Food and Zits

About a year ago I wrote about the link between chocolate and pimples and found the evidence poor. Since then there have been a couple of reviews of the diet data so I thought I would share them with you.

Good parent, bad teenager

Parents have long handed out dietary advice to reduce pimple production, seemingly based more on socially accepted dogma (avoid sugar, soft drinks and confectionery) rather than any good quality research. No doubt, it suited the good parent/bad teenager model of family life. Since the turn of the century there has been some, but not many, well designed studies to try and determine whether our diet does influence acne.

Glycaemic Load

I took a look at a couple of review papers and both agree that the best evidence is that a low Glycaemic Load diet has the greatest ability to control pimples, that is, a diet that has the least effect on blood glucose levels. For example, it means less rice crackers and crispbreads, cornflakes, crumpets, one-minute oats and more fruit, legumes, nuts, vegetables and dairy foods.

Of course, many people are adamant that certain foods trigger their acne, and there is no argument from me. It is plausible that for some folk specific foods or greasy takeaways can be manifest on their face the next morning. Trying to give general anti-acne diet advice to all is the tricky bit.

Other theories

There have been other theories of late, such as a diet rich in omega-3 fats from fish helps protect against acne, but there is no clear link between other aspects of the diet and pimples. There has been conjecture that dairy foods, like skim milk, increases the risk of acne by increasing Insulin-like Growth Factor (IGF-1) production, a hormone that elevates the sex hormones that cause acne. The jury is out on that one. The most convincing evidence remains for the high Glycaemic Load diet.

What does it all mean?

For a start, there doesn’t seem much point in trying to scare those with acne into thinking that avoiding jelly beans and soft drink is a solution. Avoiding the occasional treat is hardly going rid the skin of pimples.

What is clear is that it has been particularly difficult to isolate one aspect of the diet that promotes or defends against acne, meaning that other factors are unavoidable, with adolescent hormones being an obvious one. For example, when you lower the Glycaemic Load of the diet (ie get people to eat better), people of ample size often lose weight and one wonders if the weight loss is equally helpful as low Glycaemic Index (GI) foods in reducing the incidence of zits.

On the other hand, eating well seems to be the most effective way to put diet in your corner for the acne battle. Choosing low GI foods is helpful, except GI is such a difficult physiological concept to get across, so maybe just telling people to eat mainly minimally processed foods will help. Getting them to do so is not so easy.

References:

Journal of the American Academy of Dermatology 2010; 63: 124-141

Clinics in Dermatology 2010; 28: 12-16

Vinegar and your Blood Glucose

When you eat well you limit the excursions in your blood glucose levels, generally making it easier to control your weight, your pimples and your diabetes, should they be problems. It has been known for some time that adding a tablespoon of vinegar to a meal (eg vinegar in your salad dressing) can reduce the blood glucose response to the meal by 30%.

The theory is that adding vinegar to a meal slows down the rate at which food empties from the stomach and enters the small intestine for digestion, therefore slowing the absorption of glucose.

A recent paper (Eur J Clinical Nutrition 2010; 64: 727-732) indicates that the vinegar effect is more pronounced after high GI meals and not the low GI meals we suggest for good health (and less zits). They used a wine vinegar. I assume the effect is still present with a flavoursome 4-clover leaf balsamic.

Low joule sweeteners & appetite

Sweetening agents in food or as a powder or tablet have been around for many years. I have already told you that my folks used saccharin during the sugar restrictions of the 2^nd World War. Much misinformation on sweeteners circulates the internet because the world loves to hate stuff they don’t understand.

One thought has been that sweeteners like aspartame (Nutrasweet) at best didn’t make you eat less kilojoules and at worst, made you overeat, countering the close-to-zero calories they offer.

Sugar vs sweeteners

Sugar has been thought as a culprit in weight gain since the 1960s, so replacing sugar with a sweet substitute that provided very few calories was always seen as part of the remedy and would help weight loss. To test whether people compensated for the “missing kilojoules” when consuming low joule sweeteners, researchers first gave test subjects a “pre-load” meal that had either sucrose (cane sugar), or the low joule sweeteners aspartame or stevia (a sweet extract from the leaf of Stevia rebaudiana). They were blind as to which pre-load snack they got.

The participants had a controlled breakfast. Later in the day they were given one of the three pre-load snacks, followed 20 minutes later by a regular lunch. In the evening they were given another of the three pre-loads (with either sucrose, aspartame or stevia) followed by a dinner to their liking.

Appetite not affected

The pre-load snack had an extra 200 Cals (835 kJ) when the sugar was added, compared to the sweetener. If the low joule sweeteners aspartame or stevia had no effect on appetite, then the subjects should have made up the difference in kilojoules by the end of the day, such that they ate the same number of kilojoules independent of whether the pre-load meal had sugar or sweetener.

