Saturday, August 15, 2015

Nutrition can be quite simple, given a chance

One favourite way of getting an answer to a nutrition and health question is to gather all the most recent published studies, put them in a data melting pot, and see if you can extract a “truth”. One review did this recently and found pretty much what you might expect, depending on your personal nutrition mantra or affiliation. They compared various foods groups and types to the risk of common diet-related disease such as heart disease, cancers, gut disease, bone and organ diseases and even mental illness.

Very simply put, they found that:
  1. Drinking tea may reduce the risk of type 2 diabetes, heart disease, Parkinson’s disease and some cancers eg breast and stomach cancer.
  2. Coffee drinking wasn’t quite as powerful as tea, yet seemed to drop the risk of type 2 diabetes, mental illness, heart disease and colon cancer.
  3. Milk pretty well had a neutral effect on long-term health, although it did a good job on maintaining good bone density
  4. Wine helped lower the risk of heart disease and many cancers (yoo-hoo!), but there was a warning: every glass bumped up the chance of getting breast cancer by 5%. Usual message – respect alcohol.
  5. Sweetened drinks increased the chance of overweight and diabetes, but only when consumed in unhealthy amounts.
  6. Fruit and veg, as expected, are wonderful for your health, especially for heart disease and cancer, as well as helping keep your weight in check.
  7. Wholegrains look good on all fronts, but white rice was associated with an increase in type 2 diabetes risk. The authors say that wholegrains are more health protective than fruit and veg.
  8. Legumes are another food that looks great for health, especially with a lower risk of most cancers.
  9. Nuts and seeds are great for keeping heart disease away, with nut lovers at 37% lower risk of heart problems. I guess they mean the unsalted type.
  10. Meat never seems to get good press, but the negatives are usually associated with a high consumption of red meat (see my comment below).

Any food over-consumed, be it meat, soft drink/sodas, wine or coffee, will always be associated with poor health, because if you over-eat something you are likely to be under-eating something else, usually something wholesome. Drink two litres of cola a day and you aren’t likely to be drinking milk for calcium and protein. Drink a bottle of wine each night and I doubt if you are eating much fruit. Eat lots of takeaways and your vegetable intake will suffer. Nutrition is just as much about “too little” as “too much”.

So whenever you see nutrition research being sold as the truth then always reflect on your own diet and ask:
  • Is it varied?
  • Is it nutrient-dense?
  • Is it minimally processed?
  • Is the emphasis on plant-based foods?

Answer yes to all four and there is a good chance you are eating well without having (boring) discussions about whether you should fuss about carbs or fat or the type of fat, or if there is a teaspoon of sugar in the house. We sadly forget that health is about the quality and nutrient density of food, the sentiment of which was captured in a recent article by Rosemary Stanton.

Smelling farts is good for you

Immediately you feel obligated to read this, don’t you? It was a common interpretation of a published research study by the media last year, especially in the UK. It’s a headline that will get plenty of attention, and the story exists only because people easily misinterpret science, leap to conclusions or get just too lazy to ask the study authors for an explanation.

If you have already clicked on the link and read the abstract, you will immediately see that it has nothing, absolutely nothing at all, to do with farting and your health.
Hydrogen Sulfide
It is a study about hydrogen sulfide (H2S), that smelly gas that is produced by your intestinal bacteria after they have chomped through the fibre in your meals. So any study about H2S must also relate to breaking wind, right?

Actually, the H2S story has its own fascination. From a physiological perspective H2S is called a gasotransmitter and has a really interesting role. Just so you know, nitric oxide (NO) and carbon monoxide (CO) are also gasotransmitters that you may have heard about.

All three gasotransmitters are vasodilators, which just means that they help your arteries to widen with ease, which in turn means that blood flows through easier. So, if the heart requires less pressure to pump blood through your arteries, then your blood pressure is lower. It doesn’t stop there. H2S also reduces the level of inflammation linked to heart disease, and is critical for the health of your mitochondria, famous for delivering energy for muscle contraction. And, because they are smart molecules, H2S, NO and CO all “talk” to each other to make sure they are all cruising through your body at ideal levels.

Depending upon levels, H2S is either toxic or healthy
While we knew that atmospheric H2S was toxic to the body for many years (and I don’t mean from passive farting, we are talking industrial waste levels here) it has only been since 1996 that we began to appreciate its role when very small amounts are manufactured within the body. Problems with the natural production of H2S have been linked to hypertension and diabetes, and conditions of chronic inflammation such as rheumatoid arthritis. When your body produces normal levels of H2S, you get up with a smile on your face and a zip in your step.

