Trust Me, I’m a Doctor: You Don’t Want Macular Degeneration

Remember...peanuts aren't nuts, they're legumes

Remember…peanuts aren’t nuts, they’re legumes

I saw an optometrist a few months ago for a new eyeglass prescription and mentioned that age-related macular degeneration (ARMD or AMD) runs in my family. ARMD is the leading cause of adult blindness in the West.

The optometrist suggested I start taking eye vitamins to help prevent ARMD. Popular eye vitamin preparations around here are Ocuvite and I-Caps. He said a multivitamin like Centrum might be just as effective.

Steve Parker MD, eye chart, eye exam

Macular degeneration is the opposite of this: blacked-out or fuzzy vision in the center, clearer at the periphery

UpToDate.com, a source I trust, says that supplements for prevention probably don’t work and are not recommended. Which means Centrum would be just as effective: i.e., none of them work.

Instead, UpToDate recommends regular exercise, not smoking, and relatively high consumption of leafy green vegetables, fruits, fish and nuts. Although they didn’t mention it by name, the traditional Mediterranean diet provides all of those.

On the other hand, if you already have macular degeneration (wet or dry), UpToDate recommends these supplements (probably based on the AREDS-2 study):

  • vitamin C 500 mg/day
  • vitamin E 400 mg/day
  • lutein 10 mg/day
  • zeaxanthin 1 mg/day
  • zinc 80 mg/day (as zinc oxide)
  • copper 2 mg/day (as cupric oxide)

An reasonable alternative for non-smokers and never-smokers is the standard AREDS formula. It’s the same as above except it substitutes beta carotene for lutein or zeaxanthin. You can buy both formulations over-the-counter in the U.S. pre-mixed so you don’t have to swallow a handful of pills, just one.

I was in a supermarket yesterday checking out eye vitamins and noted that Bausch and Lomb’s AREDS-2 formula costs about $10/month.

I’m not taking these supplements for now. I taking the diet, exercise, and non-smoking route.

Steve Parker, M.D.

Undisturbed Hunter-Gatherers Don’t Have Near-Sightedness

…according to an article at Nutrition Research. That’s in stark contrast to the developed world. Asian Scientist reports that:

In certain developed parts of East Asia, nearsightedness is skyrocketing, with the prevalence of myopia now at an estimated 80 to 90 percent of the population. In areas of the world where families cannot afford eyeglasses, poor vision from nearsightedness is a serious disability that can affect a person’s ability to learn and work.

Steve Parker MD, paleobetic diet,

Should have spent more time outdoors

The authors of the article at Nutrition Research suggest that the better vision of hunter-gatherers as compared to an agrarian culture is related to greater variety and larger quantities of phytochemicals in the H-G group. Here’s their abstract:

Myopia [near-sightedness] is absent in undisturbed hunter-gatherers but ubiquitous in modern populations. The link between dietary phytochemicals and eye health is well established, although transition away from a wild diet has reduced phytochemical variety. We hypothesized that when larger quantities and greater variety of wild, seasonal phytochemicals are consumed in a food system, there will be a reduced prevalence of degenerative-based eye disease as measured by visual acuity. We compared food systems and visual acuity across isolated Amazonian Kawymeno Waorani hunter-gatherers and neighboring Kichwa subsistence agrarians, using dietary surveys, dietary pattern observation, and Snellen Illiterate E visual acuity examinations. Hunter-gatherers consumed more food species (130 vs. 63) and more wild plants (80 vs. 4) including 76 wild fruits, thereby obtaining larger variety and quantity of phytochemicals than agrarians. Visual acuity was inversely related to age only in agrarians (r = -.846, P < .001). As hypothesized, when stratified by age (<40 and ≥ 40 years), Mann-Whitney U tests revealed that hunter-gatherers maintained high visual acuity throughout life, whereas agrarian visual acuity declined (P values < .001); visual acuity of younger participants was high across the board, however, did not differ between groups (P > .05). This unusual absence of juvenile-onset vision problems may be related to local, organic, whole food diets of subsistence food systems isolated from modern food production. Our results suggest that intake of a wider variety of plant foods supplying necessary phytochemicals for eye health may help maintain visual acuity and prevent degenerative eye conditions as humans age.