At the end of the day, when the pre-load snack had a low joule sweetener, the people ate around 300 Cals (1255 kJ) less food than those who had sugar included. Conclusion: low joule sweeteners helped lower the amount of Cals/kJs eaten over 24 hours.

Caveats

The pre-load snacks were solid (crackers and cream cheese sweetened with sugar, stevia or aspartame). The results may have been different if the choice was regular or diet soft drink. The people chosen did not have psychological problems with their food. Had they been aware of the kilojoule content of their snacks (or knew they were drinking diet soft drink) they may have made psychological adjustments to what they chose at lunch or dinner. The study was over 24 hours and a compensatory calorie catch-up may have occurred on subsequent days. All the same, this research is consistent with other research suggesting that “diet” food and drinks can help weight control in many people.

What does it all mean?

When I fly I usually have a water, Diet Coke or Pepsi Max (I’m one of those who can’t really tell the difference) to counter the dry atmosphere in an aircraft. The occasional diet soft drink or food with a low kilojoule sweetener can play its part in stopping overeating. As always, controlling your weight is about eating well and being fit. Low joule sweetened foods can help in a small way.

Reference: Appetite 2010; 55: 37-43

Hash brown content of Harley Davidson's

While reading Martin Lindstrom’s book Buyology (http://www.martinlindstrom.com) he mentioned that Harley Davidson had tried to trade mark its engine sound when Japanese bike manufacturers tried to mimic that engine rumble. He described it as the signature fast “potato-potato-potato” sound. I hadn’t heard the sound described that way before. You probably have, and so have many others (put Harley and potato into your search engine).

Ok, nothing to do with food. I just liked the analogy, but not around my house after 10pm please (because the sound wedges into my consciousness and fries my sleep. Hey, I know it’s not funny, but I didn’t think you would read this far). The photo was taken at the Elvis Festival, Parkes, NSW in January 2008. From memory, Kelvin the owner, paid $35,000 for it. And yes, he has the complete Elvis outfit and wig.

Popeye didn't eat spinach for iron

Three generations of children have been told to eat their spinach so they get enough iron and grow up to be a strong as Popeye. Leaving aside the fact that muscle strength has got more to do with training and eating well, more than a focus on a single nutrient, we face those funny things called facts.

Spinach and iron

Spinach does contain iron. Half a cup of cooked spinach provides around 4 mg of iron. That’s pretty impressive considering the average bloke needs 8 mg a day and young ladies need 18 mg a day. Most other vegetables barely give you 1 mg of iron per half cup served. So, spinach has quite a bit of iron. And that’s about as far as some people look.

Although spinach is high in iron it is a lousy source of iron. How’s that? Well, it all revolves around the word “bio-availability”, that is, the ability of the body to absorb a nutrient from the intestines and use it within the body. Most of the iron in spinach is bound to oxalate (in the form of ferrous oxalate) and you do not have a digestive enzyme to split that binding to release the iron. That means that most, estimated at 95%, of the iron goes in one end and out the other about a day later. Spinach is iron’s way of taking a 10 metre (11 yd) voyage through your guts.

The decimal point fallacy

Now, Popeye is unlikely to have known that because he was created around 1929, featuring in his own cartoon in December 1930. A British Medical Journal paper from 1981 claimed that the fallacy of spinach being high in iron came about because the decimal point was placed in the wrong spot in the original analysis back in the 19^th century, giving spinach an iron content ten times more than it was in reality.

Earlier this year, Dr Mike Sutton from Nottingham Trent University in the UK, refutes the whole argument stating that there is no evidence that a decimal point was ever placed in the wrong spot. He has even written to author of the BMJ article and says the response from the author provided no proof for the claim.

The really, really interesting bit

Well, to me at least. OK, so spinach is not a great source of iron and it never appeared to be. When Popeye was created in 1930 we knew about the minerals like iron and calcium and only the vitamins A, B1, C, D and E. Vitamins like folate, B12 and niacin were yet to be isolated.

Did Popeye himself say he ate spinach for iron? No. Not once, according to Mike Sutton. He did, on 3^rd July 1932, mention that he ate spinach for one particular nutrient. Vitamin A (see cartoon). You and I know that there isn’t pure vitamin A in spinach; it’s in the pre-vitamin A form of beta-carotene. All the same, Popeye ate spinach for a vitamin, not a mineral.

What does it all mean?

It is wonderful when someone goes that extra distance to get information. So, hat’s off to Mike Sutton. I didn’t take Mike’s word for it. I went and bought the first two years of Popeye cartoons (because I yam what I yam), and I agree with Mike: Popeye only mentions vitamin A. Popeye is right, spinach is a great source of beta-carotene (and folate). Eat your spinach for the vitamins, not for the minerals.

If you would like to read the complete report by Mike Sutton then just got to: http://www5.in.tum.de/~huckle/Sutton_Spinach_Iron_and_Popeye_March_2010.pdf. Warning: it is a 35 page in-depth study as you might expect from a criminologist, which is just what Mike is.

