clinical trials exploring the role of omega-3s. The data suggest plenty of biological mechanisms such as reducing inflammation and protection against amyloid-beta protein deposits.

"Fish is good for your brain," Dr. Cederholm said, noting that intake may assist in early stages of cognitive impairment. However, he added, intake did not appear to assist in patients who already had Alzheimer's disease.

Lastly, Joshua Miller, Ph.D., a professor of pathology of University of California, Davis, discussed new research findings that vitamin D played a major role in the brain development and function. The epidemiological and animal studies suggest a positive effect in the prevention or treatment of cognitive impairment, he said, but randomized controlled trials in humans were lacking. Unlike other micronutrients, he added, vitamin D has a complexity because of seasonal variation, which suggests it's important to measure both in summer and in winter when performing studies.

What is a reasonable vitamin D level?

The figure and table below are from Vieth (1999); one of the most widely cited articles on vitamin D. The figure shows the gradual increase in blood concentrations of 25-Hydroxyvitamin, or 25(OH)D, following the start of daily vitamin D3 supplementation of 10,000 IU/day. The table shows the average levels for people living and/or working in sun-rich environments; vitamin D3 is produced by the skin based on sun exposure.

25(OH)D is also referred to as calcidiol. It is a pre-hormone that is produced by the liver based on vitamin D3. To convert from nmol/L to ng/mL, divide by 2.496. The figure suggests that levels start to plateau at around 1 month after the beginning of supplementation, reaching a point of saturation after 2-3 months. Without supplementation or sunlight exposure, levels should go down at a comparable rate. The maximum average level shown on the table is 163 nmol/L (65 ng/mL), and refers to a sample of lifeguards.

From the figure we can infer that people on average will plateau at approximately 130 nmol/L, after months of 10,000 IU/d supplementation. That is 52 ng/mL. Assuming a normal distribution with a standard deviation of about 20 percent of the range of average levels, we can expect about 68 percent of the population to be in the 42 to 63 ng/mL range.

This might be the range most of us should expect to be in at an intake of 10,000 IU/d. This is the equivalent to the body’s own natural production through sun exposure.

Approximately 32 percent of the population can be expected to be outside this range. A person who is two standard deviations (SDs) above the mean (i.e., average) would be at around 73 ng/mL. Three SDs above the mean would be 83 ng/mL. Two SDs below the mean would be 31 ng/mL.

There are other factors that may affect levels. For example, being overweight tends to reduce them. Excess cortisol production, from stress, may also reduce them.

Supplementing beyond 10,000 IU/d to reach levels much higher than those in the range of 42 to 63 ng/mL may not be optimal. Interestingly, one cannot overdose through sun exposure, and the idea that people do not produce vitamin D3 after 40 years of age is a myth.

One would be taking in about 14,000 IU/d of vitamin D3 by combining sun exposure with a supplemental dose of 4,000 IU/d. Clear signs of toxicity may not occur until one reaches 50,000 IU/d. Still, one may develop other complications, such as kidney stones, at levels significantly above 10,000 IU/d.

See this post by Chris Masterjohn, which makes a different argument, but with somewhat similar conclusions. Chris points out that there is a point of saturation above which the liver is unable to properly hydroxylate vitamin D3 to produce 25(OH)D.

How likely it is that a person will develop complications like kidney stones at levels above 10,000 IU/d, and what the danger threshold level could be, are hard to guess. Kidney stone incidence is a sensitive measure of possible problems; but it is, by itself, an unreliable measure. The reason is that it is caused by factors that are correlated with high levels of vitamin D, where those levels may not be the problem.

There is some evidence that kidney stones are associated with living in sunny regions. This is not, in my view, due to high levels of vitamin D3 production from sunlight. Kidney stones are also associated with chronic dehydration, and populations living in sunny regions may be at a higher than average risk of chronic dehydration. This is particularly true for sunny regions that are also very hot and/or dry.

Reference

Vieth, R. (1999). Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety. American Journal of Clinical Nutrition, 69(5), 842-856.

Vitamin D levels: Sunlight, age, and toxicity

Calcidiol is a pre-hormone that is produced based on vitamin D3 in the liver. Blood concentration of calcidiol is considered to be a reliable indicator of vitamin D status. In the research literature, calcidiol is usually referred to as 25-Hydroxyvitamin or 25(OH)D. Calcidiol is converted in the kidneys into calcitriol, which is the active form of vitamin D.

The table below (from: Vieth, 1999; full reference at the end of this post; click on it to enlarge), shows the average blood vitamin D levels of people living or working in sun-rich environments. To convert from nmol/L to ng/mL, divide by 2.496. For example, 100 nmol/L = 100 / 2.496 ng/mL = 40.1 ng/mL. At the time of this writing, Vieth (1999) had 692 citations on Google Scholar, and probably more than that on Web of Science. This article has had, and continues having, a high impact among researchers.

The maximum average level of blood (or serum) vitamin D shown in the table is 163 nmol/L (65 ng/mL). Given that the human body produces vitamin D naturally from sunlight, it is reasonable to assume that those blood vitamin D levels are not yet at the toxic range. In fact, one of the individuals, a farmer in Puerto Rico, had a level of 225 nmol/L (90 ng/mL). That individual had no signs of toxicity.

Several studies show that pre-sunburn full-body exposure to sunlight is equivalent to an oral vitamin D intake of approximately 250 µg (10,000 IU).

In spite of claims to the contrary, vitamin D production based on sunlight does not cease after 40 years of age or so. Studies reviewed by Vieth suggest that among the elderly (i.e., those aged 65 or above) pre-sunburn full-body exposure to sunlight is equivalent to an oral vitamin D intake of 218 µg (8,700 IU).