Who says low-carb paleo diets are mostly meat?

Certain fruits and vegetables are also linked with lower risk of macular degeneration

In the developed world, kids might prevent near-sightedness by basking in the bright sunlight of outdoors or simply by spending time outdoors. I suspect prevention has a lot to do with using our distant vision for hours instead of looking at a screen two feet away or the interior walls of our homes.

Steve Parker, M.D.

Reference: London, D.D. and Beezhold. A phytochemical-rich diet may explain the absence of age-related decline in visual acuity of Amazonian hunter-gatherers in Ecuador. Nutrition Research 2015 Feb;35(2):107-17. doi: 10.1016/j.nutres.2014.12.007. Epub 2014 Dec 31.

Paleolithic Diet May Help Reduce Risk of Obesity

…according to a basic science study published in the British Journal of Nutrition. The mechanism for reducing obesity risk would be increased satiety. We’ve seen that before with the paleo diet as compared to a Mediterranean-style diet. Disappointingly, the researchers didn’t see any paleo diet benefits in these healthy study participants in terms of glucose and insulin metabolism.

I haven’t read the report, don’t have it, don’t know when I’ll read it.

Abstract

There is evidence for health benefits from ‘Palaeolithic’ diets; however, there are a few data on the acute effects of rationally designed Palaeolithic-type meals. In the present study, we used Palaeolithic diet principles to construct meals comprising readily available ingredients: fish and a variety of plants, selected to be rich in fibre and phyto-nutrients. We investigated the acute effects of two Palaeolithic-type meals (PAL 1 and PAL 2) and a reference meal based on WHO guidelines (REF), on blood glucose control, gut hormone responses and appetite regulation. Using a randomised cross-over trial design, healthy subjects were given three meals on separate occasions. PAL2 and REF were matched for energy, protein, fat and carbohydrates; PAL1 contained more protein and energy. Plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and peptide YY (PYY) concentrations were measured over a period of 180 min. Satiation was assessed using electronic visual analogue scale (EVAS) scores. GLP-1 and PYY concentrations were significantly increased across 180 min for both PAL1 (P= 0·001 and P< 0·001) and PAL2 (P= 0·011 and P= 0·003) compared with the REF. Concomitant EVAS scores showed increased satiety. By contrast, GIP concentration was significantly suppressed. Positive incremental AUC over 120 min for glucose and insulin did not differ between the meals. Consumption of meals based on Palaeolithic diet principles resulted in significant increases in incretin and anorectic gut hormones and increased perceived satiety. Surprisingly, this was independent of the energy or protein content of the meal and therefore suggests potential benefits for reduced risk of obesity.

Steve Parker, M.D.

Reference: Bligh H.F., et al. British J Nutr. 2015 Feb 28;113(4):574-84. doi: 10.1017/S0007114514004012. Epub 2015 Feb 9.
Plant-rich mixed meals based on Palaeolithic diet principles have a dramatic impact on incretin, peptide YY and satiety response, but show little effect on glucose and insulin homeostasis: an acute-effects randomised study.

White Skin in Europeans Only Took Off 6,000 Years Ago

…according to an article at Science magazine. Europeans 10,000 years ago didn’t look much like those of today.

When it comes to skin color, the team found a patchwork of evolution in different places, and three separate genes that produce light skin, telling a complex story for how European’s skin evolved to be much lighter during the past 8000 years. The modern humans who came out of Africa to originally settle Europe about 40,000 years are presumed to have had dark skin, which is advantageous in sunny latitudes. And the new data confirm that about 8500 years ago, early hunter-gatherers in Spain, Luxembourg, and Hungary also had darker skin: They lacked versions of two genes—SLC24A5 and SLC45A2—that lead to depigmentation and, therefore, pale skin in Europeans today.

