Читать книгу The Doctor’s Kitchen - Dr Rupy Aujla - Страница 16

Diet choice fatigue

I’ll let you into a secret you probably already know by now: there is no such thing as a ‘perfect diet’.

We are all unique as a result of our cultural backgrounds, genetic variations and even gut microbe populations. Our physical attributes are the sum of so many variables, it is unfathomable to think that any one regimen would be suitable for an entire population.

Our diets are fluid, ever-changing interactions that involve the environment and even our life cycle. The food we eat is dictated by geography, convenience and personal choices. Our nutritional needs are determined by age, hormone profile and emotional state, and that’s before we even start considering medical conditions. We are complicated beings. Forcing ourselves to rigidly stick to a list of foods that are labelled ‘good’ or ‘bad’ will never reflect the intricacies of our requirements.

My goal is for you to enjoy food and appreciate the phenomenal effects it can have on your body, your mental outlook and overall health. I’m not here to scaremonger you or belittle any successes you may have had with previous experiences of diets; if you have used one of these in the past and felt better, that’s fantastic! As long as you feel healthy, it fits into your lifestyle, and it doesn’t lead to a nutritional deficiency or personal risk of disease, you’re doing a great job. I’m not here to warn you off a way of eating that works for you and I’m very open-minded to the success of certain diets for different people. As a doctor, I just want to make sure you’re safe and healthy.

If you’re new to this world, I want you to understand the importance of individuality. I would rather empower you to create a unique way of eating that caters for your requirements, than suggest you follow a ‘one-size-fits-all’ approach.

Eating is a lifestyle, not an uncompromising ‘diet’. It’s a personal and experimental process that needs adapting as you and your environment change. This book, or any other book for that matter, will not contain the answer to everyone’s dietary requirements. But don’t despair! I’ve included principles of eating here that I think are applicable to most people, then the tweaking of elements really depends on you. Seek appropriate advice and get a second opinion if you have concerns about a specific medical condition.

Most diets out there promote a way of eating that is generally better than the typical Western diet of refined carbohydrates and a lack of fibre and micronutrients. So, no wonder there are so many success stories with a lot of them! This doesn’t necessarily validate these diets as a way of eating for all of us. But, it’s likely that you’ll incorporate elements and principles from a variety of diets to create the perfect way of eating for you. Because I get asked about these in clinic all the time, I’ve decided to give you my opinion on the most popular diets around: the good, the bad and the science that doesn’t always stack up.

Just cut the carbs!

+ Paleo, Low-carb high-fat, Atkins, South Beach, Ketogenic I know proponents of each of these diets will argue that these shouldn’t be grouped together because there are slight variations between each, but for simplicity’s sake, I have. Patients don’t appear to differentiate between them and lately I’ve been hearing the same line in my surgery: ‘So, Doctor, I’ve decided to cut out carbs. That’s good, isn’t it?’ Well, not necessarily.

The principles of Paleo, South Beach and Atkins are quite similar. They revolve around reducing your intake of carbohydrate and replacing it with varying proportions of protein and fats, with ‘low-carb high-fat’ (aka LCHF) and Ketogenic diets being the most excessive in terms of fat consumption. They’ve been reported in clinical studies to improve markers of diabetes^103,104 and famously autoimmune disease¹⁰⁵ in a number of protocols. The most exciting promise for Ketogenic diets is in treating childhood epilepsy and chronic pain.^106,107

I think these types of diets do have a place for certain people looking to re-sensitise themselves to insulin after a longstanding over-indulgence in refined carbohydrates and sugar. There is small-scale evidence to show its potential in improving diabetes, insulin sensitivity¹⁰⁸ and symptoms of PCOS.^109,110

However, there is some evidence pointing toward high protein intake being similarly harmful as high carbohydrate intake, which is the trap a lot of people fall into when following these diets.¹¹¹

And let’s not forget the side effects that include: constipation, halitosis, nausea, renal stones, osteoporosis and a potentially increased risk of bowel cancer (among many others).

A lot of people can’t maintain the diet for these reasons, and when they return to eating carbohydrate there appears to be a trend toward regaining all the weight they had lost with potentially worse outcomes and health risks than before they began.