Sunlight-induced vitamin D production does seem to decrease with age, but not dramatically.

Post-sunburn sunlight exposure does not increase vitamin D production. Since each person is different, a good rule of thumb to estimate the number of minutes of sunlight exposure needed to maximize vitamin D production is the number of minutes preceding sunburn. For a light-skinned person, this can be as little as 7 minutes.

Vitamin D accumulation in the body follows a battery-like pattern, increasing and decreasing gradually. The figure below, from Vieth’s article, shows the gradual increase in blood vitamin D concentrations following the start of daily supplementation. This suggests that levels start to plateau at around 1 month, with higher levels reaching a plateau after 2 months.

While sunlight exposure does not lead to toxic levels of vitamin D, oral intake may. Below is a figure, also from Vieth’s article, that plots blood levels of vitamin D against oral intake amounts. The X’s indicate points at which intoxication symptoms were observed. While typically intoxication starts at the 50,000 IU intake level, one individual displayed signs of intoxication at 10,000 IU. That individual received a megadose that was supposed to provide vitamin D for an extended period of time.

Non-toxic levels of 10,000 IU are achieved naturally through sunlight exposure. This applies to modern humans and probably our Paleolithic ancestors. Yet, modern humans normally limit their sun exposure and intake of vitamin D to levels (400 IU) that are only effective to avoid osteomalacia, the softening of the bones due to poor mineralization.

Very likely the natural production of 10,000 IU based on sunlight was adaptive in our evolutionary past, and also necessary for good health today. This is consistent with the many reports of diseases associated with chronic vitamin D deficiency, even at levels that avoid osteomalacia. Among those diseases are: hypertension, tuberculosis, various types of cancer, gingivitis, multiple sclerosis, chronic inflammation, seasonal affective disorder, and premature senescence.

Reference:

Reinhold Vieth (May 1999). Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety. American Journal of Clinical Nutrition, Vol. 69, No. 5, 842-856.

How long does it take for a food-related trait to evolve?

Often in discussions about Paleolithic nutrition, and books on the subject, we see speculations about how long it would take for a population to adapt to a particular type of food. Many speculations are way off mark; some think that even 10,000 years are not enough for evolution to take place.

This post addresses the question: How long does it take for a food-related trait to evolve?

We need a bit a Genetics 101 first, discussed below. For more details see, e.g., Hartl & Clark, 2007; and one of my favorites: Maynard Smith, 1998. Full references are provided at the end of this post.

New gene-induced traits, including traits that affect nutrition, appear in populations through a deceptively simple process. A new genetic mutation appears in the population, usually in one single individual, and one of two things happens: (a) the genetic mutation disappears from the population; or (b) the genetic mutation spreads in the population. Evolution is a term that is generally used to refer to a gene-induced trait spreading in a population.

Traits can evolve via two main processes. One is genetic drift, where neutral traits evolve by chance. This process dominates in very small populations (e.g., 50 individuals). The other is selection, where fitness-enhancing traits evolve by increasing the reproductive success of the individuals that possess them. Fitness, in this context, is measured as the number of surviving offspring (or grand-offspring) of an individual.

Yes, traits can evolve by chance, and often do so in small populations.

Say a group of 20 human ancestors became isolated for some reason; e.g., traveled to an island and got stranded there. Let us assume that the group had the common sense of including at least a few women in it; ideally more than men, because women are really the reproductive bottleneck of any population.

In a new generation one individual develops a sweet tooth, which is a neutral mutation because the island has no supermarket. Or, what would be more likely, one of the 20 individuals already had that mutation prior to reaching the island. (Genetic variability is usually high among any group of unrelated individuals, so divergent neutral mutations are usually present.)

By chance alone, that new trait may spread to the whole (larger now) population in 80 generations, or around 1,600 years; assuming a new generation emerging every 20 years. That whole population then grows even further, and gets somewhat mixed up with other groups in a larger population (they find a way out of the island). The descendants of the original island population all have a sweet tooth. That leads to increased diabetes among them, compared with other groups. They find out that the problem is genetic, and wonder how evolution could have made them like that.

The panel below shows the formulas for the calculation of the amount of time it takes for a trait to evolve to fixation in a population. It is taken from a set of slides I used in a presentation (PowerPoint file here). To evolve to fixation means to spread to all individuals in the population. The results of some simulations are also shown. For example, a trait that provides a minute selective advantage of 1% in a population of 10,000 individuals will possibly evolve to fixation in 1,981 generations, or 39,614 years. Not the millions of years often mentioned in discussions about evolution.

I say “possibly” above because traits can also disappear from a population by chance, and often do so at the early stages of evolution, even if they increase the reproductive success of the individuals that possess them. For example, a new beneficial metabolic mutation appears, but its host fatally falls off a cliff by accident, contracts an unrelated disease and dies etc., before leaving any descendant.

How come the fossil record suggests that evolution usually takes millions of years? The reason is that it usually takes a long time for new fitness-enhancing traits to appear in a population. Most genetic mutations are either neutral or detrimental, in terms of reproductive success. It also takes time for the right circumstances to come into place for genetic drift to happen – e.g., massive extinctions, leaving a few surviving members. Once the right elements are in place, evolution can happen fast.

So, what is the implication for traits that affect nutrition? Or, more specifically, can a population that starts consuming a particular type of food evolve to become adapted to it in a short period of time?

The answer is yes. And that adaptation can take a very short amount of time to happen, relatively speaking.

