Low Starch Diet for Ankylosing Spondylitis: Part 2 – The Scientific Evidence

November 2, 2014

We have already seen (in the last blog) the theoretical possibility of a ‘Low starch diet’ being beneficial for Ankylosing Spondylitis. Let us now see whether it really works in real life & whether there is sound medical evidence to support it.

Today’s medicine works on the basis of evidence. If a new medicine/ intervention is thought to be useful, it is tested in clinical trials. A group of patients is given the standard treatment & placebo (an inert substance that has no effect on disease activity) while another comparable group is given the standard treatment & the experimental therapy/ intervention. A ‘double blinded study’ that ensures that neither the investigator nor the patient knows whether he is taking the experimental drug or placebo is ideal to avoid any bias; both on the investigator or the patient front. This is not possible for studies with dietary modifications as blinding is not possible & bias tends to creep in.

As against medicines, it is very difficult to keep an exact track of the diet of any patient for obvious reasons. It is extremely difficult to ensure that a patient sticks to a particular diet in the long run throughout the study period.

These two factors make studies based on dietary interventions difficult to conduct as well as interpret.

For the reasons mentioned, there are hardly any studies about ‘low starch diet’ in Ankylosing spondylitis. In 1996, Dr. Ebringer discussed the disease activity trend of one of his patients following the diet for a long period (1983- 1995). His ESR showed a continuously decreasing trend. In another study (mentioned widely on the internet with no reliable data available on any of the medical literature sites) 36 patients received Dr. Ebringer’s diet & showed considerable improvement in symptoms. These two studies would be highly inadequate for any definite conclusions.

So, as we have seen, the utility of ‘low starch diet’ in Ankylosing spondylitis is not yet proven scientifically.

One way of looking at things would be to give it a try & see whether it works. However it has to be weighed against the risks involved in pursuing such a diet.

In the next blogpost, let us look at what a ‘low starch diet’ includes/ excludes & the possible health hazards of such a diet.

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“Low starch diet’ for ankylosing Spondylitis

October 25, 2014

Many patients keep asking me about the role of ‘Low starch diet’ to control Ankylosing Spondylitis. This has been a hot topic of discussion on most Ankylosing spondylitis groups on social media & many confirming the good results of a low starch diet.

The original idea of a ‘low starch diet for Ankylosing Spondylitis’ comes from Dr. Alan Ebringer, Prof of Immunology at King’s College London. He found high levels of a gut pathogen called Klebsiella Pneumoniae in stool samples of patients with Ankylosing spondylitis. He also found high levels of antibodies to klebsiella in the blood of patients with Ankylosing spondylitis. These findings indicated the presence of the bacteria in the gut of patients with Ankylosing spondylitis & the body’s immune reaction to it.

These findings evoked further research & Dr. Alan’s further research showed that K. pneumoniae was isolated more frequently during the active phase of Ankylosing Spondylitis & clinical relapse was preceded by appearance of the bacteria in fecal samples. This meant that Klebsiella Pnemoniae was somehow related to inflammation of Ankylosing Spondylitis.

Dr. Alan’s research continued & he went on to show that there are similarities in structure of the HLA-B27 molecule & enzyme Pullulanase produced by the Klebsiella bacteria. There is also similarity between the enzyme & type I, III & IV collagens found in joints & other organs. This gave rise to the ‘Molecular mimicry theory’. The human immunity recognizes Klebsiella as foreign & attacks it. However, since HLA-B27 & collagens have similar structure, they get attacked to. This may be responsible for the inflammation in joints & other structures like the eyes in Ankylosing spondylitis.

One can infer from the proposed ‘molecular mimicry theory’ that by reducing the klebsiella bacteria in the gut, one can reduce the inflammation associated with Ankylosing spondylitis.

Various studies have shown that the gut bacteria including klebsiella grow on undigested starch in the gut. Hence a reduction in starch in the diet may help reduce the klebsiella bacteria in the gut. Klebsiella bacteria is well adapted to the human gut & produces the Pullulanase enzyme that can break down the starch, derive nutrition & thrive in the gut.

The rationale of the ‘low starch diet’ is to cut down on the starch, make life difficult for the klebsiella bacteria. This may indirectly help control the Ankylosing spondylitis.

This is the exact basis of the ‘low starch diet’ for Ankylosing Spondylitis.

Now that we know the basis of the theory, we also need to look at the following points—
1. What is a ‘low starch diet’?
2. Are there any studies conducted in patients with Ankylosing spondylitis to prove the benefits of ‘low starch diet’?
3. If the concept looks so convincing, why do Rheumatologists not recommend it on a regular basis?

I would be answering these questions in the subsequent blog posts. These posts are coming soon & follow my blog so that you don’t miss out on any of those useful posts.

References: Erbinger A, Wilson C. J Med Microbiol 2000; 49: 305-311 http://jmm.sgmjournals.org/content/49/4/305.abstract


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