Yet Another Reason A High Fat, High Carb Diet Is Bad For You

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Saturated fat is a prime suspect in the onset of osteoarthritis after Australian scientists found it actually changed the composition of cartilage, particularly in the weight-bearing joints of the hip and knee.

The research is possibly the first study to investigate the association between osteoarthritis and common dietary fatty acids.

It was conducted by Professor Yin Xiao from QUT's Institute of Health and Biomedical Innovation and his team, in collaboration with Professor Lindsay Brown and his team at University of Southern Queensland.

The researchers studied the effects on joints of diets rich in a variety of saturated fatty acids found in such foods as butter, coconut oil, palm oil and animal fat, and simple carbohydrates – a high-fat, high carbohydrate diet common to "junk food".

"Our findings suggest that it's not wear and tear but diet that has a lot to do with the onset of osteoarthritis," Professor Xiao said.

The main function of cartilage is to seal the bone ends in a joint and absorb pressure on the bones during weight-bearing movement such as walking. The researchers found that a diet containing simple carbohydrates together with 20 per cent saturated fats produced osteoarthritic-like changes in the knee.

"Saturated fatty acid deposits in the cartilage change its metabolism and weaken the cartilage, making it more prone to damage. This would, in turn, lead to osteoarthritic pain from the loss of the cushioning effect of cartilage," Professor Xiao said.

They also found changes in the bone under the cartilage on a diet rich in saturated fat.

PhD student Sunder Sekar said the team tested lauric acid, a saturated fatty acid found in coconut oil.

"Interestingly, when we replaced the meat fat in the diet with lauric acid we found decreased signs of cartilage deterioration and metabolic syndrome so it seems to have a protective effect," Mr Sekar said.

He said fatty acids could cause tissue inflammation in the entire "joint environment".

"We tested a variety of saturated fats and found that long term use of animal fat, butter, and palm oil could weaken the cartilage.

"Replacement of traditional diets containing coconut-derived lauric acid with palm oil-derived palmitic acid or animal fat-derived stearic acid has the potential to worsen the development of both metabolic syndrome and osteoarthritis."

Professor Xiao's previous research has found that antioxidants and anti-cholesterol drugs could slow the progression of joint damage caused by fatty acids.

The study was supported by the Prince Charles Hospital Research Foundation.

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    I'm curious what groups they tested this on. My diet has been pretty bad a lot of the time, though I try to eat right most of the time. I had frequent, almost constant knee and hip pain (felt "grindy") until I started regular exercise and weight work at the gym. Within a few weeks of that the painful knees and hip went back pretty much to normal.

    Anyway, I wonder whether the correlation of fat+carbs to cartilage damage may in fact be related to the bad diet affecting the amount of exercise in the group being tested? ie: Lack of exercise may be a large part of the problem, not just high fat and carbs.

      Did you also find that when you started regular exercise that your diet became healthier?

      Interesting point. Can I ask Skrybe, did you loose any weight once you started exercising? Could the reduction in pain be attributed to less mass impact on the joints? I only ask because I found that too, I lost some weight a few years back (wife made me do it...I was happy living on cheese burgers!), and it certainly helped the pain in my knee.

        @bigatom: Not particularly. My diet is good (or at least reasonable) a lot of the time, but I eat pizza or other junk food pretty regularly, and I don't even think twice about eating chips/chocolate or having a coke. I get a ton of carbs (sugar) through drinks.

        I certainly lost weight after starting to exercise more, but the joint pain went away before there was any appreciable weight loss. Maybe dropped a kilo or two before the pain went away. So I doubt that made a difference. Having dropped about 20 kilos from my peak weight I did feel a lot better all round though.

        I wonder if our cartilage production is like most of the other systems in the body - governed by use. Our bone density increases/decreases based on the amount of work we put on them. Same with muscle mass. Maybe it's a similar thing?

          Brilliant effort mate, 20 kgs is no small feat. I can't quite remember "when" my pain left me, I just assumed it was from the weight loss, but after reading your comment, it got me thinking that it may have been very close to when I started changing my diet, and...exercising, which happened simultaneously.
          Being idle may well be part of the problem with cartilage. I don't doubt the weight loss has certainly aided, but Im beginning to think as you said, that exercise (movement and use) may be a contributing factor.

            Thanks, I put some back on and I'm working to get rid of it again. Every winter lol

            I remembered because it was a really striking change pain wise. Went from feeling like I had sand or broken glass in the joints grinding away to pretty much normal in a short time. I wouldn't be surprised if weight has an effect too. Logically it's gotta put more stress on joints, so it could be a double bonus.

            Side note: I think low-medium impact cardio works better for it that just weight-training. Ideally a mix of both is great.

    Am I missing something or did they fail to test the obvious inflammation causing thing, carbs?

    Low carb high fat has been known to reduce inflammation among other things, yet it seems that wasn't tested?

    Very interesting topic.
    I'm currently at home with knee problems and wondering what to do to improve my Hba1c and overall health.
    March 2017 my Hba1c was 110
    Beg July 2017 my Hba1c was 64
    I no longer want to eat keto and looking to eat in Dr Furhman nutritarian way with Turkey/mackerel/eggs as accent.
    When I went for x ray yesterday that osteoarthritis word was on my report.
    I have tight quads and hamstrings but don't want to make things worse with wrong type of fats.
    Less chicken and moderate avocado maybe way for me

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