Let us assume that all members of an isolated population start on a particular diet, which is not the optimal diet for them. The exception is one single lucky individual that has a special genetic mutation, and for whom the diet is either optimal or quasi-optimal. Let us also assume that the mutation leads the individual and his or her descendants to have, on average, twice as many surviving children as other unrelated individuals. That translates into a selective advantage (s) of 100%. Finally, let us conservatively assume that the population is relatively large, with 10,000 individuals.

In this case, the mutation will spread to the entire population in approximately 396 years.

Descendants of individuals in that population (e.g., descendants of the Yanomamö) may posses the trait, even after some fair mixing with descendants of other populations, because a trait that goes into fixation has a good chance of being associated with dominant alleles. (Alleles are the different variants of the same gene.)

This Excel spreadsheet (link to a .xls file) is for those who want to play a bit with numbers, using the formulas above, and perhaps speculate about what they could have inherited from their not so distant ancestors. Download the file, and open it with Excel or a compatible spreadsheet system. The formulas are already there; change only the cells highlighted in yellow.

References:

Hartl, D.L., & Clark, A.G. (2007). Principles of population genetics. Sunderland, MA: Sinauer Associates.

Maynard Smith, J. (1998). Evolutionary genetics. New York, NY: Oxford University Press.

Lecithin - good for your brain and liver

Lecithin provides choline, which is a precursor for the neurotransmitter acetylcholine in the brain.(1) Choline is also necessary to remove fat from the liver.(2) Thus, supplementation could be extremely beneficial for alcoholics to prevent against cirrhosis.(2)

References

1. http://www.jacn.org/cgi/content/abstract/11/5/473
2. http://www.medschool.northwestern.edu/newsworthy/past-years/2002/2002H-May/choline.htm

What's the new rage? Omega-3 Index

Blood omega-3 oils could be just as or more important than blood LDL cholesterol levels.

Last week I attended a conference in Las Vegas where I heard a cardiologist say bluntly that doctors need to be retrained to stop limiting their focus to blood LDL cholesterol for preventing heart disease and start using the novel Omega-3 Index.

What's that?

According to a 2004 article in Preventative Medicine, the index serves as a "novel, physiologically relevant, easily modified, independent, and graded risk factor for death from CHD that could have significant clinical utility."(1)

The Omega-3 Index is used as a biomarker to measure the percentage of EPA and DHA omega-3 fatty acids in the blood cell membranes.(2) The omega-3 oils replace other fatty acids.(2)

A high value of omega-3 oils is linked to reduced risk of cardiovascular disease as well as other benefits.(2) A value of 8 percent or above in omega-3 oils can mean a 90 percent reduced risk of sudden cardiac death.(2)

References

1. Harris, WS, Von Schacky, C. The Omega-3 Index: a new risk factor for death from coronary heart disease. Available at: http://www.ncbi.nlm.nih.gov/pubmed/15208005. Accessed on November 1, 2008.

2. Daniells, S. Omega-3 index could be goalpoasts for max heart health. Available at: http://www.nutraingredients.com/Research/Omega-3-index-could-be-goalposts-for-max-heart-health. Accessed on November 1, 2008.

Promoters say cholesterol is a nutrient - not true

I am a bit stunned by argument for consuming cholesterol by cholesterol-promoterscholesterol-and-health.com because the body makes all the cholesterol it needs (about a gram a day)and a dietary amount is unnecessary.(1) For this reason, I'm not sure I can bring myself to call the lipid a nutrient.

While it is true that cholesterol-rich foods such as eggs may be considered good for the body and could even reduce risk heart disease, these benefits are not attributed to their cholesterol amounts, but to other nutrients that come with the cholesterol.(2)

From what I can gather, the only real reason for seeking out dietary cholesterol is if a person has a genetic disorder that would interfere with the body's own cholesterol production.(3)

References

1. American Heart Association. Cholesterol. Available at: http://www.americanheart.org/presenter.jhtml?identifier=4488. Accessed on November 1, 2008.

2. Harvard's School of Public Health. Nutrition Source: Eggs and heart disease. Available at: http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/eggs/index.html. Accessed on November 1, 2008.

3. University of Utah Genetic Science Learning Center. Smith-Lemli-Opitz Syndrome. Available at: http://learn.genetics.utah.edu/content/disorders/whataregd/slos/. Accessed on November 1, 2008.

3 reasons to still avoid cholesterol (even though it's not bad for you)

More than 50 years have gone by since it was first discovered that too much LDL cholesterol in the blood is linked to heart disease, and, in response, healthcare professionals of all kinds have provided a simple message: "cholesterol is bad".(1)

More recent research, however, tells a different story -- that eggs, liver, shrimp and lobster are not the demons they were once thought to be.(1) Most people who eat these cholesterol-rich foods will find they have little or no impact on blood cholesterol levels.(1) This is good news for the average man who eats 337 milligrams and average woman who eats 217 milligrams daily.(2)

Why then do the American Heart Association and many informed healthcare professionals still recommend intake of cholesterol be no more than 300 milligrams?(2)

Reason 1: Dietary cholesterol comes from animal foods usually along with saturated fat.(2) Both saturated fat and trans fat have a significant impact on higher amounts of LDL cholesterol in the blood.(2)

Reason 2: The body produces about a gram of cholesterol a day, all it needs.(2) Extra cholesterol from the diet is unnecessary and must be removed from the body via the liver.(2)

Reason 3: Cholesterol intake can have an impact on blood LDL cholesterol levels in certain individuals.(2) Thus, those with high blood cholesterol should be conscious of this fact.(2)

References
1. Harvard School of Public Health. The bottom line: Choose healthy fats, limit saturated fat, and avoid trans fat. Nutrition Source: Fats and Cholesterol [online]. Available at: http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-full-story/index.html. Accessed on Nov. 1, 2008.
2. American Heart Association. Cholesterol. Available at: http://www.americanheart.org/presenter.jhtml?identifier=4488. Accessed on Nov. 1, 2008.