But in the far north—where low light levels would favor pale skin—the team found a different picture in hunter-gatherers: Seven people from the 7700-year-old Motala archaeological site in southern Sweden had both light skin gene variants, SLC24A5 and SLC45A2. They also had a third gene, HERC2/OCA2, which causes blue eyes and may also contribute to light skin and blond hair. Thus ancient hunter-gatherers of the far north were already pale and blue-eyed, but those of central and southern Europe had darker skin.

Pale skin may be advantageous in northern latitudes because it allows production of more vitamin D.

The article also discusses European evolution of lactose tolerance and height. The ability to digest milk in adulthood apparently didn’t spread through Europe until about 4,ooo years ago.

RTWT.

Short-Term Paleo Diet Improves Glucose Control in Obese Type 2 Diabetes (the Masharani Study)

UCSF is here

UCSF is here

A three-week Paleolithic-style diet improved blood sugars and lipids in obese type 2 diabetics, according to researchers at the University of California—San Francisco. This is the Lynda Frassetto study I’ve been waiting over a year for. The first named author is U. Masharani, so I’ll refer to this work in the future as the Masharani study. Sorry, Lynda.

To understand the impact of this study, you need to know about a blood test called fructosamine, which reflects blood sugar levels over the preceding 2–3 weeks. You may already be familiar with a blood test called hemoglobin A1c: it tells us about blood sugars over the preceding three months. Blood glucose binds to proteins in our blood in a process called glycation. The higher the blood glucose, the more bonding. Glucose bound to hemoglobin molecules is measured in HgbA1c. Glucose bound to plasma proteins (predominantly albumin) is measured as fructosamine. It probably has nothing to do with fructose. Fructosamine is a generic name for plasma ketoamines.

If you’re doing a diabetic diet study over over 2–3 weeks, as in the report at hand, changes in glucose control will mostly be detected in fructosamine rather than HgbA1c levels.

How Was the Research Done?

Twenty-five obese diabetics in the San Francisco Bay area were randomly assigned to either a paleo-style diet or one based on American Diabetes Association (ADA) guidelines. They followed the diets for three weeks, with various measurements taken before and after intervention.

Participants were aged 50-69; you have to guess the sex breakdown. Average body mass index was 34. Over half (63%) were White/European American; there were three each of Asian, African American, and Hispanic ethnicity. They had normal blood pressures and diabetes was well controlled, with hemoglobin A1c’s around 7% and fructosamine levels close to normal. Four subjects were on no diabetes medications; 14 were taking metformin alone, five were on metformin and a sulfonylurea, one was on long-acting insulin and a sulfonylurea. No drug dosages were changed during the study.

Both intervention diets were designed for weight maintenance, i.e., avoidance of weight loss or gain. If participants lost weight, they were instructed to eat more. All food was prepared and provided for the participants. Three meals and three snacks were provided for daily consumption.

Fourteen subjects completed the paleo diet intervention. They ate lean meats, fruits, vegetables, tree nuts, poultry, eggs, canola oil, mayonnaise, and honey. No added salt. No cereal grains, dairy, legumes, or potatoes. Calorie percentages from protein, fat, and carbohydrate were 18%, 27%, and 58%, respectively. Compared to the ADA diet, the paleo diet was significantly lower in saturated fat, calcium, and sodium (under half as much), while higher in potassium (twice as much). These dieters eased into the full paleo diet over the first week, allowing bodies to adjust to higher fiber and potassium consumption. The paleo diet had about 40 grams of fiber, over twice as much as the ADA diet.

[I wonder why they chose canola over other oils.]

Ten subjects completed the ADA diet, which included moderate salt, low-fat dairy, whole grains, rice, bread, legumes, and pasta. Calorie percentages from protein, fat, and carbohydrate were 20%, 29%, and 54%, respectively (very similar to the paleo diet). I don’t have any additional description for you. I assume it included meat, poultry, eggs, and fruit.

Diet compliance was confirmed via urine measurements of sodium, potassium, pH, and calcium.

What Did the Researchers Find?

Both groups on average lost about 2 kg (4-5 lb).