On balance, long-term evidence to advocate these diets is lacking. Essentially, it’s a temporary fix. I appreciate the potential therapeutic value of these diets as a short-term strategy, but personally, I think a diet concentrated on plant nutrition far outweighs one focused on meat. More research is needed to validate the claims of these diets that drastically remove beneficial carbohydrate sources, and the lack of fruit, vegetables and fibre is something that would concern me. We know fibre is essential for proper functioning of our digestive system: our microbes feed off these materials and lack of fibre puts us at risk of bowel cancer.¹¹² For those reasons, I can’t condone low-carb lifestyles long-term, but I don’t doubt that some people have found them beneficial and they may have a role in clinical care.

SIRT diet

While I welcome excitement about foods that have the potential to impact our genetic make-up, the SIRT diet’s focus on a small list of foods impacting some genetic pathways detracts from how multifaceted and complicated human nutrition is. ‘SIRT’ genes are what this diet is named after and increasing the activity of these genes (and the proteins they code for) is thought to reduce inflammation, control blood sugar and has been linked to reducing cancer risk.¹¹³

Yes, parsley, dark chocolate and green tea all increase SIRT gene expression but they also contain catechins, luteolin and a host of micronutrients that are essential for processes in our body’s cells. As do lupini beans, cavolo nero, broccoli, coriander, chilli and a whole bunch of foods that don’t fit a particular list. I think it completely misses the point to focus on an exclusive group of ingredients, and it doesn’t encourage a healthy relationship with food. Every ingredient deserves a platform.

Our grocery aisles are lined with unbelievable health-promoting foods, our seasons provide constant variety and our multicultural society introduces spices and herbs from across the planet. As I alluded to in the previous section, we are merely scratching the surface when it comes to the importance of different interactions between ingredients and our genes. I could have quite easily picked out a few fruits, vegetables and spices affecting one of many inflammatory pathways and called it the ‘NRF2 diet’, or how about the ‘TNF diet’? The Telomere diet? Do these sound scientifically valid enough?

The interaction between food and our genetics is a fascinating field.¹¹⁴ But it is one layer of a multi-faceted process that I haven’t made the cavalier attempt of trying to explain in its entirety. It certainly cannot be explained with one set of genes. Don’t let yourselves be patronised. Our understanding of these pathways is minuscule at best¹¹⁵ … and don’t get me started on ‘juice cleanses’!

The interaction between food and our genetics is a fascinating field.

5:2 diet

The science used to formulate intermittent fasting diets like the 5:2 diet is impressive.¹¹⁶ There appear to be benefits of cyclical fasting,^117,118 but our way of eating needs to be sustainable¹¹⁹ and more importantly, enjoyable. Who wants to endure restricting themselves on a weekly basis … for life? I am convinced that some people have found benefits from this practice,¹²⁰ but if I were to tell the majority of patients I see in clinic to reduce their calories to 500 for two whole days, I know exactly where they’d be telling me to go!

And this brings me nicely to another topic. I don’t count calories. For the majority of people it’s a complete waste of time because it shifts the focus toward indiscriminate numbers on packets of food and away from what is actually important: the quality of food we introduce into our body. Clearly, a bag of sugar compared to an equal calorie content of spinach is going to have drastically different effects on our body. Calorie counting does not account for this difference. It focuses unnecessarily on a logic that was once thought to be scientifically accurate but is now shown to be flawed in many ways.

+ A NOTE ON CALORIES

The long-held idea that excessive calorie consumption leads to weight gain and reducing calories leads to weight loss is simply not accurate. Also, the metabolism of food is likely to differ from person to person depending on a host of factors such as their microbiome population, their genes, activity level, timing of meals and many other variables. A 200-calorie lunch isn’t necessarily ‘healthier’ than the 500-calorie one, and two identical calorie meals can have entirely different metabolic effects. The majority of people I see in clinic do not need to diligently measure and obsess about these numbers.

When we encourage concentrating on calories, or even the Glycaemic Index (GI) of foods, we lose sight of the bigger picture. People find themselves picking up ready-made desserts and putting down bananas. This is madness. There is a huge difference between the metabolic effect of packaged meals and a whole food. Diets that promote this are not educative and they serve to confuse rather than inspire, with dire consequences. Relax, cook as often as possible at home using whole ingredients, and put the calorie counters away.