Vitamin E

Alpha tocopherol is a type of vitamin E that exists naturally as d-alpha tocopherol, but supplement manufacturers also market synthetic "mirror image" l-alpha tocopherol as well as a mixture of d- and l-alpha tocopherol.

The synthetic kind and the mix are cheaper, but l-alpha tocopherol has little or no actual vitamin E activity in the body. It may interfere with d-alpha tocopherol activity and there's no long-term safety data.

When buying vitamin E supplements, be sure to choose d-alpha tocopherol along with other natural tocopherols such as beta-, gamma- and delta-.

Reference

1. Gaby, A. Does high-dose vitamin E kill people? Townsend Letter for Doctors and Patients. Available at: http://findarticles.com/p/articles/mi_m0ISW/is_259-260/ai_n10299312/pg_2. Accessed on Oct. 25, 2008.

ADHD and omega-3

According to an article in the Scandinavian Journal of Nutrition (Scandinavia being where much of our purified fish oil supplements comes from), there is "mounting evidence" showing that fish oil DHA/EPA omega-3 fatty acids can be used in clinical treatment of ADHD.(1)

Several studies have reported that supplementation with fish oil at high dosages (16g per day - that's really high) was shown to provide significant results in behavioral patterns.(2)

References

1. Richardson, A.J. The importance of omega-3 fatty acids for behaviour, cognition and mood. Available at: http://www.ingentaconnect.com/content/tandf/ssnu/2003/00000047/00000002/art00008. Accessed on Oct. 18, 2008.

2. Sorgi, P.J., Hallowell, E.M., Hutchins, H.L, & Sears, B. "Effects of an open-label pilot study with high-dose EPA/DHA concentrates on plasma phospholipids and behavior in children with attention deficit hyperactivity disorder." Journal of Developmental & Behavioural Pediatrics; 2007, 28:82-91.

Why do pregnant women need iron?

Pregnant women need additional iron intake, but if the body controls absorption and uptake, then why is diet not enough? While it may be true that the diet doesn't provide enough, it may also include other factors beyond iron intake that may also affect women pre- and post-pregnancy.

There are many dietary factors that can inhibit iron absorption.(1) Among these factors are:

- polyphenols of gallic acid that are found in coffee and tea,
- oxalic acid of spinach, chard, berries, chocolate and tea,
- phytates found in legumes,
- preservatives like EDTA,
- phosvitin found in egg yolks;
- and other minerals such as calcium, calcium phosphate salts, zinc, manganese, and nickel.(1p422)

In addition, there are factors that enhance iron absorption. These include:

- acids like ascorbic, citric, lactic and tartaric acid
- sugars
- meat, poultry and fish
- and mucin.(1p422)

When iron deficiency is a problem, thus, wisdom would suggest considering what is inhibiting absorption and what could be added to the diet to enhance absorption.

Reference

1. Gropper, S.S., Smith, J.L. & Groff, J.L. Advanced Nutrition and Human Metabolism, 4th ed; 2005. Belmont, CA: Thomson Wadsworth.

Sodium supplements or salt shakers?

I couldn't imagine why anyone would supplement with sodium. We do so much "supplementation" already with our salt shakers. All that shaking is linked to hypertension, but overall, when food is salted lightly, the salting may not be all bad.

When you eat salt, it guards you against sodium deficiency. The deficiency is not as likely now, but in earlier days it may have been an issue and continues to be a problem with anorexia.(1) The deficiency's symptoms include nausea, muscle atrophy, poor growth and weight loss.(1p380)

Plus, if the salt is iodized, then it helps guard against iodine deficiency. Iodine is extremely variable in foods so having it as part of salt is beneficial.(1p468) The thyroid collects the iodine, in its ionic form iodide, and uses it for genesis of hormones.(1p418)

Reference

1. Gropper, S.S., Smith, J.L. & Groff, J.L. Advanced Nutrition and Human Metabolism, 4th ed; 2005. Belmont, CA: Thomson Wadsworth.

Vitamin Supplementation Debate

Vitamin supplementation may have its place in clinical nutrition, but confusion of how or when to supplement can ultimately harm the consumer.(1) The confusion arises from "extreme" views of healthcare practitioners who say supplementation is not necessary at all and those who push for too much supplementation.(1p119) Non-credentialed experts and vitamins manufacturers interested in making profits may also lead consumers in the wrong paths.(1p119)

Pros of Supplementation

As a person ages or changes his or her diet or environment, vitamin needs can change resulting in a potential need for help from vitamin supplementation.(1p119)

Supplementation can remove the guesswork out of making sure enough of a certain vitamin is in the diet. A woman, for example, who has a need for additional folic acid during times of pregnancy may choose supplementation rather than attempting to make significant changes to diet.(1p119) A child or adolescent can also be given supplements to be sure of healthy growth despite a reluctance to eat a balanced diet.(1p119)

Supplementation can be used to prevent clinical issues.(1p119) An example includes infants given vitamin K and D and trace minerals iron and fluoride.(p119)

Impaired nutrient absorption, storage and usage can be helped by supplementation.(1p119) An example includes elderly who may may need vitamin C, thiamin, riboflavin, pyridoxine and cobalamin.(1p119)

Lifestyle choices may influence need of supplementation.(1p120) Use of oral contraceptives, restricted diets, exercise programs, smoking, alcohol and caffeine can all generate situations of vitamin deficiency due to insufficient dietary intake and/or interference with absorption of vitamins.(1p120)

Certain diseases may create a situation where a person could benefit from supplementation.(1p120) Especially in cases of long-term illness, supplementation can be used to meet increased vitamin needs to support the body.(1p120)

Cons of Supplementation

While there are many "pros" to vitamin supplementation, the "cons" can be equal in detriment. A large amount of a certain vitamin can be toxic such as the case of retinol, which has potential of causing liver or brain damage.(1p120)

Megadoses of vitamins can also lead to a deficiency of another vitamin due to how they work together in the body.(1p120) An "artificially induced" deficiency can result when a person suddenly stops taking a large amount of a certain vitamin, such as infants who develop scurvy because their mothers took megadoses of vitamin C during pregnancy.(1p121)

A non-credentialed "expert" or vitamin manufacturer may miss these points as he or she recommends or markets certain vitamins to unsuspecting customers.