Compared to their baseline values, the paleo group saw reductions in total cholesterol, HDL cholesterol, LDL cholesterol, HgbA1c (down 0.3% absolute reduction), and fructosamine. Fructosamine fell from 294 to 260 micromole/L. [The normal non-diabetic range for fructosamine is 190-270 micromole/L.]

Compared to their baseline values, the ADA diet group saw reductions in HDL cholesterol and HgbA1c (down 0.2% absolute reduction) but no change in fructosamine, total cholesterol, and LDL cholesterol.

Comparing the groups to each other, the difference in fructosamine change was right on the cusp of statistical significance at p = 0.06.

Within each group, insulin resistance trended down, but didn’t reach statistical significance. However, when they looked at the folks who were the most insulin resistant, only the paleo dieters improved their resistance. By the way, insulin resistance was measure via euglycemic hyperinsulinemic clamp instead of the short-cut HOMA-IR method.

Blood pressures didn’t change.

The authors don’t mention hypoglycemia at all, nor alcohol consumption.

They note that some of the paleo dieters complained about the volume of food they had to eat.

Errata

I found what I think are a couple misprints. Table 1 has incorrect numbers for the amount of sodium and potassium in the ADA diet. See the text for correct values. Table 2 give fructosamine values in mg/dl; they should be micromoles/L.

Final Thoughts

This particular version of the paleo diet indeed seems to have potential to help control diabetes in obese type 2’s, perhaps even better than an ADA diet, and despite the high carb content. Obviously, it’s a very small study and I’d like to see it tested in a larger population for several months, and in type 1 diabetics. But it will be years, if ever, before we see those research results. Diabetics alive today have to decide what they’ll eat tomorrow.

I wish the researchers had explained why they chose their paleo diet macronutrient breakdown: calorie percentages from protein, fat, and carbohydrate were 18%, 27%, and 58%, respectively. Perhaps they were trying to match the ratios of the ADA diet. But from what I’ve read, the average ancestral paleo diet carbohydrate energy percentage is 30-35%, not close to 60%. My experience is that reducing carb calorie consumption to 30% or less helps even more with glucose control. Reducing carbs that low in this study would have necessitated diabetes drug adjustments and increased the risk of hypoglycemia.

The authors wonder if the high fiber content of the paleo diet drove the lowered glucose levels.

High HDL cholesterol is thought to be protective against coronary artery disease and other types of atherosclerosis. Both diet groups here saw reductions in HDL. That’s something to keep an eye on.

The ADA diet group saw a drop in HgbA1c but not fructosamine. I can’t explain how HgbA1c goes down over three weeks without a change in fructosamine level.

You have to wonder if the paleo diet results would have been more impressive if the test subjects at baseline had been sicker, with poorly controlled blood pressures and HgbA1c’s of 9% or higher. And it sounds like some of these folks would have lost weight if not forced to eat more. The paleo diet is more satiating than some.

The article was well-written and a pleasure to read, in contrast to some I’ve suffered through recently.

Steve Parker, M.D.

Reference: Masharani, U., et al. Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. European Journal of Clinical Nutrition, advance online April 1, 2015. doi: 10.1038/ejcn.2015.39

A Brief History of Human Evolution and Migration

paleo diet, Paleolithic diet, hunter-gatherer diet

Huaorani hunter in Ecuador

Evolutionary theory holds that we humans—Homo sapiens—evolved from non-human primates (hominins) in a process that started 2.5 million years ago in Africa. Prominent ancestors include Homo habilis (2.3 million years ago) and Homo erectus (1.8 million years ago).

Homo sapiens eventually hit the scene 200,000 years ago, probably in east Africa, which is considered the cradle of humanity. (All Americans can honestly fill out forms that ask for our race as “African-American.”) The paleoanthropologists tell us we share many genetic traits with long-extinct hominins from two million years ago.