What does it all mean?
We make the same mistake all the time, assuming that a compound has a similar effect inside and outside the body. The classic example was assuming that cholesterol in food became cholesterol in blood, so everyone stopped eating eggs, yet body weight, genetics and maybe too much saturated fat are the real culprits. Just because H2S is very useful when manufactured by body cells, doesn’t mean that snorting your own gas emissions will have the same positive effect. The same goes for CO. Inhale car emissions in a concentrated space and you will eventually collapse and die. Yet the tiny bit of CO produced by your body is good for you.

As you know:
1. Nothing is bad; it is the amount that determines whether it is bad.
2. Journalists don’t specialise in science or asking smart questions.
3. By the time you have reached your 17th birthday you will have ignited some H2S. Ok, maybe not all the ladies. Just most.

Oh, why spell it sulfide and not sulphide? Because the Royal Society of Chemistry and the International Union of Pure and Applied Chemistry both spell it sulfide and you just don’t mess with purity and royalty.

Tuesday, July 14, 2015

Cutting Calories in Rice

Reader Gillian Street alerted me to a news item suggesting that we had found a way to reduce the energy (Calories/kilojoules) in rice by 10%, and possibly by as much as 50% soon, and this would result in a “healthier rice”. Immediately I was sensing a headline and not a story. Why?

Creating resistant starch
Researcher Sudhair James reported at a conference that if you added coconut oil to simmering rice, then chilled the rice for 12 hours after cooking, the proportion of resistant starch increases.

To make sense of this first we need to know what is resistant starch (RS). We don’t digest all of the starch in food. Some of it is in a form that is resistant to digestion, hence the term. The undigested starch then goes into the large bowel to be consumed by the resident friendly bacteria. This is good, being the main role of dietary fibre too. Foods such as breads, pasta, legumes, bananas, potatoes and corn chips all provide a reasonable amount of RS.

RS benefits
We already knew that if you cool cooked rice, pasta and potatoes that the level of resistant starch rises, meaning that you digest less starch in a cold rice, pasta or potato salad than in hot stir-fried rice, spaghetti marinara or baked potatoes. The cooled starch becomes less soluble and harder to digest.

What are the potential benefits of RS? It helps lower the Glycemic Index of a meal, has a laxation effect, increases the satiety of the meal, and as the healthy bacteria in your large bowel chew through the RS they produce acids that protect the bowel lining, reducing the risk of bowel cancer. Pretty cool eh?

10% fewer Calories
OK, back to the rice story. Sudhair James’ cooking method reduced the kJs by about 10%, which is quite minor in the scheme of things. Why not just eat a little less rice or, even better, not eat that biscuit or pastry for morning tea, or not buy the Maltesers at the movies, or the cake with coffee. It’s quicker, easier and more effective than going through the cook-add-oil-chill-for-12-hours-then-microwave process of saving a few Calories. A cup of steamed rice is 960 kJs (230 Cals) so a 10% saving is 96 kJs (23 Cals) or about one-third of a chocolate biscuit. Get my drift?

Maybe a company will produce rice that has been pre-cooked with oil and dried before putting a packet, but a reduction of 10% kJs would have a net result of zero when it comes to body weight, in my opinion.

OK, but what if they get up to a 50% cut in kJs, wouldn’t that shatter the earth in some manner? Yes, I suppose so, but that is purely speculative for the sake of the story, in my view.

What does it all mean?
Right now we eat an average of 5g of resistant starch each day, yet our goal should be closer to 20g. A rice with more RS could have potential health benefits, no doubt. My guess is that it will come at a premium cost, and may even cause some gut discomfort with all that RS being eaten by bacteria creating gas as a by-product. In the meantime, I suggest you do something radical, yet exceptionally dull, which is to eat regular rice and serve with wholesome plant-based foods and maybe a little meat. No way that will get you a headline.

Kefir 2: made using grains and water

Alberto Gómez from Buenos Aires asked about kefir. He very politely pointed out that I had misunderstood his question about using kefir as a sports drink. So he wrote:

“When I mentioned that kefir could be used as an isotonic drink, I was referring to the kefir prepared with water, not milk. The way to prepare it is to have three spoons of kefir grains, a litre of filtered water, three spoons of brown sugar, a lemon split in halves and three dried plums or dates. You put all of them in a glass container leaving enough air on it and they cultivate in 1-3 days. I do it in two days.

Every day you have to stir the mix. After the time is over, you filter the mix, reuse the kefir grains which amount has increased (separate a portion and use the right proportion, the unused grains could be kept in the fridge for several days keeping them in water with sugar), squeeze the lemon and if you want some fizz just leave the juice in a tight recipient for few hours, put it on the fridge and...voilá!!! you have the isotonic beverage.”

One additional comment from Alberto: “Kefir grains for milk and water are not the same, they share same origin but are different. Advantage of kefir prepared with water is that there are no limits for consumption, the one prepared with milk is heavier and should be consumed with moderation.”

Let me add that I’m still using my milk-based kefir on my cereal in the morning. Adds a pleasant tart sweetness to the start of my day. Thanks again Alberto.