Conclusion

Proper vitamin supplementation should be done with wisdom and care. Supplementation principles include reading labels carefully, understanding that large doses can be harmful, that supplement use is governed by individual needs, that all nutrients work together, and that food remains the best source of nutrients.(1p121) Lastly, sound knowledge and evidence should guide reasons for supplementation.(1p121)

Reference

1. Nix, S. Williams' Basic Nutrition &Diet Therapy, 12th ed, Elsvier Mosby, 2001; 119-121.

Health Starts in The Gut

Going in with the gut, I'm led to deduce that health begins exactly there.

The gut and other parts of the gastrointestinal system make up the basic conduit of nutrition.(1) Food eaten is broken down by the system into simpler substances, nutrients are absorbed and transported to cells, and then are metabolized for creation of new body substances or for energy. (1p58)

Clinical Applications of Digestion, Metabolism and Absorption

Clinical application begins with the knowledge of how the process of digestion works. A nutritionist can then begin applying solutions.(1p67) To help a patient limit burping, a nutritionist can suggest he or she avoid nervously gulping down carbonated beverages through a straw.(1p67) To limit flatulence in a patient, the nutritionist can recommend he or she limit fiber and slowly reintroduce it in the diet or take a lactase supplement before consuming milk.(1p67)

Nutritionists can use diet therapy to also encourage absorption and metabolism of nutrients. An example is inclusion of non-digestible oligosaccharides to the diet. Understanding how these nutrients affect growth of intestinal flora helps a nutritionist encourage proper mineral absorption such as calcium in a patient.(2, 3, 4)

Clinical Applications of Energy Balance

Energy balance is a chief factor when nutritionists consider diet therapy. The food the body digests is partly converted to energy through cell metabolism.(1p74) Nutritionists should know how foods affect energy via each kilocalorie present.(1p75) For proper health, the body must have a sufficient amount of kilocalories from food for fuel and function, but not so much daily that would lead to gain of too much weight.(1p75, 81)

The amount of kilocalories for proper energy balance requires evaluation of daily energy requirements. Nutritionists would consider the body’s uses of energy, namely resting metabolic rate, physical activity and thermic effect of food.(1p81) A calculation of total energy output can then determine how many calories a patient should receive.(1p81)

Basing clinical diet therapy on energy balance as well as digestion, absorption and metabolism, the patient is adequately served and sure to receive best results.

References

1. Nix, Staci, Williams' Basic Nutrition &Diet Therapy, 12th edition, Elsvier Mosby, 2001; 57-86.

2. Kolida, S & Gibson. Prebiotic capacity of inulin-type fructans. In: Inulin and oligofructose: Health benefits and claims-A critical review. J of Nutrition. November 2007; 137 (suppl):11S.

3. Scholz-Ahrens, KE & Schrezenmeir, J. Inulin and oligofructose and mineral metabolism: The evidence from animal trials. In: Inulin and oligofructose: Health benefits and claims-A critical review. J of Nutrition. November 2007; 137 (suppl):11S.

4. Abrams, SA, Griffin, J, and Hawthorne, KM. Young adolescents who respond to an inulin-type fructan substantially increase total absorbed calcium and daily calcium accretion to the skeleton. In: Inulin and oligofructose: Health benefits and claims-A critical review. J of Nutrition. November 2007; 137 (suppl):11S.

Why we need fats

Nothing else can stimulate the taste buds quite like the smell of fat. The human body comes adapted with a special affinity for this resource, according to evolutionary nutrition researchers S. Boyd Eaton, MD, and Stanley B. Eaton III (a father-son duo) (1998). Dr. Eaton and Eaton suggest early hominids eventually ate a greater amount of nuts and seeds and later, around 2.5 million years ago, humans on a hunter-gatherer diet might have preferred animal fat, specifically supplied in the brain and marrow—an alteration of diet that may have been a factor in supporting a larger brain (1998). This history of fat in the diet helps shape understanding of how vital fat is for the diet.

The body needs fat for various functions as well as other fat-related substances in the family of lipids. Most lipids in the body are of a type called triglycerides—three fatty acids with a glycerol backbone—which act as concentrated sources of energy stored in greater amounts in adipose tissue cells (Tortora & Derrikson, 2006, p. 46). Triglycerides are used as a “back-up” fuel source, as insulation to help maintain body temperature, and as “protective padding for vital organs” (Nix, 2005, pp. 34 & 40). The major lipid that makes up cell membranes is the phospholipid—two fatty acids with a glycerol backbone—along with other fat-related substances cholesterol and lipoproteins (Tortora & Derrikson, 2006, p. 46). Multiple types of lipids also play a role as a protective covering for nerve cells called a myelin sheath, which is also important for increasing speed of nerve impulses (Tortora & Derrikson, 2006, p. 410). To maintain proper amount of lipids in the body, dietary fat is important.