African Diaspora

 

The “Out of Africa” hypothesis to explain the worldwide spread of humans says that Homo sapiens arose in Africa, then began migrating out 50 or 100,000 years ago. A competing “multiregional” hypothesis involves Homo erectus dispersing to many regions throughout Africa, Europe, and Asia, then somehow interbreeding and culminating in Homo sapiens in several regions. Homo erectus may have begun to spread out of Africa as long as 1.4 million years ago. Among the experts, the Out of Africa theory is currently favored over the multiregional hypothesis.

Anyway, starting roughly 100,000 years ago, anatomically modern humans began migrating out of Africa, into the Near East. By 50,000 years ago we were into South Asia, then Australia 40 or 50,000 years ago. We spread to Europe 40,000 years ago. Northeast Asians moved into North America (Alaska) 12 to 30,000 years ago; South America followed. We have evidence of behaviorally modern humans from about 50,000 years ago, if not longer. In other words, in addition to looking like us, they acted like us. At this point, we’ve made it to every spot on Earth that can support life. Not to mention the moon.

As points of reference, the Bronze Age started 5,500 years ago in the Near East and the earliest known writing was 5,000 years ago.

I wonder if God made Adam and Eve 200,000 years ago, and Homo habilis, Homo erectus, and our other hominin “ancestors” are just extinct animals like the dodo bird and dinosaurs. Probably not.

Steve Parker, M.D.

Recipe: Frozen Fruit Smoothie #2

 

Similar to an Icee, but healthier for you

Similar to an Icee, but healthier for you

Try this for dessert instead of calorie-laden items like pie, cake, cookies, and ice cream. Unlike this smoothie, those aren’t very nutrient-dense, either. Since I provide the nutritional analysis below, you can easily incorporate this into most diabetic diets, such as the Paleobetic Diet. Most diabetics need to limit their carbohydrate consumption. Twelve fl oz of this smoothie has almost 40 digestible carb grams, so you may need to reduce the serving size or eat few other carbohydrates with your meal.

At the Parker Compound, we mix this in a Vitamix. Other devices may work, but I’m not familiar with them.

It's all here

It’s all here

Ingredients

1 cup (240 ml) frozen raspberries

1/2 cup (120 ml) frozen blueberries

1 cup (240 ml) frozen strawberries

1 frozen banana (7 inches or 18 cm), cut into 3–4 pieces

1 tbsp (13 g) chia seeds

1 handful (1/2 ounce?) raw kale

2.5 cups (590 ml) water

1 cup (240 ml) ice cubes

Instructions

First item into the Vitamix is the water, then banana, all berries, chia seeds, then top off with the ice. Start mixing on variable speed 1 then slowly increase spin rate to 10, for a total mix of 45–60 seconds. Soon after you get started you’ll probably have to use the “plunger” a few times to un-clump the top items.

Loaded and ready to spin

Loaded and ready to spin

Depending on your batch of fruits, this drink may not be as sweet as you like. You could easily sweeten it up with your favorite artificial non-caloric sweetener. I used 1.5 tsp (7.5 ml) of Truvia to good effect, just thrown in with every thing else before or after the primary mix. Or you could use table sugar, about 4 tsp (20 ml), instead of the Truvia. Most of us eat too much sugar. If you go the sugar route, you’ll increase the calories per serving by 15, and increase carbohydrate grams by 4 per serving.

My able assistant wields the plunger

My able assistant wields the plunger

Number of Servings: 3.5 servings of 12 fl oz (350 ml) each

Advanced Mediterranean Diet boxes: 2 and 1/2 fruits

Nutritional Analysis per Serving:

7% fat

90% carbohydrate

3% protein

190 calories

46 g carbohydrate

7 g fiber

39 g digestible carbohydrate

5 mg sodium

290 mg potassium

Prominent features: Rich in vitamin C, fair amount of fiber, homeopathic amounts of sodium

Steve Parker, M.D.

PS: I credit my wife with this recipe.

 

Fruit Smoothie #1

 

A 12 fl oz serving

A 12 fl oz serving

My wife began experimenting with smoothies last year after seeing a Vitamix demonstration at Costco. Most Americans should probably eat more fruit; smoothies are one way to do that. Today’s recipe is one she concocted. Note the trendy chia seeds and kale. Smoothies are a great substitute for junk food desserts.