Reference: British Medical Journal 1981; 283: 1671-1674

Alcohol & Rheumatoid Arthritis

Health advisors often have differing views on alcohol. Is it a healthy drink to help avoid heart disease or is it an insidious and evil beverage that causes social turmoil? I agree with the words of Abraham Lincoln, or maybe his speech writer, who said: “It has long been recognised that the problems with alcohol relate not to the use of a bad thing, but to the abuse of a good thing.” Well, it was more interesting than saying “drink in moderation”.

1-2% population affected by RA

From UK researchers comes further indication that the occasional drink can be helpful and healthful. As alcohol has anti-inflammatory and a mild analgesic effect, they proposed that rheumatoid arthritis (RA) might be less likely or less severe in people who drank alcohol.

According to this [http://www.aihw.gov.au/publications/phe/phe-110-10524/phe-110-10524.pdf booklet] from the Australian Institute of Health and Welfare rheumatoid arthritis is an autoimmune disease in which the body attacks its own organs and joints, especially the joints on the knees, wrists, fingers and elbows. This debilitating condition affects around 400,000 Australians (about 1 in 50 people). It is more common in ladies and older folk.

Don’t smoke; drink frequently

The research compared 873 Caucasians with RA to 1004 without the condition, all from around Sheffield in England. Each one underwent clinical and radiological assessment as well as completing a survey. Those with RA were more likely to be older, smoke and female when compared to the control group. The more frequently someone drank, the less likely they were to have RA, and the less severe were the symptoms if they had RA.

Dr James Maxwell, the lead author of the paper, said: “Patients who had drunk alcohol most frequently had symptoms that were less severe than those who had never drunk alcohol or only drunk it infrequently. X-rays showed there was less damage to joints, blood tests showed lower levels of inflammation and there was less joint pain, swelling and disability”.

What does it all mean?

Note that only frequency of alcohol consumption was measured, not the amount of alcohol, and alcohol consumption was based on a questionnaire, always a problem as humans have lousy memories and like to give socially acceptable answers. Despite this, the protective effect of alcohol against RA was pretty persuasive and cannot be ignored. Like all good researchers, they did say: “Further research is needed to confirm the results.” If they are confirmed, health authorities will hope that only 1, maybe 2, standard drinks does the trick, because then we can keep giving out the same advice as we always do.

Reference: Rheumatology. 2010; doi:10.1093/rheumatology/keq202

Is weight loss good for overweight people ?

Sensible answer: of course it is. I mean, haven’t you seen all those public weight loss campaigns? When overweight folk lose weight, their health risks tend towards normal, that is, blood pressure drops, blood glucose lowers and blood cholesterol improves. A good thing, no? Not so fast, say a couple of American scientists who have crunched the numbers.

Intentional vs unintentional

Previous research has revealed that weight loss is linked to an increased chance of dying. Yes, that’s right, weight loss = early death. Clever readers will note that sick people usually unintentionally lose weight before they die, so such people will skew the statistics. There are other confounding factors too. Intentional weight loss is often via an unbalanced and low nutrient starvation diet (do you feel just too vibrant and joyful? Then try the Israeli Army diet) and semi-starvation has never been associated with longevity. These diets often mean a loss of muscle tissue and not just body fat. So, we have to be careful when we say that weight loss increases the chance of early death.

Too much weight loss unhealthy

Anyway, the statisticians looked at over 6000 men and women who were 50 years plus. They were followed for about 20 years and in that time 1600 died. Once they had adjusted for age, health and smoking and all the other things they adjust, guess what? If you lose more than 15% of your weight, whether you are male or female, obese or overweight, you die earlier than if you had lost only 5% of your weight. Women doubled their risk of early death and men increased their risk one and a half times by losing over 15% of their weight.

Let’s say you weigh 120 kg (265 lb) and lost 18 kg (40 lb) then you have probably brought your funeral forward. Are you listening at The Biggest Loser as you cheer Bob or Jane who has gone from 140 kg to 85 kg in a 12 week season?

What does it all mean?

Not every chunky person needs to lose weight. It is well regarded that people over 75 years do better and live longer with a little extra padding. The overweight unwell shouldn’t be placed on weight loss programs either. An otherwise healthy overweight person should lose weight slowly and not use televised “reality” weight loss programs as a guide.

This study is not saying that overweight people won’t benefit from weight loss, but it is making us ask whether encouraging a huge weight loss down to a supposed “ideal weight” is a good idea for everyone. Being very overweight is not healthy; promoting big weight loss doesn’t appear to be wise either. Right now we just don’t know what is a healthy rate or level of weight loss. The current advice for the overweight to lose around 0.5 kg (1.1 lb) a week and accept they probably won’t ever be super-lean is still the best advice.

Reference: International Journal of Obesity. 2010; 34: 1044-1050