Dietary fat, however, occurs in various ways. The “building blocks” of fats are fatty acids, which can consist of short-, medium- or long-chains of carbon atoms with a methyl group on one end and carboxyl group on the other (Nix, 2005, p. 31). The fatty acids can also be “saturated’ or “unsaturated” (including polyunsaturated) depending on their amount of hydrogen atoms (p. 31). The saturated are generally from animal origin and the unsaturated from plant origin, although there are plants that contain saturated fat and animals will have unsaturated fat (p. 31-33). Essential fatty acids are specifically types of polyunsaturated fats that are necessary for the body (p. 33). Trans fats occur when unsaturated fats are chemically “saturated” to make them more solid at room temperature (p.35). With the various types of fatty acids, confusion may lie in how to best utilize food with proper amounts of each in the diet.

Too much fat is harmful, but so is not enough. When the diet is high in fat over time, higher incidence of chronic diseases (Nix, 2006, p. 39). Heart disease is a good example being the leading killer of men and women in the U.S.A. According to the American Heart Association (AHA), great amounts of fat, especially of saturated fat and trans fat, contribute to obesity and heart disease (2008). A low-fat diet, then can help protect the heart. However, when the body does not take in sufficient fat, however, essential fatty acid deficiency can occur (Nix, 2006, p. 39). Essential fatty acid deficiency is rare, but signs include scaly dermatitis, alopecia, thrombocytopenia and growth retardation (Morley, 2007). The key to the health is a correct balance.

Fat intake in the right amounts as well as the right kinds leads to a healthy lifestyle. U.S. Dietary Guidelines recommend no more than 20% to 35% of total fat, no more than 10% calories from saturated fat, and no more than 300 mg/day of dietary cholesterol (Nix, 39, 2006). AHA adds that it is best to avoid saturated and trans fats, replacing them with mono- and polyunsaturated fats “while still limiting” total fat (2008). Of the polyunsaturated, it’s important to remember that two are essential—omega-6 and omega-3 fatty acids.

Omega-3 is the more important of the two. In 2002 AHA began recommending people without heart disease consume fish at least twice a week to help maintain a health heart as long as a close watch was instituted over intake of fish contaminants (e.g. mercury) (Kris-Etherton et al). Further, AHA recommends those with heart disease take at least 1 g per day of EPA/DHA omega-3 fatty acids in capsule form (to avoid contaminants of eating fish), and for 2 to 4 grams daily in capsule form for those who needed to lower triglycerides (Kris-Etherton et al). In addition, the U.S. Food and Drug Administration (FDA) put out a qualified claim about “reduced risk of coronary artery disease” for any whole food, packaged food or dietary supplement that contained both EPA/DHA omega-3 fatty acids (2004). The information suggests that a low-fat diet with an emphasis on polyunsaturated oils especially omega-3 fatty acids is best for health. Since the brain is made up of mostly omega-3 fats, that would explain why hunter-gatherers preferred the brain on the menu.

References

American Heart Association. (2008, Sept 21). Face the Fats. Retrieved Sept. 17, 2008 from http://www.americanheart.org/presenter.jhtml?identifier=3046074.

Department of Health and Human Services Centers for Disease Control and Prevention. (2008). Heart Disease. Retrieved Sept. 17, 2008 from http://www.cdc.gov/heartdisease/.

Eaton, S.B. & Eaton, S.B. III, (1998). Evolution, diet and health. [Scientific Session – International Congress of Anthropological and Ethnological Sciences in Williamsburg, VA]. Retrieved Sept. 17, 2008 from http://www.cast.uark.edu/local/icaes/conferences/wburg/posters/sboydeaton/eaton.htm.

Kris-Etherton, P.M., Harris, W.S., & Appel, L.J. (2002). Fish consumption, fish oil, omega-3 fatty acids and cardiovascular disease. Circulation: Journal of the American Heart Association, 106; 2747-2757. Retrieved Sept. 22 from http://circ.ahajournals.org/cgi/reprint/106/21/2747.

Morley, J.E. (2007, June). Essential Fatty Acid Deficiency. The Merck Manual for Healthcare Professionals. Retrieved Sept. 21 from http://www.merck.com/mmpe/sec01/ch002/ch002d.html.

Nix, S. (2005). Williams’ Basic Nutrition & Diet Therapy, 12th ed. St. Louis, MO: Elsevier Mosby.

Tortora, G.J., & Derrikson, B. (2006). Principles of Anatomy and Physiology, 11th ed. New York: John Wiley & Sons.

U.S. Food and Drug Association (2004). FDA announces qualified health claims for omega-3 fatty acids. Retrieved on Sept. 21, 2008 from http://www.fda.gov/bbs/topics/news/2004/NEW01115.html

Even a Caveman Can Eat Low-Carb

With good reason carbohydrates (carbs) are the staple fuel source for most diets in the world. Not only are they plentiful and cheap to produce—created by plant photosynthesis—but also utilized easily by the body. The body’s process, in fact, according to Staci Nix, MS, RD, CD, is “far more efficient than any man-made machine (2005, p.16). There are different types of carbs: the simple, which are quickly absorbed by the body, and the complex, which are more slowly absorbed.

Simple carbs have one sugar molecule such as monosaccharides such as glucose, fructose and galactose, or disaccharides such as sucrose, lactose and maltose (Nix, 2005, pp. 16-17). The complex carbs (polysaccharides) include starches, glycogen, dietary fiber, cellulose, noncellulose polysaccharides and lignins. With the exception of dietary fiber and noncellulose polysaccharides, the body breaks down these carb types, turns them into glucose and distributes the glucose through blood circulation to all the cells that need it in the body.