We’re using a Vitamix mixer. Other devices may be able to get the job done. The mixing speeds our device range from one to 10. (Tip for a competitor: make one that goes to 11.) We love our Vitamix and have no regrets about the purchase, although it was expensive (over $500 USD). It is hard to hear anything else when it’s running at top speed.

Since I provide nutritional analysis below, most diabetics can fit this smoothie into their diets without guessing the carb grams. Twelve fl oz or 350 ml provides 32 digestible carb grams. Most diabetics should probably reduce the serving size by a third, down to 8 fl oz (240 ml) and 11 digestible carb grams.

One potential advantage of blending these fruits is that one fruit may provide nutrients that the others lack

One potential advantage of blending these fruits is that one fruit may provide nutrients that the others lack

Ingredients

1 cup (240 ml) grapes, green seedless

1 mandarin orange, peeled, halved

1 banana (7 inches or 18 cm), peeled, cut into 3–4 pieces

1 pear, medium-size, cored, quartered (ok to leave peel on)

1/2 tbsp (7 g) chia seeds

1 cup (50 g) raw kale

Instructions

First put the water in the Vitamix, then grapes, pear, orange, banana, chia seeds, kale, and finally ice. Ice is always last. Then blend on variable speed 1 and gradually go up to high level (10). Total spin time is about 45 seconds.

Full speed ahead!

Full speed ahead!

Number of Servings: 2.5 consisting of 12 fl oz (350 ml) each.

Advanced Mediterranean Diet boxes: 2 fruits

Nutritional Analysis per Serving:

7% fat

88% carbohydrate

5% protein

160 calories

38 g carbohydrate

6 g fiber

32 g digestible carbohydrate

15 mg sodium

520 mg potassium

Prominent features: Good source of vitamin C, fair amount of fiber, miniscule sodium.

Steve Parker, M.D.

 

 

More Evidence That Modern Diets Are Bad For Our Teeth

Australian Aborigine in Swamp Darwin

Australian Aborigine in Swamp Darwin

Phys.org has an article on dental changes associated with the transition from hunter-gatherer cultures to less mobile agricultural ones. The transition occured 10,000 to 12,000 years ago at the end of the Paleolithic period. Some quotes:

“Our findings show that the hunter gatherer populations have an almost “perfect harmony” between their lower jaws and teeth,” he explains. “But this harmony begins to fade when you examine the lower jaws and teeth of the earliest farmers”.

*   *   *

The diet of the hunter-gatherer was based on “hard” foods like wild uncooked vegetables and meat, while the staple diet of the sedentary farmer is based on “soft” cooked or processed foods like cereals and legumes. With soft cooked foods there is less of a requirement for chewing which in turn lessens the size of the jaws but without a corresponding reduction in the dimensions of the teeth, there is no adequate space in the jaws and this often results in malocclusion and dental crowding.

You can read the original research report in PLOS One.

Steve Parker, M.D.

h/t Diet Doctor Eenfeldt

This bedrock metate was used by Indians (aka Native Americans) for grinding maize, acorns, and other foods

This bedrock metate was used by Indians (aka Native Americans) for grinding maize, acorns, and other foods. Rainwater fills this 4-inch deep rounded depression in granite about 10 miles from my house.

Are Your Computers Giving You E-mentia?

Thinking about it...

Exercise your brain

I saw a patient at the hospital a couple years ago who had been brought in by ambulance after suffering some trauma (not to his brain). He couldn’t call any friends or relatives to let them know what was going on because he didn’t have his cellphone. His phone had all his contact numbers so he had no reason to memorize any. Would you be in the same boat?

DailyMail has an interesting article on whether our use of technology is making us dumber. If we turn over mental tasks like navigation and math to computers, do our brains waste away? Will we be seeing more and earlier cases of age-related dementia? E-mentia?

This is worth keeping an eye on.

Steve Parker, M.D.

PS: The five other members of my household all have cellphones. The only number I’ve memorized is my wife’s.