Fasting, and the variations of fasting practices¹²⁰, is an interesting area and warrants further research. But, what I think is potentially as effective and easier to incorporate into daily working life is the concept of defined eating periods.¹²¹ A time period during the day when you eat versus a period when you do not eat. Research also shows that the simple effort of ensuring you eat at regular times and within a 10–11-hour window can reduce your risk of diabetes and cardiovascular disease.¹²² It stabilises insulin release and leads to less fat around the organs (which is dangerous). It makes logical sense to me and a lot of my patients are easily able to slot this convenient ‘fasting’ practice into their eating habits that doesn’t require obsessive calorie counting or restriction.

Alkaline diet

I’m going to give you some insight as to why there is such a divide between physicians and the wellness industry. When non-medically trained, self-styled, health ‘gurus’ are given a platform to influence people into believing they can change their blood pH with a diet high in alkaline foods, it is incredibly frustrating. You can change the pH of your urine using food, but the suggestion that this diet has a miraculous, transformational total-body effect is a huge oversimplification of the science.¹²³

Fundamentally, this diet encourages us to eat more dark green leafy vegetables and generally healthier foods, which isn’t a bad thing.^124,125 However, people deserve to be educated and told the truth about how food interacts with our biochemistry, instead of being duped into thinking this is how our bodies work. When you’ve spent time in intensive care, learnt about the complexities of acid-base balance in ill patients and tried to get your head around how complicated pH control is,^126,127 you can understand why the use of alkaline theories to promote products annoy doctors all round. We have intelligently evolved organs that precisely control our blood pH using mechanisms that still continue to amaze me.

Introducing ‘alkaline’ foods such as brassica vegetables and colourful fruits is fantastic, but rather than just focusing on ‘alkalinity’, we should appreciate the phytochemical content, the fibre and micronutrients like folate and magnesium. We also need to consider the relatively low sugar content and the endless chemicals that we haven’t yet fully investigated. Focusing on ‘alkalinity’ confuses the matter and I fear it will create an obsession among patients akin to calorie counting. I am an open-minded doctor, so perhaps one day we will learn more about ‘alkalinity’, but for now the science just does not support these claims.^128,123,129 I would have great reservations for the liberal use of these ideas, especially by those who cannot appreciate the scientific controversy.

Low Fat/Slimming World/NHS Choices

The medical profession’s obsession with reducing the fat content of our food and encouraging processed, low-fat options over the past few decades has probably been the most effective, yet destructive, health campaign of all time. It’s a message I myself have been guilty of promoting. An over-indulgence in calories, particularly from fat, combined with apathy toward exercise was the generally accepted explanation for why patients were overweight and sick. It was arrogant and naïve to accept this assumption that gluttony was the underlying cause of patients’ illnesses and not question its legitimacy. It’s obvious, now, that this was not correct.^130,131

Hydrogenated fats, ‘cholesterol-lowering’ products and sugar-laden alternatives that we promoted are terrible options for the vulnerable cohort of patients we were trying to help.^132–135 The recommendations for extreme restriction of saturated fat, cholesterol and total fat are now becoming obsolete and further analysis is proving fat not to be as detrimental to health as we once thought.^136,137 The morbid result of our fixation with replacing fats with refined carbohydrates and sugar is exemplified by our current lifestyle-related disease epidemic.¹³⁸

However, the restricted fat message still exists, particularly among supporters of plant-based lifestyles. To their credit, some small studies demonstrate remarkable cardiovascular disease reversal and cancer improvement using fat restriction and lifestyle change.^139,73 On the other hand, the Mediterranean diet, one of the largest and longest studied of eating habits, comprises three times more fat than ‘fat-restricted’ diets with – again – impressive cardiovascular, cancer and diabetes protective effects.^50,48

My honest opinion is that we shouldn’t fear fat. We don’t exactly know why some people thrive on low fat intake while others suffer, but I’m certain it comes down to the individual.¹⁴⁰ Your environment, gut microbes and ancestry play a major role in predicting the success of any given diet and lowering your risk of disease, but I believe a good proportion of good-quality fats are essential to health.