The glucose—whether produced by simple or complex carbs—is not only important for energy, but for sparing the need to use stores of protein and fat, which can be used to sustain the body in other ways (Nix, 2005, p. 24). More important is glucose’s role in supplying adequate fuel to the nervous system including the brain (p. 24). Unlike carbs, protein and fat energy cannot supply a constant stream of glucose to the brain, giving carbohydrates a role that is vital for life.

The amount of carbohydrates needed in the diet, however, has been a hotly contested debate. Nix mentions that sugar is not “the villain,” but that too much of its use is problematic (2005, p.24). Harvard nutritionist and physician Walter Willet, Ph.D. Willet agrees that the USDA food pyramid should be modified to steer people away from refined carb foods. They provide little nutrients, he says, but more detrimentally, they spike blood glucose causing higher needs for insulin only to bring glucose “crashing down” (Discover, 2003, http://discovermagazine.com/2003/mar/breakdialogue). The scenario happening regularly adds to higher risk of Type II diabetes. His “Healthy Eating Pyramid” stresses more focus on whole grains and fruits and vegetables and not the refined carbs (President and Fellows at Harvard College, 2008, http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/pyramid/index.html).

Low-carb dieting for encouraging weight loss has been led partly by some who have developed theories surrounding the diet of early humans. According to Loren Cordain, Ph.D., (2002, Chapter 1 [digital version]) and Noel T. Boaz (2002, Location 2309, Table 7 [digital version]), both top-selling authors of books with collected research on human evolution and diet of Paleolithic populations, suggest that the body may be adapted to a diet of high-protein, high-fiber, and low-carbohydrates.

Significant health problems, however, can occur as a result of low-carb dieting and should not be overlooked. Without enough carbs the body has to use the body’s protein and fat supply for creating quick energy (p. 24). According to Nix, muscle may be catabolized for its protein, muscle maintenance prevented, and the break down of fat stores for fast fuel can result in “incomplete fat oxidation”, thus creating an excess of strongly acidic ketones (2005, p.24). The ketoacidosis that occurs can become toxic to the body.

Many may have found themselves with ketoacidosis when on an extremely low-carb diet. A report in The Lancet of a 40-year-old woman hospitalized while following the popular low-carb Atkins diet is just one of several reports (Groch, 2006,http://www.medpagetoday.com/PrimaryCare/DietNutrition/tb/2878.). She had eaten nothing but meat, cheese and salad for in the month before the event. Criticism along with the report included comments by Lyn Steffen, Ph.D., M.P.H. and Jennifer Nettleton, Ph.D., who said the ketoacidosis would lead to “constipation, halitosis, diarrhea, headache and fatigue,” and long-term ketoacidosis would create problems for the kidneys and bones. Note that the Atkins diet has since been revised, according to Atkins Nutritionals (2008, http://www.atkins.com).

Considered moderately low-carb, the Mediterranean diet, which includes plenty of fruits, vegetables, and monounsaturated oils may be a better choice. According to an Israeli study published in the New England Journal of Medicine on three typical diets—a typical low-fat diet, a pre-revised-Atkins diet and the Mediterranean diet (based on recommendations by Walter Willet)—all the diets were regarded as safe, both low-carbohydrate diets provided metabolism benefits, but only the Mediterranean diet showed significant improvement for glucose and insulin levels (Shai et al, 2008). When it comes to carbs, as Staci Nix points out, “moderation is once again is the key” (2005, p. 24).



References

Atkins Nutritionals Inc. (2008). “Thoughtful approach. Powerful science.” Retrieved on Sept. 12, 2008 from http://www.atkins.com.

Boaz, N.T. (2002). Evolving Health: The Origins of Illness and How the Modern World Is Making Us Sick [digital version]. New York: John Wiley & Sons.

Cordain, L. (2002). The Paleo Diet: Lose Weight and Get Healthy by Eating the Food You Were Designed to Eat [digital version].New York: John Wiley & Sons.

Discover [interview with Walter Willett]. (March, 2003). “Nutritionist and physician Walter Willett—a voice of reason on diet.” Retrieved on Sept. 12, 2008 from http://discovermagazine.com/2003/mar/breakdialogue.

Groch, J. (2006). Atkins dieter develops life-threatening complications. Medical News: Diet & Nutrition. Retrieved on Sept. 13, 2008 from http://www.medpagetoday.com/PrimaryCare/DietNutrition/tb/2878.

Nix, S. (2005). Williams' Basic Nutrition & Diet Therapy. Philadelphia: Mosby.

President and Fellows at Harvard College. (2008). “The nutrition source healthy eating pyramid.” Retrieved on Sept. 12, 2008 from http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/pyramid/index.html.

Shai, I., Schwarzfuchs, D., Yaakov, H., Sahar, D.R., Witkow, S., et al. (July, 2008). Weight loss with a low-carbohydrate, Mediterranean or low-fat diet. The New England Journal of Medicine, 359:229-241.

Man can't live by bread and water alone

Imagine you have been on a "bread and water" diet for three weeks and have noticed that a cut on your shin won't heal and bleeds easily. Why?

The inability to heal would largely be due to lack of vitamin C. Proper maintenance and repair of tissue depends on this essential nutrient (Tortora & Derrikson, 2006).

Once confirming a deficiency of vitamin C, assume signs of scurvy. According to Medline, along with skin hemmorrhages, general weakness, anemia, and gum disease.

Just an orange a day is sufficient for preventing scurvy, according to researchers from University of Toronto (Weinstein, Babyn & Zlotkin, 2001). The vitamin C in the citrus fruit serve as the right treatment.

