New Frontiers in Fibre

New Frontiers in FibreI spent Thursday afternoon at at St Thomas’ Hospital, attending #BNFNewFibre, a British Nutrition Foundation half day seminar on dietary fibre research. In four short hours we heard from eight nutrition academics and researchers studying new uses for fibre.

The European Food Safety Authority (EFSA) has deemed specific forms of fibre may be recommended for maintaining cholesterol levels, maintaining normal bowel function, reducing post-prandial glycemic levels, increasing fecal bulk and reducing intestinal transit time.

It is the term “fibre” that is problematic, though: soluble vs insoluble; dietary vs functional; whole food sources vs manufactured, extracted and refined, and so on. Since many health claims do not specify the precise type of fibre they are talking about, it is difficult to make sweeping conclusions about intake and effect.

And of course, we are each biochemically unique, the health of our microbiome affected by many factors (age, genetics, pregnancy, lactation, environment, dietary habits, medical conditions and interventions, antibiotic use, etc) not all of which we can control or even identify. These same factors determine our need for fibre, which feeds the hundreds of different strains of beneficial bacteria throughout the length of our digestive system.

We have only identified some 200 unique strains, and 600,000 unique microbial genes, so we have barely begun to learn the position and role these play within our metabolism.

We don’t yet have a good understanding of how fibre works in the microbiome to protect against cardiovascular disease or increase calcium uptake (to protect against osteoporosis), or how it may interact with bile acids, in gene expression or in immune support. Research suggests it may increase satiety, leading to weight loss or protecting against obesity.

Fibre is often included in health advice (either avoiding or adding to the diet) for treatment or prevention of a whole array of medical conditions (colorectal cancers, enteral feeding, irritable bowel disease, irritable bowel syndrome, diverticulitis, radiation toxicity, constipation..)

The speakers whirled through dozens of studies in these areas – published and in process – and left us with the unsurprising conclusion that fibre studies are maddeningly difficult to do with accuracy and consistency (humans being maddeningly diverse in their habits and behaviour, subjects being less than numerous in many studies due most likely to the expense of dietary research, and the very nature of fibre which differs greatly in its chemical composition and effects in the body). And that much more needs to be known.

All this was discussed in the context of last year’s daunting Scientific Advisory Committee on Nutrition (SACN) recommendations which propose raising the already unattained 18g recommended daily fibre consumption to 30g/day for British adults (in Canada it’s 38g for men under 50 or 25 for women).

Chocolate – may not be the answer to Alzheimer’s after all

ChocCupcakesSad news for fans of a favourite medicine who cheered at recent news that cocoa flavanols may offer promise in Alzheimer’s research.

But: according to a more considered look at the issues, it turns out that although flavanols can relax blood vessels, improve blood flow and help with age related memory loss, these effects “…largely disappear once the cocoa bean is heated, fermented and processed into chocolate.

In other words, making chocolate destroys the very ingredient that is supposed to make it healthy.” Moreover, the study included only 37 participants and was funded by Mars, Inc., so may have been ever so slightly lacking in objectivity and rigour.

Even raw cocoa isn’t the conclusive answer, since there are no standards governing raw food production. There is, moreover, a risk of salmonella contamination – from the stages of harvest and fermentation. Producers use high temperature roasting of beans (120c-160c) to kill this bacteria for conventional chocolate. If that’s been done, your raw cocoa might not be as raw as you think. And those flavanols won’t be in evidence either.

The heat generated by fermentation (typically 45c and 50c, but not usually measured by rural producers) is not enough to do the trick as salmonella can grow within that range. So nor is the 45c (114f) steaming or dehydration temperature used in raw production. Pasteurization used to kill salmonella normally uses 1–10 mins at 60c or less than 1 min at 70c, although there are more heat-tolerant strains.

Conclusions? Life is short and all things in moderation is usually the answer. Still waiting on that magic bullet for Alzheimer’s.

Sweet peril

Sugar’s the new bad. Well ok, maybe not new but definitely bad, and the top choice of something to avoid if you want to be healthier, slimmer, happier, wealthier… It appeals to us because of its addictive properties, explained in some detail and complexity – and length – in Robert Lustig‘s now-famous talk Sugar: The Bitter Truth. Here’s a shorter, simpler version that explains the mechanics of sugar metabolism, and why it’s such a compelling taste:

If you’re wanting to cut back but are used to eating lots of sweets, you’ll have to re-train your palate to expect less sugar with each mouthful. Here are some suggestions for getting the sweetness you crave while minimizing the harm:

  • Be an educated consumer: read up on natural sweeteners. Some are better than others.. but they’re all sugar of some kind.
  • “Sugar-free desserts” are often in the realm of  ‘too good to be true’. They usually rely upon artificial sweeteners (bad!) or natural sweeteners (see above) so approach with caution.
  • Retrain your palate Cut the amount of sugar called for in baking recipes by 1/3 and taste; if it’s not sweet enough for you try 1/4 and then gradually reduce each time you make it. Raisins can add a little sweetness to muffins and cookies so you don’t need as much sugar.
  • Use naturally sweet foods as sweeteners: add a few raisins, fresh berries or some diced cooked sweet potato to your hot cereal instead of sprinkling on the sugar.
  • When you do need a treat, try to stick to high-fibre sweet treats, like fresh fruit or (strictly limited quantities of) high-fibre baked goods (Nairn’s ginger oatcakes spring all-too readily to mind).

New year, new herbs

Herb table at London's Garden Museum
Herb table at London’s Garden Museum

Happy 2015! And welcome to my new blog and new business. I’ve been a food & poetry blogger for many years, but now that I’ve qualified as a Registered Holistic Nutritionist, I’m starting up this blog to capture the nittier grittier side of food and nutrition.

I’ve been in the UK for a few weeks and a recent visit to London’s Garden Museum made me think a bit about the many properties of herbs.

The museum’s own garden is in its winter sleep, by and large, but outside the cafe door is a small table of herbs, showing a simple and elegant way to grow your own. In Permaculture design, such herbs are always placed within easy reach of the kitchen, which seems obvious, but isn’t always part of the plan. Herbs are a great thing for novice gardeners to grow because they are usually fairly hardy, self-seeding or perennial, and more or less immune from interference by pests and grazing animals. Some of them grow a little too well (mint and lemon balm for example can go berserk with little prompting) so a container, or series of large pots are recommended.

While we tend to think of herbs as flavourings, they have medicinal and nutritional benefits too. A handful of common, easy-growing herbs and uses include:

Lemon balm (Melissa officinalis) – a calming, soothing herb, promoting sleep, easing indigestion and boosting the immune system. Take fresh or dried as a tea.

Rosemary (Rosmarinus officinalis) – a good source of vitamin A, it’s an antioxidant, aids indigestion and concentration, eases anxiety and stress. Infuse in hot water for tea, sprinkle in your bath water and of course ingest in Mediterranean cuisine.

Sage (Salvia officinalis) – anti-inflammatory, soothing to the digestive tract, antioxidant, memory enhancer, may help to control blood sugar and an excellent source of vitamin K1. Fresh leaves are delicious crisped in butter and tossed with pasta; it complements squash, game, poultry and pork dishes.

Thyme (Thymus vulgaris) – antimicrobial, antioxidant; it eases digestion and gas, soothes sore throats and respiratory problems. Add to tea mixes or lavish in your bean, egg and vegetable dishes. Nutritionally, it is an excellent source of vitamin C, a very good source of vitamin A, and a good source of iron, manganese, copper, and dietary fiber.