+ RETHINKING FATS

Fats, including cholesterol, are vital to the functioning of our brains, the composition of cell structures and essential for hormone synthesis. Reducing them to ‘good’ and ‘bad’ fats completely negates the science and lacks an appreciation for how complicated our bodies are. My belief is that a high-sugar, refined-carbohydrate diet in combination with poor-quality fats is the cause of ill health.¹⁴¹ This toxic blend causes inflammation and a cascade of medical problems thereafter, but like a lot of topics in nutrition, the explanation is fraught with complexity. Our thinking about how dietary cholesterol affects heart disease is also changing.^142,143,144 Consuming cholesterol, which is only found in animal products, does not necessarily increase the level of cholesterol found in your blood nor increase your risk of heart disease. I know this is quite hard for a lot of people to accept, given the dietary dogma most of us have been subjected to over the last 40 years, but it is based on evidence. Equally, I don’t recommend people actively try to consume more cholesterol. We need to learn from our past mistakes of damning an entire macronutrient to the extent that people are scared into radically removing it, but what I am witnessing now is a swing of the metaphorical pendulum in the opposite direction! Even though butter has been exonerated to some degree, you won’t find me spooning it into my coffee – I like my Americano freshly brewed without lipid-rich particles floating in it, thank you very much. For simplicity’s sake, I stick to the types of fats found in the Mediterranean diet which is packed with nuts, seeds and, of course, extra-virgin olive oil. My simple mantra to patients is: eat whole food and stay away from anything that’s marketed as ‘low fat’ or ‘a healthier alternative to …’ Your body is worth more than those cheap, tasteless alternatives. Some quality fats to enjoy in the context of a whole-foods diet include those found in flaxseeds, nuts, seeds, avocado, extra-virgin olive oil, butter from grass-fed cows, full-fat yoghurt and delicious dark chocolate.

Veganism

In recent times plant-based eating has become exceptionally popular. A number of documentaries have convinced many people of the supposed health benefits of veganism and the health risks of red meat. They do have a lot of successes to feel smug about, that are well documented in the literature. Lower rates of cancer,¹⁴⁵ diabetes,¹⁴⁶ cardiovascular disease¹⁴⁷… the list goes on. It’s compelling stuff and, obviously, I’m a huge supporter of a diet largely made up of fruits and vegetables, but pure veganism doesn’t come without its caveats. B vitamins are noticeably lacking in vegans, as well as zinc, essential fatty acids and vitamin D.¹⁴⁸ Careful supplementation with extra nutrients is something I would advise all 100-per-cent plant-based eaters to discuss with their health practitioner.

Also, it’s important to remember that just because you go vegan doesn’t automatically turn you into a dementia-proof, cancer-kicking superhuman with spotless arteries. If I lived on chips and pasta with tomato sauce I could feel pretty ethically minded about not having killed an animal for my dinner, but I probably wouldn’t live for very long to tell people about it.

Ultimately, I have a deep respect for those who choose to live a life on plants alone, whatever their reasons, but my priority would be to make sure everyone is doing it safely.

Wrapping up

What a lot of these diets have in common is a focus on weight loss as a positive outcome, but is this what we should be striving for? Is weight management a reliable biomarker of general health and should this be the common denominator against which we judge the success of a diet? BMI is such a poor predictor of outcomes yet many studies continue to use this as a standard.¹⁴⁹

Everyone has the ability to lose weight, tone up and feel lighter, but sometimes it’s at the expense of health rather than in pursuit of it. I want you to feel ‘well’. I’m convinced that good health, contrary to popular belief, is independent of size and especially weight.¹⁵⁰ I think we could all do with a little less emphasis on weight as an outcome and more of a focus on wellbeing. Health and wellness conjure images of slim, vivacious, young 20-somethings, but a focus on this as the ultimate goal detracts from why we are trying to achieve a healthier life. I believe it is for the sum of our daily interactions to be positive in mind and physicality. It is to live a fulfilling and happy life. This doesn’t necessarily correspond to a certain number on a machine, even though an industry, and perhaps even your doctor, is trying to convince you it does. Your focus should be on health goals and habits rather than a physical endpoint.

There are endless ways in which you can add nutrient-dense foods to your diet on a daily basis and I want to encourage people to think along these lines. We have an opportunity to be truly nourished, rather than skip from diet to diet in the hope that we hit the ‘carb-protein-fat ratio jackpot’ and achieve that dazzling ‘perfect weight’.

I’m convinced that good health, contrary to popular belief, is independent of size and especially weight.