My body would also need protein to produce healing. Nutrition consultant James Collier says the amino acids, along with vitamin C and zinc, are essential for the production of collagen and even a short duration of lack of protein can significantly slow healing (n.d.). Collier also suggests B vitamins, vitamin K, carbohydrates and fats are important. A few of these nutrients may have been supplied by the bread. Lack of protein would also significantly slow healing because your body would hold onto it for other vital functions (Tortora & Derrikson, 2006).

References

Collier, J. (n.d.). "Nutrition and wound healing." Retrieved on Sept. 14, 2008 from http://www.dietetics.co.uk/article-nutrition-wound-healing.asp.

Medline Plus. (2008). "Medical Encyclopedia: Scurvy." Retrieved on Sept. 14, 2008 from http://www.nlm.nih.gov/medlineplus/ency/article/000355.htm.

Tortora, G.J. & Derrikson, B. (2006). Principles of Anatomy and Physiology. New York: John Wiley & Sons.

Weinstein, M., Babyn, P. & Zlotkin, S. (2001). An orange a day keeps the doctor away: Scurvy in the year 2000. Pediatrics, 108:3, p. e55. Retrieved on Sept. 14, 2008 from http://pediatrics.aappublications.org/cgi/content/abstract/108/3/e55.

What fluids should I use before my marathon?

Marathon runners can become dehydrated due to the extreme physical activity. What types of fluids should they consume in order to rehydrate their cells?

When you’re dehydrated, water is the hypotonic solution of choice for speedily moving via osmosis from blood directly into body cells that need rehydration (Tortora & Derrickson, 2006). Marathon runners, however, may need a little more solutes in the solution.

The physical exertion of running can create need of other nutrients for these athletes. Regular sweating and using up of glycogen calls for needs of carbohydrates to maintain blood glucose and salts for proper balance of plasma osmalility (Chen & Zimmerman, 1978). Sports drinks can offer an answer for proper running, but too many solutes in a drink would stop its hydration ability.

A good sports drink should remaining effective as a hypotonic solution, but still provide steady electrolytes, carbohydrates and possibly even vitamins. The extra sodium, according to British researchers of Loughborough University, results in improved performance (Merson et al, 2008). Thus, marathon runners should apply this knowledge for best results.

References

Cohen, I. & Zimmerman, A.L. (1978). Changes in serum electrolyte levels during marathon running. South Africa Medical Journal, 25:53(12):449-53.

Merson, S.J., Maughan, R.J. & Shirreffs, S.M. (July, 2008). Rehydration with drinks differing in sodium concentration and recovery from moderate exercise-induced hypohydration in man. European Journal of Applied Physiology, 103(5):585-94.

Tortora, G.J. & Derrikson, B. (2006). Principles of Anatomy and Physiology. New York: John Wiley & Sons.

Should I see a nutritionist or stick to dietary guidelines?

We may all be made of flesh and blood, but each one of us has a body with unique differences. These varying individual distinctions can call for custom measures when it comes to needs for health. For these reasons good clinicians can accept established dietary guidelines as a general route for a population to make sensible eating choices, but, when appropriate, offer a tailored alternative to provide best results for a patient.

A suitable deviance from normal recommendations, for example, may be to take milk and cheese off the menu for patients of Native American and African ancestry. Lactose intolerance has been found by Cambridge researchers to affect these populations indiscriminately, which should lead clinicians to diverge from the US Department of Agriculture’s guidelines of dairy intake when caring for such affected patients (Scrimshaw & Murray, 1988).

For others increasing dietary intake of dairy may be useful. An athletic patient seeking nutritional advice may find herself or himself encouraged to supplement with protein from dairy whey directly after exercise since Australian researchers have just found that this practice may speed recovery of muscle (Buckley et al., 2008).

Customization of diet should not be limited to genetic and other physical variations in patients. The clinician who discovers a four-year-old girl’s inclination to refuse vegetables may recommend her concerned parents try a more-likeable chewable vitamin in place.

The examples given suggest person-centered care may be better for all. A community has benefited, however, from a fixed norm developed by public policy. Guidelines should not be considered as strict, but should help the grocery store and restaurant offer options while sensitive to the health of customers as well as help the lay person make smart daily food choices.

Selected References

Buckley, J.D., Thomson, R.L., Coates, A.M., Howe, P.R., Denichilo, M.O., & Rowney, M.K. (Sept, 2008). “Supplementation with a whey protein hydrolysate enhances recovery of muscle force-generating capacity following eccentric exercise.” Journal of Science and Medicine in Sport. [Ahead of print]. Retrieved Sept. 5, 2008, from Pubmed online database.

Scrimshaw, N.S. and Murray, E.B. (Oct.1988). “The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance.” American Journal of Clinical Nutrition. 48(4 Suppl):1079-159.

A&P? Can't I just memorize my vitamins?

If you just read the side panel of a Wheaties box while eating breakfast in the morning you'll already know you need vitamins A, Bs, C, and E. The milk carton next to the cereal you know is a good source of calcium and vitamin D. Why should you know about anatomy and physiology?

Understanding the whole picture is, of course, why we break down a complex anything into its parts, including an organism. Cut the body apart into sagittal or transverse sections to discover its cavities and viscera and you learn quite a bit about how a little morsel of might end up in the mouth and through the gastrointestinal tract.

As you read these words, you begin to understand the direction of the point of this paragraph. Just as it is the job of a writer to understand how words can be used for impactful sentences that create powerful paragraphs, the nutritionist can use the alphabet of nutritional elements for supporting his or her patient's body at optimal levels.

The anatomy-physiology nutritionist considers bodily needs from a chemical and cellular level as well as analyzing detection and responsiveness of an organ-system. That kind of nutritionist is one that brings holistic results to a patient, one that does good and no harm, one that can be trusted, the type of nutritionist I aspire to be.